Activation of int-1 and int-2 loci in GRf mammary tumors.

PubMed

Gray, D A; Jackson, D P; Percy, D H; Morris, V L

1986-10-30

The Mtv-2 locus is known to be associated with a high mammary tumor incidence (97%) and early development of mammary tumors (3-13 months) in GR mice. However, it was not previously known whether the provirus which resides at the Mtv-2 locus is tumorigenic in and of itself or whether reintegration of proviruses generated from Mtv-2 is required for tumorigenesis. Foster-nursing GR mice on C57/BL mice eliminates the milk-borne source of GR virus, and allows the study of Mtv-2 derived proviruses alone. Using this approach, we have tested predictions which follow from the "positional" versus "reintegrational" models of tumorigenesis. Specifically, we have examined tumors from primary foster-nursed (GRf) mice to determine if MMTV proviruses derived from Mtv-2 were scattered randomly throughout the genome or were clustered in the vicinity of the int-1 and int-2 loci, which are thought to be associated with mammary tumorigenesis. It was found that the majority of spontaneous GRf mammary tumors that were tested have MMTV proviral integrations in either or both of the int-1 and int-2 loci and have transcription of either or both of the int loci. Tumors induced by Mtv-2, therefore, appear to have arisen via a mechanism similar to the activation of the int loci by exogenous (milk-borne) MMTV proviruses.

Short Exogenous Peptides Regulate Expression of CLE, KNOX1, and GRF Family Genes in Nicotiana tabacum.

PubMed

Fedoreyeva, L I; Dilovarova, T A; Ashapkin, V V; Martirosyan, Yu Ts; Khavinson, V Kh; Kharchenko, P N; Vanyushin, B F

2017-04-01

Exogenous short biologically active peptides epitalon (Ala-Glu-Asp-Gly), bronchogen (Ala-Glu-Asp-Leu), and vilon (Lys-Glu) at concentrations 10 -7 -10 -9  M significantly influence growth, development, and differentiation of tobacco (Nicotiana tabacum) callus cultures. Epitalon and bronchogen, in particular, both increase growth of calluses and stimulate formation and growth of leaves in plant regenerants. Because the regulatory activity of the short peptides appears at low peptide concentrations, their action to some extent is like that of the activity of phytohormones, and it seems to have signaling character and epigenetic nature. The investigated peptides modulate in tobacco cells the expression of genes including genes responsible for tissue formation and cell differentiation. These peptides differently modulate expression of CLE family genes coding for known endogenous regulatory peptides, the KNOX1 genes (transcription factor genes) and GRF (growth regulatory factor) genes coding for respective DNA-binding proteins such as topoisomerases, nucleases, and others. Thus, at the level of transcription, plants have a system of short peptide regulation of formation of long-known peptide regulators of growth and development. The peptides studied here may be related to a new generation of plant growth regulators. They can be used in the experimental botany, plant molecular biology, biotechnology, and practical agronomy.

Interactions of GRF(1-29)NH2 with plasma proteins and their effects on the release of the peptide from a PLAGA matrix.

PubMed

Mariette, B; Coudane, J; Vert, M

2005-09-02

The administration of the GRF(1-29)NH2 Growth Hormone Releasing Hormone analog is known as relevant of the concept of drug delivery system using a bioresorbable matrix. However, the release of this peptide from poly(dl-lactic acid-co-glycolic acid) matrices is affected by its insolubility at neutral in salted media and in plasma as well. In order to investigate the origin and the nature of the insolubility in these media in more details, the precipitates collected when the peptide was set in contact with saline, isotonic pH=7.4 phosphate buffer and plasma were analyzed by various techniques, namely weighting, gel chromatography, 1D- and 2D-immunoelectrophoresis, and dialysis to discern the soluble from the insoluble or aggregated fractions. It is shown that precipitation in protein-free salted media is due to a salting out phenomenon complemented by the neutralization of the solubilizing electrostatic charges in the isotonic buffer. In contrast, the precipitation in plasma is due to inter polyelectrolyte-type complexation that involved polyanionic proteins having a rather low isoelectric point like albumin, transferin, haptoglobulin and IgG immunoglobulins. When a rather large quantity of GRF(1-29)NH2 was entrapped in bioresorbable pellets working at a percolating regime after subcutaneous implantation in rats, the peptide was slowly released despite the complexation with plasma proteins. However only a very small part of the peptide was found in blood, this small part being still large enough to cause a detectable increase of the circulating growth hormone concentration. Attempts made to increase the solubility of the peptide in plasma were successful when the peptide was combined with arginine, an amino acid known to promote the poor hormonal activity of injected GRF(1-29)NH2 solutions under clinical conditions.

Efficient transcription of the glycolytic gene ADH1 and three translational component genes requires the GCR1 product, which can act through TUF/GRF/RAP binding sites.

PubMed Central

Santangelo, G M; Tornow, J

1990-01-01

Glycolytic gene expression in Saccharomyces cerevisiae is thought to be activated by the GCR and TUF proteins. We tested the hypothesis that GCR function is mediated by TUF/GRF/RAP binding sites (UASRPG elements). We found that UASRPG-dependent activation of a heterologous gene and transcription of ADH1, TEF1, TEF2, and RP59 were sensitive to GCR1 disruption. GCR is not required for TUF/GRF/RAP expression or in vitro DNA-binding activity. Images PMID:2405258

Inhibition of growth hormone-releasing factor suppresses both sleep and growth hormone secretion in the rat.

PubMed

Obál, F; Payne, L; Kapás, L; Opp, M; Krueger, J M

1991-08-23

To study the possible involvement of hypothalamic growth hormone-releasing factor (GRF) in sleep regulation, a competitive GRF-antagonist, the peptide (N-Ac-Tyr1,D-Arg2)-GRF(1-29)-NH2, was intracerebroventricularly injected into rats (0.003, 0.3, and 14 nmol), and the EEG and brain temperature were recorded for 12 h during the light cycle of the day. Growth hormone (GH) concentrations were determined from plasma samples taken at 20-min intervals for 3 h after 14 nmol GRF-antagonist. The onset of non-rapid eye movement sleep (NREMS) was delayed in response to 0.3 and 14 nmol GRF-antagonist, the duration of NREMS was decreased for one or more hours and after 14 nmol EEG slow wave amplitudes were decreased during NREMS in postinjection hour 1. The high dose of GRF-antagonist also suppressed REMS for 4 h, inhibited GH secretion, and elicited a slight biphasic variation in brain temperature. These findings, together with previous observations indicating a sleep-promoting effect for GRF, support the hypothesis that hypothalamic GRF is involved in sleep regulation and might be responsible for the correlation between NREMS and GH secretion reported in various species.

Parallel studies of His-DTrp-Ala-Trp-DPhe-Lys-NH2 and human pancreatic growth hormone-releasing factor-44-NH2 in rat primary pituitary cell monolayer culture.

PubMed

Sartor, O; Bowers, C Y; Chang, D

1985-03-01

His-DTrp-Ala-Trp-DPhe-Lys-NH2 (GH-RP-6) is a synthetic hexapeptide that specifically releases GH both in vivo and in vitro in pituitary incubates. In this study, for the first time, GH-RP-6 was studied in primary pituitary cell monolayer culture. Parallel studies were performed with human pancreatic GH-releasing factor-44 (hpGRF-44). Culture conditions optimal for GH-RP-6 were not optimal for hpGRF-44. Both peptides released GH in a dose- and time-dependent manner. In this assay system, the ED50 for GH-RP-6 was 9 nM, and the ED50 for hp-GRF-44 was 1.6 nM. Calcium-blocking agents inhibited the GH responses of both peptides as well as basal GH release. Pretreatment with GH-RP-6 decreased the subsequent response to both GH-RP-6 and hpGRF-44. hpGRF-44 down regulated itself but not GH-RP-6. Rat sera potentiated the GH response of hpGRF-44 but not that of GH-RP-6. GH-RP-6 and hpGRF-44 GH responses were additive. These results suggest that GH-RP-6 and hpGRF-44 stimulate GH release via different somatotroph receptors.

Plasma growth hormone response to human growth hormone releasing factor in rats administered with chlorpromazine and antiserum against somatostatin. Effects of hypo- and hyperthyroidism.

PubMed

Wakabayashi, I; Tonegawa, Y; Ihara, T; Hattori, M; Shibasaki, T; Ling, N

1985-10-01

The effect of hypo- and hyperthyroidism on the plasma growth hormone (GH) response to synthetic human growth hormone releasing factor (GRF) was determined in conscious, freely moving rats pretreated with chlorpromazine and antiserum against somatostatin. Chlorpromazine plus somatostatin antiserum pretreated rats gave consistent response to GRF which was not observed in untreated rats. Chlorpromazine alone has no effect on GH secretion induced by GRF in rat pituitary monolayer culture. In rats made hypothyroid by thyroidectomy, both basal and peak plasma GH responses to a small (0.25 microgram/kg bw) and a moderate dose of GRF (1 microgram/kg bw) were significantly reduced as compared to controls. In rats made hyperthyroid by the administration of thyroxine, basal and peak plasma GH responses to a small but not to a moderate dose of GRF were significantly reduced as compared to controls. A reduced plasma GH response to a small dose of GRF was observed 8 days after the cessation of thyroxine administration. The pituitary GH reserve was markedly reduced in hypothyroid but not in hyperthyroid rats as compared to their respective controls. These results indicate that plasma GH response to GRF is reduced both in hypo- and hyperthyroidism. The mechanism involved in the phenomenon appears to be different between the two conditions.

Teleseismic Lg of Semipalatinsk and Novaya Zemlya Nuclear Explosions Recorded by the GRF (Gräfenberg) Array: Comparison with Regional Lg (BRV) and their Potential for Accurate Yield Estimation

NASA Astrophysics Data System (ADS)

Schlittenhardt, J.

- A comparison of regional and teleseismic log rms (root-mean-square) Lg amplitude measurements have been made for 14 underground nuclear explosions from the East Kazakh test site recorded both by the BRV (Borovoye) station in Kazakhstan and the GRF (Gräfenberg) array in Germany. The log rms Lg amplitudes observed at the BRV regional station at a distance of 690km and at the teleseismic GRF array at a distance exceeding 4700km show very similar relative values (standard deviation 0.048 magnitude units) for underground explosions of different sizes at the Shagan River test site. This result as well as the comparison of BRV rms Lg magnitudes (which were calculated from the log rms amplitudes using an appropriate calibration) with magnitude determinations for P waves of global seismic networks (standard deviation 0.054 magnitude units) point to a high precision in estimating the relative source sizes of explosions from Lg-based single station data. Similar results were also obtained by other investigators (Patton, 1988; Ringdaletal., 1992) using Lg data from different stations at different distances.Additionally, GRF log rms Lg and P-coda amplitude measurements were made for a larger data set from Novaya Zemlya and East Kazakh explosions, which were supplemented with mb(Lg) amplitude measurements using a modified version of Nuttli's (1973, 1986a) method. From this test of the relative performance of the three different magnitude scales, it was found that the Lg and P-coda based magnitudes performed equally well, whereas the modified Nuttli mb(Lg) magnitudes show greater scatter when compared to the worldwide mb reference magnitudes. Whether this result indicates that the rms amplitude measurements are superior to the zero-to-peak amplitude measurement of a single cycle used for the modified Nuttli method, however, cannot be finally assessed, since the calculated mb(Lg) magnitudes are only preliminary until appropriate attenuation corrections are available for the

Altered control strategy between leading and trailing leg increases knee adduction moment in the elderly while descending stairs.

PubMed

Karamanidis, Kiros; Arampatzis, Adamantios

2011-02-24

The aim of the study was to examine the external knee adduction moments in a group of older and younger adults while descending stairs and thus the possibility of an increased risk of knee osteoarthritis due to altered knee joint loading in the elderly. Twenty-seven older and 16 younger adults descended a purpose-built staircase. A motion capture system and a force plate were used to determine the subjects' 3D kinematics and ground reaction forces (GRF) during locomotion. Calculation of the leg kinematics and kinetics was done by means of a rigid, three-segment, 3D leg model. In the initial portion of the support phase, older adults showed a more medio-posterior GRF vector relative to the ankle joint, leading to lower ankle joint moments (P<0.05). At the knee, the older adults demonstrated a more medio-posterior directed GRF vector, increasing in knee flexion and adduction in the second part of the single support phase (P<0.05). Further, GRF magnitude was lower in the initial and higher in the mid-portions of the support phase for the elderly (P<0.05). The results show that older adults descend stairs by using the trailing leg before the initiation of the double support phase more compared to the younger ones. The consequence of this altered control strategy while stepping down is a more medially directed GRF vector increasing the magnitude of external knee adduction moment in the elderly. The observed changes between leading and trailing leg in the elderly may cause a redistribution of the mechanical load at the tibiofemoral joint, affecting the initiation and progression of knee osteoarthritis in the elderly. Copyright © 2010 Elsevier Ltd. All rights reserved.

Modifying landing mat material properties may decrease peak contact forces but increase forefoot forces in gymnastics landings.

PubMed

Mills, Chris; Yeadon, Maurice R; Pain, Matthew T G

2010-09-01

This study investigated how changes in the material properties of a landing mat could minimise ground reaction forces (GRF) and internal loading on a gymnast during landing. A multi-layer model of a gymnastics competition landing mat and a subject-specific seven-link wobbling mass model of a gymnast were developed to address this aim. Landing mat properties (stiffness and damping) were optimised using a Simplex algorithm to minimise GRF and internal loading. The optimisation of the landing mat parameters was characterised by minimal changes to the mat's stiffness (<0.5%) but increased damping (272%) compared to the competition landing mat. Changes to the landing mat resulted in reduced peak vertical and horizontal GRF and reduced bone bending moments in the shank and thigh compared to a matching simulation. Peak bone bending moments within the thigh and shank were reduced by 6% from 321.5 Nm to 302.5Nm and GRF by 12% from 8626 N to 7552 N when compared to a matching simulation. The reduction in these forces may help to reduce the risk of bone fracture injury associated with a single landing and reduce the risk of a chronic injury such as a stress fracture.

Stride length: the impact on propulsion and bracing ground reaction force in overhand throwing.

PubMed

Ramsey, Dan K; Crotin, Ryan L

2018-03-26

Propulsion and bracing ground reaction force (GRF) in overhand throwing are integral in propagating joint reaction kinetics and ball velocity, yet how stride length effects drive (hind) and stride (lead) leg GRF profiles remain unknown. Using a randomised crossover design, 19 pitchers (15 collegiate and 4 high school) were assigned to throw 2 simulated 80-pitch games at ±25% of their desired stride length. An integrated motion capture system with two force plates and radar gun tracked each throw. Vertical and anterior-posterior GRF was normalised then impulse was derived. Paired t-tests identified whether differences between conditions were significant. Late in single leg support, peak propulsion GRF was statistically greater for the drive leg with increased stride. Stride leg peak vertical GRF in braking occurred before acceleration with longer strides, but near ball release with shorter strides. Greater posterior shear GRF involving both legs demonstrated increased braking with longer strides. Conversely, decreased drive leg propulsion reduced both legs' braking effects with shorter strides. Results suggest an interconnection between normalised stride length and GRF application in propulsion and bracing. This work has shown stride length to be an important kinematic factor affecting the magnitude and timing of external forces acting upon the body.

Primary mechanical factors contributing to foot eversion moment during the stance phase of running.

PubMed

Tsujimoto, Norio; Nunome, Hiroyuki; Ikegami, Yasuo

2017-05-01

Rearfoot external eversion moments due to ground reaction forces (GRF) during running have been suggested to contribute to overuse running injuries. This study aimed to identify primary factors inducing these rearfoot external eversion moments. Fourteen healthy men ran barefoot across a force plate embedded in the middle of 30-m runway with 3.30 ± 0.17 m · s -1 . Total rearfoot external eversion/inversion moments (Mtot) were broken down into the component Mxy due to medio-lateral GRF (Fxy) and the component Mz due to vertical GRF (Fz). Ankle joint centre height and medio-lateral distance from the centre of pressure to the ankle joint centre (a_cop) were calculated as the moment arm of these moments. Mxy dominated Mtot just after heel contact, with the magnitude strongly dependent on Fxy, which was most likely caused by the medio-lateral foot velocity before heel contact. Mz then became the main generator of Mtot throughout the first half of the stance phase, during which a_cop was the critical factor influencing the magnitude. Medio-lateral foot velocity before heel contact and medio-lateral distance from the centre of pressure to the ankle joint centre throughout the first half of the stance phase were identified as primary factors inducing the rearfoot external eversion moment.

Protective properties of 6-gingerol-rich fraction from Zingiber officinale (Ginger) on chlorpyrifos-induced oxidative damage and inflammation in the brain, ovary and uterus of rats.

PubMed

Abolaji, Amos O; Ojo, Mercy; Afolabi, Tosin T; Arowoogun, Mary D; Nwawolor, Darlinton; Farombi, Ebenezer O

2017-05-25

Chlorpyrifos (CPF) is an organophosphorus pesticide widely used in agricultural applications and household environments. 6-Gingerol-rich fraction from Zingiber officinale (Ginger, 6-GRF) has been reported to possess potent anti-oxidative, anti-inflammatory and anti-apoptotic properties. Here, we investigated the protective properties of 6-GRF on CPF-induced oxidative damage and inflammation in the brain, ovary and uterus of rats. Five groups of rats containing 14 rats/group received corn oil (control), CPF (5 mg/kg), 6-GRF (100 mg/kg), CPF (5 mg/kg) + 6-GRF (50 mg/kg) and CPF (5 mg/kg) + 6-GRF (100 mg/kg) through gavage once per day for 35 days respectively. The results showed that 6-GRF protected against CPF-induced increases in oxidative stress ((hydrogen peroxide (H 2 O 2 ) and malondialdehyde (MDA)), inflammatory (myeloperoxidase (MPO), nitric oxide (NO) and tumour necrosis factor-α (TNF- α)), and apoptotic (caspase-3) markers. Also, 6-GRF improved the activities of antioxidant enzymes catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) as well as glutathione (GSH) level in the brain, ovary and uterus of rats exposed to CPF (p < 0.05). Overall, the protective effects of 6-GRF on CPF-induced toxicity in the brain and reproductive organs of rats may be due to its potent antioxidative, anti-inflammatory and antiapoptotic properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Growth-inducing effects of argon plasma on soybean sprouts via the regulation of demethylation levels of energy metabolism-related genes.

PubMed

Zhang, Jiao Jiao; Jo, Jin Oh; Huynh, Do Luong; Mongre, Raj Kumar; Ghosh, Mrinmoy; Singh, Amit Kumar; Lee, Sang Baek; Mok, Young Sun; Hyuk, Park; Jeong, Dong Kee

2017-02-07

This study was conducted to determine the effects of argon plasma on the growth of soybean [Glycine max (L.) Merr.] sprouts and investigate the regulation mechanism of energy metabolism. The germination and growth characteristics were modified by argon plasma at different potentials and exposure durations. Upon investigation, plasma treatment at 22.1 kV for 12 s maximized the germination and seedling growth of soybean, increasing the concentrations of soluble protein, antioxidant enzymes, and adenosine triphosphate (ATP) as well as up-regulating ATP a1, ATP a2, ATP b1, ATP b2, ATP b3, target of rapamycin (TOR), growth-regulating factor (GRF) 1-6, down-regulating ATP MI25 mRNA expression, and increasing the demethylation levels of the sequenced region of ATP a1, ATP b1, TOR, GRF 5, and GRF 6 of 6-day-old soybean sprouts. These observations indicate that argon plasma promotes soybean seed germination and sprout growth by regulating the demethylation levels of ATP, TOR, and GRF.

Growth-inducing effects of argon plasma on soybean sprouts via the regulation of demethylation levels of energy metabolism-related genes

NASA Astrophysics Data System (ADS)

Zhang, Jiao Jiao; Jo, Jin Oh; Huynh, Do Luong; Mongre, Raj Kumar; Ghosh, Mrinmoy; Singh, Amit Kumar; Lee, Sang Baek; Mok, Young Sun; Hyuk, Park; Jeong, Dong Kee

2017-02-01

This study was conducted to determine the effects of argon plasma on the growth of soybean [Glycine max (L.) Merr.] sprouts and investigate the regulation mechanism of energy metabolism. The germination and growth characteristics were modified by argon plasma at different potentials and exposure durations. Upon investigation, plasma treatment at 22.1 kV for 12 s maximized the germination and seedling growth of soybean, increasing the concentrations of soluble protein, antioxidant enzymes, and adenosine triphosphate (ATP) as well as up-regulating ATP a1, ATP a2, ATP b1, ATP b2, ATP b3, target of rapamycin (TOR), growth-regulating factor (GRF) 1-6, down-regulating ATP MI25 mRNA expression, and increasing the demethylation levels of the sequenced region of ATP a1, ATP b1, TOR, GRF 5, and GRF 6 of 6-day-old soybean sprouts. These observations indicate that argon plasma promotes soybean seed germination and sprout growth by regulating the demethylation levels of ATP, TOR, and GRF.

Functional Properties of Glutinous Rice Flour by Dry-Heat Treatment.

PubMed

Qin, Yang; Liu, Chengzhen; Jiang, Suisui; Cao, Jinmiao; Xiong, Liu; Sun, Qingjie

2016-01-01

Glutinous rice flour (GRF) and glutinous rice starch (GRS) were modified by dry-heat treatment and their rheological, thermal properties and freeze-thaw stability were evaluated. Compared with the native GRF and GRS, the water-holding ability of modified GRF and GRS were enhanced. Both the onset and peak temperatures of the modified samples increased while the endothermic enthalpy change decreased significantly (p < 0.05). Meanwhile, dry heating remarkably increased the apparent viscosities of both GRF and GRS. Importantly, compared with GRS samples, the storage modulus (G') and loss modulus (G") values of modified GRF increased more greatly and the tanδ values decreased more remarkably, indicating that the dry-heat treatment showed more impact on the GRF and a higher viscoelasticity compared with GRS. Our results suggest the dry-heat treatment of GRF is a more effective method than that of GRS, which omits the complex and tedious process for purifying GRS, and thereby has more practical applications in the food industry.

Functional Properties of Glutinous Rice Flour by Dry-Heat Treatment

PubMed Central

Qin, Yang; Liu, Chengzhen; Jiang, Suisui; Cao, Jinmiao; Xiong, Liu; Sun, Qingjie

2016-01-01

Glutinous rice flour (GRF) and glutinous rice starch (GRS) were modified by dry-heat treatment and their rheological, thermal properties and freeze-thaw stability were evaluated. Compared with the native GRF and GRS, the water-holding ability of modified GRF and GRS were enhanced. Both the onset and peak temperatures of the modified samples increased while the endothermic enthalpy change decreased significantly (p < 0.05). Meanwhile, dry heating remarkably increased the apparent viscosities of both GRF and GRS. Importantly, compared with GRS samples, the storage modulus (G') and loss modulus (G") values of modified GRF increased more greatly and the tanδ values decreased more remarkably, indicating that the dry-heat treatment showed more impact on the GRF and a higher viscoelasticity compared with GRS. Our results suggest the dry-heat treatment of GRF is a more effective method than that of GRS, which omits the complex and tedious process for purifying GRS, and thereby has more practical applications in the food industry. PMID:27537844

Experiment K-7-22: Growth Hormone Regulation Synthesis and Secretion in Microgravity. Part 2; Hypothalamic Growth Hormone-Releasing Factor, Somatostatin Immunoreactivity, and Messenger RNA Levels in Microgravity

NASA Technical Reports Server (NTRS)

Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

1994-01-01

Immunohistochemical analyses of hypothalamic hormones carried out on tissue from rats flown on an earlier flight (Cosmos 1887) suggested preferential effects on hypophysiotropic principles involved in the regulation of growth hormone secretion and synthesis. We found that staining in the median eminence for peptides that provide both stimulatory (growth hormone-releasing factor, or GRF) and inhibitory (somatostatin, SS) influences on growth hormone secretion were depressed in flight animals relative to synchronous controls, while staining for other neuroendocrine peptides, cortocotropin-releasing factor and arginine vasopressin, were similar in these two groups. While this suggests some selective impact of weightlessness on the two principal central nervous system regulators of growth hormone dynamics, the fact that both GRF- and SS-immunoreactivity (IR) appeared affected in the same direction is somewhat problematic, and makes tentative any intimation that effects on CNS control mechanisms may be etiologically significant contributors to the sequelae of reduced growth hormone secretion seen in prolonged space flight. To provide an additional, and more penetrating, analysis we attempted in hypothalamic material harvested from animals flown on Cosmos 2044 to complement immunohistochemical analyses of GRF and SS staining with quantitative, in situ assessments of messenger RNAs encoding the precursors for both these hormones.

Real100G.RF: A Fully Packaged 240 GHz Transmitter with In-Antenna Power Combining in 0.13 μm SiGe Technology

NASA Astrophysics Data System (ADS)

Malz, Stefan; Goettel, Benjamin; Eisenbeis, Joerg; Boes, Florian; Grzyb, Janusz; Vazquez, Pedro Rodriguez; Zwick, Thomas; Pfeiffer, Ullrich R.

2017-09-01

This paper reports on the research activities during the first phase of the project Real100G.RF, which is part of the German Research Foundation (DFG) priority programm SPP1655. The project's main objective is to research silicon-based wireless communication above 200 GHz to enable data rates in excess of 100 gigabit per second (Gbps). To that end, this paper presents a fully packaged 240 GHz RF transmitter front-end with power combining antenna in 0.13 μm SiGe technology. The design of circuit building blocks, passives, antenna and high-speed packaging is discussed. Communication measurements show data rates of 8 Gbps with an EVM of 12.4% using 16-QAM, 24 Gbps with 26.5% EVM using QPSK and 30 Gbps with 27.9% EVM using 8-PSK.

Delayed release formulation of the somatostatin analog RC-160 inhibits the growth hormone (GH) response to GH-releasing factor-(1-29)NH2 and decreases elevated prolactin levels in rats.

PubMed

Bokser, L; Schally, A V

1988-10-01

Recently, we have developed a long-acting delivery system for our somatostatin (SS) analog RC-160 based on injectable microcapsules in poly-(D,L-lactide-coglycolide). We studied the capacity of this formulation to repeatedly block the GH secretion induced by administration of GRF-(1-29)NH2 (GRF) on different days. Male rats anesthetized with pentobarbital were injected iv with 2.5 micrograms/kg BW GRF-(1-29)NH2 or saline. Five minutes later, blood samples were taken for GH measurement, and the animals were injected im with RC-160 microcapsules at a dose calculated to release 25 micrograms/day of the analog for 7 days or with the vehicle. The GRF stimuli were repeated 48 h, 96 h, and 8 days after administration of SS analog in microcapsules. GRF administration increased GH levels at the four times tested (P less than 0.01) in the control group injected with vehicle, while RC-160 microcapsules inhibited the GH response for more than 96 h (P less than 0.01). The GH levels augmented by pentobarbital were also decreased by the RC-160 microcapsules (P less than 0.01). Animals treated with microcapsules showed smaller increases in their body weight than untreated rats (P less than 0.05). We also investigated the effect of RC-160 microcapsules on hyperprolactinemic female rats implanted with pituitary glands under the kidney capsules. High PRL levels in rats bearing pituitary grafts showed a significant decrease when measured 4 days after the administration of RC-160 microcapsules. These results demonstrate the efficacy of the long-acting delivery system of the SS analog RC-160 and suggest the possible clinical usefulness of this formulation for lowering GH and PRL levels.

Kinematic and ground reaction force accommodation during weighted walking.

PubMed

James, C Roger; Atkins, Lee T; Yang, Hyung Suk; Dufek, Janet S; Bates, Barry T

2015-12-01

Weighted walking is a functional activity common in daily life and can influence risks for musculoskeletal loading, injury and falling. Much information exists about weighted walking during military, occupational and recreational tasks, but less is known about strategies used to accommodate to weight carriage typical in daily life. The purposes of the study were to examine the effects of weight carriage on kinematics and peak ground reaction force (GRF) during walking, and explore relationships between these variables. Twenty subjects walked on a treadmill while carrying 0, 44.5 and 89 N weights in front of the body. Peak GRF, sagittal plane joint/segment angular kinematics, stride length and center of mass (COM) vertical displacement were measured. Changes in peak GRF and displacement variables between weight conditions represented accommodation. Effects of weight carriage were tested using analysis of variance. Relationships between peak GRF and kinematic accommodation variables were examined using correlation and regression. Subjects were classified into sub-groups based on peak GRF responses and the correlation analysis was repeated. Weight carriage increased peak GRF by an amount greater than the weight carried, decreased stride length, increased vertical COM displacement, and resulted in a more extended and upright posture, with less hip and trunk displacement during weight acceptance. A GRF increase was associated with decreases in hip extension (|r|=.53, p=.020) and thigh anterior rotation (|r|=.57, p=.009) displacements, and an increase in foot anterior rotation displacement (|r|=.58, p=.008). Sub-group analysis revealed that greater GRF increases were associated with changes at multiple sites, while lesser GRF increases were associated with changes in foot and trunk displacement. Weight carriage affected walking kinematics and revealed different accommodation strategies that could have implications for loading and stability. Copyright © 2015 Elsevier B

A Rare Allele of GS2 Enhances Grain Size and Grain Yield in Rice.

PubMed

Hu, Jiang; Wang, Yuexing; Fang, Yunxia; Zeng, Longjun; Xu, Jie; Yu, Haiping; Shi, Zhenyuan; Pan, Jiangjie; Zhang, Dong; Kang, Shujing; Zhu, Li; Dong, Guojun; Guo, Longbiao; Zeng, Dali; Zhang, Guangheng; Xie, Lihong; Xiong, Guosheng; Li, Jiayang; Qian, Qian

2015-10-05

Grain size determines grain weight and affects grain quality. Several major quantitative trait loci (QTLs) regulating grain size have been cloned; however, our understanding of the underlying mechanism that regulates the size of rice grains remains fragmentary. Here, we report the cloning and characterization of a dominant QTL, grain size on chromosome 2 (GS2), which encodes Growth-Regulating Factor 4 (OsGRF4), a transcriptional regulator. GS2 localizes to the nucleus and may act as a transcription activator. A rare mutation of GS2 affecting the binding site of a microRNA, OsmiR396c, causes elevated expression of GS2/OsGRF4. The increase in GS2 expression leads to larger cells and increased numbers of cells, which thus enhances grain weight and yield. The introduction of this rare allele of GS2/OsGRF4 into rice cultivars could significantly enhance grain weight and increase grain yield, with possible applications in breeding high-yield rice varieties. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

Automated analysis of SKS splitting to infer upper mantle anisotropy beneath Germany using more than 20 yr of GRSN and GRF data

NASA Astrophysics Data System (ADS)

Walther, M.; Plenefisch, T.; Rümpker, G.

2014-02-01

Upper mantle anisotropy beneath Germany is investigated through the measurements and analysis of shear-wave splitting using SKS phases. We analysed teleseismic events recorded by 24 broadband stations of the German Regional Seismic Network (GRSN) and three broadband stations of the Gräfenberg-Array (GRF). These permanent German networks cover an area extending from the Alps in the south up to the Northern German basin towards north. In comparison to several former studies that are based either on short observation periods or that are restricted to limited areas of Germany, we resort to 22 yr of the GRSN (1991-2012) and 34 yr of GRF data archive (1979-2012). Due to the huge amount of data, we applied a fully automatic procedure to determine SKS splitting parameters from archived recordings and also applied strong quality constraints to obtain reliable solutions. From our analysis, two main features are obvious: For the stations in the middle and southern part of Germany we found homogeneous E-W to ENE-WSW fast-axis directions. In contrast, stations in NE-Germany exhibit a NW-SE oriented fast axis. Both findings can be correlated to major tectonic features in Central Europe. The E-W to ENE-WSW orientations in the middle and southern part of Germany are nearly parallel to the strike of the Variscan mountain belts, whereas the NW-SE direction in NE-Germany corresponds to the orientation of the nearby Tornquist-Teisseyre suture zone. For the southern part of Germany, there are indications for an alignment of the fast axis parallel to the curvature of the nearby Alps. Apart from the more large-scale features there are two stations (BFO and CLZ) which seem to have an imprint related to the regional geodynamic setting, namely the rifting in the Southern Rhine Graben and the formation of the Harz Mountains, respectively. We conclude that the observed regional variations of splitting parameter over Germany advocate for a mostly lithospheric route of the anisotropy

Using ground reaction force to predict knee kinetic asymmetry following anterior cruciate ligament reconstruction.

PubMed

Dai, B; Butler, R J; Garrett, W E; Queen, R M

2014-12-01

Asymmetries in sagittal plane knee kinetics have been identified as a risk factor for anterior cruciate ligament (ACL) re-injury. Clinical tools are needed to identify the asymmetries. This study examined the relationships between knee kinetic asymmetries and ground reaction force (GRF) asymmetries during athletic tasks in adolescent patients following ACL reconstruction (ACL-R). Kinematic and GRF data were collected during a stop-jump task and a side-cutting task for 23 patients. Asymmetry indices between the surgical and non-surgical limbs were calculated for GRF and knee kinetic variables. For the stop-jump task, knee kinetics asymmetry indices were correlated with all GRF asymmetry indices (P < 0.05), except for loading rate. Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2)  ≥ 0.78, P < 0.01) asymmetry indices. For the side-cutting tasks, knee kinetic asymmetry indices were correlated with the peak propulsion vertical GRF and vertical GRF impulse asymmetry indices (P < 0.05). Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2)  ≥ 0.55, P < 0.01) asymmetry indices. The vertical GRF asymmetries may be a viable surrogate for knee kinetic asymmetries and therefore may assist in optimizing rehabilitation outcomes and minimizing re-injury rates. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dynamically adjustable foot-ground contact model to estimate ground reaction force during walking and running.

PubMed

Jung, Yihwan; Jung, Moonki; Ryu, Jiseon; Yoon, Sukhoon; Park, Sang-Kyoon; Koo, Seungbum

2016-03-01

Human dynamic models have been used to estimate joint kinetics during various activities. Kinetics estimation is in demand in sports and clinical applications where data on external forces, such as the ground reaction force (GRF), are not available. The purpose of this study was to estimate the GRF during gait by utilizing distance- and velocity-dependent force models between the foot and ground in an inverse-dynamics-based optimization. Ten males were tested as they walked at four different speeds on a force plate-embedded treadmill system. The full-GRF model whose foot-ground reaction elements were dynamically adjusted according to vertical displacement and anterior-posterior speed between the foot and ground was implemented in a full-body skeletal model. The model estimated the vertical and shear forces of the GRF from body kinematics. The shear-GRF model with dynamically adjustable shear reaction elements according to the input vertical force was also implemented in the foot of a full-body skeletal model. Shear forces of the GRF were estimated from body kinematics, vertical GRF, and center of pressure. The estimated full GRF had the lowest root mean square (RMS) errors at the slow walking speed (1.0m/s) with 4.2, 1.3, and 5.7% BW for anterior-posterior, medial-lateral, and vertical forces, respectively. The estimated shear forces were not significantly different between the full-GRF and shear-GRF models, but the RMS errors of the estimated knee joint kinetics were significantly lower for the shear-GRF model. Providing COP and vertical GRF with sensors, such as an insole-type pressure mat, can help estimate shear forces of the GRF and increase accuracy for estimation of joint kinetics. Copyright © 2016 Elsevier B.V. All rights reserved.

Repression of Growth Regulating Factors by the MicroRNA396 Inhibits Cell Proliferation by UV-B Radiation in Arabidopsis Leaves[C][W

PubMed Central

Casadevall, Romina; Rodriguez, Ramiro E.; Debernardi, Juan M.; Palatnik, Javier F.; Casati, Paula

2013-01-01

Because of their sessile lifestyle, plants are continuously exposed to solar UV-B radiation. Inhibition of leaf growth is one of the most consistent responses of plants upon exposure to UV-B radiation. In this work, we investigated the role of GROWTH-REGULATING FACTORs (GRFs) and of microRNA miR396 in UV-B–mediated inhibition of leaf growth in Arabidopsis thaliana plants. We demonstrate that miRNA396 is upregulated by UV-B radiation in proliferating tissues and that this induction is correlated with a decrease in GRF1, GRF2, and GRF3 transcripts. Induction of miR396 results in inhibition of cell proliferation, and this outcome is independent of the UV-B photoreceptor UV resistance locus 8, as well as ATM AND RAD3–RELATED and the mitogen-activated protein kinase MPK6, but is dependent on MPK3. Transgenic plants expressing an artificial target mimic directed against miR396 (MIM396) with a decrease in the endogenous microRNA activity or plants expressing miR396-resistant copies of several GRFs are less sensitive to this inhibition. Consequently, at intensities that can induce DNA damage in Arabidopsis plants, UV-B radiation limits leaf growth by inhibiting cell division in proliferating tissues, a process mediated by miR396 and GRFs. PMID:24076976

A Novel Gibberellin-Induced Gene from Rice and Its Potential Regulatory Role in Stem Growth1

PubMed Central

van der Knaap, Esther; Kim, Jeong Hoe; Kende, Hans

2000-01-01

Os-GRF1 (Oryza sativa-GROWTH-REGULATING FACTOR1) was identified in a search for genes that are differentially expressed in the intercalary meristem of deepwater rice (Oryza sativa L.) internodes in response to gibberellin (GA). Os-GRF1 displays general features of transcription factors, contains a functional nuclear localization signal, and has three regions with similarities to sequences in the database. One of these regions is similar to a protein interaction domain of SWI2/SNF2, which is a subunit of a chromatin-remodeling complex in yeast. The two other domains are novel and found only in plant proteins of unknown function. To study its role in plant growth, Os-GRF1 was expressed in Arabidopsis. Stem elongation of transformed plants was severely inhibited, and normal growth could not be recovered by the application of GA. Our results indicate that Os-GRF1 belongs to a novel class of plant proteins and may play a regulatory role in GA-induced stem elongation. PMID:10712532

Sex differences in force attenuation: a clinical assessment of single-leg hop performance on a portable force plate

PubMed Central

Harrison, A D; Ford, K R; Myer, G D; Hewett, T E

2014-01-01

Objective Impaired biomechanics and neuromuscular control have been suggested as probable links to female sex bias in the onset of patellofemoral pain syndrome. There are limited objective, clinical measures for assessment of impaired biomechanics and neuromuscular control. The primary objective of this investigation was to examine sex differences in vertical ground reaction force (vGRF) and force loading rate in young athletes performing maximum, repeated vertical single-leg hops (RVSHs). The authors hypothesised that females would demonstrate greater vGRF and force loading rate than males and show interlimb differences in force attenuation. Design Cross-sectional study. Setting Paediatric sports medicine clinic. Participants 109 Healthy high school, soccer and basketball athletes. Assessment of risk factors Participants performed RVSHs for 15 seconds on a portable force plate with a sampling rate of 400 Hz (Accupower; AMTI, Watertown, Massachusetts, USA). Main outcome measurements Raw vGRF was filtered with a generalised cross-validation spline using a 50-Hz cutoff frequency and then normalised to potential energy. Force loading rate was calculated by dividing normalised vGRF by time-to-peak force. Group means were compared using analysis of variance. Results The females demonstrated significantly greater normalised vGRF (p<0.001) and force loading rate (p<0.001) during landing than their male counterparts. Neither sex demonstrated significant interlimb differences in force attenuation (p>0.05). Conclusions The female athletes may have altered force attenuation capability during RVSHs as identified by increased vGRF and force loading rate compared with the male athletes. Portable force plates may be potential tools to identify altered force attenuation in clinical settings. PMID:19858114

UV-B Inhibits Leaf Growth through Changes in Growth Regulating Factors and Gibberellin Levels1[OPEN

PubMed Central

Fina, Julieta; AbdElgawad, Hamada; Prinsen, Els

2017-01-01

Ultraviolet-B (UV-B) radiation affects leaf growth in a wide range of species. In this work, we demonstrate that UV-B levels present in solar radiation inhibit maize (Zea mays) leaf growth without causing any other visible stress symptoms, including the accumulation of DNA damage. We conducted kinematic analyses of cell division and expansion to understand the impact of UV-B radiation on these cellular processes. Our results demonstrate that the decrease in leaf growth in UV-B-irradiated leaves is a consequence of a reduction in cell production and a shortened growth zone (GZ). To determine the molecular pathways involved in UV-B inhibition of leaf growth, we performed RNA sequencing on isolated GZ tissues of control and UV-B-exposed plants. Our results show a link between the observed leaf growth inhibition and the expression of specific cell cycle and developmental genes, including growth-regulating factors (GRFs) and transcripts for proteins participating in different hormone pathways. Interestingly, the decrease in the GZ size correlates with a decrease in the concentration of GA19, the immediate precursor of the active gibberellin, GA1, by UV-B in this zone, which is regulated, at least in part, by the expression of GRF1 and possibly other transcription factors of the GRF family. PMID:28400494

Ground reaction forces and plantar pressure distribution during occasional loaded gait.

PubMed

Castro, Marcelo; Abreu, Sofia; Sousa, Helena; Machado, Leandro; Santos, Rubim; Vilas-Boas, João Paulo

2013-05-01

This study compared the ground reaction forces (GRF) and plantar pressures between unloaded and occasional loaded gait. The GRF and plantar pressures of 60 participants were recorded during unloaded gait and occasional loaded gait (wearing a backpack that raised their body mass index to 30); this load criterion was adopted because is considered potentially harmful in permanent loaded gait (obese people). The results indicate an overall increase (absolute values) of GRF and plantar pressures during occasional loaded gait (p < 0.05); also, higher normalized (by total weight) values in the medial midfoot and toes, and lower values in the lateral rearfoot region were observed. During loaded gait the magnitude of the vertical GRF (impact and thrust maximum) decreased and the shear forces increased more than did the proportion of the load (normalized values). These data suggest a different pattern of GRF and plantar pressure distribution during occasional loaded compared to unloaded gait. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

6-Gingerol-rich fraction from Zingiber officinale ameliorates carbendazim-induced endocrine disruption and toxicity in testes and epididymis of rats.

PubMed

Salihu, M; Ajayi, B O; Adedara, I A; de Souza, D; Rocha, J B T; Farombi, E O

2017-06-01

This study evaluated the protective effects of 6-gingerol-rich fraction (6-GRF) from Zingiber officinale on carbendazim (CBZ)-induced reproductive toxicity in rats. Adult male rats were treated with either CBZ (50 mg/kg) alone or in combination with 6-GRF (50, 100 and 200 mg/kg) for 14 consecutive days. Gas chromatography-mass spectrometry (GCMS) analysis revealed that 6-GRF consists of ten bioactive chemical components with 6-gingerol being the most abundant (30.76%). Administration of 6-GRF significantly (p < .05) prevented CBZ-mediated increase in absolute and relative testes weights as well as restored the sperm quantity and quality in the treated rats to near control. In testes and epididymis, 6-GRF significantly abolished CBZ-mediated increase in oxidative damage as well as augmented antioxidant enzymes activities and glutathione level in the treated rats. Moreover, CBZ administration alone significantly decreased plasma levels of testosterone, thyrotropin, triiodothyronine and tetraiodothyronine, whereas follicle-stimulating hormone was significantly elevated without affecting luteinising hormone and prolactin levels when compared with the control. Conversely, 6-GRF ameliorated the disruption in the hormonal levels and restored their levels to near normalcy in CBZ-treated rats. Collectively, 6-GRF inhibited the adverse effects of CBZ on the antioxidant defence systems, hormonal balance and histology of the testes and epididymis in rats. © 2016 Blackwell Verlag GmbH.

Arabidopsis Protein Phosphatase DBP1 Nucleates a Protein Network with a Role in Regulating Plant Defense

PubMed Central

Naumann, Kai; Lassowskat, Ines; Navarrete-Gómez, Marisa; Scheel, Dierk; Vera, Pablo

2014-01-01

Arabidopsis thaliana DBP1 belongs to the plant-specific family of DNA-binding protein phosphatases. Although recently identified as a novel host factor mediating susceptibility to potyvirus, little is known about DBP1 targets and partners and the molecular mechanisms underlying its function. Analyzing changes in the phosphoproteome of a loss-of-function dbp1 mutant enabled the identification of 14-3-3λ isoform (GRF6), a previously reported DBP1 interactor, and MAP kinase (MAPK) MPK11 as components of a small protein network nucleated by DBP1, in which GRF6 stability is modulated by MPK11 through phosphorylation, while DBP1 in turn negatively regulates MPK11 activity. Interestingly, grf6 and mpk11 loss-of-function mutants showed altered response to infection by the potyvirus Plum pox virus (PPV), and the described molecular mechanism controlling GRF6 stability was recapitulated upon PPV infection. These results not only contribute to a better knowledge of the biology of DBP factors, but also of MAPK signalling in plants, with the identification of GRF6 as a likely MPK11 substrate and of DBP1 as a protein phosphatase regulating MPK11 activity, and unveils the implication of this protein module in the response to PPV infection in Arabidopsis. PMID:24595057

Factors in Daily Physical Activity Related to Calcaneal Mineral Density in Men

NASA Technical Reports Server (NTRS)

Hutchinson, Teresa M.; Whalen, Robert T.; Cleek, Tammy M.; Vogel, John M.; Arnaud, Sara B.

1995-01-01

To determine the factors in daily physical activity that influence the mineral density of the calcaneus, we recorded walking steps and the type and duration of exercise in 43 healthy 26-to 51-yr-old men. Areal (g/sq cm) calcaneal bone mineral density (CBMD) was measured by single energy x-ray densitometry. Subjects walked a mean (+/- SD) of 7902(+/-2534) steps per day or approximately 3.9(+/-1.2) miles daily. Eight subjects reported no exercise activities. The remaining 35 subjects spent 143(2-772) (median and range) min/wk exercising. Twenty-eight men engaged in exercise activities that generate single leg peak vertical ground reaction forces (GRF(sub z)) of 2 or more body weights (high loaders, HL), and 15 reported exercise or daily activities that typically generate GRF(sub z) less than 1.5 body weights (low loaders, LL). CBMD was 12% higher in HL than LL (0.668 +/- 0.074 g/sq cm vs 0.597 +/- 0.062 g/sq cm, P less than 0.004). In the HL group, CBMD correlated to reported minutes of high load exercise (r = 0.41, P less than 0.03). CBMD was not related to the number of daily walking steps (N = 43, r = 0.03, NS). The results of this study support the concept that the dominant factor in daily physical activity relating to bone mineral density is the participation in site specific high loading activities, i.e., for the calcaneus, high calcaneal loads.

Ground reaction forces on stairs: effects of stair inclination and age.

PubMed

Stacoff, Alex; Diezi, Christian; Luder, Gerhard; Stüssi, Edgar; Kramers-de Quervain, Inès A

2005-01-01

The goals of the study were to compare data of vertical ground reaction force (GRF) parameters during level walking, stair ascent and descent on three different stair inclinations and three different age groups. Twenty healthy subjects of three age groups (young 33.7 years; middle 63.6 years; old 76.5 years) were tested during the seven test conditions with 8-10 repetitions. Vertical forces were measured during two consecutive steps with force plates embedded in the walkway and the staircase. The results showed that during level walking the vertical GRF curves were very regular and repetitive, the trail-to-trial variability and left-right asymmetry of defined test parameters being around 2-5% and 3-5%. During stair ascent the vertical GRF force pattern was found to change slightly compared to level gait, but considerably compared to stair descent. On the steep stair the average vertical load increased up to 1.6 BW, and variability (5-10%) and asymmetry (5-15%) were increased significantly. The steep stair descent condition was found to be the most demanding test showing the largest variability and asymmetry and thus, the least stable gait pattern. Age was found to be a factor which should be considered, because the young age group walked faster and produced larger vertical GRF maxima during level walking and on stair ascent than the middle and old age group. Differences between the middle and old age group were found to be small. The present investigation is the first to provide normative data of GRF parameters on gait variability and symmetry of two consecutive steps during level gait and stair ambulation. It is the intention that the results of this study may be used as a basis for comparison with patient data.

The influence of heel height on vertical ground reaction force during landing tasks in recreationally active and athletic collegiate females.

PubMed

Lindenberg, Kelly M; Carcia, Christopher R

2013-02-01

To determine if heel height alters vertical ground reaction forces (vGRF) when landing from a forward hop or drop landing. Increased vGRF during landing are theorized to increase ACL injury risk in female athletes. Fifty collegiate females performed two single-limb landing tasks while wearing heel lifts of three different sizes (0, 12 & 24 mm) attached to the bottom of a athletic shoe. Using a force plate, peak vGRF at landing was examined. Repeated measures ANOVAs were used to determine the influence of heel height on the dependent measures. Forward hop task- Peak vGRF (normalized for body mass) with 0 mm, 12 mm, and 24 mm lifts were 2.613±0.498, 2.616±0.497 and 2.495±0.518% BW, respectively. Significant differences were noted between 0 and 24 mm lift (p<.001) and 12 and 24 mm lifts (p=.004), but not between the 0 and 12 mm conditions (p=.927). Jump-landing task- No significant differences were found in peak vGRF (p=.192) between any of the heel lift conditions. The addition of a 24 mm heel lift to the bottom of a sneaker significantly alters peak vGRF upon landing from a unilateral forward hop but not from a jumping maneuver.

Braking and Propulsive Impulses Increase with Speed during Accelerated and Decelerated Walking

PubMed Central

Peterson, Carrie L.; Kautz, Steven A.; Neptune, Richard R.

2011-01-01

The ability to accelerate and decelerate is important for daily activities and likely more demanding than maintaining a steady-state walking speed. Walking speed is modulated by anterior-posterior (AP) ground reaction force (GRF) impulses. The purpose of this study was to investigate AP impulses across a wide range of speeds during accelerated and decelerated walking. Kinematic and GRF data were collected from ten healthy subjects walking on an instrumented treadmill. Subjects completed trials at steady-state speeds and at four rates of acceleration and deceleration across a speed range of 0 to 1.8 m/s. Mixed regression models were generated to predict AP impulses, step length and frequency from speed, and joint moment impulses from AP impulses during non-steady-state walking. Braking and propulsive impulses were positively related to speed. The braking impulse had a greater relationship with speed than the propulsive impulse, suggesting that subjects modulate the braking impulse more than the propulsive impulse to change speed. Hip and knee extensor, and ankle plantarflexor moment impulses were positively related to the braking impulse, and knee flexor and ankle plantarflexor moment impulses were positively related to the propulsive impulse. Step length and frequency increased with speed and were near the subjects’ preferred combination at steady-state speeds, at which metabolic cost is minimized in nondisabled walking. Thus, these variables may be modulated to minimize metabolic cost while accelerating and decelerating. The outcomes of this work provide the foundation to investigate motor coordination in pathological subjects in response to the increased task demands of non-steady-state walking. PMID:21356590

Ground reaction force analysed with correlation coefficient matrix in group of stroke patients.

PubMed

Szczerbik, Ewa; Krawczyk, Maciej; Syczewska, Małgorzata

2014-01-01

Stroke is the third cause of death in contemporary society and causes many disorders. Clinical scales, ground reaction force (GRF) and objective gait analysis are used for assessment of patient's rehabilitation progress during treatment. The goal of this paper is to assess whether signal correlation coefficient matrix applied to GRF can be used for evaluation of the status of post-stroke patients. A group of patients underwent clinical assessment and instrumented gait analysis simultaneously three times. The difference between components of patient's GRF (vertical, fore/aft, med/lat) and normal ones (reference GRF of healthy subjects) was calculated as correlation coefficient. Patients were divided into two groups ("worse" and "better") based on the clinical functional scale tests done at the beginning of rehabilitation process. The results obtained by these two groups were compared using statistical analysis. An increase of median value of correlation coefficient is observed in all components of GRF, but only in non-paretic leg. Analysis of GRF signal can be helpful in assessment of post-stroke patients during rehabilitation. Improvement in stroke patients was observed in non-paretic leg of the "worse" group. GRF analysis should not be the only tool for objective validation of patient's improvement, but could be used as additional source of information.

Physicochemical and organoleptic characteristics of seasoned beef patties with added glutinous rice flour.

PubMed

Yi, Hae Chang; Cho, Hyunnho; Hong, Jae Joon; Ryu, Rae Kyeong; Hwang, Keum Taek; Regenstein, Joe M

2012-12-01

This study was conducted to determine if glutinous rice flour (GRF) could be a functional food additive to potentially replace corn starch (CS), soy protein isolate (SPI) and/or sodium tripolyphosphate (STPP) to improve the physicochemical and organoleptic characteristics of seasoned beef patties. GRF had a lower cook loss among the treatment groups due to an increase in fat and moisture retentions (p<0.05). GRF lowered texture profile values for hardness, gumminess, springiness, and chewiness (p<0.05) of the patties, which are generally beneficial for this product. The beef patties with GRF were juicier and more tender than the control and other treatments (p<0.05). Hedonic scores for juiciness, tenderness and overall acceptability were the highest for the beef patties with 1 and 3% GRFs, suggesting that GRF may be an effective functional ingredient to improve the textural quality of seasoned beef patties. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Gaussian random field model for similarity-based smoothing in Bayesian disease mapping.

PubMed

Baptista, Helena; Mendes, Jorge M; MacNab, Ying C; Xavier, Miguel; Caldas-de-Almeida, José

2016-08-01

Conditionally specified Gaussian Markov random field (GMRF) models with adjacency-based neighbourhood weight matrix, commonly known as neighbourhood-based GMRF models, have been the mainstream approach to spatial smoothing in Bayesian disease mapping. In the present paper, we propose a conditionally specified Gaussian random field (GRF) model with a similarity-based non-spatial weight matrix to facilitate non-spatial smoothing in Bayesian disease mapping. The model, named similarity-based GRF, is motivated for modelling disease mapping data in situations where the underlying small area relative risks and the associated determinant factors do not vary systematically in space, and the similarity is defined by "similarity" with respect to the associated disease determinant factors. The neighbourhood-based GMRF and the similarity-based GRF are compared and accessed via a simulation study and by two case studies, using new data on alcohol abuse in Portugal collected by the World Mental Health Survey Initiative and the well-known lip cancer data in Scotland. In the presence of disease data with no evidence of positive spatial correlation, the simulation study showed a consistent gain in efficiency from the similarity-based GRF, compared with the adjacency-based GMRF with the determinant risk factors as covariate. This new approach broadens the scope of the existing conditional autocorrelation models. © The Author(s) 2016.

Ground reaction forces and heart rate profile of aerobic dance instructors during a low and high impact exercise programme.

PubMed

Rousanoglou, E N; Boudolos, K D

2005-06-01

The magnitude of ground reaction forces (GRF) has been associated, although never verified, with the high incidence of lower extremities injuries in aerobic dance (AD) instructors. Moreover, during their working activities AD instructors have demonstrated HR levels, such as 70% HRmax, values, more in training rather in working status. This study was designed to investigate GRF and heart rate (HR) exhibited by AD instructors of both genders, during a simulated AD instruction, from the perspective of accepted occupational workloads. Fourteen females and 14 males instructors performed a 35 min AD exercise programme (warm up--low impact (LI) interval--in high impact (HI) interval--cool down). Four GRF measurements were taken during LI and HI time intervals, respectively. HR was recorded throughout the whole experimental procedure and was synchronised to GRF measurements. All GRF and HR values were significantly increased in HI exercise (p<0.05) with a non significant (p>0.05) time effect for GRF. In both LI and HI exercises, females demonstrated significantly higher vertical but lower lateral GRF (p<0.05) and significantly shorter cycles of movement (p<0.05) while in HI exercise they had significant longer flight times (p<0.05). For both genders, HR was kept at 70% and 80% of HR(max-calc) and RHR was 60% and 70%, during LI and HI intervals respectively, with females showing a trend, though non-significant, for higher HR values. The gender specificity of the significant vertical and lateral GRF pattern differences, may possibly be associated with the significant anthropometric differences of male and female AD instructors. HR(max-calc) and RHR exceeded the accepted occupational levels rising to training status levels. We suggest that AD instructors take up such instructing methods which allow them to minimize the magnitude or the rate of GRF, as well as HR levels, developed in the course of their working hour.

A comparison of take-off dynamics during three different spikes, block and counter-movement jump in female volleyball players.

PubMed

Kabacinski, Jaroslae; Dworak, Lecholslaw B; Murawa, Michal; Ostarello, John; Rzepnicka, Agata; Maczynski, Jacek

2016-12-01

The purpose of the study was to compare the take-off dynamics in counter-movement jump (CMJ), volleyball block and spikes. Twelve professional female players, representing the highest volleyball league in Poland, participated in the laboratory tests. A force platform was used to record ground reaction force (GRF) during take-off phase in CMJ test, block from a run-up and spikes: front row attack, slide attack, back row attack. Vertical (v) GRF (peak: Rmax and integral mean: ), impulse of vGRF (J) and mechanical power (peak: Pmax and integral mean:

) were analyzed. Significant differences (P<0.05) of values of the dynamic parameters (Rmax, , J, Pmax, and

) were found between CMJ, block from a run-up and three different technique spikes. The highest values were recorded during take-off in the back row attack: peak vGRF (2.93±0.05 BW), integral mean vGRF (1.90±0.08 BW), impulse of vGRF (354±40 Ns), peak power (5320±918 W) and integral mean power (3604±683 W). Peak power (2608±217 W) and integral mean power (1417±94 W) were determined in CMJ test to evaluate the force-velocity capabilities of the players. In terms of GRF and the mechanical power, high level of dynamics in take-off influences positively the jumping height and significantly increases the effectiveness of attacks during spike of the ball over the block of the opponent.

Weight Bearing through Lower Limbs in a Standing Frame with and without Arm Support and Low-Magnitude Whole Body Vibration in Men and Women with Complete Motor Paraplegia

PubMed Central

Bernhardt, Kathie A.; Beck, Lisa A.; Lamb, Jeffry L.; Kaufman, Kenton R.; Amin, Shreyasee; Wuermser, Lisa-Ann

2014-01-01

Objective To determine the proportion of body weight (BW) borne through the lower limbs in persons with complete, motor paraplegia using a standing frame, with and without support of their arms. We also examined the effect of low-magnitude whole body vibration on loads borne by the lower extremities. Design Vertical ground reaction forces (GRF) were measured in 11 participants (6 men and 5 women) with paraplegia of traumatic origin (injury level T3 to T12) standing on a low-magnitude vibrating plate using a standing frame. GRF were measured in four conditions: 1) no vibration with arms on standing frame tray; 2) no vibration with arms at side; 3) vibration with arms on tray; 4) vibration with arms at side. Results GRF with arms on tray, without vibration, was 0.76 ± 0.07 BW. With arms at the side, GRF increased to 0.85 ± 0.12 BW. With vibration, mean GRF did not significantly differ from no-vibration conditions for either arm positions. Oscillation of GRF with vibration was significantly different from no-vibration conditions (p<0.001) but similar in both arm positions. Conclusion Men and women with paraplegia using a standing frame bear the majority of their weight through their lower limbs. Supporting their arms on the tray reduces the GRF by ~10% BW. Low-magnitude vibration provided additional oscillation of the load-bearing forces and was proportionally similar regardless of arm position. PMID:22407161

Somatotroph Hyperplasia

PubMed Central

Thorner, M. O.; Perryman, R. L.; Cronin, M. J.; Rogol, A. D.; Draznin, M.; Johanson, A.; Vale, W.; Horvath, E.; Kovacs, K.

1982-01-01

A 21-yr-old woman with Turner's syndrome presented with signs and symptoms of acromegaly. The serum growth hormone (GH) (95±9.4 ng/ml; mean±SEM) and somatomedin C (11 U/ml) levels were elevated, and an increase in GH levels after glucose instead of normal suppression, increase after thyrotropin-releasing hormone (TRH) administration instead of no change, and decrease after dopamine administration instead of stimulation were observed. The pituitary fossa volume was greater than normal (1,440 mm3) and the presence of a pituitary tumor was assumed. After tissue removal at transsphenoidal surgery, histological study revealed somatotroph hyperplasia rather than a discrete adenoma. Postoperatively, she remained clinically acromegalic and continued to show increased GH and somatomedin levels. A search was made for ectopic source of a growth hormone-releasing factor (GRF). Computer tomographic scan revealed a 5-cm Diam tumor in the tail of the pancreas. Following removal of this tumor, serum GH fell from 70 to 3 ng/ml over 2 h, and remained low for the subsequent 5 mo. Serum somatomedin C levels fell from 7.2 to normal by 6 wk postoperatively. There were no longer paradoxical GH responses to glucose, TRH, and dopamine. Both the medium that held the tumor cells at surgery and extracts of the tumor contained a peptide with GRF activity. The GRF contained in the tumor extract coeluted on Sephadex G-50 chromatography with rat hypothalamic GH-releasing activity. Stimulation of GH from rat somatotrophs in vitro was achieved at the nanomolar range, using the tumor extract. The patient's course demonstrates the importance of careful interpretation of pituitary histology. Elevated serum GH and somatomedin C levels in a patient with an enlarged sella turcica and the characteristic responses seen in acromegaly to TRH, dopamine, and glucose do not occur exclusively in patients with discrete pituitary tumors and acromegaly. This condition can also occur with somatotroph hyperplasia

Limb contribution to increased self-selected walking speeds during body weight support in individuals poststroke.

PubMed

Hurt, Christopher P; Burgess, Jamie K; Brown, David A

2015-03-01

Individuals poststroke walk at faster self-selected speeds under some nominal level of body weight support (BWS) whereas nonimpaired individuals walk slower after adding BWS. The purpose of this study was to determine whether increases in self-selected overground walking speed under BWS conditions of individuals poststroke can be explained by changes in their paretic and nonparetic ground reaction forces (GRF). We hypothesize that increased self-selected walking speed, recorded at some nominal level of BWS, will relate to decreased braking GRFs by the paretic limb. We recruited 10 chronic (>12 months post-ictus, 57.5±9.6 y.o.) individuals poststroke and eleven nonimpaired participants (53.3±4.1 y.o.). Participants walked overground in a robotic device, the KineAssist Walking and Balance Training System that provided varying degrees of BWS (0-20% in 5% increments) while individuals self-selected their walking speed. Self-selected walking speed and braking and propulsive GRF impulses were quantified. Out of 10 poststroke individuals, 8 increased their walking speed 13% (p=0.004) under some level of BWS (5% n=2, 10% n=3, 20% n=3) whereas nonimpaired controls did not change speed (p=0.470). In individuals poststroke, changes to self-selected walking speed were correlated with changes in paretic propulsive impulses (r=0.68, p=0.003) and nonparetic braking impulses (r=-0.80, p=0.006), but were not correlated with decreased paretic braking impulses (r=0.50 p=0.14). This investigation demonstrates that when individuals poststroke are provided with BWS and allowed to self-select their overground walking speed, they are capable of achieving faster speeds by modulating braking impulses on the nonparetic limb and propulsive impulses of the paretic limb. Copyright © 2015 Elsevier B.V. All rights reserved.

Monitoring recovery following syndesmosis sprain: a case report.

PubMed

Spaulding, S J

1995-10-01

A sprain to the tibial-fibular syndesmosis often results in prolonged rehabilitation or surgical intervention before recovery occurs. This paper documents gait recovery both before and after surgery for a syndesmosis sprain. Ground reaction force (GRF) data were available before injury and before surgery. Data were also collected every 3 days from 4 days to 4 months after syndesmosis screw removal (8 weeks after surgery). Weightbearing during the stance phase of gait did not approach normal values until approximately 4 months after syndesmosis screw removal. The push-off phase of gait also was slow to recover. When it was possible for the subject to use one or two crutches, differences in GRF were evident, such that walking with one crutch demonstrated increased force production at the ground. Bracing the ankle with a semirigid brace increased GRF, whereas a boot-type lace-up brace resulted in decreased GRF. In this case report of a combined ankle and syndesmosis sprain, results suggest the weightbearing and push-off force were seriously compromised. Decreasing the number of walking assistive devices and wearing a semirigid ankle brace increased the amount of weightbearing through the affected leg and may have merit in encouraging muscle function.

Effects of vest loading on sprint kinetics and kinematics.

PubMed

Cross, Matt R; Brughelli, Matt E; Cronin, John B

2014-07-01

The effects of vest loading on sprint kinetics and kinematics during the acceleration and maximum velocity phases of sprinting are relatively unknown. A repeated measures analysis of variance with post hoc contrasts was used to determine whether performing 6-second maximal exertion sprints on a nonmotorized force treadmill, under 2 weighted vest loading conditions (9 and 18 kg) and an unloaded baseline condition, affected the sprint mechanics of 13 males from varying sporting backgrounds. Neither vest load promoted significant change in peak vertical ground reaction force (GRF-z) outputs compared with baseline during acceleration, and only 18-kg loading increased GRF-z at the maximum velocity (8.8%; effect size [ES] = 0.70). The mean GRF-z significantly increased with 18-kg loading during acceleration and maximum velocity (11.8-12.4%; ES = 1.17-1.33). Horizontal force output was unaffected, although horizontal power was decreased with the 18-kg vest during maximum velocity (-14.3%; ES = -0.48). Kinematic analysis revealed decreasing velocity (-3.6 to -5.6%; ES = -0.38 to -0.61), decreasing step length (-4.2%; ES = -0.33 to -0.34), increasing contact time (5.9-10.0%; ES = 1.01-1.71), and decreasing flight time (-17.4 to -26.7%; ES = -0.89 to -1.50) with increased loading. As a vertical vector-training stimulus, it seems that vest loading decreases flight time, which in turn reduces GRF-z. Furthermore, it seems that heavier loads than that are traditionally recommended are needed to promote increases in the GRF-z output during maximum velocity sprinting. Finally, vest loading offers little as a horizontal vector-training stimulus and actually compromises horizontal power output.

Balance and Gait in People with Multiple Sclerosis: A Comparison with Healthy Controls and the Immediate Change after an Intervention based on the Bobath Concept.

PubMed

Ilett, P; Lythgo, N; Martin, C; Brock, K

2016-06-01

The objective of this study is to compare the balance and gait of 11 people with multiple sclerosis (MS) to 11 healthy controls and to investigate the immediate change after a single intervention based on the Bobath concept on these activities in the MS group. Balance was assessed by ground reaction forces (GRF) and centre of pressure movements during single limb standing (SLS), the Lateral Reach Test (LRT) and the Four Square Step Test (FSST). Gait was evaluated by GRF, ankle kinematics and spatiotemporal measures. Baseline measures in the MS group showed significantly greater vertical GRF variability (p = 0.008) during SLS reached less distance on the LRT (p = 0.001) and were slower completing the FSST (p < 0.001). During gait, the MS group walked slower (p = 0.005) and had less ankle plantarflexion (PF) (p = 0.001) than the control group. Less peak vertical GRF (p < 0.001) and peak propulsive GRF (p = 0.004) at terminal stance and increased vertical GRF in midstance (p = 0.005) were observed. The measures of balance and gait were re-assessed in the MS group immediately after a 20-min intervention based on the Bobath concept delivered to the most impaired foot and ankle. After the intervention, the MS group had significant changes towards the control group values with reduced mediolateral (p = 0.002) and vertical (p = 0.016) GRF variability in the SLS task, faster FSST time (p = 0.006) and increased ankle PF during gait (p = 0.002). This study provides further evidence of balance and gait limitations in people with MS and indicates that a single treatment based on principles of the Bobath concept to the foot and ankle can result in immediate improvements in balance and ankle PF during gait in people with MS. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

MicroRNA and Transcription Factor: Key Players in Plant Regulatory Network

PubMed Central

Samad, Abdul F. A.; Sajad, Muhammad; Nazaruddin, Nazaruddin; Fauzi, Izzat A.; Murad, Abdul M. A.; Zainal, Zamri; Ismail, Ismanizan

2017-01-01

Recent achievements in plant microRNA (miRNA), a large class of small and non-coding RNAs, are very exciting. A wide array of techniques involving forward genetic, molecular cloning, bioinformatic analysis, and the latest technology, deep sequencing have greatly advanced miRNA discovery. A tiny miRNA sequence has the ability to target single/multiple mRNA targets. Most of the miRNA targets are transcription factors (TFs) which have paramount importance in regulating the plant growth and development. Various families of TFs, which have regulated a range of regulatory networks, may assist plants to grow under normal and stress environmental conditions. This present review focuses on the regulatory relationships between miRNAs and different families of TFs like; NF-Y, MYB, AP2, TCP, WRKY, NAC, GRF, and SPL. For instance NF-Y play important role during drought tolerance and flower development, MYB are involved in signal transduction and biosynthesis of secondary metabolites, AP2 regulate the floral development and nodule formation, TCP direct leaf development and growth hormones signaling. WRKY have known roles in multiple stress tolerances, NAC regulate lateral root formation, GRF are involved in root growth, flower, and seed development, and SPL regulate plant transition from juvenile to adult. We also studied the relation between miRNAs and TFs by consolidating the research findings from different plant species which will help plant scientists in understanding the mechanism of action and interaction between these regulators in the plant growth and development under normal and stress environmental conditions. PMID:28446918

MicroRNA and Transcription Factor: Key Players in Plant Regulatory Network.

PubMed

Samad, Abdul F A; Sajad, Muhammad; Nazaruddin, Nazaruddin; Fauzi, Izzat A; Murad, Abdul M A; Zainal, Zamri; Ismail, Ismanizan

2017-01-01

Recent achievements in plant microRNA (miRNA), a large class of small and non-coding RNAs, are very exciting. A wide array of techniques involving forward genetic, molecular cloning, bioinformatic analysis, and the latest technology, deep sequencing have greatly advanced miRNA discovery. A tiny miRNA sequence has the ability to target single/multiple mRNA targets. Most of the miRNA targets are transcription factors (TFs) which have paramount importance in regulating the plant growth and development. Various families of TFs, which have regulated a range of regulatory networks, may assist plants to grow under normal and stress environmental conditions. This present review focuses on the regulatory relationships between miRNAs and different families of TFs like; NF-Y, MYB, AP2, TCP, WRKY, NAC, GRF, and SPL. For instance NF-Y play important role during drought tolerance and flower development, MYB are involved in signal transduction and biosynthesis of secondary metabolites, AP2 regulate the floral development and nodule formation, TCP direct leaf development and growth hormones signaling. WRKY have known roles in multiple stress tolerances, NAC regulate lateral root formation, GRF are involved in root growth, flower, and seed development, and SPL regulate plant transition from juvenile to adult. We also studied the relation between miRNAs and TFs by consolidating the research findings from different plant species which will help plant scientists in understanding the mechanism of action and interaction between these regulators in the plant growth and development under normal and stress environmental conditions.

Metabolic Rate and Ground Reaction Force During Motorized and Non-Motorized Treadmill Exercise

NASA Technical Reports Server (NTRS)

Everett, Meghan E.; Loehr, James A.; DeWitt, John K.; Laughlin, Mitzi; Lee, Stuart M. C.

2010-01-01

PURPOSE: To measure vertical ground reaction force (vGRF) and oxygen consumption (VO2) at several velocities during exercise using a ground-based version of the ISS treadmill in the M and NM modes. METHODS: Subjects (n = 20) walked or ran at 0.89, 1.34, 1.79, 2.24, 2.68, and 3.12 m/s while VO2 and vGRF data were collected. VO2 was measured using open-circuit spirometry (TrueOne 2400, Parvo-Medics). Data were averaged over the last 2 min of each 5-min stage. vGRF was measured in separate 15-s bouts at 125 Hz using custom-fitted pressure-sensing insoles (F-Scan Sport Sensors, Tekscan, Inc). A repeated-measures ANOVA was used to test for differences in VO2 and vGRF between M and NM and across speeds. Significance was set at P < 0.05. RESULTS: Most subjects were unable to exercise for 5 min at treadmill speeds above 1.79 m/s in the NM mode; however, vGRF data were obtained for all subjects at each speed in both modes. VO2 was approx.40% higher during NM than M exercise across treadmill speeds. vGRF increased with treadmill speed but was not different between modes. CONCLUSION: Higher VO2 with no change in vGRF suggests that the additional metabolic cost associated with NM treadmill exercise is accounted for in the horizontal forces required to move the treadmill belt. Although this may limit the exercise duration at faster speeds, high-intensity NM exercise activates the hamstrings and plantarflexors, which are not specifically targeted or well protected by other in-flight countermeasures.

Greater Mechanical Loading During Walking Is Associated With Less Collagen Turnover in Individuals With Anterior Cruciate Ligament Reconstruction.

PubMed

Pietrosimone, Brian; Blackburn, J Troy; Harkey, Matthew S; Luc, Brittney A; Hackney, Anthony C; Padua, Darin A; Driban, Jeffrey B; Spang, Jeffrey T; Jordan, Joanne M

2016-02-01

Individuals who have sustained an anterior cruciate ligament (ACL) injury and undergo ACL reconstruction (ACLR) are at higher risk of developing knee osteoarthritis. It is hypothesized that altered knee loading may influence the underlying joint metabolism and hasten development of posttraumatic knee osteoarthritis. To explore the associations between serum biomarkers of cartilage metabolism and peak vertical ground-reaction force (vGRF) and vGRF loading rate in the injured and uninjured limbs of individuals with ACLR. Descriptive laboratory study. Patients with a history of a primary unilateral ACLR who had returned to unrestricted physical activity (N = 19) participated in the study. Resting blood was collected from each participant before completing 5 walking gait trials at a self-selected comfortable speed. Peak vGRF was extracted for both limbs during the first 50% of the stance phase of gait, and the linear vGRF loading rate was determined between heel strike and peak vGRF. Sera were assessed for collagen breakdown (collagen type II cleavage product [C2C]) and synthesis (collagen type II C-propeptide [CPII]), as well as aggrecan concentrations, via commercially available specific enzyme-linked immunosorbent assays. Pearson product-moment correlations (r) and Spearman rank-order correlations (ρ) were used to evaluate associations between loading characteristics and biomarkers of cartilage metabolism. Lower C2C:CPII ratios were associated with higher peak vGRF in the injured limb (ρ = -0.59, uncorrected P = .007). There were no significant associations between peak vGRF or linear vGRF loading rate and CPII, C2C, or aggrecan serum concentrations. Lower C2C:CPII ratios were associated with higher peak vGRF in the ACLR limb during gait, suggesting that higher peak loading in the ACLR limb is related to lower type II collagen breakdown relative to type II collagen synthesis. These data suggest that type II collagen synthesis may be higher relative to the amount

Knee biomechanics during a jump-cut maneuver: Effects of gender & ACL surgery

PubMed Central

Miranda, Daniel L.; Fadale, Paul D.; Hulstyn, Michael J.; Shalvoy, Robert M.; Machan, Jason T.; Fleming, Braden C.

2012-01-01

Purpose The purpose of this study was to compare kinetic and knee kinematic measurements from male and female ACL-intact (ACLINT) and ACL-reconstructed (ACLREC) subjects during a jump-cut maneuver using biplanar videoradiography. Methods Twenty subjects were recruited; 10 ACLINT (5 males, 5 females) and 10 ACLREC (4 males, 6 females; five years post surgery). Each subject performed a jump-cut maneuver by landing on a single leg and performing a 45° side-step cut. Ground reaction force was measured by a force plate and expressed relative to body weight. Six-degree-of-freedom knee kinematics were determined from a biplanar videoradiography system and an optical motion capture system. Results ACLINT female subjects landed with a larger peak vertical GRF (p<0.001) compared to ACLINT male subjects. ACLINT subjects landed with a larger peak vertical GRF (p≤0.036) compared to ACLREC subjects. Regardless of ACL reconstruction status, female subjects underwent less knee flexion angle excursion (p=0.002) and had an increased average rate of anterior tibial translation (0.05±0.01%/millisecond; p=0.037) after contact compared to male subjects. Furthermore, ACLREC subjects had a lower rate of anterior tibial translation compared to ACLINT subjects (0.05±0.01%/millisecond; p=0.035). Finally, no striking differences were observed in other knee motion parameters. Conclusion Women permit a smaller amount of knee flexion angle excursion during a jump-cut maneuver, resulting in a larger peak vertical GRF and increased rate of anterior tibial translation. Notably, ACLREC subjects also perform the jump cut maneuver with lower GRF than ACLINT subjects five years post surgery. This study proposes a causal sequence whereby increased landing stiffness (larger peak vertical GRF combined with less knee flexion angle excursion) leads to an increased rate of anterior tibial translation while performing a jump-cut maneuver. PMID:23190595

The gearing function of running shoe longitudinal bending stiffness.

PubMed

Willwacher, Steffen; König, Manuel; Braunstein, Björn; Goldmann, Jan-Peter; Brüggemann, Gert-Peter

2014-07-01

The purpose of the present study was to investigate whether altered longitudinal bending stiffness (LBS) levels of the midsole of a running shoe lead to a systematic change in lower extremity joint lever arms of the ground reaction force (GRF). Joint moments and GRF lever arms in the sagittal plane were determined from 19 male subjects running at 3.5 m/s using inverse dynamics procedures. LBS was manipulated using carbon fiber insoles of 1.9 mm and 3.2 mm thickness. Increasing LBS led to a significant shift of joint lever arms to a more anterior position. Effects were more pronounced at distal joints. Ankle joint moments were not significantly increased in the presence of higher GRF lever arms when averaged over all subjects. Still, two individual strategies (1: increase ankle joint moments while keeping push-off times almost constant, 2: decrease ankle joint moments and increase push-off times) could be identified in response to increased ankle joint lever arms that might reflect individual differences between subjects with respect to strength capacities or anthropometric characteristics. The results of the present study indicate that LBS systematically influences GRF lever arms of lower extremity joints during the push-off phase in running. Further, individual responses to altered LBS levels could be identified that could aid in finding optimum LBS values for a given individual. Copyright © 2014 Elsevier B.V. All rights reserved.

Running quietly reduces ground reaction force and vertical loading rate and alters foot strike technique.

PubMed

Phan, Xuan; Grisbrook, Tiffany L; Wernli, Kevin; Stearne, Sarah M; Davey, Paul; Ng, Leo

2017-08-01

This study aimed to determine if a quantifiable relationship exists between the peak sound amplitude and peak vertical ground reaction force (vGRF) and vertical loading rate during running. It also investigated whether differences in peak sound amplitude, contact time, lower limb kinematics, kinetics and foot strike technique existed when participants were verbally instructed to run quietly compared to their normal running. A total of 26 males completed running trials for two sound conditions: normal running and quiet running. Simple linear regressions revealed no significant relationships between impact sound and peak vGRF in the normal and quiet conditions and vertical loading rate in the normal condition. t-Tests revealed significant within-subject decreases in peak sound, peak vGRF and vertical loading rate during the quiet compared to the normal running condition. During the normal running condition, 15.4% of participants utilised a non-rearfoot strike technique compared to 76.9% in the quiet condition, which was corroborated by an increased ankle plantarflexion angle at initial contact. This study demonstrated that quieter impact sound is not directly associated with a lower peak vGRF or vertical loading rate. However, given the instructions to run quietly, participants effectively reduced peak impact sound, peak vGRF and vertical loading rate.

Fall risk factors analysis based on sample entropy of plantar kinematic signal during stance phase.

PubMed

Shengyun Liang; Huiyu Jia; Zilong Li; Huiqi Li; Xing Gao; Zuchang Ma; Yingnan Ma; Guoru Zhao

2016-08-01

Falls are a multi-causal phenomenon with a complex interaction. The aim of our research is to study the effect of multiple variables for potential risk of falls and construct an elderly fall risk assessment model based on demographics data and gait characteristics. A total of 101 subjects, whom belong to Malianwa Street, aged above 50 years old and participated in questionnaire survey. Participants were classified into three groups (high, medium and low risk group) according to the score of elderly fall risk assessment scale. In addition, the data of ground reaction force (GRF) and ground reaction moment (GRM) was record when they performed walking at comfortable state. The demographic variables, sample entropy of GRF and GRM, and impulse difference of bilateral foot were considered as potential explanatory variables of risk assessment model. Firstly, we investigated whether different groups could present difference in every variable. Statistical differences were found for the following variables: age (p=2.28e-05); impulse difference (p=0.02036); sample entropy of GRF in vertical direction (p=0.0144); sample entropy of GRM in anterior-posterior direction (p=0.0387). Finally, the multiple regression analysis results indicated that age, impulse difference and sample entropy of resultant GRM could identify individuals who had different levels of fall risk. Therefore, those results could potentially be useful in the fall risk assessment and monitor the state of physical function in elderly population.

Femoral loading mechanics in the Virginia opossum, Didelphis virginiana: torsion and mediolateral bending in mammalian locomotion.

PubMed

Gosnell, W Casey; Butcher, Michael T; Maie, Takashi; Blob, Richard W

2011-10-15

Studies of limb bone loading in terrestrial mammals have typically found anteroposterior bending to be the primary loading regime, with torsion contributing minimally. However, previous studies have focused on large, cursorial eutherian species in which the limbs are held essentially upright. Recent in vivo strain data from the Virginia opossum (Didelphis virginiana), a marsupial that uses a crouched rather than an upright limb posture, have indicated that its femur experiences appreciable torsion during locomotion as well as strong mediolateral bending. The elevated femoral torsion and strong mediolateral bending observed in D. virginiana might result from external forces such as a medial inclination of the ground reaction force (GRF), internal forces deriving from a crouched limb posture, or a combination of these factors. To evaluate the mechanism underlying the loading regime of opossum femora, we filmed D. virginiana running over a force platform, allowing us to measure the magnitude of the GRF and its three-dimensional orientation relative to the limb, facilitating estimates of limb bone stresses. This three-dimensional analysis also allows evaluations of muscular forces, particularly those of hip adductor muscles, in the appropriate anatomical plane to a greater degree than previous two-dimensional analyses. At peak GRF and stress magnitudes, the GRF is oriented nearly vertically, inducing a strong abductor moment at the hip that is countered by adductor muscles on the medial aspect of the femur that place this surface in compression and induce mediolateral bending, corroborating and explaining loading patterns that were identified in strain analyses. The crouched orientation of the femur during stance in opossums also contributes to levels of femoral torsion as high as those seen in many reptilian taxa. Femoral safety factors were as high as those of non-avian reptiles and greater than those of upright, cursorial mammals, primarily because the load

Midsole material-related force control during heel-toe running.

PubMed

Kersting, Uwe G; Brüggemann, Gert-Peter

2006-01-01

The impact maximum and rearfoot eversion have been used as indicators of load on internal structures in running. The midsole hardness of a typical running shoe was varied systematically to determine the relationship between external ground reaction force (GRF), in-shoe force, and kinematic variables. Eight subjects were tested during overground running at 4 m/s. Rearfoot movement as well as in-shoe forces and external GRF varied nonsystematically with midsole hardness. Kinematic parameters such as knee flexion and foot velocity at touchdown (TD), also varied nonsystematically with altered midsole hardness. Results demonstrate that considerable variations of in-shoe loading occur that were not depicted by external GRF measurements alone. Individuals apparently use different strategies of mechanical and neuromuscular adaptation in response to footwear modifications. In conclusion, shoe design effects on impact forces or other factors relating to injuries depend on the individual and therefore cannot be generalized.

Pooling sexes when assessing ground reaction forces during walking: Statistical Parametric Mapping versus traditional approach.

PubMed

Castro, Marcelo P; Pataky, Todd C; Sole, Gisela; Vilas-Boas, Joao Paulo

2015-07-16

Ground reaction force (GRF) data from men and women are commonly pooled for analyses. However, it may not be justifiable to pool sexes on the basis of discrete parameters extracted from continuous GRF gait waveforms because this can miss continuous effects. Forty healthy participants (20 men and 20 women) walked at a cadence of 100 steps per minute across two force plates, recording GRFs. Two statistical methods were used to test the null hypothesis of no mean GRF differences between sexes: (i) Statistical Parametric Mapping-using the entire three-component GRF waveform; and (ii) traditional approach-using the first and second vertical GRF peaks. Statistical Parametric Mapping results suggested large sex differences, which post-hoc analyses suggested were due predominantly to higher anterior-posterior and vertical GRFs in early stance in women compared to men. Statistically significant differences were observed for the first GRF peak and similar values for the second GRF peak. These contrasting results emphasise that different parts of the waveform have different signal strengths and thus that one may use the traditional approach to choose arbitrary metrics and make arbitrary conclusions. We suggest that researchers and clinicians consider both the entire gait waveforms and sex-specificity when analysing GRF data. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification of types of landings after blocking in volleyball associated with risk of ACL injury.

PubMed

Zahradnik, David; Jandacka, Daniel; Farana, Roman; Uchytil, Jaroslav; Hamill, Joseph

2017-03-01

Landing with a low knee flexion angle after volleyball block jumps may be associated with an increased risk of anterior cruciate ligament (ACL) injury. The aim of the present study was to identify the types of volleyball landings after blocks where the knee flexion angle is found to be under a critical knee flexion angle value of 30° at the instant of the first peak of the ground reaction force (GRF). Synchronized kinematic and kinetic data were collected for each trial. T-tests were used to determine if each knee flexion angle at the instant of the peak GRF was significantly different from the critical value of 30°. A repeated measures ANOVA was used to compare knee flexion angle, time to first peak and the magnitude of the first peak of the resultant GRF and knee stiffness. Significantly lower knee flexion angles were found in the "go" landing (p = .01, ES = 0.6) and the "reverse" landing (p = .02, ES = 0.6) only. The results for knee flexion angle and GRF parameters indicated a significant difference between a "reverse" and "go" and other types of landings, except the "side stick" landing for GRF. The "reverse" and "go" landings may present a risk for ACL injury due to the single-leg landing of these activities that have an associated mediolateral movement.

A comparison of gait biomechanics of flip-flops, sandals, barefoot and shoes

PubMed Central

2013-01-01

Background Flip-flops and sandals are popular choices of footwear due to their convenience. However, the effects of these types of footwear on lower extremity biomechanics are still poorly understood. Therefore, the objective of this study was to investigate differences in ground reaction force (GRF), center of pressure (COP) and lower extremity joint kinematic and kinetic variables during level-walking in flip-flops, sandals and barefoot compared to running shoes. Methods Ten healthy males performed five walking trials in the four footwear conditions at 1.3 m/s. Three-dimensional GRF and kinematic data were simultaneously collected. Results A smaller loading rate of the 1st peak vertical GRF and peak propulsive GRF and greater peak dorsiflexion moment in early stance were found in shoes compared to barefoot, flip-flops and sandals. Barefoot walking yielded greater mediolateral COP displacement, flatter foot contact angle, increased ankle plantarflexion contact angle, and smaller knee flexion contact angle and range of motion compared to all other footwear. Conclusions The results from this study indicate that barefoot, flip-flops and sandals produced different peak GRF variables and ankle moment compared to shoes while all footwear yield different COP and ankle and knee kinematics compared to barefoot. The findings may be helpful to researchers and clinicians in understanding lower extremity mechanics of open-toe footwear. PMID:24196492

A comparison of gait biomechanics of flip-flops, sandals, barefoot and shoes.

PubMed

Zhang, Xiuli; Paquette, Max R; Zhang, Songning

2013-11-06

Flip-flops and sandals are popular choices of footwear due to their convenience. However, the effects of these types of footwear on lower extremity biomechanics are still poorly understood. Therefore, the objective of this study was to investigate differences in ground reaction force (GRF), center of pressure (COP) and lower extremity joint kinematic and kinetic variables during level-walking in flip-flops, sandals and barefoot compared to running shoes. Ten healthy males performed five walking trials in the four footwear conditions at 1.3 m/s. Three-dimensional GRF and kinematic data were simultaneously collected. A smaller loading rate of the 1st peak vertical GRF and peak propulsive GRF and greater peak dorsiflexion moment in early stance were found in shoes compared to barefoot, flip-flops and sandals. Barefoot walking yielded greater mediolateral COP displacement, flatter foot contact angle, increased ankle plantarflexion contact angle, and smaller knee flexion contact angle and range of motion compared to all other footwear. The results from this study indicate that barefoot, flip-flops and sandals produced different peak GRF variables and ankle moment compared to shoes while all footwear yield different COP and ankle and knee kinematics compared to barefoot. The findings may be helpful to researchers and clinicians in understanding lower extremity mechanics of open-toe footwear.

Combining Enhanced Root and Shoot Growth Reveals Cross Talk between Pathways That Control Plant Organ Size in Arabidopsis1[C][W][OA

PubMed Central

Vercruyssen, Liesbeth; Gonzalez, Nathalie; Werner, Tomáš; Schmülling, Thomas; Inzé, Dirk

2011-01-01

Functionally distinct Arabidopsis (Arabidopsis thaliana) genes that positively affect root or shoot growth when ectopically expressed were combined to explore the feasibility of enhanced biomass production. Enhanced root growth resulting from cytokinin deficiency was obtained by overexpressing CYTOKININ OXIDASE/DEHYDROGENASE3 (CKX3) under the control of the root-specific PYK10 promoter. Plants harboring the PYK10-CKX3 construct were crossed with four different transgenic lines showing enhanced leaf growth. For all combinations, the phenotypic traits of the individual lines could be combined, resulting in an overall growth increase. Unexpectedly, three out of four combinations had more than additive effects. Both leaf and root growth were synergistically enhanced in plants ectopically expressing CKX3 and BRASSINOSTEROID INSENSITIVE1, indicating cross talk between cytokinins and brassinosteroids. In agreement, treatment of PYK10-CKX3 plants with brassinolide resulted in a dramatic increase in lateral root growth that could not be observed in wild-type plants. Coexpression of CKX3 and the GROWTH-REGULATING FACTOR5 (GRF5) antagonized the effects of GRF5 overexpression, revealing an interplay between cytokinins and GRF5 during leaf cell proliferation. The combined overexpression of CKX3 and GIBBERELLIN 20-OXIDASE1 led to a synergistic increase in leaf growth, suggesting an antagonistic growth control by cytokinins and gibberellins. Only additive effects on root and shoot growth were visible in plants ectopically expressing both CKX3 and ARABIDOPSIS VACUOLAR PYROPHOSPHATASE1, hinting at an independent action mode. Our results show new interactions and contribute to the molecular and physiological understanding of biomass production at the whole plant level. PMID:21205622

Antagonist muscle co-contraction during a double-leg landing maneuver at two heights.

PubMed

Mokhtarzadeh, Hossein; Yeow, Chen Hua; Goh, James Cho Hong; Oetomo, Denny; Ewing, Katie; Lee, Peter Vee Sin

2017-10-01

Knee injuries are common during landing activities. Greater landing height increases peak ground reaction forces (GRFs) and loading at the knee joint. As major muscles to stabilize the knee joint, Quadriceps and Hamstring muscles provide internal forces to attenuate the excessive GRF. Despite the number of investigations on the importance of muscle function during landing, the role of landing height on these muscles forces using modeling during landing is not fully investigated. Participant-specific musculoskeletal models were developed using experimental motion analysis data consisting of anatomic joint motions and GRF from eight male participants performing double-leg drop landing from 30 and 60 cm. Muscle forces were calculated in OpenSim and their differences were analyzed at the instances of high risk during landing i.e. peak GRF for both heights. The maximum knee flexion angle and moments were found significantly higher from a double-leg landing at 60 cm compared to 30 cm. The results showed elevated GRF, and mean muscle forces during landing. At peak GRF, only quadriceps showed significantly greater forces at 60 cm. Hamstring muscle forces did not significantly change at 60 cm compared to 30 cm. Quadriceps and hamstring muscle forces changed at different heights. Since hamstring forces were similar in both landing heights, this could lead to an imbalance between the antagonist muscles, potentially placing the knee at risk of injury if combined with small flexion angles that was not observed at peak GRF in our study. Thus, enhanced neuromuscular training programs strengthening the hamstrings may be required to address this imbalance. These findings may contribute to enhance neuromuscular training programs to prevent knee injuries during landing.

Cocoa Intensification Scenarios and Their Predicted Impact on CO2 Emissions, Biodiversity Conservation, and Rural Livelihoods in the Guinea Rain Forest of West Africa

NASA Astrophysics Data System (ADS)

Gockowski, Jim; Sonwa, Denis

2011-08-01

The Guinean rain forest (GRF) of West Africa, identified over 20 years ago as a global biodiversity hotspot, had reduced to 113,000 km2 at the start of the new millennium which was 18% of its original area. The principal driver of this environmental change has been the expansion of extensive smallholder agriculture. From 1988 to 2007, the area harvested in the GRF by smallholders of cocoa, cassava, and oil palm increased by 68,000 km2. Field results suggest a high potential for significantly increasing crop yields through increased application of seed-fertilizer technologies. Analyzing land-use change scenarios, it was estimated that had intensified cocoa technology, already developed in the 1960s, been pursued in Cote d'Ivoire, Ghana, Nigeria and Cameroon that over 21,000 km2 of deforestation and forest degradation could have been avoided along with the emission of nearly 1.4 billion t of CO2. Addressing the low productivity of agriculture in the GRF should be one of the principal objectives of REDD climate mitigation programs.

Influence of Large Lakes on Methane Greenhouse Forcing in the Early Eocene

NASA Astrophysics Data System (ADS)

Whiteside, J. H.; Granberg, D. L.; Kasprak, A. H.; Taylor, K. W.; Pancost, R. D.

2011-12-01

Long-duration elevated global temperatures and increased atmospheric pCO2 levels (~1000-2000 ppm) characterized the earliest portion of the Eocene (Ypressian; ~55 to 49 Ma). This extended period of global warmth was also punctuated by a series of short (sub-precessional) hyperthermal events in which atmospheric CO2 (>2000 ppm) and global temperatures rose with unprecedented and (as of yet) unexplained rapidity. This interval is perhaps the best temporal analog for assessing contemporary response of the biosphere and global carbon cycle to increased CO2 emissions. Although these hyperthermals appear paced by 100 Ka and 1 Ma scale orbital (eccentricity) cycles in the marine realm, high frequency forcing processes have not yet been examined, and long continental records have yet to be explored for their expression. To identify sub-eccentricity (<100,000 year) scale variability in Early Eocene carbon cycling, we examined lacustrine records of organic carbon isotopes and carbon content from a ~5 Ma record in the Green River Formation (GRF) in the Uinta Basin of Utah, U.S.A. and a ~1 Ma record from the Messel Shale, (Darmstadt, Germany.) We demonstrate that in addition to the expected 100 Ka eccentricity cycle, the 40 Ka cycle of obliquity is also an important component of climate variability as reflected in the lacustrine carbon cycle and hence a potential driver of global carbon cycling. We further investigated carbon cycle dynamics by examining biomarker evidence for changes in the terrestrial methane cycle during this time interval. Due to their increased volumes (>60,000 km2), highly stratified and cyclically anoxic lakes of the Eocene could have provided enough methane to alter global radiative forcing. This is consistent with our data, which demonstrate that the GRF and Messel Shale both exhibit strongly reducing conditions as well as abundant methanogen and methanotroph biomarkers. Further, the GRF lacustrine environment was highly stratified with, at times

Locomotion Strategy and Magnitude of Ground Reaction Forces During Treadmill Training on ISS.

PubMed

Fomina, Elena; Savinkina, Alexandra

2017-09-01

Creation of the cosmonaut in-flight physical training process is currently based on the leading role of support afferents in the development of hypogravity changes in the motor system. We assume that the strength of support afferents is related to the magnitude of the ground reaction forces (GRF). For this purpose it was necessary to compare the GRF magnitude on the Russian BD-2 treadmill for different locomotion types (walking and running), modes (active and passive), and subjects. Relative GRF values were analyzed while subjects performed walking and running during active and passive modes of treadmill belt movement under 1 G (N = 6) and 0 G (N = 4) conditions. For different BD-2 modes and both types of locomotion, maximum GRF values varied in both 0 G and 1 G. Considerable individual variations were also found in the locomotion strategies, as well as in maximum GRF values. In 0 G, the smallest GRF values were observed for walking in active mode, and the largest during running in passive mode. In 1 G, GRF values were higher during running than while walking, but the difference between active and passive modes was not observed; we assume this was due to the uniqueness of the GRF profile. The maximum GRF recorded during walking and running in active and passive modes depended on the individual pattern of locomotion. The maximum GRF values that we recorded on BD-2 were close to values found by other researchers. The observations from this study could guide individualized countermeasures prescriptions for microgravity.Fomina E, Savinkina A. Locomotion strategy and magnitude of ground reaction forces during treadmill training on ISS. Aerosp Med Hum Perform. 2017; 88(9):841-849.

Muscle optimization techniques impact the magnitude of calculated hip joint contact forces.

PubMed

Wesseling, Mariska; Derikx, Loes C; de Groote, Friedl; Bartels, Ward; Meyer, Christophe; Verdonschot, Nico; Jonkers, Ilse

2015-03-01

In musculoskeletal modelling, several optimization techniques are used to calculate muscle forces, which strongly influence resultant hip contact forces (HCF). The goal of this study was to calculate muscle forces using four different optimization techniques, i.e., two different static optimization techniques, computed muscle control (CMC) and the physiological inverse approach (PIA). We investigated their subsequent effects on HCFs during gait and sit to stand and found that at the first peak in gait at 15-20% of the gait cycle, CMC calculated the highest HCFs (median 3.9 times peak GRF (pGRF)). When comparing calculated HCFs to experimental HCFs reported in literature, the former were up to 238% larger. Both static optimization techniques produced lower HCFs (median 3.0 and 3.1 pGRF), while PIA included muscle dynamics without an excessive increase in HCF (median 3.2 pGRF). The increased HCFs in CMC were potentially caused by higher muscle forces resulting from co-contraction of agonists and antagonists around the hip. Alternatively, these higher HCFs may be caused by the slightly poorer tracking of the net joint moment by the muscle moments calculated by CMC. We conclude that the use of different optimization techniques affects calculated HCFs, and static optimization approached experimental values best. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Atrial natriuretic factor increases vascular permeability

NASA Technical Reports Server (NTRS)

Lockette, Warren; Brennaman, Bruce

1990-01-01

An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). In this study, it was determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of (I-125)-albumin and (C-14)-dextran of similar molecular size. Blood pressure was monitored, and serial determinations of hematocrits were made. Animals infused with 1.0 microg/kg per min ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of (I-125)-albumin, but not (C-14)-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.

Circadian misalignment increases cardiovascular disease risk factors in humans

PubMed Central

Morris, Christopher J.; Purvis, Taylor E.; Hu, Kun; Scheer, Frank A. J. L.

2016-01-01

Shift work is a risk factor for hypertension, inflammation, and cardiovascular disease. This increased risk cannot be fully explained by classic risk factors. One of the key features of shift workers is that their behavioral and environmental cycles are typically misaligned relative to their endogenous circadian system. However, there is little information on the impact of acute circadian misalignment on cardiovascular disease risk in humans. Here we show—by using two 8-d laboratory protocols—that short-term circadian misalignment (12-h inverted behavioral and environmental cycles for three days) adversely affects cardiovascular risk factors in healthy adults. Circadian misalignment increased 24-h systolic blood pressure (SBP) and diastolic blood pressure (DBP) by 3.0 mmHg and 1.5 mmHg, respectively. These results were primarily explained by an increase in blood pressure during sleep opportunities (SBP, +5.6 mmHg; DBP, +1.9 mmHg) and, to a lesser extent, by raised blood pressure during wake periods (SBP, +1.6 mmHg; DBP, +1.4 mmHg). Circadian misalignment decreased wake cardiac vagal modulation by 8–15%, as determined by heart rate variability analysis, and decreased 24-h urinary epinephrine excretion rate by 7%, without a significant effect on 24-h urinary norepinephrine excretion rate. Circadian misalignment increased 24-h serum interleukin-6, C-reactive protein, resistin, and tumor necrosis factor-α levels by 3–29%. We demonstrate that circadian misalignment per se increases blood pressure and inflammatory markers. Our findings may help explain why shift work increases hypertension, inflammation, and cardiovascular disease risk. PMID:26858430

Ground reaction forces during level ground walking with body weight unloading

PubMed Central

Barela, Ana M. F.; de Freitas, Paulo B.; Celestino, Melissa L.; Camargo, Marcela R.; Barela, José A.

2014-01-01

Background: Partial body weight support (BWS) systems have been broadly used with treadmills as a strategy for gait training of individuals with gait impairments. Considering that we usually walk on level ground and that BWS is achieved by altering the load on the plantar surface of the foot, it would be important to investigate some ground reaction force (GRF) parameters in healthy individuals walking on level ground with BWS to better implement rehabilitation protocols for individuals with gait impairments. Objective: To describe the effects of body weight unloading on GRF parameters as healthy young adults walked with BWS on level ground. Method: Eighteen healthy young adults (27±4 years old) walked on a walkway, with two force plates embedded in the middle of it, wearing a harness connected to a BWS system, with 0%, 15%, and 30% BWS. Vertical and horizontal peaks and vertical valley of GRF, weight acceptance and push-off rates, and impulse were calculated and compared across the three experimental conditions. Results: Overall, participants walked more slowly with the BWS system on level ground compared to their normal walking speed. As body weight unloading increased, the magnitude of the GRF forces decreased. Conversely, weight acceptance rate was similar among conditions. Conclusions: Different amounts of body weight unloading promote different outputs of GRF parameters, even with the same mean walk speed. The only parameter that was similar among the three experimental conditions was the weight acceptance rate. PMID:25590450

Weight bearing through lower limbs in a standing frame with and without arm support and low-magnitude whole-body vibration in men and women with complete motor paraplegia.

PubMed

Bernhardt, Kathie A; Beck, Lisa A; Lamb, Jeffry L; Kaufman, Kenton R; Amin, Shreyasee; Wuermser, Lisa-Ann

2012-04-01

The aim of the study was to determine the proportion of body weight borne through the lower limbs in persons with complete motor paraplegia using a standing frame, with and without the support of their arms. We also examined the effect of low-magnitude whole-body vibration on loads borne by the lower limbs. Vertical ground reaction forces (GRFs) were measured in 11 participants (six men and five women) with paraplegia of traumatic origin (injury level T3-T12) standing on a low-magnitude vibrating plate using a standing frame. GRFs were measured in four conditions: (1) no vibration with arms on standing frame tray, (2) no vibration with arms at side, (3) vibration with arms on tray, and (4) vibration with arms at side. GRF with arms on tray, without vibration, was 0.76 ± 0.07 body weight. With arms at the side, GRF increased to 0.85 ± 0.12 body weight. With vibration, mean GRF did not significantly differ from no-vibration conditions for either arm positions. Oscillation of GRF with vibration was significantly different from no-vibration conditions (P < 0.001) but similar in both arm positions. Men and women with paraplegia using a standing frame bear most of their weight through their lower limbs. Supporting their arms on the tray reduces the GRF by approximately 10% body weight. Low-magnitude vibration provided additional oscillation of the load-bearing forces and was proportionally similar regardless of arm position.

Changing Sagittal-Plane Landing Styles to Modulate Impact and Tibiofemoral Force Magnitude and Directions Relative to the Tibia

PubMed Central

Shimokochi, Yohei; Ambegaonkar, Jatin P.; Meyer, Eric G.

2016-01-01

Context: Ground reaction force (GRF) and tibiofemoral force magnitudes and directions have been shown to affect anterior cruciate ligament loading during landing. However, the kinematic and kinetic factors modifying these 2 forces during landing are unknown. Objective: To clarify the intersegmental kinematic and kinetic links underlying the alteration of the GRF and tibiofemoral force vectors secondary to changes in the sagittal-plane body position during single-legged landing. Design: Crossover study. Setting: Laboratory. Patients or Other Participants: Twenty recreationally active participants (age = 23.4 ± 3.6 years, height = 171.0 ± 9.4 cm, mass = 73.3 ± 12.7 kg). Intervention(s): Participants performed single-legged landings using 3 landing styles: self-selected landing (SSL), body leaning forward and landing on the toes (LFL), and body upright with flat-footed landing (URL). Three-dimensional kinetics and kinematics were recorded. Main Outcome Measure(s): Sagittal-plane tibial inclination and knee-flexion angles, GRF magnitude and inclination angles relative to the tibia, and proximal tibial forces at peak tibial axial forces. Results: The URL resulted in less time to peak tibial axial forces, smaller knee-flexion angles, and greater magnitude and a more anteriorly inclined GRF vector relative to the tibia than did the SSL. These changes led to the greatest peak tibial axial and anterior shear forces in the URL among the 3 landing styles. Conversely, the LFL resulted in longer time to peak tibial axial forces, greater knee-flexion angles, and reduced magnitude and a more posteriorly inclined GRF vector relative to the tibia than the SSL. These changes in LFL resulted in the lowest peak tibial axial and largest posterior shear forces among the 3 landing styles. Conclusions: Sagittal-plane intersegmental kinematic and kinetic links strongly affected the magnitude and direction of GRF and tibiofemoral forces during the impact phase of single-legged landing

Ground Reaction Forces and Gait Parameters during Motorized and Non-Motorized Treadmill Walking and Runing on the International Space Station Treadmill

NASA Technical Reports Server (NTRS)

Hagan, Ronald Donald; Norcross, Jason; DeWitt, John; Lee, Stuart M.; McCleary, Frank; Edwards, W. Brent

2006-01-01

Both motorized (T-M) and non-motorized (T-NM) treadmill locomotion are used on the International Space Station (ISS) as countermeasures to the deleterious effects of prolonged weightlessness. However, the ground reaction forces (GRF) and gait parameters of these exercise modes have not been examined. The purpose of this study was to determine if differences in GRF and gait parameters exist while walking (1.34 m/s) and running (3.13 m/s) on T-M and T-NM. Dissimilar GRF and gait parameters suggest that T-M and T-NM locomotion may elicit different physiologic effects. T-NM may result in a reduced stimulus to bone formation due to a lower LR, but an increased energy cost as a result of shorter, more frequent strides. Therefore, the usage of each mode should depend upon the desired training stimulus.

R-Ras contributes to LTP and contextual discrimination.

PubMed

Darcy, M J; Jin, S-X; Feig, L A

2014-09-26

The ability to discriminate between closely related contexts is a specific form of hippocampal-dependent learning that may be impaired in certain neurodegenerative disorders such as Alzheimer's and Down Syndrome. However, signaling pathways regulating this form of learning are poorly understood. Previous studies have shown that the calcium-dependent exchange factor Ras-GRF1, an activator of Rac, Ras and R-Ras GTPases, is important for this form of learning and memory. Moreover, the ability to discriminate contexts was linked to the ability of Ras-GRF1 to promote high-frequency stimulation long-term potentiation (HFS-LTP) via the activation of p38 Map kinase. Here, we show that R-Ras is involved in this form of learning by using virally-delivered miRNAs targeting R-Ras into the CA1 region of the dorsal hippocampus and observing impaired contextual discrimination. Like the loss of GRF1, knockdown of R-Ras in the CA1 also impairs the induction of HFS-LTP and p38 Map kinase. Nevertheless, experiments indicate that this involvement of R-Ras in HFS-LTP that is required for contextual discrimination is independent of Ras-GRF1. Thus, R-Ras is a novel regulator of a form of hippocampal-dependent LTP as well as learning and memory that is affected in certain forms of neurodegenerative diseases. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

R-Ras Contributes to LTP and Contextual Discrimination

PubMed Central

Darcy, Michael J.; Jin, Shan-Xue; Feig, Larry A.

2014-01-01

The ability to discriminate between closely related contexts is a specific form of hippocampal-dependent learning that may be impaired in certain neurodegenerative disorders such as Alzheimer's and Down Syndrome. However, signaling pathways regulating this form of learning are poorly understood. Previous studies have shown that the calcium-dependent exchange factor Ras-GRF1, an activator of Rac, Ras and R-Ras GTPases, is important for this form of learning and memory. Moreover, the ability to discriminate contexts was linked to the ability of Ras-GRF1 to promote high-frequency stimulation (HFS)-LTP via the activation of p38 Map kinase. Here, we show that R-Ras is involved in this form of learning by using virally-delivered miRNAs targeting R-Ras into the CA1 region of dorsal hippocampus and observing impaired contextual discrimination. Like the loss of GRF1, knockdown of R-Ras in the CA1 also impairs the induction of HFS-LTP and p38 Map kinase. Nevertheless, experiments indicate that this involvement of R-Ras in HFS-LTP that is required for contextual discrimination is independent of Ras-GRF1. Thus, R-Ras is a novel regulator of a form of hippocampal-dependent LTP as well as learning and memory that is affected in certain forms of neurodegenerative diseases. PMID:25043327

Atrial natriuretic factor increases vascular permeability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lockette, W.; Brennaman, B.

An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). Since elevations in plasma ANF are found in clinical syndromes associated with edema, and since space motion sickness induced by microgravity is associated with an increase in central blood volume and facial edema, we determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of 125I-albumin and 14C-dextran of similar molecular size. Blood pressure was monitored and serial determinationsmore » of hematocrits were made. Animals infused with 1.0 micrograms.kg-1.min-1 ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of 125I-albumin, but not 14C-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.« less

Ground reaction force characteristics of Tai Chi push hand.

PubMed

Chang, Yao-Ting; Chang, Jia-Hao; Huang, Chen-Fu

2014-01-01

Push Hand is an advanced training technique for the Yang-style old frame 108 forms Tai Chi Chuan. It is performed by two practitioners. To clarify how people use forces during Push Hand training, it is important to review the ground reaction force (GRF). Here, we quantify the characteristics of the GRF during Push Hand training. Kinematic data and GRF data from 10 Tai Chi Chuan practitioners (29.9 ± 7.87 years) were synchronously recorded using a three-dimensional motion analysis system (200 frames · s(-1)) and three-dimensional force plates (1000 Hz). The resultant GRF for both feet for the 0%, 50% and 100% phases of attack and defence were compared to body weight using a paired-samples t-test. The differences in the resultant GRF between the 0%, 50% and 100% phases of attack and defence were tested by one-way repeated-measures ANOVA. The significance level was set to 0.05. The total resultant GRF was almost equal to the participant's body weight in push hand. This result was consistent throughout the entire push hand process. Our results revealed that the GRF was comparable to the body weight, implying that practitioners do not push or resist their opponents during the push hand process.

Effects of spaceflight on hypothalamic peptide systems controlling pituitary growth hormone dynamics

NASA Technical Reports Server (NTRS)

Sawchenko, P. E.; Arias, C.; Krasnov, I.; Grindeland, R. E.; Vale, W.

1992-01-01

Possible effects of reduced gravity on central hypophysiotropic systems controlling growth hormone (GH) secretion were investigated in rats flown on Cosmos 1887 and 2044 biosatellites. Immunohistochemical (IHC)staining for the growth hormone-releasing factor (GRF), somatostatin (SS), and other hypothalamic hormones was performed on hypothalami obtained from rats. IHC analysis was complemented by quantitative in situ assessments of mRNAs encoding the precursors for these hormones. Data obtained suggest that exposure to microgravity causes a preferential reduction in GRF peptide and mRNA levels in hypophysiotropic neurons, which may contribute to impared GH secretion in animals subjected to spaceflight. Effects of weightlessness are not mimicked by hindlimb suspension in this system.

Ground reaction force and 3D biomechanical characteristics of walking in short-leg walkers.

PubMed

Zhang, Songning; Clowers, Kurt G; Powell, Douglas

2006-12-01

Short-leg walking boots offer several advantages over traditional casts. However, their effects on ground reaction forces (GRF) and three-dimensional (3D) biomechanics are not fully understood. The purpose of the study was to examine 3D lower extremity kinematics and joint dynamics during walking in two different short-leg walking boots. Eleven (five females and six males) healthy subjects performed five level walking trials in each of three conditions: two testing boot conditions, Gait Walker (DeRoyal Industries, Inc.) and Equalizer (Royce Medical Co.), and one pair of laboratory shoes (Noveto, Adidas). A force platform and a 6-camera Vicon motion analysis system were used to collect GRFs and 3D kinematic data during the testing session. A one-way repeated measures analysis of variance (ANOVA) was used to evaluate selected kinematic, GRF, and joint kinetic variables (p<0.05). The results revealed that both short-leg walking boots were effective in minimizing ankle eversion and hip adduction. Neither walker increased the bimodal vertical GRF peaks typically observed in normal walking. However, they did impose a small initial peak (<1BW) earlier in the stance phase. The Gait Walker also exhibited a slightly increased vertical GRF during midstance. These characteristics may be related to the sole materials/design, the restriction of ankle movements, and/or the elevated heel heights of the tested walkers. Both walkers appeared to increase the demand on the knee extensors while they decreased the demand of the knee and hip abductors based on the joint kinetic results.

External Load Affects Ground Reaction Force Parameters Non-uniformly during Running in Weightlessness

NASA Technical Reports Server (NTRS)

DeWitt, John; Schaffner, Grant; Laughlin, Mitzi; Loehr, James; Hagan, R. Donald

2004-01-01

Long-term exposure to microgravity induces detrimefits to the musculcskdetal system (Schneider et al., 1995; LeBlanc et al., 2000). Treadmill exercise is used onboard the International Space Station as an exercise countermeasure to musculoskeletal deconditioning due to spaceflight. During locomotive exercise in weightlessness (0G), crewmembers wear a harness attached to an external loading mechanism (EL). The EL pulls the crewmember toward the treadmill, and provides resistive load during the impact and propulsive phases of gait. The resulting forces may be important in stimulating bone maintenance (Turner, 1998). The EL can be applied via a bungee and carabineer clip configuration attached to the harness and can be manipulated to create varying amounts of load levels during exercise. Ground-based research performed using a vertically mounted treadmill found that peak ground reaction forces (GRF) during running at an EL of less than one body weight (BW) are less than those that occur during running in normal gravity (1G) (Davis et al., 1996). However, it is not known how the GRF are affected by the EL in a true OG environment. Locomotion while suspended may result in biomechanics that differ from free running. The purpose of this investigation was to determine how EL affects peak impact force, peak propulsive force, loading rate, and impulse of the GRF during running in 0G. It was hypothesized that increasing EL would result in increases in each GRF parameter.

Ground Reaction Forces and Throwing Performance in Elite and Novice Players in Two Types of Handball Shot

PubMed Central

Rousanoglou, Elissavet; Noutsos, Konstantinos; Bayios, Ioannis; Boudolos, Konstantinos

2014-01-01

The purpose of this study was to examine the differences in the ground reaction force (GRF) patterns between elite and novice players during two types of handball shots, as well as the relationships between throwing performance and the GRF variables. Ball velocity and throwing accuracy were measured during jump shots and 3-step shots performed by 15 elite and 15 novice players. The GRF pattern was recorded for the vertical and the anterior-posterior GRF components (Kistler forceplate type-9281, 750Hz). One-way ANOVA was used for the group differences and the Pearson coefficient for the correlation between throwing performance and GRF variables (SPSS 21.0, p ≤ 0.05). The elite players performed better in both types of shot. Both groups developed consistent and similar GRF patterns, except for the novices’ inconsistent Fz pattern in the 3-step shot. The GRF variables differed significantly between groups in the 3-step shot (p ≤ 0.05). Significant correlations were found only for ball velocity and predominantly for the novice players during the 3-step shot (p ≤ 0.05). The results possibly highlight a shortage in the novice ability to effectively reduce their forward momentum so as to provide a stable base of support for the momentum transfer up the kinetic chain, a situation that may predispose athletes to injury. PMID:25031672

Ground reaction forces and throwing performance in elite and novice players in two types of handball shot.

PubMed

Rousanoglou, Elissavet; Noutsos, Konstantinos; Bayios, Ioannis; Boudolos, Konstantinos

2014-03-27

The purpose of this study was to examine the differences in the ground reaction force (GRF) patterns between elite and novice players during two types of handball shots, as well as the relationships between throwing performance and the GRF variables. Ball velocity and throwing accuracy were measured during jump shots and 3-step shots performed by 15 elite and 15 novice players. The GRF pattern was recorded for the vertical and the anterior-posterior GRF components (Kistler forceplate type-9281, 750Hz). One-way ANOVA was used for the group differences and the Pearson coefficient for the correlation between throwing performance and GRF variables (SPSS 21.0, p ≤ 0.05). The elite players performed better in both types of shot. Both groups developed consistent and similar GRF patterns, except for the novices' inconsistent Fz pattern in the 3-step shot. The GRF variables differed significantly between groups in the 3-step shot (p ≤ 0.05). Significant correlations were found only for ball velocity and predominantly for the novice players during the 3-step shot (p ≤ 0.05). The results possibly highlight a shortage in the novice ability to effectively reduce their forward momentum so as to provide a stable base of support for the momentum transfer up the kinetic chain, a situation that may predispose athletes to injury.

Spectroscopic studies on the conformational transitions of a bovine growth hormone releasing factor analog

NASA Astrophysics Data System (ADS)

Sarver, Ronald W.; Friedman, Alan R.; Thamann, Thomas J.

1997-10-01

The secondary structure of the bovine growth hormone releasing factor analog, [Ile 2, Ser 8,28, Ala 15, Leu 27, Hse 30] bGRF(1-30)-NH-Ethyl, acetate salt (U-90699F) was studied in solution by Fourier transform infrared and Raman spectroscopies. Spectroscopic studies revealed that concentrated aqueous solutions of U-90699F (100 mg ml -1) undergo a secondary structure transition from disordered coil/α-helix to intermolecular β-sheet. Disordered coil and α-helical structure were grouped together in the infrared and Raman studies since the amide I vibrations are close in frequency and overlap in assignments was possible. Before the conformational transition, the facile exchange of the peptide's amide hydrogens for deuterium indicated that the majority of amide hydrogens were readily accessible to solvent. The kinetics of the conformational transition coincided with an increase in solution viscosity and turbidity. An initiation phase preceded the conformational transition during which only minor spectral changes were observed by infrared spectroscopy. The initiation phase and reaction kinetics were consistent with a highly cooperative nucleation ultimately leading to a network of intermolecular β-sheet structure and gel formation. Increased temperature accelerated the conformational transition. The conformational transition was thermally irreversible but the β-sheet structure of aggregated or gelled peptide could be disrupted by dilution and agitation.

Risk Factors for Increased Severity of Paediatric Medication Administration Errors

PubMed Central

Sears, Kim; Goodman, William M.

2012-01-01

Patients' risks from medication errors are widely acknowledged. Yet not all errors, if they occur, have the same risks for severe consequences. Facing resource constraints, policy makers could prioritize factors having the greatest severe–outcome risks. This study assists such prioritization by identifying work-related risk factors most clearly associated with more severe consequences. Data from three Canadian paediatric centres were collected, without identifiers, on actual or potential errors that occurred. Three hundred seventy-two errors were reported, with outcome severities ranging from time delays up to fatalities. Four factors correlated significantly with increased risk for more severe outcomes: insufficient training; overtime; precepting a student; and off-service patient. Factors' impacts on severity also vary with error class: for wrong-time errors, the factors precepting a student or working overtime significantly increase severe-outcomes risk. For other types, caring for an off-service patient has greatest severity risk. To expand such research, better standardization is needed for categorizing outcome severities. PMID:23968607

Ground reaction forces and bone parameters in females with tibial stress fracture.

PubMed

Bennell, Kim; Crossley, Kay; Jayarajan, Jyotsna; Walton, Elizabeth; Warden, Stuart; Kiss, Z Stephen; Wrigley, Tim

2004-03-01

Tibial stress fracture is a common overuse running injury that results from the interplay of repetitive mechanical loading and bone strength. This research project aimed to determine whether female runners with a history of tibial stress fracture (TSF) differ in ground reaction force (GRF) parameters during running, regional bone density, and tibial bone geometry from those who have never sustained a stress fracture (NSF). Thirty-six female running athletes (13 TSF; 23 NSF) ranging in age from 18 to 44 yr were recruited for this cross-sectional study. The groups were well matched for demographic, training, and menstrual parameters. A force platform measured selected GRF parameters (peak and time to peak for vertical impact and active forces, and horizontal braking and propulsive forces) during overground running at 4.0 m.s.(-1). Lumbar spine, proximal femur, and distal tibial bone mineral density were assessed by dual energy x-ray absorptiometry. Tibial bone geometry (cross-sectional dimensions and areas, and second moments of area) was calculated from a computerized tomography scan at the junction of the middle and distal thirds. There were no significant differences between the groups for any of the GRF, bone density, or tibial bone geometric parameters (P > 0.05). Both TSF and NSF subjects had bone density levels that were average or above average compared with a young adult reference range. Factor analysis followed by discriminant function analysis did not find any combinations of variables that differentiated between TSF and NSF groups. These findings do not support a role for GRF, bone density, or tibial bone geometry in the development of tibial stress fractures, suggesting that other risk factors were more important in this cohort of female runners.

Prediction of human gait parameters from temporal measures of foot-ground contact

NASA Technical Reports Server (NTRS)

Breit, G. A.; Whalen, R. T.

1997-01-01

Investigation of the influence of human physical activity on bone functional adaptation requires long-term histories of gait-related ground reaction force (GRF). Towards a simpler portable GRF measurement, we hypothesized that: 1) the reciprocal of foot-ground contact time (1/tc); or 2) the reciprocal of stride-period-normalized contact time (T/tc) predict peak vertical and horizontal GRF, loading rates, and horizontal speed during gait. GRF data were collected from 24 subjects while they walked and ran at a variety of speeds. Linear regression and ANCOVA determined the dependence of gait parameters on 1/tc and T/tc, and prediction SE. All parameters were significantly correlated to 1/tc and T/tc. The closest pooled relationship existed between peak running vertical GRF and T/tc (r2 = 0.896; SE = 3.6%) and improved with subject-specific regression (r2 = 0.970; SE = 2.2%). We conclude that temporal measures can predict force parameters of gait and may represent an alternative to direct GRF measurements for determining daily histories of habitual lower limb loading quantities necessary to quantify a bone remodeling stimulus.

Evaluation of gelatin hydrogel crosslinked with various crosslinking agents as bioadhesives: in vitro study.

PubMed

Sung, H W; Huang, D M; Chang, W H; Huang, R N; Hsu, J C

1999-09-15

Bioadhesives are used for tissue adhesion and hemostasis in surgery. A gelatin-resorcinol mixture crosslinked with formaldehyde (GRF glue) and/or glutaraldehyde (GRG) is used for this purpose. Although the bonding strength of the GRF glue to tissue is satisfactory, concerns about the cytotoxicity of formaldehyde are reported in the literature. It was suggested that the cytotoxicity problem of the GRF glue may be overcome by changing its crosslinking method. The study was therefore undertaken to assess the feasibility of using an epoxy compound (GRE glue), a water-soluble carbodiimide (GAC glue), or genipin (GG glue) to crosslink with a gelatin hydrogel as new bioadhesives. GRF glue and GRG glue were used as controls. The results of our cytotoxicity study suggested that the cellular compatibility of the GAC and GG glues was superior to the GRF, GRG, and GRE glues. The gelation time for the GG glue was relatively longer than the GRF and GRG glues, while no gelation time could be determined for the GAC glue. Additionally, it took approximately 17 h for the GRE glue to become adhesive. The GRF and GRG glues had the greatest bonding strengths to tissue among all test adhesives, while the bonding strengths of the GAC and GG glues were comparable. In contrast, there was almost no bonding strength to tissue for the GRE glue. However, the GRF and GRG glues were less flexible than the GAC and GG glues. Subsequent to the bonding strength measurement, each test adhesive was found to adhere firmly to the tissue surface and underwent cohesive failure during the bond breaking. In conclusion, the GRF and GRG glues may be used as tissue adhesives when their ability to bind tissue rapidly and tightly is required; the GAC and GG glues are preferable when the adhesive action must be accompanied with minimal cytotoxicity and stiffness; and the GRE glue is not suitable for bioadhesion in clinical applications. Copyright 1999 John Wiley & Sons, Inc.

USE OF MOLECULAR BIOLOGICAL TECHNIQUES TO EVALUATE EFFECT OF ENDOGENOUS HORMONES AND A XENOBIOTIC PESTICIDE ON GROWTH OF SHEEPSHEAD MINNOW

EPA Science Inventory

We have developed a teleost model to screen physiological effects of endocrine disrupting chemicals (EDCs) on somatic growth. Growth is largely controlled by the endocrine system via the growth-hormone releasing hormone (GRF) - growth hormone (GH) - insulin-like growth factor (IG...

Ground reaction force comparison of bilateral symmetry with pneumatic resistance squat device and free weights - biomed 2009.

PubMed

Paulus, David C; Schilling, Brian K

2009-01-01

The unloading of spaceflight leads to bone and muscle atrophy, and a pneumatic resistance squat exercise countermeasure has the potential to provide optimized controllable resistance in a lightweight and compact configuration. However each end of the barbell in the proposed device is connected to a separate resistance cylinder which could lead to bilaterally asymmetric loading. Therefore, the purpose of the study is to compare the unilateral ground reaction forces (GRF) of the new squat device compared to free weights. Four previously trained men (mean +/- SD; age = 20+/-2 years, body mass = 99+/-18 kg) performed three sets of three repetitions of maximal exertion squat exercises with pneumatically controlled constant resistance and free weights each with a resistance level set to half of the body weight of each subject. Unilateral GRF data for each lifting modality at the negative to positive transition of the squat exercise was measured with a force plate under each foot. The pneumatic resistance GRF (N; mean +/- SD) was 749+/-114 on the left leg and 786+/-123 on the right leg and the free weight GRF was 786+/-114 left and 861+/-111 right resulting in a 5% difference between left and right GRF with pneumatics and 9% difference with free weights. The correlation coefficient between left and right GRF was 0.92 with pneumatics and 0.80 with free weights. Because the pneumatic device elicited more bilaterally symmetric GRF than traditional free weights, the separate resistance cylinders are an acceptable design configuration.

Reducing retrogradation and lipid oxidation of normal and glutinous rice flours by adding mango peel powder.

PubMed

Siriamornpun, Sirithon; Tangkhawanit, Ekkarat; Kaewseejan, Niwat

2016-06-15

Green and ripe mango peel powders (MPP) were added to normal rice flour (NRF) and glutinous rice flour (GRF) at three levels (400, 800 and 1200 ppm) and their effects on physicochemical properties and lipid oxidation inhibition were investigated. Overall, MPP increased the breakdown viscosity and reduced the final viscosity in rice flours when compared to the control. Decreasing in retrogradation was observed in both NRF and GRF with MPP added of all levels. MPP addition also significantly inhibited the lipid oxidation of all flours during storage (30 days). Retrogradation values were strongly negatively correlated with total phenolic and flavonoid contents, but not with fiber content. The hydrogen bonds and hydrophilic interactions between phenolic compounds with amylopectin molecule may be involved the decrease of starch retrogradation, especially GRF. We suggest that the addition of MPP not only reduced the retrogradation but also inhibited the lipid oxidation of rice flour. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Association between the decline in global fertility rate and the incorporation of women to the workforce].

PubMed

Stefanelli, María de Los Ángeles; Valenzuela, María Teresa; Cárcamo, Marcela; Urquidi, Cinthya; Cavada, Gabriel; San Martín P, Pamela

2016-05-01

The global fertility rate (GFR) is defined as the mean number of children that a woman could have in a hypothetical cohort, not exposed to death during the fertile period. GFR has fallen from 3.4 to 1.9 children per women in the period 1970-2010. To explore the relationship between the fall in GFR and the incorporation of women to work in the period 1960-2011. Data from the National Statistics Institute was used. GRF was calculated using specific fertility rates for each year considering women aged 15 to 49 years. Work rates were obtained from yearly vital statistics reports. Between 1960 and 2011, GRF decreased from 5.5 to 1.9 in Chile. The first inflection occurred in 1970. In the same period, female workforce increased from 22.4 to 40.2%. To motivate the participation of female work-force without decrease the GRF allowing population replacement, it is suggested the need to create new public policies with benefits and support from the state.

Walking Gait Asymmetries Six Months Following Anterior Cruciate Ligament Reconstruction Predict Twelve-Month Patient-Reported Outcomes.

PubMed

Pietrosimone, Brian; Blackburn, J Troy; Padua, Darin A; Pfeiffer, Steven J; Davis, Hope C; Luc-Harkey, Brittney A; Harkey, Matthew S; Stanley, Laura E; Frank, Barnett S; Creighton, R Alexander; Kamath, Ganesh M; Spang, Jeffery T

2018-05-21

The study sought to determine the association between gait biomechanics (vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR]) collected six months following anterior cruciate ligament reconstruction (ACLR) with patient-reported outcomes at twelve months following ACLR. Walking gait mechanics and all subsections of the Knee Injury and Osteoarthritis Outcomes Score (KOOS) were collected at six and twelve months following ACLR, respectively, in 25 individuals with a unilateral ACLR. Peak vGRF and peak instantaneous vGRF-LR were extracted from the first 50% of the stance phase. Limb symmetry indices (LSI) were used to normalize outcomes in the ACLR limb to that of the uninjured limb (ACLR /uninjured). Linear regression analyses were used to determine associations between biomechanical outcomes and KOOS while accounting for walking speed. Receiver operator characteristic curves were used to determine the accuracy of 6-month biomechanical outcomes for identifying individuals with acceptable patient-reported outcomes, using previously defined KOOS cut-off scores,12 months post-ACLR. Individuals with lower peak vGRF LSI 6 months post-ACLR demonstrated worse patient-reported outcomes (KOOS Pain, Activities of Daily life, Sport and Recreation, Quality of Life) at the 12-month exam. A peak vGRF LSI ≥0.99 6 months following ACLR associated with 13.33x higher odds of reporting acceptable patient-reported outcomes 12 months post-ACLR. Lesser peak vGRF LSI during walking at 6-months post-ACLR may be a critical indicator of worse future patient-reported outcomes. Achieving early symmetrical lower extremity loading and minimizing under-loading of the ACLR limb during walking may be a potential therapeutic target for improving patient-reported outcomes post-ACLR. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Dynamic knee valgus alignment influences impact attenuation in the lower extremity during the deceleration phase of a single-leg landing.

PubMed

Tamura, Akihiro; Akasaka, Kiyokazu; Otsudo, Takahiro; Shiozawa, Jyunya; Toda, Yuka; Yamada, Kaori

2017-01-01

Dynamic knee valgus during landings is associated with an increased risk of non-contact anterior cruciate ligament (ACL) injury. In addition, the impact on the body during landings must be attenuated in the lower extremity joints. The purpose of this study was to investigate landing biomechanics during landing with dynamic knee valgus by measuring the vertical ground reaction force (vGRF) and angular impulses in the lower extremity during a single-leg landing. The study included 34 female college students, who performed the single-leg drop vertical jump. Lower extremity kinetic and kinematic data were obtained from a 3D motion analysis system. Participants were divided into valgus (N = 19) and varus (N = 15) groups according to the knee angular displacement during landings. The vGRF and angular impulses of the hip, knee, and ankle were calculated by integrating the vGRF-time curve and each joint's moment-time curve. vGRF impulses did not differ between two groups. Hip angular impulse in the valgus group was significantly smaller than that in the varus group (0.019 ± 0.033 vs. 0.067 ± 0.029 Nms/kgm, p<0.01), whereas knee angular impulse was significantly greater (0.093 ± 0.032 vs. 0.045 ± 0.040 Nms/kgm, p<0.01). There was no difference in ankle angular impulse between the groups. Our results indicate that dynamic knee valgus increases the impact the knee joint needs to attenuate during landing; conversely, the knee varus participants were able to absorb more of the landing impact with the hip joint.

The need to increase awareness of the risk factors of COPD.

PubMed

Roche, Nicolas

2016-07-01

COPD is a heterogeneous disease responsible for a major burden on public and individual health. A wide variety of intrinsic and environmental risk factors are involved, and exert their influence at various time points during the life span of individuals. Knowledge of these factors is of utmost importance to develop appropriate screening and prevention programs, and may help improving the pathophysiological knowledge of the disease. Accordingly, there are multiple targets of information and education on risk factors for COPD, including the general population and patients, workers and employers, doctors and other healthcare professionals, researchers, policy-makers, payers, etc. Gender and socioeconomic factors need to be specifically considered. Importantly, it is likely that increasing the specific knowledge of COPD risk factors among the above-mentioned targets cannot not be obtained without increasing the general knowledge of COPD in the population, which at present is dramatically low.

Influence of heel height and shoe insert on comfort perception and biomechanical performance of young female adults during walking.

PubMed

Hong, Wei-Hsien; Lee, Yung-Hui; Chen, Hsieh-Ching; Pei, Yu-Cheng; Wu, Ching-Yi

2005-12-01

The possible negative effects of high-heeled shoes on subjective comfort perception and objective biomechanical assessment have been noted. Although shoe inserts have been widely applied in footwear to increase comfort and to reduce the frequency of movement-related injury, no study has attempted to identify insert effectiveness in high heels. The purpose of this study was to determine the effects of heel height and shoe inserts on comfort and biomechanics as represented by plantar pressure and ground reaction force (GRF). Twenty young female adults performed the test conditions formed by the cross-matching of shoe inserts (shoe without insert and shoe with total contact insert [TCI]) and heel height (a flat, a low heel [3.8 cm] and a high heel [7.6 cm]). Two-way analyses of variance for repeated measures design were used to test condition effects on comfort rating, plantar pressure, and GRF during gait. To determine the biomechanical variables that can predict comfort, a multiple linear regression with stepwise method was done. The results showed that discomfort increased with heel height. In high heels, the plantar pressure in the heel and midfoot shifted to the medial forefoot, and the vertical and anteroposterior GRF increased. Use of the TCI reduced the peak pressure in the medial forefoot. Interestingly, the effectiveness of the TCI was greater in the higher heels than in the lower heels and in flat heels. The peak pressure in the medial forefoot, impact force, and the first peak vertical GRF could explain 75.6% of the variance of comfort in high-heeled gait. These findings suggest that higher heels result in decreased comfort, which can be reflected by both the subjective rating scale and biomechanical variables. Use of a TCI altered the biomechanics and therefore improved the comfort in high-heeled shoes.

Differences in pediatric vertical ground reaction force between planovalgus and neutrally aligned feet.

PubMed

Pauk, Jolanta; Szymul, Joanna

2014-01-01

Ground reaction forces (GRF) reflect the force history of human body contact with the ground. The purpose of this study was to explore human gait abnormalities due to planovalgus by comparing vertical GRF data between individuals with planovalgus and those with neutrally aligned feet. Second we estimated associations between various measurements and vertical GRF parameters in a pediatric population. Boys and girls between the ages of 4 and 18 years (72 planovalgus feet and 74 neutrally aligned feet) took part in this study. Ground reaction forces were recorded by two Kistler platforms and normalized to body weight. Comparison of vertical GRF between planovalgus and neutrally aligned feet suggests that the first and the second peaks of vertical force (Fz1, Fz2) are most affected by planovalgus. The results also indicate that neutrally aligned feet display a different ground reaction force pattern than planovalgus, and that differences between boys and girls may be observed. The shape of the vertical GRF curve can help in clinical interpretation of abnormal gait.

The analysis of three-dimensional ground reaction forces during gait in children with autism spectrum disorders.

PubMed

Hasan, Che Zawiyah Che; Jailani, Rozita; Md Tahir, Nooritawati; Ilias, Suryani

2017-07-01

Minimal information is known about the three-dimensional (3D) ground reaction forces (GRF) on the gait patterns of individuals with autism spectrum disorders (ASD). The purpose of this study was to investigate whether the 3D GRF components differ significantly between children with ASD and the peer controls. 15 children with ASD and 25 typically developing (TD) children had participated in the study. Two force plates were used to measure the 3D GRF data during walking. Time-series parameterization techniques were employed to extract 17 discrete features from the 3D GRF waveforms. By using independent t-test and Mann-Whitney U test, significant differences (p<0.05) between the ASD and TD groups were found for four GRF features. Children with ASD demonstrated higher maximum braking force, lower relative time to maximum braking force, and lower relative time to zero force during mid-stance. Children with ASD were also found to have reduced the second peak of vertical GRF in the terminal stance. These major findings suggest that children with ASD experience significant difficulties in supporting their body weight and endure gait instability during the stance phase. The findings of this research are useful to both clinicians and parents who wish to provide these children with appropriate treatments and rehabilitation programs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factors Associated With Increases in US Health Care Spending, 1996-2013

PubMed Central

Squires, Ellen; Bui, Anthony L.; Campbell, Madeline; Chapin, Abigail; Hamavid, Hannah; Horst, Cody; Li, Zhiyin; Matyasz, Taylor; Reynolds, Alex; Sadat, Nafis; Schneider, Matthew T.; Murray, Christopher J. L.

2017-01-01

Importance Health care spending in the United States increased substantially from 1995 to 2015 and comprised 17.8% of the economy in 2015. Understanding the relationship between known factors and spending increases over time could inform policy efforts to contain future spending growth. Objective To quantify changes in spending associated with 5 fundamental factors related to health care spending in the United States: population size, population age structure, disease prevalence or incidence, service utilization, and service price and intensity. Design and Setting Data on the 5 factors from 1996 through 2013 were extracted for 155 health conditions, 36 age and sex groups, and 6 types of care from the Global Burden of Disease 2015 study and the Institute for Health Metrics and Evaluation’s US Disease Expenditure 2013 project. Decomposition analysis was performed to estimate the association between changes in these factors and changes in health care spending and to estimate the variability across health conditions and types of care. Exposures Change in population size, population aging, disease prevalence or incidence, service utilization, or service price and intensity. Main Outcomes and Measures Change in health care spending from 1996 through 2013. Results After adjustments for price inflation, annual health care spending on inpatient, ambulatory, retail pharmaceutical, nursing facility, emergency department, and dental care increased by $933.5 billion between 1996 and 2013, from $1.2 trillion to $2.1 trillion. Increases in US population size were associated with a 23.1% (uncertainty interval [UI], 23.1%-23.1%), or $269.5 (UI, $269.0-$270.0) billion, spending increase; aging of the population was associated with an 11.6% (UI, 11.4%-11.8%), or $135.7 (UI, $133.3-$137.7) billion, spending increase. Changes in disease prevalence or incidence were associated with spending reductions of 2.4% (UI, 0.9%-3.8%), or $28.2 (UI, $10.5-$44.4) billion, whereas changes in

miR396 affects mycorrhization and root meristem activity in the legume Medicago truncatula.

PubMed

Bazin, Jérémie; Khan, Ghazanfar Abbas; Combier, Jean-Philippe; Bustos-Sanmamed, Pilar; Debernardi, Juan Manuel; Rodriguez, Ramiro; Sorin, Céline; Palatnik, Javier; Hartmann, Caroline; Crespi, Martin; Lelandais-Brière, Christine

2013-06-01

The root system is crucial for acquisition of resources from the soil. In legumes, the efficiency of mineral and water uptake by the roots may be reinforced due to establishment of symbiotic relationships with mycorrhizal fungi and interactions with soil rhizobia. Here, we investigated the role of miR396 in regulating the architecture of the root system and in symbiotic interactions in the model legume Medicago truncatula. Analyses with promoter-GUS fusions suggested that the mtr-miR396a and miR396b genes are highly expressed in root tips, preferentially in the transition zone, and display distinct expression profiles during lateral root and nodule development. Transgenic roots of composite plants that over-express the miR396b precursor showed lower expression of six growth-regulating factor genes (MtGRF) and two bHLH79-like target genes, as well as reduced growth and mycorrhizal associations. miR396 inactivation by mimicry caused contrasting tendencies, with increased target expression, higher root biomass and more efficient colonization by arbuscular mycorrhizal fungi. In contrast to MtbHLH79, repression of three GRF targets by RNA interference severely impaired root growth. Early activation of mtr-miR396b, concomitant with post-transcriptional repression of MtGRF5 expression, was also observed in response to exogenous brassinosteroids. Growth limitation in miR396 over-expressing roots correlated with a reduction in cell-cycle gene expression and the number of dividing cells in the root apical meristem. These results link the miR396 network to the regulation of root growth and mycorrhizal associations in plants. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

External kinetics of the kettlebell snatch in amateur lifters

PubMed Central

Wilson, Cameron J.; Lorenzen, Christian

2017-01-01

Background Kettlebell lifting has gained increased popularity as both a form of resistance training and as a sport, despite the paucity of literature validating its use as a training tool. Kettlebell sport requires participants to complete the kettlebell snatch continuously over prolonged periods of time. Kettlebell sport and weightlifting involve similar exercises, however, their traditional uses suggest they are better suited to training different fitness qualities. This study examined the three-dimensional ground reaction force (GRF) and force applied to the kettlebell over a 6 min kettlebell snatch set in 12 kettlebell-trained males. Methods During this set, VICON was used to record the kettlebell trajectory with nine infrared cameras while the GRF of each leg was recorded with a separate AMTI force plate. Over the course of the set, an average of 13.9 ± 3.3 repetitions per minute were performed with a 24 kg kettlebell. Significance was evaluated with a two-way ANOVA and paired t-tests, whilst Cohen’s F (ESF) and Cohen’s D (ESD) were used to determine the magnitude. Results The applied force at the point of maximum acceleration was 814 ± 75 N and 885 ± 86 N for the downwards and upwards phases, respectively. The absolute peak resultant bilateral GRF was 1,746 ± 217 N and 1,768 ± 242 N for the downwards and upwards phases, respectively. Bilateral GRF of the first and last 14 repetitions was found to be similar, however there was a significant difference in the peak applied force (F (1.11) = 7.42, p = 0.02, ESF = 0.45). Unilateral GRF was found have a significant difference for the absolute anterior–posterior (F (1.11) = 885.15, p < 0.0001, ESF = 7) and medio-lateral force vectors (F (1.11) = 5.31, p = 0.042, ESF = 0.67). Discussion Over the course of a single repetition there were significant differences in the GRF and applied force at multiple points of the kettlebells trajectory. The kettlebell snatch loads each leg differently throughout a

External kinetics of the kettlebell snatch in amateur lifters.

PubMed

Ross, James A; Keogh, Justin W L; Wilson, Cameron J; Lorenzen, Christian

2017-01-01

Kettlebell lifting has gained increased popularity as both a form of resistance training and as a sport, despite the paucity of literature validating its use as a training tool. Kettlebell sport requires participants to complete the kettlebell snatch continuously over prolonged periods of time. Kettlebell sport and weightlifting involve similar exercises, however, their traditional uses suggest they are better suited to training different fitness qualities. This study examined the three-dimensional ground reaction force (GRF) and force applied to the kettlebell over a 6 min kettlebell snatch set in 12 kettlebell-trained males. During this set, VICON was used to record the kettlebell trajectory with nine infrared cameras while the GRF of each leg was recorded with a separate AMTI force plate. Over the course of the set, an average of 13.9 ± 3.3 repetitions per minute were performed with a 24 kg kettlebell. Significance was evaluated with a two-way ANOVA and paired t -tests, whilst Cohen's F (ESF) and Cohen's D (ESD) were used to determine the magnitude. The applied force at the point of maximum acceleration was 814 ± 75 N and 885 ± 86 N for the downwards and upwards phases, respectively. The absolute peak resultant bilateral GRF was 1,746 ± 217 N and 1,768 ± 242 N for the downwards and upwards phases, respectively. Bilateral GRF of the first and last 14 repetitions was found to be similar, however there was a significant difference in the peak applied force ( F (1.11) = 7.42, p = 0.02, ESF = 0.45). Unilateral GRF was found have a significant difference for the absolute anterior-posterior ( F (1.11) = 885.15, p < 0.0001, ESF = 7) and medio-lateral force vectors ( F (1.11) = 5.31, p = 0.042, ESF = 0.67). Over the course of a single repetition there were significant differences in the GRF and applied force at multiple points of the kettlebells trajectory. The kettlebell snatch loads each leg differently throughout a repetition and performing the kettlebell snatch

Effect of the walking speed to the lower limb joint angular displacements, joint moments and ground reaction forces during walking in water.

PubMed

Miyoshi, Tasuku; Shirota, Takashi; Yamamoto, Shin-ichiro; Nakazawa, Kimitaka; Akai, Masami

2004-06-17

The purpose of this study was to compare the changes in ground reaction forces (GRF), joint angular displacements (JAD), joint moments (JM) and electromyographic (EMG) activities that occur during walking at various speeds in water and on land. Fifteen healthy adults participated in this study. In the water experiments, the water depth was adjusted so that body weight was reduced by 80%. A video-motion analysis system and waterproof force platform was used to obtain kinematics and kinetics data and to calculate the JMs. Results revealed that (1) the anterior-posterior GRF patterns differed between walking in water and walking on land, whereas the medio-lateral GRF patterns were similar, (2) the JAD patterns of the hip and ankle were similar between water- and land-walking, whereas the range of motion at the knee joint was lower in water than on land, (3) the JMs in all three joints were lower in water than on land throughout the stance phase, and (4) the hip joint extension moment and hip extensor muscle EMG activity were increased as walking speed increase during walking in water. Rehabilitative water-walking exercise could be designed to incorporate large-muscle activities, especially of the lower-limb extensor muscles, through full joint range of motion and minimization of joint moments.

A very-low-fat vegan diet increases intake of protective dietary factors and decreases intake of pathogenic dietary factors.

PubMed

Dewell, Antonella; Weidner, Gerdi; Sumner, Michael D; Chi, Christine S; Ornish, Dean

2008-02-01

There is increasing evidence that dietary factors in plant-based diets are important in the prevention of chronic disease. This study examined protective (eg, antioxidant vitamins, carotenoids, and fiber) and pathogenic (eg, saturated fatty acids and cholesterol) dietary factors in a very-low-fat vegan diet. Ninety-three early-stage prostate cancer patients participated in a randomized controlled trial and were assigned to a very-low-fat (10% fat) vegan diet supplemented with soy protein and lifestyle changes or to usual care. Three-day food records were collected at baseline (n=42 intervention, n=43 control) and after 1 year (n=37 in each group). Analyses of changes in dietary intake of macronutrients, vitamins, minerals, carotenoids, and isoflavones from baseline to 1 year showed significantly increased intake of most protective dietary factors (eg, fiber increased from a mean of 31 to 59 g/day, lycopene increased from 8,693 to 34,464 mug/day) and significantly decreased intake of most pathogenic dietary factors (eg, saturated fatty acids decreased from 20 to 5 g/day, cholesterol decreased from 200 to 10 mg/day) in the intervention group compared to controls. These results suggest that a very-low-fat vegan diet can be useful in increasing intake of protective nutrients and phytochemicals and minimizing intake of dietary factors implicated in several chronic diseases.

The Relationship Between the Push Off Ground Reaction Force and Ball Speed in High School Baseball Pitchers.

PubMed

Oyama, Sakiko; Myers, Joseph B

2018-05-01

Oyama, S and Myers, JB. The relationship between the push off ground reaction force and ball speed in high school baseball pitchers. J Strength Cond Res 32(5): 1324-1328, 2018-Baseball pitching is a sequential movement that requires transfer of momentum from the lower extremity to the throwing arm. Therefore, the ground reaction force (GRF) during push off is suggested to play a role in production of ball speed. The purpose of this study was to investigate the correlation between GRF characteristics during push off and ball speed in high school baseball pitchers. A total of 52 pitchers performed fast pitches from an indoor pitching mound. A force plate embedded in an indoor mound was used to capture the push off GRF. The GRF characteristics (peak anterior, vertical, and resultant forces, vertical and resultant forces at the time of peak anterior GRF, and impulse produced by the anterior GRF) from the 3 fastest strike pitches from each pitcher were used for analyses. Spearman's rank correlation coefficients were used to describe the relationships between ball speed and the GRF characteristics. Ball speed was only weakly correlated with peak resultant force (ρ = 0.32, p = 0.02) and vertical (ρ = 0.45, p < 0.001) and resultant (ρ = 0.42, p = 0.002) forces at the time of peak anterior force. The ball speed was not correlated with other variables. The correlation between ball speed and push off force in high school pitchers was weak, especially when compared with what was reported for adult pitchers in other studies. Unlike for adult pitchers, higher push off force is only weakly correlated with ball velocity in high school pitchers, which suggests that training to better use body momentum may help high school pitchers improve ball speed.

Design and Development of a Model to Simulate 0-G Treadmill Running Using the European Space Agency's Subject Loading System

NASA Technical Reports Server (NTRS)

Caldwell, E. C.; Cowley, M. S.; Scott-Pandorf, M. M.

2010-01-01

Develop a model that simulates a human running in 0 G using the European Space Agency s (ESA) Subject Loading System (SLS). The model provides ground reaction forces (GRF) based on speed and pull-down forces (PDF). DESIGN The theoretical basis for the Running Model was based on a simple spring-mass model. The dynamic properties of the spring-mass model express theoretical vertical GRF (GRFv) and shear GRF in the posterior-anterior direction (GRFsh) during running gait. ADAMs VIEW software was used to build the model, which has a pelvis, thigh segment, shank segment, and a spring foot (see Figure 1).the model s movement simulates the joint kinematics of a human running at Earth gravity with the aim of generating GRF data. DEVELOPMENT & VERIFICATION ESA provided parabolic flight data of subjects running while using the SLS, for further characterization of the model s GRF. Peak GRF data were fit to a linear regression line dependent on PDF and speed. Interpolation and extrapolation of the regression equation provided a theoretical data matrix, which is used to drive the model s motion equations. Verification of the model was conducted by running the model at 4 different speeds, with each speed accounting for 3 different PDF. The model s GRF data fell within a 1-standard-deviation boundary derived from the empirical ESA data. CONCLUSION The Running Model aids in conducting various simulations (potential scenarios include a fatigued runner or a powerful runner generating high loads at a fast cadence) to determine limitations for the T2 vibration isolation system (VIS) aboard the International Space Station. This model can predict how running with the ESA SLS affects the T2 VIS and may be used for other exercise analyses in the future.

Effects of Different Lifting Cadences on Ground Reaction Forces during the Squat Exercise

NASA Technical Reports Server (NTRS)

Bentley, Jason R.; Amonette, William E.; Hagan, R. Donald

2008-01-01

The purpose of this investigation was to determine the effect of different cadences on the ground reaction force (GRF(sub R)) during the squat exercise. It is known that squats performed with greater acceleration will produce greater inertial forces; however, it is not well understood how different squat cadences affect GRF(sub R). It was hypothesized that faster squat cadences will result in greater peak GRF(sub R). METHODS: Six male subjects (30.8+/-4.4 y, 179.5+/-8.9 cm, 88.8+/-13.3 kg) with previous squat experience performed three sets of three squats using three different cadences (FC = 1 sec descent/1 sec ascent; MC = 3 sec descent/1 sec ascent; SC = 4 sec descent/2 sec ascent) with barbell mass equal to body mass. Ground reaction force was used to calculate inertial force trajectories of the body plus barbell (FI(sub system)). Forces were normalized to body mass. RESULTS: Peak GRF(sub R) and peak FI(sub system) were significantly higher in FC squats compared to MC (p=0.0002) and SC (p=0.0002). Range of GRF(sub R) and FI(sub system) were also significantly higher in FC compared to MC (p<0.05), and MC were significantly higher than SC (p<0.05). DISCUSSION: Faster squat cadences result in significantly greater peak GRF(sub R) due to the inertia of the system. GRF(sub R) was more dependent upon decent cadence than on ascent cadence. PRACTICAL APPLICATION: This study demonstrates that faster squat cadences produce greater ground reaction forces. Therefore, the use of faster squat cadences might enhance strength and power adaptations to long-term resistance exercise training. Key Words: velocity, weight training, resistive exercise

Nanomolar electrochemical detection of caffeic acid in fortified wine samples based on gold/palladium nanoparticles decorated graphene flakes.

PubMed

Thangavelu, Kokulnathan; Raja, Nehru; Chen, Shen-Ming; Liao, Wei-Cheng

2017-09-01

Amalgamation of noble metal nanomaterials on graphene flakes potentially paves one way to improve their physicochemical properties. This paper deals with the simultaneous electrochemical deposition of gold and palladium nanoparticles on graphene flakes (Au/PdNPs-GRF) for the sensitive determination of caffeic acid (CA). The physiochemical properties of the prepared Au/PdNPs-GRF was characterized by using numerous analytical techniques such as scanning electron microscopy, electron dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, Raman spectroscopy and electrochemical impedance spectroscopy. The enhanced electrochemical determination of CA at Au/PdNPs deposition on GRF were studied by using cyclic voltammetry and differential pulse voltammetry. In results, Au/PdNPs-GRF electrode exhibited an excellent electrocatalytic activity towards CA with wide linear range and low limit of detection of 0.03-938.97µM and 6nM, respectively. Eventually, the Au/PdNPs-GRF was found as a selective and stable active material for the sensing of CA. In addition, the proposed sensor showed the adequate results in real sample analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Sex and Fatigue on Biomechanical Measures During the Drop-Jump Task in Children

PubMed Central

Briem, Kristín; Jónsdóttir, Kolbrún Vala; Árnason, Árni; Sveinsson, Þórarinn

2017-01-01

Background: Female athletes have a higher rate of anterior cruciate ligament (ACL) injury than males from adolescence and into maturity, which is suggested to result from sex-specific changes in dynamic movement patterns with maturation. Few studies have studied movement strategies and response to fatigue in children. Purpose: To evaluate the effect of fatigue on biomechanical variables associated with increased risk for ACL injury during a drop-jump (DJ) performance in children. Study Design: Controlled laboratory study. Methods: A total of 116 children (mean age, 10.4 years) were recruited from local sports clubs and performed 5 repetitions of a DJ task before and after a fatigue protocol. Kinematic and kinetic data from initial contact (IC) to the first peak vertical ground reaction force (vGRF) were analyzed for both limbs, including limb and fatigue as within-subject factors for analyses between boys and girls. Pearson correlation coefficients were calculated to identify associations between variables of interest. Results: Girls demonstrated greater peak vGRF values than boys (by 8.1%; P < .05), there were greater peak vGRF values for the right limb than the left (by 6.2%; P < .001), and fatigue led to slightly greater values (P < .05). Although weak, the correlation between peak vGRF values and knee flexion excursion was stronger for girls (r = –0.20) than boys (r = –0.08) (P < .006). Fatigue resulted in greater knee flexion angles at IC and less excursion during landing, more so for girls (by 6.1° vs 1.4°; interaction, P < .001), although the knee flexion moment was generally lowered by fatigue (P < .001). Limb asymmetry in knee flexion moments was more pronounced for boys than for girls (interaction, P < .05), contrary to that seen in frontal plane knee moments, where asymmetry was much greater in girls than boys (interaction, P < .001). Conclusion: Even as young athletes, girls and boys seem to adopt dissimilar movement strategies and are differently

Contribution of the six major gait determinants on the vertical center of mass trajectory and the vertical ground reaction force.

PubMed

Hayot, C; Sakka, S; Lacouture, P

2013-04-01

Saunders et al. (1953) stated that the introduction of six gait determinants (pelvic rotation, pelvic obliquity, stance knee flexion, foot and ankle mechanisms, and tibiofemoral angle) to a compass gait model (two rigid legs hinged at the hips) provides an accurate simulation of the actual trajectory of the whole body center of mass (CoM). Their respective actions could also explain the shape of the vertical ground reaction force (GRF) pattern. Saunders' approach is considered as a kinematic description of some features of gait and is subject to debate. The purpose of this study is to realize a rigorous mechanical evaluation of the gait determinants theory using an appropriated mathematical model in which specific experimental data of gait trials are introduced. We first simulate a compass-like CoM trajectory using the proposed 3D mathematical model. Then, factorizing the model to introduce successively the kinematic data related to each gait determinant, we assess their respective contribution to both the CoM trajectory and the pattern of vertical GRF at different gait speeds. The results show that the stance knee flexion significatively decreases the estimated position of the CoM during midstance. Stance knee extension and pelvic obliquity contribute to the appearance of the pattern of vertical GRF during stance. The stance ankle dorsiflexion significatively contributes to CoM vertical excursion and the ankle plantarflexion contributes to the vertical GRF during terminal stance. The largest contribution towards the minimization of the CoM vertical amplitude during the complete gait step appears when considering the foot mechanisms and the pelvic obliquity in the proposed model. Copyright © 2012 Elsevier B.V. All rights reserved.

HGF/scatter factor selectively promotes cell invasion by increasing integrin avidity.

PubMed

Trusolino, L; Cavassa, S; Angelini, P; Andó, M; Bertotti, A; Comoglio, P M; Boccaccio, C

2000-08-01

Hepatocyte growth factor/scatter factor (HGF/SF) controls a genetic program known as 'invasive growth', which involves as critical steps cell adhesion, migration, and trespassing of basement membranes. We show here that in MDA-MB-231 carcinoma cells, these steps are elicited by HGF/SF but not by epidermal growth factor (EGF). Neither factor substantially alters the production or activity of extracellular matrix proteases. HGF/SF, but not EGF, selectively promotes cell adhesion on laminins 1 and 5, fibronectin, and vitronectin through a PI3-K-dependent mechanism. Increased adhesion is followed by enhanced invasiveness through isolated matrix proteins as well as through reconstituted basement membranes. Inhibition assays using function-blocking antibodies show that this phenomenon is mediated by multiple integrins including beta1, beta3, beta4, and beta5. HGF/SF triggers clustering of all these integrins at actin-rich adhesive sites and lamellipodia but does not quantitatively modify their membrane expression. These data suggest that HGF/SF promotes cell adhesion and invasiveness by increasing the avidity of integrins for their specific ligands.

Factors Increasing Vulnerability to Health Effects before, during and after Floods

PubMed Central

Lowe, Dianne; Ebi, Kristie L.; Forsberg, Bertil

2013-01-01

Identifying the risk factors for morbidity and mortality effects pre-, during and post-flood may aid the appropriate targeting of flood-related adverse health prevention strategies. We conducted a systematic PubMed search to identify studies examining risk factors for health effects of precipitation-related floods, among Organisation for Economic Co-Operation and Development (OECD) member countries. Research identifying flood-related morbidity and mortality risk factors is limited and primarily examines demographic characteristics such as age and gender. During floods, females, elderly and children appear to be at greater risk of psychological and physical health effects, while males between 10 to 29 years may be at greater risk of mortality. Post-flood, those over 65 years and males are at increased risk of physical health effects, while females appear at greater risk of psychological health effects. Other risk factors include previous flood experiences, greater flood depth or flood trauma, existing illnesses, medication interruption, and low education or socio-economic status. Tailoring messages to high-risk groups may increase their effectiveness. Target populations differ for morbidity and mortality effects, and differ pre-, during, and post-flood. Additional research is required to identify the risk factors associated with pre- and post-flood mortality and post-flood morbidity, preferably using prospective cohort studies. PMID:24336027

Factors increasing vulnerability to health effects before, during and after floods.

PubMed

Lowe, Dianne; Ebi, Kristie L; Forsberg, Bertil

2013-12-11

Identifying the risk factors for morbidity and mortality effects pre-, during and post-flood may aid the appropriate targeting of flood-related adverse health prevention strategies. We conducted a systematic PubMed search to identify studies examining risk factors for health effects of precipitation-related floods, among Organisation for Economic Co-Operation and Development (OECD) member countries. Research identifying flood-related morbidity and mortality risk factors is limited and primarily examines demographic characteristics such as age and gender. During floods, females, elderly and children appear to be at greater risk of psychological and physical health effects, while males between 10 to 29 years may be at greater risk of mortality. Post-flood, those over 65 years and males are at increased risk of physical health effects, while females appear at greater risk of psychological health effects. Other risk factors include previous flood experiences, greater flood depth or flood trauma, existing illnesses, medication interruption, and low education or socio-economic status. Tailoring messages to high-risk groups may increase their effectiveness. Target populations differ for morbidity and mortality effects, and differ pre-, during, and post-flood. Additional research is required to identify the risk factors associated with pre- and post-flood mortality and post-flood morbidity, preferably using prospective cohort studies.

Some Factors Being Overlooked as We Increase Tuition at Our Public Senior Institutions.

ERIC Educational Resources Information Center

Graziano, Anthony F.

Tuition increases in Illinois public senior institutions are reviewed in light of factors being overlooked. These factors suggest the new emphasis on tuition could (1) spiral into higher tuition in the future, (2) create increased state response to provide financial support for students who would otherwise find higher charges a barrier to…

Effects on motor unit potentiation and ground reaction force from treadmill exercise

NASA Technical Reports Server (NTRS)

Elam, Reid P.

1989-01-01

This study was conducted to analyze the characteristics of motor unit potentiation (MUP) and ground reaction force (GRF) in treadmill exercise at the inclines of 0, 5.5 and 11 percent with conjuctive speeds of 7.5, 6, and 5 mph respectively. These speeds and corresponding inclines were set to provide equivalent physiological workloads at 12.5 METS. EMG recordings were taken from the rectus femoris and gastrocnemius of the right leg from 5 subjects. Simultaneous GRF recordings were obtained from a Delmar Avionic treadmill rigged with load cells. Measures for MUP and GRF were taken over a period containing 10 strides at steady pace. It was concluded that the gastrocnemius was more evident in EMG activity in all speed/incline settings over the rectus femoris, and that inclines from 5.5 to 11 percent produced greater GRF's over 0 percent. Recommendations for future studies was made.

Developing a Low-Cost Force Treadmill via Dynamic Modeling.

PubMed

Hong, Chih-Yuan; Guo, Lan-Yuen; Song, Rong; Nagurka, Mark L; Sung, Jia-Li; Yen, Chen-Wen

2017-01-01

By incorporating force transducers into treadmills, force platform-instrumented treadmills (commonly called force treadmills) can collect large amounts of gait data and enable the ground reaction force (GRF) to be calculated. However, the high cost of force treadmills has limited their adoption. This paper proposes a low-cost force treadmill system with force sensors installed underneath a standard exercise treadmill. It identifies and compensates for the force transmission dynamics from the actual GRF applied on the treadmill track surface to the force transmitted to the force sensors underneath the treadmill body. This study also proposes a testing procedure to assess the GRF measurement accuracy of force treadmills. Using this procedure in estimating the GRF of "walk-on-the-spot motion," it was found that the total harmonic distortion of the tested force treadmill system was about 1.69%, demonstrating the effectiveness of the approach.

Modifiable Risk Factors for Increased Arterial Stiffness in Outpatient Nephrology

PubMed Central

Elewa, Usama; Fernandez-Fernandez, Beatriz; Alegre, Raquel; Sanchez-Niño, Maria D.; Mahillo-Fernández, Ignacio; Perez-Gomez, Maria Vanessa; El-Fishawy, Hussein; Belal, Dawlat; Ortiz, Alberto

2015-01-01

Arterial stiffness, as measured by pulse wave velocity (PWV), is an independent predictor of cardiovascular events and mortality. Arterial stiffness increases with age. However, modifiable risk factors such as smoking, BP and salt intake also impact on PWV. The finding of modifiable risk factors may lead to the identification of treatable factors, and, thus, is of interest to practicing nephrologist. We have now studied the prevalence and correlates of arterial stiffness, assessed by PWV, in 191 patients from nephrology outpatient clinics in order to identify modifiable risk factors for arterial stiffness that may in the future guide therapeutic decision-making. PWV was above normal levels for age in 85/191 (44.5%) patients. Multivariate analysis showed that advanced age, systolic BP, diabetes mellitus, serum uric acid and calcium polystyrene sulfonate therapy or calcium-containing medication were independent predictors of PWV. A new parameter, Delta above upper limit of normal PWV (Delta PWV) was defined to decrease the weight of age on PWV values. Delta PWV was calculated as (measured PWV) - (upper limit of the age-adjusted PWV values for the general population). Mean±SD Delta PWV was 0.76±1.60 m/sec. In multivariate analysis, systolic blood pressure, active smoking and calcium polystyrene sulfonate therapy remained independent predictors of higher delta PWV, while age, urinary potassium and beta blocker therapy were independent predictors of lower delta PWV. In conclusion, arterial stiffness was frequent in nephrology outpatients. Systolic blood pressure, smoking, serum uric acid, calcium-containing medications, potassium metabolism and non-use of beta blockers are modifiable factors associated with increased arterial stiffness in Nephrology outpatients. PMID:25880081

Estimation of Ground Reaction Forces and Moments During Gait Using Only Inertial Motion Capture

PubMed Central

Karatsidis, Angelos; Bellusci, Giovanni; Schepers, H. Martin; de Zee, Mark; Andersen, Michael S.; Veltink, Peter H.

2016-01-01

Ground reaction forces and moments (GRF&M) are important measures used as input in biomechanical analysis to estimate joint kinetics, which often are used to infer information for many musculoskeletal diseases. Their assessment is conventionally achieved using laboratory-based equipment that cannot be applied in daily life monitoring. In this study, we propose a method to predict GRF&M during walking, using exclusively kinematic information from fully-ambulatory inertial motion capture (IMC). From the equations of motion, we derive the total external forces and moments. Then, we solve the indeterminacy problem during double stance using a distribution algorithm based on a smooth transition assumption. The agreement between the IMC-predicted and reference GRF&M was categorized over normal walking speed as excellent for the vertical (ρ = 0.992, rRMSE = 5.3%), anterior (ρ = 0.965, rRMSE = 9.4%) and sagittal (ρ = 0.933, rRMSE = 12.4%) GRF&M components and as strong for the lateral (ρ = 0.862, rRMSE = 13.1%), frontal (ρ = 0.710, rRMSE = 29.6%), and transverse GRF&M (ρ = 0.826, rRMSE = 18.2%). Sensitivity analysis was performed on the effect of the cut-off frequency used in the filtering of the input kinematics, as well as the threshold velocities for the gait event detection algorithm. This study was the first to use only inertial motion capture to estimate 3D GRF&M during gait, providing comparable accuracy with optical motion capture prediction. This approach enables applications that require estimation of the kinetics during walking outside the gait laboratory. PMID:28042857

Personalized instructor responses to guided student reflections: Analysis of two instructors' perspectives and practices

NASA Astrophysics Data System (ADS)

Reinholz, Daniel L.; Dounas-Frazer, Dimitri R.

2017-11-01

One way to foster a supportive culture in physics departments is for instructors to provide students with personal attention regarding their academic difficulties. To this end, we have developed the Guided Reflection Form (GRF), an online tool that facilitates student reflections and personalized instructor responses. In the present work, we report on the experiences and practices of two instructors who used the GRF in an introductory physics lab course. Our analysis draws on two sources of data: (i) post-semester interviews with both instructors and (ii) the instructors' written responses to 134 student reflections. Interviews focused on the instructors' perceptions about the goals and framing of the GRF activity, and characteristics of good or bad feedback. Their GRF responses were analyzed for the presence of up to six types of statement: encouraging statements, normalizing statements, empathizing statements, strategy suggestions, resource suggestions, and feedback to the student on the structure of students' reflections. We find that both instructors used all six response types, in alignment with their perceptions of what counts as good feedback. In addition, although each instructor had their own unique feedback style, both instructors' feedback practices were compatible with two principles for effective feedback: praise should focus on effort, express confidence in students' abilities, and be sincere; and process-level feedback should be specific and strategy-oriented. This exploratory qualitative investigation demonstrates that the GRF can serve as a mechanism for instructors to pay personal attention to their students. In addition, it opens the door to future work about the impact of the GRF on student-teacher interactions.

AGU journals increase in importance according to 2010 Impact Factors

NASA Astrophysics Data System (ADS)

Cook, Bill

2011-07-01

AGU journals continue to rank highly in many categories in the 2010 Journal Citation Report (JCR), which was released by Thomson Reuters on 28 June. JCR reports on several measures of journal usage, including a journal's Eigenfactor score, its Article Influence score, its Impact Factor, and its rank within a cohort of similar journals. According to the 2010 statistics, AGU again has outperformed its larger competitors. Four different AGU titles are ranked in the top three journals in six different cohorts. The Impact Factor of several AGU journals increased significantly over the previous year.

Factors associated with increasing nursing home closures.

PubMed

Castle, Nicholas G; Engberg, John; Lave, Judith; Fisher, Andrew

2009-06-01

We determine the rate of nursing home closures for 7 years (1999-2005) and examine internal (e.g., quality), organizational (e.g., chain membership), and external (e.g., competition) factors associated with these closures. The names of the closed facilities and dates of closure from state regulators in all 50 states were obtained. This information was linked to the Online Survey, Certification, and Reporting data, which contains information on internal, organizational, and market factors for almost all nursing homes in the United States. One thousand seven hundred and eighty-nine facilities closed over this time period (1999-2005). The average annual rate of closure was about 2 percent of facilities, but the rate of closure was found to be increasing. Nursing homes with higher rates of deficiency citations, hospital-based facilities, chain members, small bed size, and facilities located in markets with high levels of competition were more likely to close. High Medicaid occupancy rates were associated with a high likelihood of closure, especially for facilities with low Medicaid reimbursement rates. As states actively debate about how to redistribute long-term care services/dollars, our findings show that they should be cognizant of the potential these decisions have for facilitating nursing home closures.

Edaphic fauna in a vegetation gradient in the Sete Cidades National Park.

PubMed

Nunes, L A P L; Araújo, A S F; Pessoa, M M C; Sousa, R S; Silva, J D C; Matos-Filho, C H A

2018-04-09

The vegetation physionomy and cover can show patterns of diversity and composition of the edaphic community, depending on the quantity and quality of litter in a specific habitat. The objective of this study was to evaluate the effect of the vegetation gradient formed by Graminoid Field (GRF), Cerrado Sensu Stricto (CSS), Cerradão (CRD) and Semideciduous Seasonal Forest (SSF) on density, diversity and composition of the edaphic fauna community in two seasons of the year, in the Sete Cidades National Park (Piauí state). For fauna sampling, a total of eight pitfall traps, distanced 10 m, were placed in each area in the central part of each system, where they remained for seven days. In the wet period, there was a tendency to increase the number of individuals as a function of the complexity of the vegetation formation, with the inverse occurring in the dry period. It was verified an environmental variation of the climatic factors temperature and humidity according to the vegetal formation, contributing to a heterogeneous distribution of the fauna. The GRF formation presented a significantly lower value of average richness only in the dry period. Regarding the variables of diversity and uniformity, they did not show drastic variations in relation to the vegetation gradient studied. The dominant groups in the vegetation gradient were Formicidae, Coleoptera, Aranae, Acari and Collembola, with reduction of the number of Coleoptera in the dry season. Principal component analysis (PCA) revealed greater differences in the composition of the communities between the vegetation formations for the rainy season. At this time, the formations SSF and CRD were associated to a greater diversity of invertebrates than CSS and GRF, demonstrating the influence of the vegetation complexity on the soil fauna community.

Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

PubMed Central

Morin, Jean-Benoît; Gimenez, Philippe; Edouard, Pascal; Arnal, Pierrick; Jiménez-Reyes, Pedro; Samozino, Pierre; Brughelli, Matt; Mendiguchia, Jurdan

2015-01-01

Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability. PMID:26733889

Evaluation of a Kinematically-Driven Finite Element Footstrike Model.

PubMed

Hannah, Iain; Harland, Andy; Price, Dan; Schlarb, Heiko; Lucas, Tim

2016-06-01

A dynamic finite element model of a shod running footstrike was developed and driven with 6 degree of freedom foot segment kinematics determined from a motion capture running trial. Quadratic tetrahedral elements were used to mesh the footwear components with material models determined from appropriate mechanical tests. Model outputs were compared with experimental high-speed video (HSV) footage, vertical ground reaction force (GRF), and center of pressure (COP) excursion to determine whether such an approach is appropriate for the development of athletic footwear. Although unquantified, good visual agreement to the HSV footage was observed but significant discrepancies were found between the model and experimental GRF and COP readings (9% and 61% of model readings outside of the mean experimental reading ± 2 standard deviations, respectively). Model output was also found to be highly sensitive to input kinematics with a 120% increase in maximum GRF observed when translating the force platform 2 mm vertically. While representing an alternative approach to existing dynamic finite element footstrike models, loading highly representative of an experimental trial was not found to be achievable when employing exclusively kinematic boundary conditions. This significantly limits the usefulness of employing such an approach in the footwear development process.

Difference in peak weight transfer and timing based on golf handicap.

PubMed

Queen, Robin M; Butler, Robert J; Dai, Boyi; Barnes, C Lowry

2013-09-01

Weight shift during the golf swing has been a topic of discussion among golf professionals; however, it is still unclear how weight shift varies in golfers of different performance levels. The main purpose of this study was to examine the following: (a) the changes in the peak ground reaction forces (GRF) and the timing of these events between high (HHCP) and low handicap (LHCP) golfers and (b) the differences between the leading and trailing legs. Twenty-eight male golfers were recruited and divided based on having an LHCP < 9 or HHCP > 9. Three-dimensional GRF peaks and the timing of the peaks were recorded bilaterally during a golf swing. The golf swing was divided into different phases: (a) address to the top of the backswing, (b) top of the backswing to ball contact, and (c) ball contact to the end of follow through. Repeated measures analyses of variance (α = 0.05) were completed for each study variable: the magnitude and the timing of peak vertical GRF, peak lateral GRF, and peak medial GRF (α = 0.05). The LHCP group had a greater transfer of vertical force from the trailing foot to the leading foot in phase 2 than the HHCP group. The LHCP group also demonstrated earlier timing of peak vertical force throughout the golf swing than the HHCP group. The LHCP and HHCP groups demonstrated different magnitudes of peak lateral force. The LHCP group had an earlier timing of peak lateral GRF in phase 2 and earlier timing of peak medial GRF in phases 1 and 2 than the HHCP group. In general, LHCP golfers demonstrated greater and earlier force generation than HHCP golfers. It may be relevant to consider both the magnitude of the forces and the timing of these events during golf-specific training to improve performance. These data reveal weight shifting differences that can be addressed by teaching professionals to help their students better understand weight transfer during the golf swing to optimize performance.

The Effect of Variation of Plyometric Push-Ups on Force-Application Kinetics and Perception of Intensity.

PubMed

Dhahbi, Wissem; Chaouachi, Anis; Dhahbi, Anis Ben; Cochrane, Jodie; Chèze, Laurence; Burnett, Angus; Chamari, Karim

2017-02-01

To examine differences between ground-reaction-force (GRF)-based parameters collected from 5 types of plyometric push-ups. Between-trials reliability and the relationships between parameters were also assessed. Thirty-seven highly active commando soldiers performed 3 trials of 5 variations of the plyometric push-up in a counterbalanced order: standard countermovement push-up (SCPu), standard squat push-up (SSPu), kneeling countermovement push-up (KCPu), kneeling squat push-up (KSPu), and drop-fall push-up (DFPu). Vertical GRF was measured during these exercises using a portable Kistler force plate. The GRF applied by the hands in the starting position (initial force supported), peak GRF and rate of force development during takeoff, flight time, impact force, and rate of force development impact on landing were determined. During standard-position exercises (SCPu and SSPu) the initial force supported and impact force were higher (P < .001) than with kneeling exercises (KCPu, KSPu, and DFPu). The peak GRF and rate of force development during takeoff were higher (P < .001) in the countermovement push-up exercises ([CMP] SCPu, KCPu, and DFPu) than squat push-up exercises ([SP] SSPu and KSPu). Furthermore, the flight time was greater (P < .001) during kneeling exercises than during standard-position exercises. A significant relationship (P < .01) between impact force and the rate of force development impact was observed for CMP and SP exercises (r = .83 and r = .62, respectively). The initial force supported was also negatively related (P < .01) to the flight time for both CMP and SP (r = -.74 and r = -.80, respectively). It was revealed that the initial force supported and the peak GRF during takeoff had excellent reliability; however, other parameters had poor absolute reliability. It is possible to adjust the intensity of plyometric push-up exercises and train athletes' muscle power by correctly interpreting GRF-based parameters. However, caution is required as some

Ground reaction force, spinal kinematics and their relationship to lower back pain and injury in cricket fast bowling: A review.

PubMed

Senington, Billy; Lee, Raymond Y; Williams, Jonathan Mark

2018-03-09

Fast bowlers display a high risk of lower back injury and pain. Studies report factors that may increase this risk, however exact mechanisms remain unclear. To provide a contemporary analysis of literature, up to April 2016, regarding fast bowling, spinal kinematics, ground reaction force (GRF), lower back pain (LBP) and pathology. Key terms including biomechanics, bowling, spine and injury were searched within MEDLINE, Google Scholar, SPORTDiscuss, Science Citation Index, OAIster, CINAHL, Academic Search Complete, Science Direct and Scopus. Following application of inclusion criteria, 56 studies (reduced from 140) were appraised for quality and pooled for further analysis. Twelve times greater risk of lumbar injury was reported in bowlers displaying excessive shoulder counter-rotation (SCR), however SCR is a surrogate measure which may not describe actual spinal movement. Little is known about LBP specifically. Weighted averages of 5.8 ± 1.3 times body weight (BW) vertically and 3.2 ± 1.1 BW horizontally were calculated for peak GRF during fast bowling. No quantitative synthesis of kinematic data was possible due to heterogeneity of reported results. Fast bowling is highly injurious especially with excessive SCR. Studies adopted similar methodologies, constrained to laboratory settings. Future studies should focus on methods to determine biomechanics during live play.

Possible risk factors for increased suicide following bariatric surgery.

PubMed

Mitchell, James E; Crosby, Ross; de Zwaan, Martina; Engel, Scott; Roerig, James; Steffen, Kristine; Gordon, Kathryn H; Karr, Trisha; Lavender, Jason; Wonderlich, Steve

2013-04-01

There is a growing research literature suggesting that there may be elevated risk of suicide following bariatric surgery. Most of the data reported thus far has been cross-sectional and observational, and very little is known about the possible specific causal variables involved. The purpose of this report is to review this literature and to review possible risk factors for increased suicidal risk following bariatric surgery, to delineate future research directions. First a variety of medical, biological, and genetic factors, including the persistence or recurrence of medical comorbidities after bariatric surgery, the disinhibition and impulsivity secondary to changes in the absorption of alcohol, hypoglycemia, as well as pharmacokinetic changes that may affect the absorption of various medications including antidepressant medications are reviewed. Also reviewed are possible mediating factors involving changes in various peptidergic systems such as GLP-1 and Ghrelin. A number of psychosocial issues that might be involved are discussed, including lack of improvement in quality of life after surgery, continued or recurrent physical mobility restrictions, persistence or recurrence of sexual dysfunction and relationship problems, low self-esteem, and a history of child maltreatment. Inadequate weight loss or weight regain are also discussed. A number of possible contributing factors have been identified. Possible theoretical models involved and directions for research are suggested. Copyright © 2012 The Obesity Society.

Increasing Prevalence, Changes in Diagnostic Criteria, and Nutritional Risk Factors for Autism Spectrum Disorders

PubMed Central

Neggers, Yasmin H.

2014-01-01

The frequency of autism spectrum disorders (ASD) diagnoses has been increasing for decades, but researchers cannot agree on whether the trend is a result of increased awareness, improved detection, expanding definition, or an actual increase in incidence or a combination of these factors. Though both genetic and multiple environmental risk factors have been studied extensively, many potentially modifiable risk factors including nutritional and immune function related risk factors such as vitamin D, folic acid, and metabolic syndrome have not received sufficient attention. Several recent studies have put forward hypotheses to explain the mechanism of association between both folic acid and vitamin D and autism. A continuous rise in the prevalence of autism in the USA has coincided with a significant enhancement of maternal folate status with FDA mandated folic acid fortification of certain foods starting in 1998. There is also a growing body of research that suggests that vitamin D status either in utero or early in life may be a risk for autism. In this communication, controversies regarding increase in estimate of prevalence, implications of changes in definition, and possible association between some modifiable nutritional risk factors such as folic acid and vitamin D and ASD will be discussed. PMID:24967269

Epidermal Growth Factor Increases LRF/Pokemon Expression in Human Prostate Cancer Cells

PubMed Central

Aggarwal, Himanshu; Aggarwal, Anshu; Agrawal, Devendra K.

2011-01-01

Leukemia/lymphoma related factor/POK erythroid myeloid ontogenic factor (LRF/Pokemon) is a member of the POK family of proteins that promotes oncogenesis in several forms of cancer. Recently, we found higher LRF expression in human breast and prostate carcinomas compared to the corresponding normal tissues. The aim of this study was to examine the regulation of LRF expression in human prostate cells. Epidermal growth factor (EGF) and its receptors mediate several tumorigenic cascades that regulate cell differentiation, proliferation, migration and survival of prostate cancer cells. There was significantly higher level of LRF expression in the nucleus of LNCaP and PC-3 cells than RWPE-1 cells. A significant increase in LRF expression was observed with increasing doses of EGF in more aggressive and androgen-sensitive prostate cancer cells suggesting that EGF signaling pathway is critical in upregulating the expression of LRF/Pokemon to promote oncogenesis. PMID:21640721

Green Revolving Funds: An Introductory Guide to Implementation & Management

ERIC Educational Resources Information Center

Indvik, Joe; Foley, Rob; Orlowski, Mark

2013-01-01

The goal of this introductory implementation guide is to provide practical guidance for designing, implementing, and managing a green revolving fund (GRF) at a college, university, or other institution. The GRF model is widespread in higher education, with at least 79 funds in operation in North America representing over $111 million in committed…

Acute effects of heavy-load squats on consecutive squat jump performance.

PubMed

Weber, Kurt R; Brown, Lee E; Coburn, Jared W; Zinder, Steven M

2008-05-01

Postactivation potentiation (PAP) and complex training have generated interest within the strength and conditioning community in recent years, but much of the research to date has produced confounding results. The purpose of this study was to observe the acute effects of a heavy-load back squat [85% 1 repetition maximum (1RM)] condition on consecutive squat jump performance. Twelve in-season Division I male track-and-field athletes participated in two randomized testing conditions: a five-repetition back squat at 85% 1RM (BS) and a five-repetition squat jump (SJ). The BS condition consisted of seven consecutive squat jumps (BS-PRE), followed by five repetitions of the BS at 85% 1RM, followed by another set of seven consecutive squat jumps (BS-POST). The SJ condition was exactly the same as the BS condition except that five consecutive SJs replaced the five BSs, with 3 minutes' rest between each set. BS-PRE, BS-POST, SJ-PRE, and SJ-POST were analyzed and compared for mean and peak jump height, as well as mean and peak ground reaction force (GRF). The BS condition's mean and peak jump height and peak GRF increased 5.8% +/- 4.8%, 4.7% +/- 4.8%, and 4.6% +/- 7.4%, respectively, whereas the SJ condition's mean and peak jump height and peak GRF decreased 2.7% +/- 5.0%, 4.0% +/- 4.9%, and 1.3% +/- 7.5%, respectively. The results indicate that performing a heavy-load back squat before a set of consecutive SJs may enhance acute performance in average and peak jump height, as well as peak GRF.

Epidermal growth factor increases LRF/Pokemon expression in human prostate cancer cells.

PubMed

Aggarwal, Himanshu; Aggarwal, Anshu; Agrawal, Devendra K

2011-10-01

Leukemia/lymphoma related factor/POK erythroid myeloid ontogenic factor (LRF/Pokemon) is a member of the POK family of proteins that promotes oncogenesis in several forms of cancer. Recently, we found higher LRF expression in human breast and prostate carcinomas compared to the corresponding normal tissues. The aim of this study was to examine the regulation of LRF expression in human prostate cells. Epidermal growth factor (EGF) and its receptors mediate several tumorigenic cascades that regulate cell differentiation, proliferation, migration and survival of prostate cancer cells. There was significantly higher level of LRF expression in the nucleus of LNCaP and PC-3 cells than RWPE-1 cells. A significant increase in LRF expression was observed with increasing doses of EGF in more aggressive and androgen-sensitive prostate cancer cells suggesting that EGF signaling pathway is critical in upregulating the expression of LRF/Pokemon to promote oncogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

Does Vertical Ground Reaction Force of the Hip, Knee, and Ankle Joints Change in Patients with Adolescent Idiopathic Scoliosis after Spinal Fusion?

PubMed

Yusof, Mohd Imran; Shaharudin, Shazlin; Sivalingarajah, Prema

2018-04-01

Comparative cross-sectional study. We measured the vertical ground reaction force (vGRF) of the hip, knee, and ankle joints during normal gait in normal patients, adolescent idiopathic scoliosis (AIS) patients with a Cobb angle <40° and in AIS patients with spinal fusion. We aimed to investigate whether vGRF in the aforementioned joints is altered in these three groups of patients. vGRF of the lower limb joints may be altered in these groups of patients. Although it is known that excessive force in the joints may induce early arthritis, there is limited relevant information in the literatures. We measured vGRF of the hip, knee, and ankle joints during heel strike, early stance, mid stance, and toe-off phases in normal subjects (group 1, n=14), AIS patients with Cobb angle <40° (group 2, n=14), and AIS patients with spinal fusion (group 3, n=13) using a gait analysis platform. Fifteen auto-reflective tracking markers were attached to standard anatomical landmarks in both the lower limbs. The captured motion images were used to define the orientations of the body segments and force exerted on the force plate using computer software. Statistical analysis was performed using independent t-test and analysis of variance to examine differences between the right and left sides as well as those among the different subject groups. The measurements during the four gait phases in all the groups did not show any significant difference ( p >0.05). In addition, no significant difference was found in the vGRF measurements of all the joints among the three groups ( p >0.05). A Cobb angle <40° and spinal fusion did not significantly create imbalance or alter vGRF of the lower limb joints in AIS patients.

Improving Vertical Jump Profiles Through Prescribed Movement Plans.

PubMed

Mayberry, John K; Patterson, Bryce; Wagner, Phil

2018-06-01

Mayberry, JK, Patterson, B, and Wagner, P. Improving vertical jump profiles through prescribed movement plans. J Strength Cond Res 32(6): 1619-1626, 2018-Developing practical, reliable, and valid methods for monitoring athlete wellness and injury risk is an important goal for trainers, athletes, and coaches. Previous studies have shown that the countermovement vertical jump (CMJ) test is both a reliable and valid metric for evaluating an athlete's condition. This study examines the effectiveness of prescribed workouts on improving the quality of movement during CMJ. The data set consists of 2,425 pairs of CMJ scans for high school, college, and professional athletes training at a privately owned facility. During each scan, a force plate recorded 3 ground reaction force (GRF) measurements known to impact CMJ performance: eccentric rate of force development (ERFD), average vertical concentric force (AVCF), and concentric vertical impulse (CVI). After an initial scan, coaches either assigned the athlete a specific 1- or 2-strength movement plan (treatment group) or instructed the athlete to choose their own workouts (control group) before returning for a follow-up scan. A multivariate analysis of covariance (MANCOVA) revealed significant differences in changes to GRF measurements between athletes in the 2 groups after adjusting for the covariates sex, sport, time between scans, and rounds of workout completed. A principal component analysis of GRF measurements further identified 4 primary groups of athlete needs and the results provide recommendations for effective workout plans targeting each group. In particular, split squats increase CVI and decrease ERFD/AVCF; deadlifts increase AVCF and decrease CVI; alternating squats/split squats increase ERFD/CVI and decrease AVCF; and alternating squats/deadlifts increase ERFD/AVCF and decrease CVI.

A unified model of Grignard reagent formation.

PubMed

Shao, Yunqi; Liu, Zhen; Huang, Pan; Liu, Boping

2018-04-25

Grignard reagents are among the most fundamental reagents in organic synthesis, yet studies have hitherto failed to fully explain the selectivity and kinetics of Grignard reagent formation (GRF). The present study provides new insights into the intermediates and pathways of GRF using density functional theory (DFT) calculations. Potential energy surfaces of RX dissociation along different directions reveal the origin of configuration retention of alkenyl and aromatic halides. Radical intermediates participate solely in the dissociation stage, and depend on the geometry of the reactant halide. Dissociation of organic halides yields stabilized surface anions, and the rest of the reaction is ionic in nature. MgX+/RMg+ were proposed as the key intermediates of Mg leaving from the surface in the self-activation of GRF, which explains the accelerated kinetics upon addition of RMgX or MgX2. The intermediacy of the cations was supported by a simple electrochemical experiment. To the best of our knowledge, this is the first unified ionic model (I-model) developed for resolving the controversial issues of GRF.

Impact differences in ground reaction force and center of mass between the first and second landing phases of a drop vertical jump and their implications for injury risk assessment.

PubMed

Bates, Nathaniel A; Ford, Kevin R; Myer, Gregory D; Hewett, Timothy E

2013-04-26

The drop vertical jump (DVJ) task is commonly used to assess biomechanical performance measures that are associated with ACL injury risk in athletes. Previous investigations have solely assessed the first landing phase. We examined the first and second landings of a DVJ for differences in the magnitude of vertical ground reaction force (vGRF) and position of center of mass (CoM). A cohort of 239 adolescent female basketball athletes completed a series of DVJ tasks from an initial box height of 31 cm. Dual force platforms and a three dimensional motion capture system recorded force and positional data for each trial. There was no difference in peak vGRF between landings (p=0.445), but side-to-side differences increased from the first to second landing (p=0.007). Participants demonstrated a lower minimum CoM during stance in the first landing than the second landing (p<0.001). The results have important implications for the future assessment of ACL injury risk behaviors in adolescent female athletes. Greater side-to-side asymmetry in vGRF and higher CoM during impact indicate the second landing of a DVJ may exhibit greater perturbation and better represent in-game mechanics associated with ACL injury risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cold-water immersion alters muscle recruitment and balance of basketball players during vertical jump landing.

PubMed

Macedo, Christiane de Souza Guerino; Vicente, Rafael Chagas; Cesário, Mauricio Donini; Guirro, Rinaldo Roberto de Jesus

2016-01-01

The purpose of this study was to evaluate the effects of cold-water immersion on the electromyographic (EMG) response of the lower limb and balance during unipodal jump landing. The evaluation comprised 40 individuals (20 basketball players and 20 non-athletes). The EMG response in the lateral gastrocnemius, tibialis anterior, fibular longus, rectus femoris, hamstring and gluteus medius; amplitude and mean speed of the centre of pressure, flight time and ground reaction force (GRF) were analysed. All volunteers remained for 20 min with their ankle immersed in cold-water, and were re-evaluated immediately post and after 10, 20 and 30 min of reheating. The Shapiro-Wilk test, Friedman test and Dunn's post test (P < 0.05) were used. The EMG response values decreased for the lateral gastrocnemius, tibialis anterior, fibular longus and rectus femoris of both athletes and non-athletes (P < 0.05). The comparison between the groups showed that the EMG response was lower for the athletes. Lower jump flight time and GRF, greater amplitude and mean speed of centre of pressure were predominant in the athletes. Cold-water immersion decreased the EMG activity of the lower limb, flight time and GRF and increased the amplitude and mean speed of centre of pressure.

Reliability of the Kinetics of British Army Foot Drill in Untrained Personnel.

PubMed

Rawcliffe, Alex J; Simpson, Richard J; Graham, Scott M; Psycharakis, Stelios G; Moir, Gavin L; Connaboy, Chris

2017-02-01

Rawcliffe, AJ, Simpson, RJ, Graham, SM, Psycharakis, SG, Moir, GL, and Connaboy, C. Reliability of the kinetics of British Army foot drill in untrained personnel. J Strength Cond Res 31(2): 435-444, 2017-The purpose of this study was to quantify the reliability of kinetic variables of British Army foot drill performance within untrained civilians and report the magnitude of vertical ground reaction force (vGRF) and vertical rate of force development (RFD) of foot drills. Fifteen recreational active males performed 3 testing sessions across a 1-week period, with each session separated by 24 hours. Within each testing session participants (mean ± SD; age 22.4 ± 1.7 years; height 177 ± 5.6 cm; weight 83 ± 8.7 kg) completed 10 trials of stand-at-attention (SaA), stand-at-ease (SaE), Halt, quick-march (QM) and a normal walking gait, with vGRF and vertical RFD measured on a force plate. Between-session and within-session reliability was calculated as systematic bias, coefficient of variation calculated from the typical error (CVte%), and intraclass correlation coefficient (ICC). Significant (p ≤ 0.05) between-session differences were found for the vGRF SaA and SaE, and vertical RFD SaA and SaE conditions. Significant (p ≤ 0.05) within-session differences were found for the vGRF SaA and SaE conditions. A mean vGRF CVte% ≤10% was observed across all foot drills. However, the mean vertical RFD CVte% observed was ≥10% (excluding SaE) across all foot drills. The ICC analyses indicated that the vGRF Halt, QM, SaA, and Walk condition achieved moderate to large levels of test-retest reliability, with only SaE failing to achieve an ICC value ≥0.75. The vertical RFD QM, SaE, and Walk condition achieved moderate levels of test-retest reliability, with Halt and SaA failing to achieve an ICC value ≥0.75. It was determined that a single familiarization session and using the mean of 8 trials of vGRF are required to achieve acceptable levels of reliability.

Comparison of the take-off ground reaction force patterns of the pole vault and the long jump.

PubMed

Plessa, E I; Rousanoglou, E N; Boudolos, K D

2010-12-01

The take-off is probably the most important phase of the pole vault. The kinematics of pole vault take-off is often described in comparison to the long jump take-off. If a kinetic similarity were also evidenced, the extra loading of carrying the pole could be avoided by using the long jump style take-off drills in pole vault take-off training. However, to our knowledge, a direct comparison of the take-off ground reaction force (GRF) pattern of the two types of jump has not been reported in the scientific or coaching literature. The purpose of this study was to compare the take-off GRF patterns of the support leg in the pole vault and the long jump. Twelve elite women jumpers undertook pole vault and long jump trials. The take-off GRF patterns were recorded by a force plate (Kistler-9286AA). Temporal and force parameters were determined for all three GRF components. Trials were videotaped to determine the take-off kinematics. Paired sample t-tests (SPSS 13.0) were applied (P≤0.05) for comparison between jumps. No significant differences were found in kinematics (P>0.05). Overall, the GRF patterns were similar, although there were particular significant (P≤0.05) differences in contact times, impulses and force peaks. This study provides scientific support for potential use of the long jump take-off drills during technical preparation for the pole vault take-off.

A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors

PubMed Central

Billings, Stephen A.; Pavic, Aleksandar; Guo, Ling-Zhong

2017-01-01

Measurement of the ground reaction forces (GRF) during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF) from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR) is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0%) using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra). Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications. PMID:28937593

Gait characteristics of individuals with multiple sclerosis before and after a 6-month aerobic training program.

PubMed

Rodgers, M M; Mulcare, J A; King, D L; Mathews, T; Gupta, S C; Glaser, R M

1999-07-01

Individuals who have multiple sclerosis (MS) typically experience problems with physical activities such as walking, resulting from the combined effects of skeletal muscle weakness, sensory disturbances, spasticity, gait ataxia, and reduction in aerobic capacity. The aim of this study was to determine whether a 6-mo exercise program designed for aerobic conditioning might also affect gait abnormalities in individuals with MS. Subjects included 18 individuals with MS who presented a range of disability. Passive range of motion (PROM) in the lower limbs was measured and gait analyzed before and after exercise conditioning. Three-dimensional kinematics, ground reaction forces (GRF), and electromyographic information were acquired as subjects walked at self-selected velocities. Hip PROM increased following conditioning. Mean walking velocity, cadence, and posterior shear GRF (push-off force) decreased. During walking, maximum ankle dorsiflexion decreased and ankle plantarflexion increased. Total knee flexion/extension range during the walking cycle decreased slightly as did maximum hip extension. Results suggest this 6-mo training program had minimal effect on gait abnormalities.

Modifiable Risk Factors in Primary Joint Arthroplasty Increase 90-Day Cost of Care.

PubMed

Schroer, William C; Diesfeld, Paul J; LeMarr, Angela R; Morton, Diane J; Reedy, Mary E

2018-04-19

Risk factors in demographics and health status have been identified that increase the risk of complications after joint arthroplasty, necessitating additional care and incurring additional charges. The purpose of this study was to identify the number of patients in a hospital network database who had one or more predefined modifiable risk factors and determine their impact on average length of stay, need for additional care during the 90-day postoperative period, and the 90-day charges for care. An electronic hospital record query of 6968 lower extremity joint arthroplasty procedures under Diagnosis-Related Group 469/470 performed in 2014-2015 was reviewed, and total 90-day charges were calculated. The case mean was compared to charges for patients with modifiable risk factors: anemia (Hgb < 10 g/dL), malnutrition (albumin < 3.4 g/dL), obesity (body mass index > 45 kg/m 2 ), uncontrolled diabetes (random glucose >180 mg/dL or A1C > 8), narcotic use (prescription filled), and tobacco use (documented within 30 days before surgery). Length of stay, emergency room visits, and hospital readmission were compared. Mean 90-day charges for Diagnosis-Related Group 469/470 were $36,647. Risk factors were associated with a significant increase in 90-day charges: anemia (+$ 15,869/126 patients), malnutrition (+$9270/592), obesity (+$2048/445), diabetes (+$5074/291), narcotic use (+$1801/1943), and tobacco use (+$2034/1882). Intensive care unit admission rate, emergency department visits, and hospital readmission were significantly increased for patients with each risk factor. Length of stay was higher in patients with anemia, malnutrition, diabetes, and tobacco use. When separated by elective vs fracture admission, 90-day charges were significantly higher for each risk factor. Medical strategies to optimize patients before joint arthroplasty are warranted to improve postoperative outcomes. Copyright © 2018 Elsevier Inc. All rights reserved.

The generation of centripetal force when walking in a circle: insight from the distribution of ground reaction forces recorded by plantar insoles.

PubMed

Turcato, Anna Maria; Godi, Marco; Giordano, Andrea; Schieppati, Marco; Nardone, Antonio

2015-01-09

Turning involves complex reorientation of the body and is accompanied by asymmetric motion of the lower limbs. We investigated the distribution of the forces under the two feet, and its relation to the trajectory features and body medio-lateral displacement during curved walking. Twenty-six healthy young participants walked under three different randomized conditions: in a straight line (LIN), in a circular clockwise path and in a circular counter-clockwise path. Both feet were instrumented with Pedar-X insoles. An accelerometer was fixed to the trunk to measure the medio-lateral inclination of the body. We analyzed walking speed, stance duration as a percent of gait cycle (%GC), the vertical component of the ground reaction force (vGRF) of both feet during the entire stance, and trunk inclination. Gait speed was faster during LIN than curved walking, but not affected by the direction of the curved trajectory. Trunk inclination was negligible during LIN, while the trunk was inclined toward the center of the path during curved trajectories. Stance duration of LIN foot and foot inside the curved trajectory (Foot-In) was longer than for foot outside the trajectory (Foot-Out). vGRF at heel strike was larger in LIN than in curved walking. At mid-stance, vGRF for both Foot-In and Foot-Out was higher than for LIN foot. At toe off, vGRF for both Foot-In and Foot-Out was lower than for LIN foot; in addition, Foot-In had lower vGRF than Foot-Out. During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot. On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot. At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In. The lower gait speed during curved walking is shaped by the control of trunk inclination and the production of asymmetric loading of heel and metatarsal heads, hence by the different contribution of the feet

Study of Factors Which Facilitate Increase of Effectiveness of University Education

ERIC Educational Resources Information Center

Albekov, Adam; Romanova, Tatyana; Vovchenko, Natalya; Epifanova, Tatyana

2017-01-01

Purpose: The purpose of this paper is to study the factors which facilitate the increase of effectiveness of university education and determination of perspectives of their management for provision of maximization of effectiveness of university education by the example of modern Russia. Design/methodology/approach: The authors define the notion…

Risk Factors Associated with Mortality and Increased Drug Costs in Nonvariceal Upper Gastrointestinal Bleeding.

PubMed

Lu, Mingliang; Sun, Gang; Zhang, Xiu-li; Zhang, Xiao-mei; Liu, Qing-sen; Huang, Qi-yang; Lau, James W Y; Yang, Yun-sheng

2015-06-01

To determine risk factors associated with mortality and increased drug costs in patients with nonvariceal upper gastrointestinal bleeding. We retrospectively analyzed data from patients hospitalized with nonvariceal upper gastrointestinal bleeding between January 2001-December 2011. Demographic and clinical characteristics and drug costs were documented. Univariate analysis determined possible risk factors for mortality. Statistically significant variables were analyzed using a logistic regression model. Multiple linear regression analyzed factors influencing drug costs. p < 0.05 was considered statistically significant. The study included data from 627 patients. Risk factors associated with increased mortality were age > 60, systolic blood pressure<100 mmHg, lack of endoscopic examination, comorbidities, blood transfusion, and rebleeding. Drug costs were higher in patients with rebleeding, blood transfusion, and prolonged hospital stay. In this patient cohort, re-bleeding rate is 11.20% and mortality is 5.74%. The mortality risk in patients with comorbidities was higher than in patients without comorbidities, and was higher in patients requiring blood transfusion than in patients not requiring transfusion. Rebleeding was associ-ated with mortality. Rebleeding, blood transfusion, and prolonged hospital stay were associated with increased drug costs, whereas bleeding from lesions in the esophagus and duodenum was associated with lower drug costs.

Changes in running kinematics, kinetics, and spring-mass behavior over a 24-h run.

PubMed

Morin, Jean-Benoît; Samozino, Pierre; Millet, Guillaume Y

2011-05-01

This study investigated the changes in running mechanics and spring-mass behavior over a 24-h treadmill run (24TR). Kinematics, kinetics, and spring-mass characteristics of the running step were assessed in 10 experienced ultralong-distance runners before, every 2 h, and after a 24TR using an instrumented treadmill dynamometer. These measurements were performed at 10 km·h, and mechanical parameters were sampled at 1000 Hz for 10 consecutive steps. Contact and aerial times were determined from ground reaction force (GRF) signals and used to compute step frequency. Maximal GRF, loading rate, downward displacement of the center of mass, and leg length change during the support phase were determined and used to compute both vertical and leg stiffness. Subjects' running pattern and spring-mass behavior significantly changed over the 24TR with a 4.9% higher step frequency on average (because of a significantly 4.5% shorter contact time), a lower maximal GRF (by 4.4% on average), a 13.0% lower leg length change during contact, and an increase in both leg and vertical stiffness (+9.9% and +8.6% on average, respectively). Most of these changes were significant from the early phase of the 24TR (fourth to sixth hour of running) and could be speculated as contributing to an overall limitation of the potentially harmful consequences of such a long-duration run on subjects' musculoskeletal system. During a 24TR, the changes in running mechanics and spring-mass behavior show a clear shift toward a higher oscillating frequency and stiffness, along with lower GRF and leg length change (hence a reduced overall eccentric load) during the support phase of running. © 2011 by the American College of Sports Medicine

Patient- and physician-related risk factors for hyperkalaemia in potassium-increasing drug-drug interactions.

PubMed

Eschmann, Emmanuel; Beeler, Patrick E; Kaplan, Vladimir; Schneemann, Markus; Zünd, Gregor; Blaser, Jürg

2014-02-01

Hyperkalaemia due to potassium-increasing drug-drug interactions (DDIs) is a clinically important adverse drug event. The purpose of this study was to identify patient- and physician-related risk factors for the development of hyperkalaemia. The risk for adult patients hospitalised in the University Hospital Zurich between 1 December 2009 and 31 December 2011 of developing hyperkalaemia was correlated with patient characteristics, number, type and duration of potassium-increasing DDIs and frequency of serum potassium monitoring. The 76,467 patients included in this study were prescribed 8,413 potentially severe potassium-increasing DDIs. Patient-related characteristics associated with the development of hyperkalaemia were pulmonary allograft [relative risk (RR) 5.1; p < 0.0001), impaired renal function (RR 2.7; p < 0.0001), diabetes mellitus (RR 1.6; p = 0.002) and female gender (RR 1.5; p = 0.007). Risk factors associated with medication were number of concurrently administered potassium-increasing drugs (RR 3.3 per additional drug; p < 0.0001) and longer duration of the DDI (RR 4.9 for duration ≥6 days; p < 0.0001). Physician-related factors associated with the development of hyperkalaemia were undetermined or elevated serum potassium level before treatment initiation (RR 2.2; p < 0.001) and infrequent monitoring of serum potassium during a DDI (interval >48 h: RR 1.6; p < 0.01). Strategies for reducing the risk of hyperkalaemia during potassium-increasing DDIs should consider both patient- and physician-related risk factors.

Increased expression of placental growth factor in high-grade endometrial carcinoma.

PubMed

Coenegrachts, Lieve; Schrauwen, Stefanie; Van Bree, Rita; Despierre, Evelyn; Luyten, Catherine; Jonckx, Bart; Stassen, Jean Marie; Vergote, Ignace; Amant, Frédéric

2013-02-01

Placental growth factor (PlGF), a homolog of vascular endothelial growth factor (VEGF), exerts pleiotropic functions in cancer by affecting tumor cells as well as endothelial and inflammatory cells. Moreover, PlGF expression correlates with tumor stage, recurrence, metastasis and patient outcome in different types of cancer. Recently, administration of anti-PlGF therapy reduced tumor growth and metastasis in preclinical tumor models. In the present study, we evaluated the diagnostic and prognostic value of systemic and local expression of PlGF in primary endometrial carcinomas. PlGF levels in tumor lysates (n=128) and serum (n=88) of patients with primary endometrial cancer were determined using ELISA. PlGF mRNA expression in endometrial carcinoma tissues was quantified by quantitative qRT-PCR. Results were compared to endometrial cancer stage and grade. Systemic PlGF levels were not altered in patients with endometrial cancer (FIGO stage I-II-III) as compared to healthy controls. Only in FIGO stage IV patients, serum PlGF levels were slightly increased. Local PlGF mRNA and protein expression in endometrial tumors progressively increased with tumor grade. In endometrioid carcinomas, PlGF mRNA expression was significantly increased in endometrioid grade 3 tumors as compared to normal endometrial tissue. PlGF protein expression was significantly increased in endometrioid grade 2 and 3 carcinomas and in serous carcinomas as compared to normal endometrial tissue. Our study showed that systemic/serum PlGF levels cannot be used as a diagnostic or prognostic marker in endometrial cancer. However, the increased local expression of PlGF, primarily in high-grade carcinomas, underscores the possibility for preclinical assessment of anti-PlGF therapy in endometrial cancer.

Oxidative stress increases eukaryotic initiation factor 4E phosphorylation in vascular cells.

PubMed Central

Duncan, Roger F; Peterson, Hazel; Hagedorn, Curt H; Sevanian, Alex

2003-01-01

Dysregulated cell growth can be caused by increased activity of protein synthesis eukaryotic initiation factor (eIF) 4E. Dysregulated cell growth is also characteristic of atherosclerosis. It is postulated that exposure of vascular cells, such as endothelial cells, smooth muscle cells and monocytes/macrophages, to oxidants, such as oxidized low-density lipoprotein (oxLDL), leads to the elaboration of growth factors and cytokines, which in turn results in smooth muscle cell hyperproliferation. To investigate whether activation of eIF4E might play a role in this hyperproliferative response, vascular cells were treated with oxLDL, oxidized lipid components of oxLDL and several model oxidants, including H(2)O(2) and dimethyl naphthoquinone. Exposure to each of these compounds led to a dose- and time-dependent increase in eIF4E phosphorylation in all three types of vascular cells, correlated with a modest increase in overall translation rate. No changes in eIF4EBP, eIF2 or eIF4B modification state were observed. Increased eIF4E phosphorylation was paralleled by increased presence of eIF4E in high-molecular-mass protein complexes characteristic of its most active form. Anti-oxidants at concentrations typically employed to block oxidant-induced cell signalling likewise promoted eIF4E phosphorylation. The results of this study indicate that increased eIF4E activity may contribute to the pathophysiological events in early atherogenesis by increasing the expression of translationally inefficient mRNAs encoding growth-promoting proteins. PMID:12215171

Increased Melanoma Growth and Metastasis Spreading in Mice Overexpressing Placenta Growth Factor

PubMed Central

Marcellini, Marcella; De Luca, Naomi; Riccioni, Teresa; Ciucci, Alessandro; Orecchia, Angela; Lacal, Pedro Miguel; Ruffini, Federica; Pesce, Maurizio; Cianfarani, Francesca; Zambruno, Giovanna; Orlandi, Augusto; Failla, Cristina Maria

2006-01-01

Placenta growth factor (PlGF), a member of the vascular endothelial growth factor family, plays an important role in adult pathological angiogenesis. To further investigate PlGF functions in tumor growth and metastasis formation, we used transgenic mice overexpressing PlGF in the skin under the control of the keratin 14 promoter. These animals showed a hypervascularized phenotype of the skin and increased levels of circulating PlGF with respect to their wild-type littermates. Transgenic mice and controls were inoculated intradermally with B16-BL6 melanoma cells. The tumor growth rate was fivefold increased in transgenic animals compared to wild-type mice, in the presence of a similar percentage of tumor necrotic tissue. Tumor vessel area was increased in transgenic mice as compared to controls. Augmented mobilization of endothelial and hematopoietic stem cells from the bone marrow was observed in transgenic animals, possibly contributing to tumor vascularization. The number and size of pulmonary metastases were significantly higher in transgenic mice compared to wild-type littermates. Finally, PlGF promoted tumor cell invasion of the extracellular matrix and increased the activity of selected matrix metalloproteinases. These findings indicate that PlGF, in addition to enhancing tumor angiogenesis and favoring tumor growth, may directly influence melanoma dissemination. PMID:16877362

Increased active von Willebrand factor during disease development in the aging diabetic patient population.

PubMed

Chen, Shuang Feng; Xia, Zuo Li; Han, Ji Ju; Wang, Yi Ting; Wang, Ji Yue; Pan, Shao Dong; Wu, Ya Ping; Zhang, Bin; Li, Guang Yao; Du, Jing Wei; Gao, Hen Qiang; de Groot, Philip G; de Laat, Bas; Hollestelle, Martine J

2013-02-01

Type 2 diabetes is known to cause endothelial activation resulting in the secretion of von Willebrand factor (VWF). We have shown that levels of VWF in a glycoprotein Ib-binding conformation are increased in specific clinical settings. The aim of the current study is to investigate whether active VWF levels increase during aging and the development of diabetes within the population of patients suffering from type 2 diabetes. Patients and controls were divided into two groups based on age: older and younger than 60 years of age. VWF antigen, VWF propeptide, VWF activation factor and total active VWF were measured. Patients older than 60 years of age had increased levels of total active VWF, VWF activation factor and VWF propeptide compared to younger patients and controls. All measured VWF parameters were associated with age in diabetic patients. Total active VWF and VWF propeptide correlated with the period of being diagnosed with diabetes. Regression analyses showed that especially the VWF activation factor was strongly associated with diabetes in patients older than 60 years of age. In conclusion, we found that the conformation of VWF could be involved in the disease process of diabetes and that the VWF in a glycoprotein Ib-binding conformation could play a role as risk marker during the development of diabetes in combination with an increase in age. Our study shows that the active quality of VWF was more important than the quantity.

The role of military footwear and workload on ground reaction forces during a simulated lateral ankle sprain mechanism.

PubMed

Simpson, Jeffrey D; DeBusk, Hunter; Hill, Christopher; Knight, Adam; Chander, Harish

2018-03-01

Ankle sprains are a common orthopedic injury in military populations, which may be attributed to occupational demands and footwear. Minimalist military boots have become popular, but their influence on ground reaction force (GRF) attenuation capabilities during an ankle inversion perturbation are unknown. Therefore, the purpose of this study was to examine potential differences in GRFs during an ankle inversion perturbation in a standard issue (STN) and minimalist military boot (MIN) before and after a simulated military workload. Twenty-one healthy adult males completed an ankle inversion perturbation protocol in each footwear condition before and after an incremental treadmill exercise protocol to volitional exhaustion while wearing a 16kg rucksack. The ankle inversion perturbation protocol consisted of stepping down from a 27cm box onto a force platform with a fulcrum (FUL), which created 25° of inversion upon landing, or flat (FLT) outer sole attached to the plantar aspect of the participants' footwear in random order. Peak vertical, anterior/posterior, and medial/lateral components of the GRF during FUL and FLT conditions were assessed, normalized to multiples of body weight in each footwear. Dependent variables were then analyzed using separate 2 (footwear)×2 (time) repeated measures ANOVA (p<0.05). The MIN footwear demonstrated significantly greater vertical GRF and significantly less medial GRF during the FUL condition. These results indicate that various mechanical and design characteristics of military footwear may influence GRF attenuation capabilities and ankle joint loading when the foot/ankle complex is forced into inversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

A comparison of ground reaction force components according to the foothold heights in 16-t truck during downward step.

PubMed

Hyun, Seung-Hyun; Ryew, Che-Cheong

2017-12-01

The aim of this study is to compare and analyze the components of ground reaction force (GRF) relative to the foothold heights during downward step of 16-t truck. Adult males (n= 10) jumped downward from each 1st, 2nd, 3rd foothold step and driver's seat orderly using hand rail. Sampling rate of force components of 3 axis (medial-lateral [ML] GRF, anterior-posterior [AP] GRF, peak vertical force [PVF]), variables (COPx, COPy, COP area) of center of pressure (COP), loading rate, and stability index (ML, AP, vertical, and dynamic postural stability index [DPSI]) processed from GRF system was cut off at 1,000 Hz. and variables was processed with repeated one-way analysis of variance. AP GRF, PVF and loading rate showed higher value in case of not used hand rail than that used hand rail in all 1st, 2nd, and 3rd of foothold step. DPSI showed more lowered stability in order of 2nd, 3rd step than 1st foothold step used with hand rail, of which showed lowest stability from driver's seat. COPx, COPy, and COP area showed higher value in case of 2nd and 3rd than that of 1st of foothold step, and showed lowest stability from driver's seat. It is more desirable for cargo truck driver to utilize an available hand rail in order of 3rd, 2nd, and 1st of foothold step than downward stepping directly, thus by which may results in decrease of falling injuries and minimization of impulsive force transferring to muscular-skeletal system.

Protein–energy malnutrition increases activation of the transcription factor, nuclear factor κB, in the gerbil hippocampus following global ischemia☆

PubMed Central

Ji, Liang; Nazarali, Adil J.; Paterson, Phyllis G.

2013-01-01

Protein–energy malnutrition (PEM) exacerbates functional impairment caused by brain ischemia. This is correlated with reactive gliosis, which suggests an increased inflammatory response. The objective of the current study was to investigate if PEM increases hippocampal activation of nuclear factor κB (NFκB), a transcription factor that amplifies the inflammatory response involved in ischemic brain injury. Mongolian gerbils (11–12 weeks old) were randomly assigned to control diet (12.5% protein) or protein-deficient diet (2%) for 4 weeks. The 2% protein group had a 15% decrease in voluntary food intake (P<.001; unpaired t test), resulting in PEM. Body weight after 4 weeks was 20% lower in the PEM group (P<.001). Gerbils were then exposed to sham surgery or global ischemia induced by 5-min bilateral common carotid artery occlusion. PEM independently increased hippocampal NFκB activation detected by electrophoretic mobility shift assay at 6 h after surgery (P=.014; 2-factor ANOVA). Ischemia did not significantly affect NFκB activation nor was there interaction between diet and ischemia. Serum glucose and cortisol concentrations at 6 h postischemia were unaltered by diet or ischemia. A second experiment using gerbils of the same age and feeding paradigm demonstrated that PEM also increases hippocampal NFκB activation in the absence of surgery. These findings suggest that PEM, which exists in 16% of elderly patients at admission for stroke, may worsen outcome by increasing activation of NFκB. Since PEM increased NFκB activation independent of ischemia or surgery, the data also have implications for the inflammatory response of the many individuals affected globally by PEM. PMID:18430555

Increased expression of placental growth factor in high-grade endometrial carcinoma

PubMed Central

COENEGRACHTS, LIEVE; SCHRAUWEN, STEFANIE; VAN BREE, RITA; DESPIERRE, EVELYN; LUYTEN, CATHERINE; JONCKX, BART; STASSEN, JEAN MARIE; VERGOTE, IGNACE; AMANT, FRÉDÉRIC

2013-01-01

Placental growth factor (PlGF), a homolog of vascular endothelial growth factor (VEGF), exerts pleiotropic functions in cancer by affecting tumor cells as well as endothelial and inflammatory cells. Moreover, PlGF expression correlates with tumor stage, recurrence, metastasis and patient outcome in different types of cancer. Recently, administration of anti-PlGF therapy reduced tumor growth and metastasis in preclinical tumor models. In the present study, we evaluated the diagnostic and prognostic value of systemic and local expression of PlGF in primary endometrial carcinomas. PlGF levels in tumor lysates (n=128) and serum (n=88) of patients with primary endometrial cancer were determined using ELISA. PlGF mRNA expression in endometrial carcinoma tissues was quantified by quantitative qRT-PCR. Results were compared to endometrial cancer stage and grade. Systemic PlGF levels were not altered in patients with endometrial cancer (FIGO stage I-II-III) as compared to healthy controls. Only in FIGO stage IV patients, serum PlGF levels were slightly increased. Local PlGF mRNA and protein expression in endometrial tumors progressively increased with tumor grade. In endometrioid carcinomas, PlGF mRNA expression was significantly increased in endometrioid grade 3 tumors as compared to normal endometrial tissue. PlGF protein expression was significantly increased in endometrioid grade 2 and 3 carcinomas and in serous carcinomas as compared to normal endometrial tissue. Our study showed that systemic/serum PlGF levels cannot be used as a diagnostic or prognostic marker in endometrial cancer. However, the increased local expression of PlGF, primarily in high-grade carcinomas, underscores the possibility for preclinical assessment of anti-PlGF therapy in endometrial cancer. PMID:23232836

Effects of Stretch Shortening Cycle Exercise Fatigue on Stress Fracture Injury Risk during Landing

ERIC Educational Resources Information Center

James, C. Roger; Dufek, Janet S.; Bates, Barry T.

2006-01-01

The purpose of this study was to examine changes in landing performance during fatigue that could result in increased stress fracture injury risk. Five participants performed nonfatigued and fatigued drop landings (0.60 m), while ground reaction force (GRF), electromyographic (EMG) activity, and kinematics were recorded. Fatigue was defined as a…

SPECT data acquisition and image reconstruction in a stationary small animal SPECT/MRI system

NASA Astrophysics Data System (ADS)

Xu, Jingyan; Chen, Si; Yu, Jianhua; Meier, Dirk; Wagenaar, Douglas J.; Patt, Bradley E.; Tsui, Benjamin M. W.

2010-04-01

The goal of the study was to investigate data acquisition strategies and image reconstruction methods for a stationary SPECT insert that can operate inside an MRI scanner with a 12 cm bore diameter for simultaneous SPECT/MRI imaging of small animals. The SPECT insert consists of 3 octagonal rings of 8 MR-compatible CZT detectors per ring surrounding a multi-pinhole (MPH) collimator sleeve. Each pinhole is constructed to project the field-of-view (FOV) to one CZT detector. All 24 pinholes are focused to a cylindrical FOV of 25 mm in diameter and 34 mm in length. The data acquisition strategies we evaluated were optional collimator rotations to improve tomographic sampling; and the image reconstruction methods were iterative ML-EM with and without compensation for the geometric response function (GRF) of the MPH collimator. For this purpose, we developed an analytic simulator that calculates the system matrix with the GRF models of the MPH collimator. The simulator was used to generate projection data of a digital rod phantom with pinhole aperture sizes of 1 mm and 2 mm and with different collimator rotation patterns. Iterative ML-EM reconstruction with and without GRF compensation were used to reconstruct the projection data from the central ring of 8 detectors only, and from all 24 detectors. Our results indicated that without GRF compensation and at the default design of 24 projection views, the reconstructed images had significant artifacts. Accurate GRF compensation substantially improved the reconstructed image resolution and reduced image artifacts. With accurate GRF compensation, useful reconstructed images can be obtained using 24 projection views only. This last finding potentially enables dynamic SPECT (and/or MRI) studies in small animals, one of many possible application areas of the SPECT/MRI system. Further research efforts are warranted including experimentally measuring the system matrix for improved geometrical accuracy, incorporating the co

Vertical ground reaction force in stationary running in water and on land: A study with a wide range of cadences.

PubMed

de Brito Fontana, Heiliane; Ruschel, Caroline; Dell'Antonio, Elisa; Haupenthal, Alessandro; Pereira, Gustavo Soares; Roesler, Helio

2018-04-01

The aim of this study was to analyze the effect of cadence, immersion level as well as body density on the vertical component (Fy max ) of ground reaction force (GRF) during stationary running (SR). In a controlled, laboratory study, thirty-two subjects ran at a wide range of cadences (85-210 steps/min) in water, immersed to the hip and to the chest, and on dry land. Fy max. was verified by a waterproof force measurement system and predicted based on a statistical model including cadence, immersion ratio and body density. The effect of cadence was shown to depend on the environment: while Fy max increases linearly with increasing cadence on land; in water, Fy max reaches a plateau at both hip and chest immersions. All factors analyzed, cadence, immersion level and body density affected Fy max significantly, with immersion (aquatic × land environment) showing the greatest effect. In water, different cadences may lead to bigger changes in Fy max than the changes obtained by moving subjects from hip to chest immersion. A regression model able to predict 69% of Fy max variability in water was proposed and validated. Cadence, Immersion and body density affect Fy max in a significant and non-independent way. Besides a model of potential use in the prescription of stationary running in water, our analysis provides insights into the different responses of GRF to changes in exercise parameters between land and aquatic environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Dynamic increase and decrease of photonic crystal nanocavity Q factors for optical pulse control.

PubMed

Upham, Jeremy; Tanaka, Yoshinori; Asano, Takashi; Noda, Susumu

2008-12-22

We introduce recent advances in dynamic control over the Q factor of a photonic crystal nanocavity system. By carefully timing a rapid increase of the Q factor from 3800 to 22,000, we succeed in capturing a 4ps signal pulse within the nanocavity with a photon lifetime of 18ps. By performing an additional transition of the Q factor within the photon lifetime, the held light is once again ejected from of the system on demand.

Lack of supervision after residential cardiac rehabilitation increases cardiovascular risk factors.

PubMed

Berent, Robert; von Duvillard, Serge P; Auer, Johann; Sinzinger, Helmut; Schmid, Peter

2010-06-01

Cardiovascular rehabilitation (CR) is an important component of care for patients with cardiovascular disease (CVD) and has been well documented and promoted by various health organizations and position statements worldwide. The purpose of this study was to investigate whether patients readmitted to CR on average 16 months after their previous discharge, maintained the reduction in CVD risk factors, maintained or improved functional capacity, occurrence of adverse cardiovascular events, and possible modifications in prescribed medications. Five hundred and seventy patients (60+/-10 years) underwent cycle ergometry and blood sampling at the beginning, the end of 21+/-2 days of the previous CR, and again at readmission to CR. The CR consisted of cycling for 17+/-4 min at frequency of six times a week and daily walking for 45 min at 60-70% of the maximal individual heart rate. Blood total cholesterol, low-density lipoprotein-cholesterol, triglycerides, and body mass index decreased significantly during CR. Resting blood pressure, maximal performance (watts), maximal oxygen uptake, and heart rate recovery improved significantly in 1 min (P<0.001). At readmission, all traditional CVD risk factors increased significantly, although medication was unchanged and angiotensin-converting enzyme inhibitors were partly replaced by angiotensin II receptor antagonists. Exercise performance remained unchanged. At readmission, we observed an increase in CVD risk factors, although, physical fitness remained stable. Thus, failure of lifestyle modification after CR indicates the cause for concern. Reinforcement of home setting sessions of CR patients or other strategies to enhance long-term compliance to lifestyle changes could reduce the observed attrition in CR benefits.

[Factors that increasing tendency to smoking cessation].

PubMed

Argüder, Emine; Hasanoğlu, H Canan; Karalezli, Ayşegül; Kılıç, Hatice

2012-01-01

Cigarette smoking is just important problem of public health. In the present study, our aim; was to determine to factors that increasing tendency to smoking cessation, the cases who are involved to policlinic of smoking cessation. Two hundred-forty five cigarette smokers were included in this study. It was recorded demographic signs, the novel of cigarette smoking, the degree of knowledge about the harmful of smoking in their opinion, the reason of starting to cigarette. It was evaluated that the principle reason to come to policlinic of smoking cessation and the other reasons. There were 53.9% male, 46.1% female in our study. Median (min-max) age was 45 (21-73) in females, 42 (20-75) in males. When evaluating the state of education; there was 35.9% primary school, 31.4% high school, 7.3% academy, 25.3% university graduates. 97.1% in all participants have used only cigarette smoking from tobacco products. Primarily reasons were 44% the fear of deterioration of health, 16.3% to be better model for their children, 9.8% to have disease at the time and 6.9% breathlessness for smoking cessation. Secondary reasons were of smoking harm to the environment, economic reasons, bad smell, being a good example of the environment and recommended by a physician. The most of cases are want to quit smoking because of smoking harm to their health. Specially, parents wish to quit smoking because of they don't want to be bad model for their children. As a result; it is given to necessary support to participants who are this awareness in policlinics of smoking cessation. However, we think that it was necessity that should be continue increase of the therapy to growing to these awareness for the smokers who couldn't be enough awareness and who didn't think of quit smoking.

Sensitivity of Surface Temperature to Oceanic Forcing via q-Flux Green’s Function Experiments. Part I: Linear Response Function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Fukai; Lu, Jian; Garuba, Oluwayemi

This paper explores the use of linear response function (LRF) to relate the mean sea surface temperature (SST) response to prescribed ocean heat convergence (q-flux) forcings. Two methods for constructing the LRF based on the fluctuation-dissipation theorem (FDT) and Green’s function (GRF) are examined. A 900-year preindustrial simulation from the Community Earth System Model with a slab ocean (CESM-SOM) is used to estimate the LRF using FDT. For GRF, 106 pairs of CESM-SOM simulations with warm and cold q-flux patches are performed. FDT is found to have skill in estimating the SST response to a q-flux forcing when the localmore » SST response is strong, but it fails in inverse estimation of the q-flux forcing for a given SST pattern. In contrast, GRF is shown to be reasonably accurate in estimating both SST response and q-flux forcing. Possible degradation in FDT may be attributed to insufficient data sampling, significant departures of the SST data from Gaussian, and the non-normality of the constructed operator. The accurately estimated GRF-based LRF is used to (i) generate a global surface temperature sensitivity map that shows the q-flux forcing in higher latitudes to be three to four times more effective than in low latitudes in producing global surface warming; (ii) identify the most excitable SST mode (neutral vector) resembling Interdecadal Pacific Oscillation; and (iii) estimate a time-invariant q-flux forcing needed for maintaining the GHG-induced SST warming pattern. The GRF experiments will be used to construct LRF for other variables to further explore climate sensitivities and feedbacks.« less

Vertical Jump Height is more Strongly Associated with Velocity and Work Performed Prior to Take-off

NASA Technical Reports Server (NTRS)

Bentley, J. R.; Loehr, J. A.; DeWitt, J. K.; Lee, S. M. C.; English, K. L.; Nash, R. E.; Leach, M. A.; Hagan, R. D.

2008-01-01

Vertical jump (VJ) height is commonly used as a measure of athletic capability in strength and power sports. Although VJ has been shown to be a predictor of athletic performance, it is not clear which kinetic ground reaction force (GRF) variables, such as peak force (PF), peak power (PP), peak velocity (PV), total work (TW) or impulse (Imp) are the best correlates. To determine which kinetic variables (PF, PP, PV, TW, and Imp) best correlate with VJ height. Twenty subjects (14 males, 6 females) performed three maximal countermovement VJs on a force platform (Advanced Mechanical Technology, Inc., Watertown, MA, USA). VJ jump height was calculated as the difference between standing reach and the highest reach point measured using a Vertec. PF, PP, PV, TW, and Imp were calculated using the vertical GRF data sampled at 1000 Hz from the lowest point in the countermovement through the concentric portion until take-off. GRF data were normalized to body mass measured using a standard scale (Detecto, Webb City, MO, USA). Correlation coefficients were computed between each GRF variable and VJ height using a Pearson correlation. VJ height (43.4 plus or minus 9.1 cm) was significantly correlated (p less than 0.001) with PF (998 plus or minus 321 N; r=0.51), PP (1997 plus or minus 772 W; r=0.69), PV (2.66 plus or minus 0.40 m (raised dot) s(sup -1); r=0.85), TW (259 plus or minus 93.0 kJ; r=0.82), and Imp (204 plus or minus 51.1 N(raised dot)s; r=0.67). Although all variables were correlated to VJ height, PV and TW were more strongly correlated to VJ height than PF, PP, and Imp. Therefore, since TW is equal to force times displacement, the relative displacement of the center of mass along with the forces applied during the upward movement of the jump are critical determinants of VJ height. PV and TW are key determinants of VJ height, and therefore successful training programs to increase VJ height should focus on rapid movement (PV) and TW by increasing power over time rather

Computer simulation of the effects of shoe cushioning on internal and external loading during running impacts.

PubMed

Miller, Ross H; Hamill, Joseph

2009-08-01

Biomechanical aspects of running injuries are often inferred from external loading measurements. However, previous research has suggested that relationships between external loading and potential injury-inducing internal loads can be complex and nonintuitive. Further, the loading response to training interventions can vary widely between subjects. In this study, we use a subject-specific computer simulation approach to estimate internal and external loading of the distal tibia during the impact phase for two runners when running in shoes with different midsole cushioning parameters. The results suggest that: (1) changes in tibial loading induced by footwear are not reflected by changes in ground reaction force (GRF) magnitudes; (2) the GRF loading rate is a better surrogate measure of tibial loading and stress fracture risk than the GRF magnitude; and (3) averaging results across groups may potentially mask differential responses to training interventions between individuals.

Metabolic acidosis increases fibroblast growth factor 23 in neonatal mouse bone

PubMed Central

Culbertson, Christopher D.; Kyker-Snowman, Kelly; Bushinsky, David A.

2012-01-01

Fibroblast growth factor 23 (FGF23) significantly increases with declining renal function, leading to reduced renal tubular phosphate reabsorption, decreased 1,25-dihydroxyvitamin D, and increased left ventricular hypertrophy. Elevated FGF23 is associated with increased mortality. FGF23 is synthesized in osteoblasts and osteocytes; however, the mechanisms by which it is regulated are not clear. Patients with chronic kidney disease have decreased renal acid excretion leading to metabolic acidosis, which has a direct effect on bone cell activity. We hypothesized that metabolic acidosis would directly increase bone cell FGF23 production. Using cultured neonatal mouse calvariae, we found that metabolic acidosis increased medium FGF23 protein levels as well as FGF23 RNA expression at 24 h and 48 h compared with incubation in neutral pH medium. To exclude that the increased FGF23 was secondary to metabolic acidosis-induced release of bone mineral phosphate, we cultured primary calvarial osteoblasts. In these cells, metabolic acidosis increased FGF23 RNA expression at 6 h compared with incubation in neutral pH medium. Thus metabolic acidosis directly increases FGF23 mRNA and protein in mouse bone. If these results are confirmed in humans with chronic kidney disease, therapeutic interventions to mitigate acidosis, such as bicarbonate administration, may also lower levels of FGF23, decrease left ventricular hypertrophy, and perhaps even decrease mortality. PMID:22647635

An exploration of the influence of diagonal dissociation and moderate changes in speed on locomotor parameters in trotting horses.

PubMed

Hobbs, Sarah Jane; Bertram, John E A; Clayton, Hilary M

2016-01-01

Background. Although the trot is described as a diagonal gait, contacts of the diagonal pairs of hooves are not usually perfectly synchronized. Although subtle, the timing dissociation between contacts of each diagonal pair could have consequences on gait dynamics and provide insight into the functional strategies employed. This study explores the mechanical effects of different diagonal dissociation patterns when speed was matched between individuals and how these effects link to moderate, natural changes in trotting speed. We anticipate that hind-first diagonal dissociation at contact increases with speed, diagonal dissociation at contact can reduce collision-based energy losses and predominant dissociation patterns will be evident within individuals. Methods. The study was performed in two parts: in the first 17 horses performed speed-matched trotting trials and in the second, five horses each performed 10 trotting trials that represented a range of individually preferred speeds. Standard motion capture provided kinematic data that were synchronized with ground reaction force (GRF) data from a series of force plates. The data were analyzed further to determine temporal, speed, GRF, postural, mass distribution, moment, and collision dynamics parameters. Results. Fore-first, synchronous, and hind-first dissociations were found in horses trotting at (3.3 m/s ± 10%). In these speed-matched trials, mean centre of pressure (COP) cranio-caudal location differed significantly between the three dissociation categories. The COP moved systematically and significantly (P = .001) from being more caudally located in hind-first dissociation (mean location = 0.41 ± 0.04) through synchronous (0.36 ± 0.02) to a more cranial location in fore-first dissociation (0.32 ± 0.02). Dissociation patterns were found to influence function, posture, and balance parameters. Over a moderate speed range, peak vertical forelimb GRF had a strong relationship with dissociation time (R = .594

Factors Affecting Canagliflozin-Induced Transient Urine Volume Increase in Patients with Type 2 Diabetes Mellitus.

PubMed

Tanaka, Hiroyuki; Takano, Kazuhiko; Iijima, Hiroaki; Kubo, Hajime; Maruyama, Nobuko; Hashimoto, Toshio; Arakawa, Kenji; Togo, Masanori; Inagaki, Nobuya; Kaku, Kohei

2017-02-01

Sodium glucose co-transporter 2 (SGLT2) inhibitors exhibit diuretic activity, which is a possible mechanism underlying the cardiovascular benefit of these inhibitors. However, the osmotic diuresis-induced increase in urine volume, and the risk of dehydration have been of concern with SGLT2 inhibitor treatment. This study aimed to investigate the mechanism underlying SGLT2 inhibitor canagliflozin-induced diuresis in Japanese type 2 diabetes mellitus (T2DM) patients. Thirteen T2DM patients received a daily oral dose of 100 mg canagliflozin before breakfast for 6 days. Blood and urine samples were collected at predetermined time points. The primary endpoint was evaluation of correlations between changes from baseline in urine volume and factors that are known to affect urine volume and between actual urine volume and these factors. Canagliflozin transiently increased urine volume and urinary sodium excretion on Day 1 with a return to baseline levels thereafter. Canagliflozin administration increased urinary glucose excretion, which was sustained during repeated-dose administration. Plasma atrial natriuretic peptide (ANP) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels decreased, while plasma renin activity increased. On Day 1 of treatment, changes in sodium and potassium excretion were closely correlated with changes in urine output. A post hoc multiple regression analysis showed changes in sodium excretion and water intake as factors that affected urine volume change at Day 1. Furthermore, relative to that at baseline, canagliflozin decreased blood glucose throughout the day and increased plasma total GLP-1 after breakfast. Canagliflozin induced transient sodium excretion and did not induce water intake at Day 1; hence, natriuresis rather than glucose-induced osmotic diuresis may be a major factor involved in the canagliflozin-induced transient increase in urine output. In addition, canagliflozin decreased plasma ANP and NT-proBNP levels and

Secretion of Growth Hormone in Response to Muscle Sensory Nerve Stimulation

NASA Technical Reports Server (NTRS)

Grindeland, Richard E.; Roy, R. R.; Edgerton, V. R.; Gosselink, K. L.; Grossman, E. J.; Sawchenko, P. E.; Wade, Charles E. (Technical Monitor)

1994-01-01

Growth hormone (GH) secretion is stimulated by aerobic and resistive exercise and inhibited by exposure to actual or simulated (bedrest, hindlimb suspension) microgravity. Moreover, hypothalamic growth hormone-releasing factor (GRF) and preproGRF mRNA are markedly decreased in spaceflight rats. These observations suggest that reduced sensory input from inactive muscles may contribute to the reduced secretion of GH seen in "0 G". Thus, the aim of this study was to determine the effect of muscle sensory nerve stimulation on secretion of GH. Fed male Wistar rats (304 +/- 23 g) were anesthetized (pentobarbital) and the right peroneal (Pe), tibial (T), and sural (S) nerves were cut. Electrical stimulation of the distal (D) or proximal (P) ends of the nerves was implemented for 15 min. to mimic the EMG activity patterns of ankle extensor muscles of a rat walking 1.5 mph. The rats were bled by cardiac puncture and their anterior pituitaries collected. Pituitary and plasma bioactive (BGH) and immunoactive (IGH) GH were measured by bioassay and RIA.

Deconstructing the power resistance relationship for squats: A joint-level analysis.

PubMed

Farris, D J; Lichtwark, G A; Brown, N A T; Cresswell, A G

2016-07-01

Generating high leg power outputs is important for executing rapid movements. Squats are commonly used to increase leg strength and power. Therefore, it is useful to understand factors affecting power output in squatting. We aimed to deconstruct the mechanisms behind why power is maximized at certain resistances in squatting. Ten male rowers (age = 20 ± 2.2 years; height = 1.82 ± 0.03 m; mass = 86 ± 11 kg) performed maximal power squats with resistances ranging from body weight to 80% of their one repetition maximum (1RM). Three-dimensional kinematics was combined with ground reaction force (GRF) data in an inverse dynamics analysis to calculate leg joint moments and powers. System center of mass (COM) velocity and power were computed from GRF data. COM power was maximized across a range of resistances from 40% to 60% 1RM. This range was identified because a trade-off in hip and knee joint powers existed across this range, with maximal knee joint power occurring at 40% 1RM and maximal hip joint power at 60% 1RM. A non-linear system force-velocity relationship was observed that dictated large reductions in COM power below 20% 1RM and above 60% 1RM. These reductions were due to constraints on the control of the movement. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of pre-contact joint kinematics and vertical impulse between vertical jump landings and step-off landings from equal heights.

PubMed

Harry, John R; Freedman Silvernail, Julia; Mercer, John A; Dufek, Janet S

2017-12-01

Although impact phase differences between vertical jump landings (VJL) and step-off landings (STL) may be related to task-specific pre-contact strategies, pre-contact mechanics are rarely examined. Thus, pre-contact kinematics and vertical ground reaction force (vGRF) impulse were examined between VJL and STL. Ten health adults (20.9 ± 1.6 yrs; 167.8 ± 4.2 cm; 68.5 ± 7.15 kg) performed 15 VJL and 15 STL from equal heights. Limb (lead; trail) by task (VJL; STL) ANOVAs (α = 0.05) compared hip, knee, and ankle joint angles 150 ms pre-contact, 100 ms pre-contact, 50 ms pre-contact, and at ground contact. Joint angular displacement was also evaluated between 150 ms pre-contact and ground contact. vGRF impulse was compared during the loading (ground contact to peak vGRF) and attenuation (peak vGRF to end of impact) phases. Greater hip flexion angles occurred during STL versus VJL at each event except 150 ms pre-contact (p ≤ .004). Trail limb knee flexion angles were greater at each event when compared to the lead limb during STL (p ≤ .019). Greater trail limb knee flexion angles occurred during STL versus VJL at all four events (p ≤ .018), while greater plantarflexion angles occurred at all four events during VJL versus STL (p ≤ .034). During STL, greater trail limb plantarflexion angles were detected at each event versus the lead limb (p < .001). Lesser hip, lead and trail limb knee displacement occurred during STL versus VJL (p < .05). Greater vGRF impulse was detected during the loading phase of VJL (<.001), while greater vGRF impulse occurred during the attenuation phase of STL (p = .025). These tasks are characterized by distinct pre-contact kinematic strategies and post-contact kinetics. The task utilized in practice should reflect the requirements of the population of interest. Copyright © 2017 Elsevier B.V. All rights reserved.

Kinetic measurements of gait for osteoarthritis research in dogs and cats

PubMed Central

Moreau, Maxim; Lussier, Bertrand; Ballaz, Laurent; Troncy, Eric

2014-01-01

Over the past 2 decades the measurement of ground reaction forces (GRF) has been extensively used in dogs and cats to gain insights on normal locomotion, discrepancies under pathologic conditions, and biomechanical changes following surgical procedures. Ground reaction forces have become a well-established outcome measure of pain-related functional impairment in animals affected by experimental and naturally occurring osteoarthritis. This paper comprehensively reviews the nature of GRF and presents arguments regarding its measurement in osteoarthritis research. PMID:25392548

Advances in pubertal growth and factors influencing it: Can we increase pubertal growth?

PubMed Central

Soliman, Ashraf; De Sanctis, Vincenzo; Elalaily, Rania; Bedair, Said

2014-01-01

Puberty is a period of development characterized by partially concurrent changes which includes growth acceleration, alteration in body composition and appearance of secondary sex characteristics. Puberty is characterized by an acceleration and then deceleration in skeletal growth. The initiation, duration and amount of growth vary considerably during the growth spurt. Pubertal growth and biological maturation are dynamic processes regulated by a variety of genetic and environmental factors. Changes in skeletal maturation and bone mineral accretion concomitant with the stage of pubertal development constitute essential components in the evaluation of growth during this pubertal period. Genetic, endocrine and nutritional factors and ethnicity contribute variably to the amount of growth gained during this important period of rapid changes. Many studies investigated the possibility of increasing pubertal growth to gain taller final adult height in adolescents with idiopathic short stature (ISS). The pattern of pubertal growth, its relation to sex maturity rating and factors affecting them has been addressed in this review. The results of different trials to increase final adult height of adolescents using different hormones have been summarized. These data enables Endocrinologists to give in-depth explanations to patients and families about the efficacy and clinical significance as well as the safety of using these therapies in the treatment of adolescents with ISS. PMID:25538878

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion

PubMed Central

Gorin, Caroline; Rochefort, Gael Y.; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Germain, Stéphane

2016-01-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. Significance The results from the present study show that fibroblast growth factor-2 (FGF-2) priming is more

Ground Reaction Force and Mechanical Differences Between the Interim Resistive Exercise Device (iRED) and Smith Machine While Performing a Squat

NASA Technical Reports Server (NTRS)

Amonette, William E.; Bentley, Jason R.; Lee, Stuart M. C.; Loehr, James A.; Schneider, Suzanne

2004-01-01

Musculoskeletal unloading in microgravity has been shown to induce losses in bone mineral density, muscle cross-sectional area, and muscle strength. Currently, an Interim Resistive Exercise Device (iRED) is being flown on board the ISS to help counteract these losses. Free weight training has shown successful positive musculoskeletal adaptations. In biomechanical research, ground reaction forces (GRF) trajectories are used to define differences between exercise devices. The purpose of this evaluation is to quantify the differences in GRF between the iRED and free weight exercise performed on a Smith machine during a squat. Due to the differences in resistance properties, inertial loading and load application to the body between the two devices, we hypothesize that subjects using iRED will produce GRF that are significantly different from the Smith machine. There will be differences in bar/harness range of motion and the time when peak GRF occurred in the ROMbar. Three male subjects performed three sets of ten squats on the iRED and on the Smith Machine on two separate days at a 2-second cadence. Statistically significant differences were found between the two devices in all measured GRF variables. Average Fz and Fx during the Smith machine squat were significantly higher than iRED. Average Fy (16.82 plus or minus.23; p less than .043) was significantly lower during the Smith machine squat. The mean descent/ascent ratio of the magnitude of the resultant force vector of all three axes for the Smith machine and iRED was 0.95 and 0.72, respectively. Also, the point at which maximum Fz occurred in the range of motion (Dzpeak) was at different locations with the two devices.

Assessing postural stability via the correlation patterns of vertical ground reaction force components.

PubMed

Hong, Chih-Yuan; Guo, Lan-Yuen; Song, Rong; Nagurka, Mark L; Sung, Jia-Li; Yen, Chen-Wen

2016-08-02

Many methods have been proposed to assess the stability of human postural balance by using a force plate. While most of these approaches characterize postural stability by extracting features from the trajectory of the center of pressure (COP), this work develops stability measures derived from components of the ground reaction force (GRF). In comparison with previous GRF-based approaches that extract stability features from the GRF resultant force, this study proposes three feature sets derived from the correlation patterns among the vertical GRF (VGRF) components. The first and second feature sets quantitatively assess the strength and changing speed of the correlation patterns, respectively. The third feature set is used to quantify the stabilizing effect of the GRF coordination patterns on the COP. In addition to experimentally demonstrating the reliability of the proposed features, the efficacy of the proposed features has also been tested by using them to classify two age groups (18-24 and 65-73 years) in quiet standing. The experimental results show that the proposed features are considerably more sensitive to aging than one of the most effective conventional COP features and two recently proposed COM features. By extracting information from the correlation patterns of the VGRF components, this study proposes three sets of features to assess human postural stability during quiet standing. As demonstrated by the experimental results, the proposed features are not only robust to inter-trial variability but also more accurate than the tested COP and COM features in classifying the older and younger age groups. An additional advantage of the proposed approach is that it reduces the force sensing requirement from 3D to 1D, substantially reducing the cost of the force plate measurement system.

QTL-seq for rapid identification of candidate genes for flowering time in broccoli × cabbage.

PubMed

Shu, Jinshuai; Liu, Yumei; Zhang, Lili; Li, Zhansheng; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao

2018-04-01

A major QTL controlling early flowering in broccoli × cabbage was identified by marker analysis and next-generation sequencing, corresponding to GRF6 gene conditioning flowering time in Arabidopsis. Flowering is an important agronomic trait for hybrid production in broccoli and cabbage, but the genetic mechanism underlying this process is unknown. In this study, segregation analysis with BC 1 P1, BC 1 P2, F 2 , and F 2:3 populations derived from a cross between two inbred lines "195" (late-flowering) and "93219" (early flowering) suggested that flowering time is a quantitative trait. Next, employing a next-generation sequencing-based whole-genome QTL-seq strategy, we identified a major genomic region harboring a robust flowering time QTL using an F 2 mapping population, designated Ef2.1 on cabbage chromosome 2 for early flowering. Ef2.1 was further validated by indel (insertion or deletion) marker-based classical QTL mapping, explaining 51.5% (LOD = 37.67) and 54.0% (LOD = 40.5) of the phenotypic variation in F 2 and F 2:3 populations, respectively. Combined QTL-seq and classical QTL analysis narrowed down Ef1.1 to a 228-kb genomic region containing 29 genes. A cabbage gene, Bol024659, was identified in this region, which is a homolog of GRF6, a major gene regulating flowering in Arabidopsis, and was designated BolGRF6. qRT-PCR study of the expression level of BolGRF6 revealed significantly higher expression in the early flowering genotypes. Taken together, our results provide support for BolGRF6 as a possible candidate gene for early flowering in the broccoli line 93219. The identified candidate genomic regions and genes may be useful for molecular breeding to improve broccoli and cabbage flowering times.

Dynamic load indicators for take-off-landing sequence in blocks and attacks of elite female volleyball players.

PubMed

Kabaciński, Jarosław; Dworak, Lechosław Bogdan; Murawa, Michał; Rzepnicka, Agata

2016-01-01

Dynamic loads during landings determined by the ground reaction forces (GRFs) may elaborate internal loads and increase the risk of overload knee injuries as a result of performing volleyball jumps many times. The study dealt with a biomechanical assessment of dynamic load indicators in female volleyball players for the motion sequence of take-off-landing in blocks and attacks. Twelve professional female volleyball players participated in the study. Blocks and attacks were filmed by two cameras. GRFs vs. time graphs were recorded with the use of a force platform. Values of dynamic load indicators in terms of the relations of peak of vertical component of GRF, build-up index of this force (BIF), and power output (P) during landing to the vGRF, BIF and P during take-off (L/T) were calculated. The statistically significant ( p < 0.05) highest values of L/T indicators were found for back row attack spikes: 2.4 (vGRF), 12.2 (BIF) and 3.1 (P). In the case of blocks, slide attack spikes and attack line spikes, results of these variables were in range: 1.8÷2.1, 5.9÷7.6 and 2.1÷2.9, respectively. The reduction of GRFs during landings contributes to decreasing the level of the load indicators L/T which should minimize the incidence of anterior cruciate ligament and patellar tendon injuries in female volleyball players.

The redox protein thioredoxin-1 (Trx-1) increases hypoxia-inducible factor 1alpha protein expression: Trx-1 overexpression results in increased vascular endothelial growth factor production and enhanced tumor angiogenesis.

PubMed

Welsh, Sarah J; Bellamy, William T; Briehl, Margaret M; Powis, Garth

2002-09-01

Hypoxia-inducible factor 1 (HIF-1), a heterodimer of HIF-1alpha and HIF-1beta subunits, is a transcriptional activator central to the cellular response to low oxygen that includes metabolic adaptation, angiogenesis, metastasis, and inhibited apoptosis. Thioredoxin-1 (Trx-1) is a small redox protein overexpressed in a number of human primary tumors. We have examined the effects of Trx-1 on HIF activity and the activation of downstream genes. Stable transfection of human breast carcinoma MCF-7 cells with human Trx-1 caused a significant increase in HIF-1alpha protein levels under both normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. Trx-1 increased hypoxia-induced HIF-1 transactivation activity measured using a luciferase reporter under the control of the hypoxia response element. Changes in HIF-1alpha mRNA levels did not account for the changes observed at the protein level, and HIF-1beta protein levels did not change. Trx-1 transfection also caused a significant increase in the protein products of hypoxia-responsive genes, including vascular endothelial growth factor (VEGF) and nitric oxide synthase 2 in a number of different cell lines (MCF-7 human breast and HT29 human colon carcinomas and WEHI7.2 mouse lymphoma cells) under both normoxic and hypoxic conditions. The pattern of expression of the different isoforms of VEGF was not changed by Trx-1. Transfection of a redox-inactive Trx-1 (C32S/C35S) markedly decreased levels of HIF-1alpha protein, HIF-1 transactivating activity, and VEGF protein in MCF-7 cells compared with empty vector controls. In vivo studies using WEHI7.2 cells transfected with Trx-1 showed significantly increased tumor VEGF and angiogenesis. The results suggest that Trx-1 increases HIF-1alpha protein levels in cancer cells and increases VEGF production and tumor angiogenesis.

Correlation between increasing tissue ischemia and circulating levels of angiogenic growth factors in peripheral artery disease.

PubMed

Jalkanen, Juho; Hautero, Olli; Maksimow, Mikael; Jalkanen, Sirpa; Hakovirta, Harri

2018-04-21

The aim of the present study was to assess the circulating levels of vascular endothelial growth factor (VEGF) and other suggested therapeutic growth factors with the degree of ischemia in patients with different clinical manifestations of peripheral arterial disease (PAD) according to the Rutherford grades. The study cohort consists of 226 consecutive patients admitted to a Department of Vascular Surgery for elective invasive procedures. PAD patients were grouped according to the Rutherford grades after a clinical assessment. Ankle-brachial pressure indices (ABI) and absolute toe pressure (TP) values were measured. Serum levels of circulating VEGF, hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF) were measured from serum and analysed against Rutherford grades and peripheral hemodynamic measurements. The levels of VEGF (P = 0.009) and HGF (P < 0.001) increased significantly as the ischaemic burden became more severe according to the Rutherford grades. PDGF behaved in opposite manner and declined along increasing Rutherford grades (P = 0.004). A significant, inverse correlations between Rutherford grades was detected as follows; VEGF (Pearson's correlation = 0.183, P = 0.004), HGF (Pearson's correlation = 0.253, P < 0.001), bFGF (Pearson's correlation = 0.169, P = 0.008) and PDGF (Pearson's correlation = 0.296, P < 0.001). In addition, VEGF had a clear direct negative correlation with ABI (Pearson's correlation -0.19, P = 0.009) and TP (Pearson's correlation -0.20, P = 0.005) measurements. Our present observations show that the circulating levels of VEGF and other suggested therapeutic growth factors are significantly increased along with increasing ischemia. These findings present a new perspective to anticipated positive effects of gene therapies utilizing VEGF, HGF, and bFGF, because the levels of these growth factors are endogenously high in end

Factors Associated with Increased Risk for Lethal Violence in Intimate Partner Relationships among Ethnically Diverse Black Women

PubMed Central

Sabri, Bushra; Stockman, Jamila K.; Campbell, Jacquelyn C.; O’Brien, Sharon; Campbell, Doris; Callwood, Gloria B.; Bertrand, Desiree; Sutton, Lorna W.; Hart-Hyndman, Greta

2014-01-01

The purpose of this study was to identify factors associated with increased risk for lethal violence among ethnically diverse Black women in Baltimore, Maryland (MD) and the US Virgin Islands (USVI). Women with abuse experiences (n=456) were recruited from primary care, prenatal or family planning clinics in Baltimore, MD and St. Thomas and St. Croix, USVI. Logistic regression was used to examine factors associated with the risk for lethal violence among abused women. Factors independently related to increased risk of lethal violence included fear of abusive partners, PTSD symptoms, and use of legal resources. These factors must be considered in assessing safety needs of Black women in abusive relationships. PMID:25429191

Hippocampal brain-derived neurotrophic factor but not neurotrophin-3 increases more in mice selected for increased voluntary wheel running.

PubMed

Johnson, R A; Rhodes, J S; Jeffrey, S L; Garland, T; Mitchell, G S

2003-01-01

Voluntary wheel running in rats increases hippocampal brain-derived neurotrophic factor (BDNF) expression, a neurochemical important for neuronal survival, differentiation, connectivity and synaptic plasticity. Here, we report the effects of wheel running on BDNF and neurotrophin-3 (NT-3) protein levels in normal control mice, and in mice selectively bred (25 generations) for increased voluntary wheel running. We hypothesized that increased voluntary wheel running in selected (S) mice would increase CNS BDNF and NT-3 protein levels more than in control (C) mice. Baseline hippocampal BDNF levels (mice housed without running wheels) were similar in S and C mice. Following seven nights of running, hippocampal BDNF increased significantly more in S versus C mice, and levels were correlated with distance run (considering C and S mice together). Spinal and cerebellar BDNF and hippocampal NT-3 levels were not significantly affected by wheel running in any group, but there was a small, positive correlation between spinal C3-C6 BDNF levels and distance run (considering C and S mice together). This is the first study to demonstrate that mice which choose to run more have greater elevations in hippocampal BDNF, suggesting enhanced potential for exercise-induced hippocampal neuroplasticity.

Variability of a "force signature" during windmill softball pitching and relationship between discrete force variables and pitch velocity.

PubMed

Nimphius, Sophia; McGuigan, Michael R; Suchomel, Timothy J; Newton, Robert U

2016-06-01

This study assessed reliability of discrete ground reaction force (GRF) variables over multiple pitching trials, investigated the relationships between discrete GRF variables and pitch velocity (PV) and assessed the variability of the "force signature" or continuous force-time curve during the pitching motion of windmill softball pitchers. Intraclass correlation coefficient (ICC) for all discrete variables was high (0.86-0.99) while the coefficient of variance (CV) was low (1.4-5.2%). Two discrete variables were significantly correlated to PV; second vertical peak force (r(5)=0.81, p=0.03) and time between peak forces (r(5)=-0.79; p=0.03). High ICCs and low CVs support the reliability of discrete GRF and PV variables over multiple trials and significant correlations indicate there is a relationship between the ability to produce force and the timing of this force production with PV. The mean of all pitchers' curve-average standard deviation of their continuous force-time curves demonstrated low variability (CV=4.4%) indicating a repeatable and identifiable "force signature" pattern during this motion. As such, the continuous force-time curve in addition to discrete GRF variables should be examined in future research as a potential method to monitor or explain changes in pitching performance. Copyright © 2016 Elsevier B.V. All rights reserved.

Different Modes of Feedback and Peak Vertical Ground Reaction Force During Jump Landing: A Systematic Review

PubMed Central

Ericksen, Hayley M.; Gribble, Phillip A.; Pfile, Kate R.; Pietrosimone, Brian G.

2013-01-01

Context: Excessive ground reaction force when landing from a jump may result in lower extremity injuries. It is important to better understand how feedback can influence ground reaction force (GRF) and potentially reduce injury risk. Objective: To determine the effect of expert-provided (EP), self-analysis (SA), and combination EP and SA (combo) feedback on reducing peak vertical GRF during a jump-landing task. Data Sources: We searched the Web of Science database on July 1, 2011; using the search terms ground reaction force, landing biomechanics, and feedback elicited 731 initial hits. Study Selection: Of the 731 initial hits, our final analysis included 7 studies that incorporated 32 separate data comparisons. Data Extraction: Standardized effect sizes and 95% confidence intervals (CIs) were calculated between pretest and posttest scores for each feedback condition. Data Synthesis: We found a homogeneous beneficial effect for combo feedback, indicating a reduction in GRF with no CIs crossing zero. We also found a homogeneous beneficial effect for EP feedback, but the CIs from 4 of the 10 data comparisons crossed zero. The SA feedback showed strong, definitive effects when the intervention included a videotape SA, with no CIs crossing zero. Conclusions: Of the 7 studies reviewed, combo feedback seemed to produce the greatest decrease in peak vertical GRF during a jump-landing task. PMID:24067153

Parenting Moderates a Genetic Vulnerability Factor in Longitudinal Increases in Youths' Substance Use

ERIC Educational Resources Information Center

Brody, Gene H.; Beach, Steven R. H.; Philibert, Robert A.; Chen, Yi-fu; Lei, Man-Kit; Murry, Velma McBride; Brown, Anita C.

2009-01-01

The authors used a longitudinal, prospective design to investigate a moderation effect in the association between a genetic vulnerability factor, a variable nucleotide repeat polymorphism in the promoter region of "5HTT" (5-HTTLPR), and increases in youths' substance use. The primary study hypothesis predicted that involved-supportive…

Worldwide C-17 Availability to Support 82nd Airborne Operations from Fort Bragg/Pope Field

DTIC Science & Technology

2016-11-06

a high probability those planes could be made available barring other demands on the force. A major assumption in this report is that GRF support is...of C-17 airdrop crew availability to support a no-notice GRF tasking in 96 hours. That analysis showed that there is a very high likelihood that 27... availability was below 70 airplanes at some times and as high as 126 airplanes at others. Interpreting the Heatmap Using the heatmap in Figure 4.1

Impact Factors Show Increased Use of AGU Journals in 2008

NASA Astrophysics Data System (ADS)

Ford, Barbara Meyers

2009-07-01

The latest numbers released from Journal Citation Reports (JCR), published annually by Thomson Reuters, show large increases in the impact factor (IF) for several AGU journals. IFs are one way for publishers to know that readers have found their journals useful and of value in research. A journal's IF is calculated by taking the total number of citations to articles published by a given journal in the past 2 years and dividing it by the total number of papers published by the journal in the same time period. More generally, it can be seen as the frequency with which articles in a journal have been cited over the past year. The numbers speak for themselves (see Table 1).

Recombinant factor concentrates may increase inhibitor development: a single centre cohort study.

PubMed

Strauss, T; Lubetsky, A; Ravid, B; Bashari, D; Luboshitz, J; Lalezari, S; Misgav, M; Martinowitz, U; Kenet, G

2011-07-01

Recent reports have raised concerns regarding potential risk factors for inhibitor development. In Israel, all haemophilia patients (n = 479) are followed by the National Hemophilia Center. Most children are neonatally exposed to factor concentrate (due to circumcision performed at the age of 8 days). The impact of early exposure and recombinant FVIII products (rFVIII) administration (approved in Israel since 1996) upon inhibitor occurrence in our cohort of haemophilia A (HA) patients was analysed. Two hundred ninety-two consecutive paediatric cases with a first symptomatic onset of HA were enrolled and followed over a median time of 7 years [min-max: 9 months to 17 years]. Study endpoint was inhibitor development against factor VIII. In addition, the treatment regimens applied, i.e. bolus administration or 'continuous infusion' and the family history of inhibitor development were investigated. During the follow-up period 31/292 children (10.6%) developed high titre inhibitors. Inhibitors occurred in 14/43 (32.5%) HA patients neonatally exposed to rFVIII, as compared to 22/249 previously treated with Plasma Derived (PD) products (8.8%). The odds ratio for inhibitor formation in rFVIII treated HA patients was 3.43 (95% CI: 1.36-8.65). Transient inhibitor evolved among 2/43 paediatric HA patients, only among those treated with rFVIII. The risk of inhibitor detection significantly increased among HA children treated by continuous infusion (P = 0.025). Our experience shows that the risk of inhibitor formation may be increased by early exposure to recombinant concentrates. The multiple variables affecting inhibitor incidence deserve further attention by larger prospective studies. © 2011 Blackwell Publishing Ltd.

Hydrogen Peroxide-Reducing Factor Released by PC12D Cells Increases Cell Tolerance against Oxidative Stress.

PubMed

Muraishi, Asami; Haneta, Emi; Saito, Yoshiro; Hitomi, Yutaka; Sano, Mamoru; Noguchi, Noriko

2018-01-01

PC12D cells, a subline of rat adrenal pheochromocytoma PC12 cells, extend neurites rapidly in response to differentiation stimuli and are used to investigate the molecular mechanisms of neurite extension. In the present study, we found significant tolerance of PC12D cells against Parkinson's disease-related stimuli such as dopamine and 6-hydroxydopamine; this tolerance was significantly decreased by a change in the medium. Conditioned medium from PC12D cells induced tolerance against oxidative stress, which suggests that cytoprotective factor may be released by PC12D cells into the culture medium. Conditioned medium-induced tolerance was not found for PC12 cells or human neuroblastoma SH-SY5Y cells. A cytoprotective factor generated by PC12D cells exhibited hydrogen peroxide-reducing activity. Chemical characterization showed that this cytoprotective factor is water soluble and has a molecular weight about 1000 Da, and that its activity is inhibited by sodium cyanide. Release of this cytoprotective factor was increased by differentiation stimuli and oxidative stress. Taken together, these results suggest that release of a hydrogen peroxide-reducing factor by PC12D cells increases cell tolerance against oxidative stress. This study provides new insights into the antioxidative properties of factors in extracellular fluid.

Vaccine to fibroblast growth factor 23 peptides increases eggshell strength.

PubMed

Ren, Z Z; Piepenburg, A J; Bütz, D E; Claus, J R; Cook, M E

2018-03-01

Strategies that would increase eggshell quality could be of considerable value to egg producers. This research demonstrated the effective use of fibroblast growth factor 23 (FGF-23) peptide vaccines to increase eggshell quality of Single Comb White Leghorn laying hens (from 69 to 72 wk of age). Hens, fed a standard diet (containing 900 IU/kg vitamin D3), were intramuscularly injected (and boosted) with either a control vaccine (n = 14 hens) or one of 2 FGF-23 peptide vaccines (peptides NP1, GMNPPPYS; and NP7, YTSTERNSFH; n = 15 hens for each peptide). During peak antibody titer, eggs were collected for shell and internal quality analysis, hens were artificially inseminated, and the hatchability of fertilized eggs was determined. Laying hens vaccinated with either FGF-23 peptide NP1 or NP7 had increased (P < 0.05) plasma phosphate level (mmol/L; NP1 = 1.74, NP7 = 1.76, control = 1.47), egg specific gravity (NP1 = 1.083, NP7 = 1.083, control = 1.079), and eggshell strength (g of force; NP1 = 4002, NP7 = 4157, control = 3102) when compared to control vaccinated hens. FGF-23 peptide NP1 vaccinated hens also had increased eggshell thickness (mm, P < 0.001), shell weight (g, P = 0.032), and shell index (% of whole egg, P = 0.023) when compared to control vaccinated hens. FGF-23 peptide NP7 vaccinated hens tended to have decreased eggshell weight (P = 0.064) when compared to control vaccinated hens. Hatchability of fertilized eggs was not affected in incubations 1 and 3, but tended to be decreased (P = 0.097) by FGF-23 peptide NP1 vaccination in incubation 2. In conclusion, vaccines to FGF-23 peptides increased eggshell quality of laying hens with minimal adverse effects on egg internal quality. The effect of FGF-23 peptide vaccination on hatchability remains to be clarified.

The influence of speed and size on avian terrestrial locomotor biomechanics: Predicting locomotion in extinct theropod dinosaurs.

PubMed

Bishop, P J; Graham, D F; Lamas, L P; Hutchinson, J R; Rubenson, J; Hancock, J A; Wilson, R S; Hocknull, S A; Barrett, R S; Lloyd, D G; Clemente, C J

2018-01-01

How extinct, non-avian theropod dinosaurs moved is a subject of considerable interest and controversy. A better understanding of non-avian theropod locomotion can be achieved by better understanding terrestrial locomotor biomechanics in their modern descendants, birds. Despite much research on the subject, avian terrestrial locomotion remains little explored in regards to how kinematic and kinetic factors vary together with speed and body size. Here, terrestrial locomotion was investigated in twelve species of ground-dwelling bird, spanning a 1,780-fold range in body mass, across almost their entire speed range. Particular attention was devoted to the ground reaction force (GRF), the force that the feet exert upon the ground. Comparable data for the only other extant obligate, striding biped, humans, were also collected and studied. In birds, all kinematic and kinetic parameters examined changed continuously with increasing speed, while in humans all but one of those same parameters changed abruptly at the walk-run transition. This result supports previous studies that show birds to have a highly continuous locomotor repertoire compared to humans, where discrete 'walking' and 'running' gaits are not easily distinguished based on kinematic patterns alone. The influences of speed and body size on kinematic and kinetic factors in birds are developed into a set of predictive relationships that may be applied to extinct, non-avian theropods. The resulting predictive model is able to explain 79-93% of the observed variation in kinematics and 69-83% of the observed variation in GRFs, and also performs well in extrapolation tests. However, this study also found that the location of the whole-body centre of mass may exert an important influence on the nature of the GRF, and hence some caution is warranted, in lieu of further investigation.

The influence of speed and size on avian terrestrial locomotor biomechanics: Predicting locomotion in extinct theropod dinosaurs

PubMed Central

Graham, D. F.; Lamas, L. P.; Hutchinson, J. R.; Rubenson, J.; Hancock, J. A.; Wilson, R. S.; Hocknull, S. A.; Barrett, R. S.; Lloyd, D. G.; Clemente, C. J.

2018-01-01

How extinct, non-avian theropod dinosaurs moved is a subject of considerable interest and controversy. A better understanding of non-avian theropod locomotion can be achieved by better understanding terrestrial locomotor biomechanics in their modern descendants, birds. Despite much research on the subject, avian terrestrial locomotion remains little explored in regards to how kinematic and kinetic factors vary together with speed and body size. Here, terrestrial locomotion was investigated in twelve species of ground-dwelling bird, spanning a 1,780-fold range in body mass, across almost their entire speed range. Particular attention was devoted to the ground reaction force (GRF), the force that the feet exert upon the ground. Comparable data for the only other extant obligate, striding biped, humans, were also collected and studied. In birds, all kinematic and kinetic parameters examined changed continuously with increasing speed, while in humans all but one of those same parameters changed abruptly at the walk-run transition. This result supports previous studies that show birds to have a highly continuous locomotor repertoire compared to humans, where discrete ‘walking’ and ‘running’ gaits are not easily distinguished based on kinematic patterns alone. The influences of speed and body size on kinematic and kinetic factors in birds are developed into a set of predictive relationships that may be applied to extinct, non-avian theropods. The resulting predictive model is able to explain 79–93% of the observed variation in kinematics and 69–83% of the observed variation in GRFs, and also performs well in extrapolation tests. However, this study also found that the location of the whole-body centre of mass may exert an important influence on the nature of the GRF, and hence some caution is warranted, in lieu of further investigation. PMID:29466362

Anisotropic Failure Strength of Shale with Increasing Confinement: Behaviors, Factors and Mechanism

PubMed Central

Cheng, Cheng; Li, Xiao; Qian, Haitao

2017-01-01

Some studies reported that the anisotropic failure strength of shale will be weakened by increasing confinement. In this paper, it is found that there are various types of anisotropic strength behaviors. Four types of anisotropic strength ratio (SA1) behaviors and three types of anisotropic strength difference (SA2) behaviors have been classified based on laboratory experiments on nine groups of different shale samples. The cohesion cw and friction angle ϕw of the weak planes are proven to be two dominant factors according to a series of bonded-particle discrete element modelling analyses. It is observed that shale is more prone to a slight increase of SA1 and significant increase of SA2 with increasing confinement for higher cohesion cw and lower to medium friction angle ϕw. This study also investigated the mechanism of the anisotropic strength behaviors with increasing confinement. Owing to different contributions of cw and ϕw under different confinements, different combinations of cw and ϕw may have various types of influences on the minimum failure strength with the increasing confinement; therefore, different types of anisotropic behaviors occur for different shale specimens as the confinement increases. These findings are very important to understand the stability of wellbore and underground tunneling in the shale rock mass, and should be helpful for further studies on hydraulic fracture propagations in the shale reservoir. PMID:29140292

The Effect of Manipulating Subject Mass on Lower Extremity Torque Patterns During Locomotion

NASA Technical Reports Server (NTRS)

DeWitt, John K.; Cromwell, Ronita L.; Hagan, R. Donald

2007-01-01

During locomotion, humans adapt their motor patterns to maintain coordination despite changing conditions (Reisman et al., 2005). Bernstein (1967) proposed that in addition to the present state of a given joint, other factors, including limb inertia and velocity, must be taken into account to allow proper motion to occur. During locomotion with added mass counterbalanced using vertical suspension to maintain body weight, vertical ground reaction forces (GRF's) increase during walking but decrease during running, suggesting that adaptation may be velocity-specific (De Witt et al., 2006). It is not known, however, how lower extremity joint torques adapt to changes in inertial forces. The purpose of this investigation was to examine the effects of increasing body mass while maintaining body weight upon lower-limb joint torque during walking and running. We hypothesized that adaptations in joint torque patterns would occur with the addition of body mass.

Adverse factors increase preeclampsia-like changes in pregnant mice with abnormal lipid metabolism.

PubMed

Ding, Xiaoyan; Yang, Zi; Han, Yiwei; Yu, Huan

2014-01-01

Preeclampsia (PE) is a multifactorial pregnancy complication. Maternal underlying condition and adverse factors both influence the pathogenesis of PE. Abnormal lipid metabolism as a maternal underlying disease may participate in the occurrence and development of PE. This study aimed to observe the effects of adverse factors on PE-like symptoms of pregnant mice with genetic abnormal lipid metabolism. Apolipoprotein C-III (ApoC3) transgenic mice with abnormal lipid metabolism were subcutaneously injected with L-arginine methyl ester (L-NAME) or normal saline (NS) daily starting at Day 7 or 16 of pregnancy (ApoC3+L-NA and ApoC3+NS groups), and wild-type (WT) mice served as a control (WT+L-NA and WT+NS groups). All mice were subdivided into early and late subgroups by injection time. The mean arterial pressure (MAP) and urinary protein were measured. Pregnancy outcomes, including fetal weight, placental weight, live birth rate, and fetal absorption rate, were analyzed. Pathologic changes in the placenta were observed by hematoxylin-eosin staining. One-way analysis of variance, t-test, and χ(2) test were used for statistical analysis. MAP significantly increased for ApoC3+NS groups compared with WT+NS groups (P < 0.05), without significant difference in urine protein. Following L-NAME injection, MAP and urinary protein significantly increased for ApoC3+L-NA and WT+L-NA compared with the corresponding NS groups (P < 0.05), and the increase for ApoC3+L-NA was more obvious. Urinary protein levels in early ApoC3+L-NA and WT+L-NA significantly increased compared with the corresponding late groups (P < 0.05). Fetal absorption rate significantly increased and fetal and placental weights significantly decreased in early ApoC3+L-NA and WT+L-NA compared with the corresponding NS groups (P < 0.05), without significant difference in late ApoC3+L-NA and WT+L-NA groups. Fetal weight in early ApoC3+L-NA was significantly lower than in early WT+L-NA group (P < 0.05). Morphologic

Kinetic comparison of walking on a treadmill versus over ground in children with cerebral palsy.

PubMed

van der Krogt, Marjolein M; Sloot, Lizeth H; Buizer, Annemieke I; Harlaar, Jaap

2015-10-15

Kinetic outcomes are an essential part of clinical gait analysis, and can be collected for many consecutive strides using instrumented treadmills. However, the validity of treadmill kinetic outcomes has not been demonstrated for children with cerebral palsy (CP). In this study we compared ground reaction forces (GRF), center of pressure, and hip, knee and ankle moments, powers and work, between overground (OG) and self-paced treadmill (TM) walking for 11 typically developing (TD) children and 9 children with spastic CP. Considerable differences were found in several outcome parameters. In TM, subjects demonstrated lower ankle power generation and more absorption, and increased hip moments and work. This shift from ankle to hip strategy was likely due to a more backward positioning of the hip and a slightly more forward trunk lean. In mediolateral direction, GRF and hip and knee joint moments were increased in TM due to wider step width. These findings indicate that kinetic data collected on a TM cannot be readily compared with OG data in TD children and children with CP, and that treadmill-specific normative data sets should be used when performing kinetic gait analysis on a treadmill. Copyright © 2015 Elsevier Ltd. All rights reserved.

6-Gingerol-Rich Fraction from Zingiber officinale Prevents Hematotoxicity and Oxidative Damage in Kidney and Liver of Rats Exposed to Carbendazim.

PubMed

Salihu, Mariama; Ajayi, Babajide O; Adedara, Isaac A; Farombi, Ebenezer O

2016-01-01

Ginger (Zingiber officinale) is a globally marketed flavoring agent and cooking spice with a long history of human health benefits. The fungicide carbendazim (CBZ) is often detected in fruits and vegetables for human nutrition and has been reported to elicit toxic effects in different experimental animal models. The present study investigated the protective effects of 6-Gingerol-rich fraction (6-GRF) from ginger on hematotoxicity and hepatorenal damage in rats exposed to CBZ. CBZ was administered at a dose of 50 mg/kg alone or simultaneously administered with 6-GRF at 50, 100, and 200 mg/kg, whereas control rats received corn oil alone at 2 mL/kg for 14 days. Hematological examination showed that CBZ-mediated toxicity to the total white blood cell (WBC), neutrophils, lymphocytes, and platelets counts were normalized to the control values in rats cotreated with 6-GRF. Moreover, administration of CBZ significantly decreased the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase as well as glutathione level in the livers and kidneys of rats compared with control. However, the levels of hydrogen peroxide (H2O2) and malondialdehyde were markedly elevated in kidneys and livers of CBZ-treated rats compared with control. The significant elevation in the plasma indices of renal and hepatic dysfunction in CBZ-treated rats was confirmed by light microscopy. Coadministration of 6-GRF exhibited chemoprotection against CBZ-mediated hematotoxicity, augmented antioxidant status, and prevented oxidative damage in the kidney and liver of rats.

The strengths and weaknesses of inverted pendulum models of human walking.

PubMed

McGrath, Michael; Howard, David; Baker, Richard

2015-02-01

An investigation into the kinematic and kinetic predictions of two "inverted pendulum" (IP) models of gait was undertaken. The first model consisted of a single leg, with anthropometrically correct mass and moment of inertia, and a point mass at the hip representing the rest of the body. A second model incorporating the physiological extension of a head-arms-trunk (HAT) segment, held upright by an actuated hip moment, was developed for comparison. Simulations were performed, using both models, and quantitatively compared with empirical gait data. There was little difference between the two models' predictions of kinematics and ground reaction force (GRF). The models agreed well with empirical data through mid-stance (20-40% of the gait cycle) suggesting that IP models adequately simulate this phase (mean error less than one standard deviation). IP models are not cyclic, however, and cannot adequately simulate double support and step-to-step transition. This is because the forces under both legs augment each other during double support to increase the vertical GRF. The incorporation of an actuated hip joint was the most novel change and added a new dimension to the classic IP model. The hip moment curve produced was similar to those measured during experimental walking trials. As a result, it was interpreted that the primary role of the hip musculature in stance is to keep the HAT upright. Careful consideration of the differences between the models throws light on what the different terms within the GRF equation truly represent. Copyright © 2014 Elsevier B.V. All rights reserved.

Multi-segment foot kinematics and ground reaction forces during gait of individuals with plantar fasciitis.

PubMed

Chang, Ryan; Rodrigues, Pedro A; Van Emmerik, Richard E A; Hamill, Joseph

2014-08-22

Clinically, plantar fasciitis (PF) is believed to be a result and/or prolonged by overpronation and excessive loading, but there is little biomechanical data to support this assertion. The purpose of this study was to determine the differences between healthy individuals and those with PF in (1) rearfoot motion, (2) medial forefoot motion, (3) first metatarsal phalangeal joint (FMPJ) motion, and (4) ground reaction forces (GRF). We recruited healthy (n=22) and chronic PF individuals (n=22, symptomatic over three months) of similar age, height, weight, and foot shape (p>0.05). Retro-reflective skin markers were fixed according to a multi-segment foot and shank model. Ground reaction forces and three dimensional kinematics of the shank, rearfoot, medial forefoot, and hallux segment were captured as individuals walked at 1.35 ms(-1). Despite similarities in foot anthropometrics, when compared to healthy individuals, individuals with PF exhibited significantly (p<0.05) (1) greater total rearfoot eversion, (2) greater forefoot plantar flexion at initial contact, (3) greater total sagittal plane forefoot motion, (4) greater maximum FMPJ dorsiflexion, and (5) decreased vertical GRF during propulsion. These data suggest that compared to healthy individuals, individuals with PF exhibit significant differences in foot kinematics and kinetics. Consistent with the theoretical injury mechanisms of PF, we found these individuals to have greater total rearfoot eversion and peak FMPJ dorsiflexion, which may put undue loads on the plantar fascia. Meanwhile, increased medial forefoot plantar flexion at initial contact and decreased propulsive GRF are suggestive of compensatory responses, perhaps to manage pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of videotape augmented feedback on drop jump landing strategy: Implications for anterior cruciate ligament and patellofemoral joint injury prevention.

PubMed

Munro, Allan; Herrington, Lee

2014-10-01

Modification of high-risk movement strategies such as dynamic knee valgus is key to the reduction of anterior cruciate ligament (ACL) and patellofemoral joint (PFJ) injuries. Augmented feedback, which includes video and verbal feedback, could offer a quick, simple and effective alternative to training programs for altering high-risk movement patterns. It is not clear whether feedback can reduce dynamic knee valgus measured using frontal plane projection angle (FPPA). Vertical ground reaction force (vGRF), two-dimensional FPPA of the knee, contact time and jump height of 20 recreationally active university students were measured during a drop jump task pre- and post- an augmented feedback intervention. A control group of eight recreationally active university students were also studied at baseline and repeat test. There was a significant reduction in vGRF (p=0.033), FPPA (p<0.001) and jump height (p<0.001) and an increase in contact time (p<0.001) post feedback in the intervention group. No changes were evident in the control group. Augmented feedback leads to significant decreases in vGRF, FPPA and contact time which may help to reduce ACL and PFJ injury risk. However, these changes may result in decreased performance. Augmented feedback reduces dynamic knee valgus, as measured via FPPA, and forces experienced during the drop jump task and therefore could be used as a tool for helping decrease ACL and PFJ injury risk prior to, or as part of, the implementation of injury prevention training programs. Copyright © 2014 Elsevier B.V. All rights reserved.

Anisotropic Failure Strength of Shale with Increasing Confinement: Behaviors, Factors and Mechanism.

PubMed

Cheng, Cheng; Li, Xiao; Qian, Haitao

2017-11-15

Some studies reported that the anisotropic failure strength of shale will be weakened by increasing confinement. In this paper, it is found that there are various types of anisotropic strength behaviors. Four types of anisotropic strength ratio ( S A 1 ) behaviors and three types of anisotropic strength difference ( S A 2 ) behaviors have been classified based on laboratory experiments on nine groups of different shale samples. The cohesion c w and friction angle ϕ w of the weak planes are proven to be two dominant factors according to a series of bonded-particle discrete element modelling analyses. It is observed that shale is more prone to a slight increase of S A 1 and significant increase of S A 2 with increasing confinement for higher cohesion c w and lower to medium friction angle ϕ w . This study also investigated the mechanism of the anisotropic strength behaviors with increasing confinement. Owing to different contributions of c w and ϕ w under different confinements, different combinations of c w and ϕ w may have various types of influences on the minimum failure strength with the increasing confinement; therefore, different types of anisotropic behaviors occur for different shale specimens as the confinement increases. These findings are very important to understand the stability of wellbore and underground tunneling in the shale rock mass, and should be helpful for further studies on hydraulic fracture propagations in the shale reservoir.

Biochemical markers of cartilage metabolism are associated with walking biomechanics 6-months following anterior cruciate ligament reconstruction.

PubMed

Pietrosimone, Brian; Loeser, Richard F; Blackburn, J Troy; Padua, Darin A; Harkey, Matthew S; Stanley, Laura E; Luc-Harkey, Brittney A; Ulici, Veronica; Marshall, Stephen W; Jordan, Joanne M; Spang, Jeffery T

2017-10-01

The purpose of our study was to determine the association between biomechanical outcomes of walking gait (peak vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR], and knee adduction moment [KAM]) 6 months following anterior cruciate ligament reconstruction (ACLR) and biochemical markers of serum type-II collagen turnover (collagen type-II cleavage product to collagen type-II C-propeptide [C2C:CPII]), plasma degenerative enzymes (matrix metalloproteinase-3 [MMP-3]), and a pro-inflammatory cytokine (interleukin-6 [IL-6]). Biochemical markers were evaluated within the first 2 weeks (6.5 ± 3.8 days) following ACL injury and again 6 months following ACLR in eighteen participants. All peak biomechanical outcomes were extracted from the first 50% of the stance phase of walking gait during a 6-month follow-up exam. Limb symmetry indices (LSI) were used to normalize the biomechanical outcomes in the ACLR limb to that of the contralateral limb (ACLR/contralateral). Bivariate correlations were used to assess associations between biomechanical and biochemical outcomes. Greater plasma MMP-3 concentrations after ACL injury and at the 6-month follow-up exam were associated with lesser KAM LSI. Lesser KAM was associated with greater plasma IL-6 at the 6-month follow-up exam. Similarly, lesser vGRF-LR LSI was associated with greater plasma MMP-3 concentrations at the 6-month follow-up exam. Lesser peak vGRF LSI was associated with higher C2C:CPII after ACL injury, yet this association was not significant after accounting for walking speed. Therefore, lesser biomechanical loading in the ACLR limb, compared to the contralateral limb, 6 months following ACLR may be related to deleterious joint tissue metabolism that could influence future cartilage breakdown. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2288-2297, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

School-level factors associated with increased fruit and vegetable consumption among students in California middle and high schools.

PubMed

Gosliner, Wendi

2014-09-01

This study assessed associations between selective school-level factors and students' consumption of fruits and vegetables at school. Better understanding of school factors associated with increased produce consumption is especially important, as students are served more produce items at school. This cross-sectional study included 5439 seventh- and ninth-grade students from 31 schools in California in 2010. Multilevel regression models estimated whether the odds of consuming fruits or vegetables at school among students eating the school lunch were associated with the length of the lunch period, quality/variety of produce options, or other factors. A longer lunch period was associated with increased odds of a student eating fruits (odds ratio [OR] = 1.40) and vegetables (OR = 1.54) at school. Better fruit quality increased the odds of a student consuming fruit (OR = 1.44). Including a salad bar and involving students in food service decisions increased a student's odds of consuming vegetables (OR = 1.48 and OR = 1.34, respectively). This study suggests that institutional factors in schools are positively associated with middle and high school students' consumption of produce items at school. Additional efforts to structure school meal environments to enhance students' consumption of produce items can benefit students' nutrition and health. © 2014, American School Health Association.

Euglycemic Hyperinsulinemia Increases Blood Pressure in Pregnant Rats Independent of Placental Antiangiogenic and Inflammatory Factors

PubMed Central

2013-01-01

BACKGROUND Although pregnancies associated with hyperinsulinemia and altered placental angiogenic and inflammatory factors are at increased risk for developing preeclampsia, the effects of euglycemic hyperinsulinemia on placental factors and blood pressure regulation during pregnancy are unclear. We hypothesized that chronic hyperinsulinemia results in increased placental soluble fms-like tyrosine kinase 1(sFlt-1) and tumor necrosis factor α (TNF- α) levels and hypertension in pregnant rats. METHODS On gestational day (GD) 14, Sprague-Dawley rats were assigned as normal pregnant or pregnant + insulin. Insulin was infused subcutaneously by osmotic minipump for 5 days at a dose of 1.5 mU/kg/min. Those rats receiving insulin were supplemented with 20% glucose in drinking water to maintain euglycemia. On GD 19, mean arterial pressure (MAP) and heart rate (HR) were assessed in conscious rats by indwelling carotid catheters, followed by collections of blood, placentas, and fetuses. In addition to pl acental sFlt-1 and TNF-α levels, circulating insulin, glucose, leptin, cholesterol, triglyceride, and free fatty acid concentrations were measured. RESULTS MAP was higher in pregnant + insulin vs. normal pregnant rats; however, HR was similar between groups. Although litter size and placental weight were comparable, fetuses from pregnant + insulin rats were heavier. Importantly, circulating insulin concentration was elevated in the pregnant + insulin group, with no change in glucose level. Moreover, circulating leptin, cholesterol, triglyceride, and free fatty acid concentrations were increased in the pregnant + insulin group. There were no differences in placental sFlt-1 and TNF-α concentrations between groups. CONCLUSIONS In summary, sustained euglycemic hyperinsulinemia, comparable with insulin levels in preeclamptic women, can raise blood pressure in pregnancy independent of recognized placental factors associated with preeclampsia. PMID:23955606

Antioxidative diet supplementation reverses high-fat diet-induced increases of cardiovascular risk factors in mice.

PubMed

Vargas-Robles, Hilda; Rios, Amelia; Arellano-Mendoza, Monica; Escalante, Bruno A; Schnoor, Michael

2015-01-01

Obesity is a worldwide epidemic that is characterized not only by excessive fat deposition but also by systemic microinflammation, high oxidative stress, and increased cardiovascular risk factors. While diets enriched in natural antioxidants showed beneficial effects on oxidative stress, blood pressure, and serum lipid composition, diet supplementation with synthetic antioxidants showed contradictive results. Thus, we tested in C57Bl/6 mice whether a daily dosage of an antioxidative mixture consisting of vitamin C, vitamin E, L-arginine, eicosapentaenoic acid, and docosahexaenoic acid (corabion) would affect cardiovascular risk factors associated with obesity. Obese mice showed increased serum triglyceride and glucose levels and hypertension after eight weeks of being fed a high-fat diet (HFD). Importantly, corabion ameliorated all of these symptoms significantly. Oxidative stress and early signs of systemic microinflammation already developed after two weeks of high-fat diet and were significantly reduced by daily doses of corabion. Of note, the beneficial effects of corabion could not be observed when applying its single antioxidative components suggesting that a combination of various nutrients is required to counteract HFD-induced cardiovascular risk factors. Thus, daily consumption of corabion may be beneficial for the management of obesity-related cardiovascular complications.

Wide step width reduces knee abduction moment of obese adults during stair negotiation.

PubMed

Yocum, Derek; Weinhandl, Joshua T; Fairbrother, Jeffrey T; Zhang, Songning

2018-05-15

An increased likelihood of developing obesity-related knee osteoarthritis may be associated with increased peak internal knee abduction moments (KAbM). Increases in step width (SW) may act to reduce this moment. The purpose of this study was to determine the effects of increased SW on knee biomechanics during stair negotiation of healthy-weight and obese participants. Participants (24: 10 obese and 14 healthy-weight) used stairs and walked over level ground while walking at their preferred speed in two different SW conditions - preferred and wide (200% preferred). A 2 × 2 (group × condition) mixed model analysis of variance was performed to analyze differences between groups and conditions (p < 0.05). Increased SW increased the loading-response peak knee extension moment during descent and level gait, decreased loading-response KAbMs, knee extension and abduction range of motion (ROM) during ascent, and knee adduction ROM during descent. Increased SW increased loading-response peak mediolateral ground reaction force (GRF), increased peak knee abduction angle during ascent, and decreased peak knee adduction angle during descent and level gait. Obese participants experienced disproportionate changes in loading-response mediolateral GRF, KAbM and peak adduction angle during level walking, and peak knee abduction angle and ROM during ascent. Increased SW successfully decreased loading-response peak KAbM. Implications of this finding are that increased SW may decrease medial compartment knee joint loading, decreasing pain and reducing joint deterioration. Increased SW influenced obese and healthy-weight participants differently and should be investigated further. Copyright © 2018. Published by Elsevier Ltd.

What Factors Control the Trend of Increasing AAOD Over the United States in the Last Decade?

NASA Technical Reports Server (NTRS)

Zhang, Li; Henze, Daven K.; Grell, Georg A.; Torres, Omar; Jethva, Hiren; Lamsal, Lok N.

2017-01-01

We examine the spatial and temporal trends of absorbing aerosol optical depth (AAOD) in the last decade over the United States (U.S.) observed by the Ozone Monitoring Instrument (OMI). Monthly average OMI AAOD has increased over broad areas of the central U.S. from 2005 to 2015, by up to a factor of 4 in some grid cells (60 km resolution). The AAOD increases in all seasons, although the percentage increases are larger in summer (June-July-August) than in winter (December-January-February) by a factor of 3. Despite enhancements in AAOD, OMI AOD exhibits insignificant trend over most of the U.S. except parts of the central and western U.S., the latter which may partly be due to decreases in precipitation. Trends in AAOD contrast with declining trends in surface concentrations of black carbon (BC) aerosol. Interannual variability of local biomass burning emissions of BC may contribute to the positive trend in AAOD over the western U.S. Changes in both dust aerosol measured at the surface (in terms of concentration and size) and dust AAOD indicate distinct enhancements, especially over the central U.S. by 50-100%, which appears to be one of the major factors that impacts positive trends in AAOD.

Granulocyte macrophage-colony stimulating factor and interleukin-3 increase expression of type II tumour necrosis factor receptor, increasing susceptibility to tumour necrosis factor-induced apoptosis. Control of leukaemia cell life/death switching.

PubMed

Rae, C; MacEwan, D J

2004-12-01

Tumour necrosis factor (TNF) induces apoptosis in a range of cell types via its two receptors, TNFR1 and TNFR2. Here, we demonstrate that proliferation and TNFR2 expression was increased in human leukaemic TF-1 cells by granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin-3 (IL-3), with TNFR1 expression unaffected. Consequently, they switch from a proliferative to a TNF-induced apoptotic phenotype. Raised TNFR2 expression and susceptibility to TNF-induced apoptosis was not a general effect of proliferation as IL-1beta and IFN-gamma both proliferated TF-1 cells with no effect on TNFR expression or apoptosis. Although raised TNFR2 expression correlated with the apoptotic phenotype, stimulation of apoptosis in GM-CSF-pretreated cells was mediated by TNFR1, with stimulation of TNFR2 alone insufficient to initiate cell death. However, TNFR2 did play a role in apoptotic and proliferative responses as they were blocked by the presence of an antagonistic TNFR2 antibody. Additionally, coincubation with cycloheximide blocked the mitotic effects of GM-CSF or IL-3, allowing only the apoptotic responses of TNF to persist. TNF life/death was also observed in K562, but not MOLT-4 and HL-60 human leukaemic cell types. These findings show a cooperative role of TNFR2 in the TNF life/death switching phenomenon.

Increased volume of distribution for recombinant activated factor VII and longer plasma-derived factor VII half-life may explain their long lasting prophylactic effect.

PubMed

Mathijssen, Natascha C J; Masereeuw, Rosalinde; Holme, Pal Andre; van Kraaij, Marian G J; Laros-van Gorkom, Britta A P; Peyvandi, Flora; van Heerde, Waander L

2013-08-01

Prophylaxis with plasma-derived or recombinant activated factor VII is beneficial in severe factor VII deficiency. To understand why prophylactic treatment with both products is efficacious, we conducted a pharmacokinetic study. Ten factor VII deficient patients were treated with either recombinant activated (20 μg/kg) or plasma-derived (25 IU/kg) factor VII in a cross-over design. Pharmacokinetic parameters were analyzed through activated factor VII activity, factor VII clotting activity, and factor VII antigen levels on depicted time points. Factor VII activity half-lifes, determined by non-compartmental and one-compartmental analysis (results in brackets), were shorter for recombinant activated (1.4h; 0.7h) than for plasma-derived factor VII (6.8h; 3.2h); both recombinant activated (5.1h; 2.1h and plasma-derived factor VII (5.8h; 3.2h) resulted in longer half-lives of factor VII antigen. Activated factor VII half-lives (based on activated factor VII activity levels) were significantly higher compared to factor VII clotting activity (1.6h; 0.9h). Volumes of distribution were significantly higher for activated factor VII (236 ml/kg; 175 ml/kg, measured by activated factor VII) as compared to plasma-derived factor VII (206 ml/kg; 64 ml/kg, measured by factor FVII activity), suggesting a plasma- and extracellular fluid distribution for recombinant activated factor VII. Recombinant activated factor VII showed significantly shorter half-lifes than plasma-derived factor VII. Volumes of distribution were significantly higher for treatment with recombinant activated factor VII. The longer half-life for plasma-derived factor VII, compared to recombinant activated factor VII, and the increased volume of distribution for recombinant activated factor VII, compared to plasma-derived factor VII may further elucidate the beneficial effect of prophylactic treatment of both products. Copyright © 2013 Elsevier Ltd. All rights reserved.

Patient factors associated with increased acute care costs of hip fractures: a detailed analysis of 402 patients.

PubMed

Aigner, R; Meier Fedeler, T; Eschbach, D; Hack, J; Bliemel, C; Ruchholtz, S; Bücking, B

2016-12-01

The aim of the present study was to identify patient factors associated with higher costs in hip fracture patients. The mean costs of a prospectively observed sample of 402 patients were 8853 €. The ASA score, Charlson comorbidity index, and fracture location were associated with increased costs. Fractures of the proximal end of the femur (hip fractures) are of increasing incidence due to demographic changes. Relevant co-morbidities often present in these patients cause high complication rates and prolonged hospital stays, thus leading to high costs of acute care. The aim of this study was to perform a precise cost analysis of the actual hospital costs of hip fractures and to identify patient factors associated with increased costs. The basis of this analysis was a prospectively observed single-center trial, which included 402 patients with fractures of the proximal end of the femur. All potential cost factors were recorded as accurately as possible for each of the 402 patients individually, and statistical analysis was performed to identify associations between pre-existing patient factors and acute care costs. The mean total acute care costs per patient were 8853 ± 5676 € with ward costs (5828 ± 4294 €) and costs for surgical treatment (1972 ± 956 €) representing the major cost factors. The ASA score, Charlson comorbidity index, and fracture location were identified as influencing the costs of acute care for hip fracture treatment. Hip fractures are associated with high acute care costs. This study underlines the necessity of sophisticated risk-adjusted payment models based on specific patient factors. Economic aspects should be an integral part of future hip fracture research due to limited health care resources.

Historical Increase in the Number of Factors Measured by Commercial Tests of Cognitive Ability: Are We Overfactoring?

ERIC Educational Resources Information Center

Frazier, Thomas W.; Youngstrom, Eric A.

2007-01-01

A historical increase in the number of factors purportedly measured by commercial tests of cognitive ability may result from four distinct pressures including: increasingly complex models of intelligence, test publishers' desires to provide clinically useful assessment instruments with greater interpretive value, test publishers' desires to…

Ground reaction force adaptations during cross-slope walking and running.

PubMed

Damavandi, Mohsen; Dixon, Philippe C; Pearsall, David J

2012-02-01

Though transversely inclined (cross-sloped) surfaces are prevalent, our understanding of the biomechanical adaptations required for cross-slope locomotion is limited. The purpose of this study was to examine ground reaction forces (GRF) in cross-sloped and level walking and running. Nine young adult males walked and ran barefoot along an inclinable walkway in both level (0°) and cross-slope (10°) configurations. The magnitude and time of occurrence of selected features of the GRF were extracted from the force plate data. GRF data were collected in level walking and running (LW and LR), inclined walking and running up-slope (IWU and IRU), and down-slope (IWD and IRD), respectively. The GRF data were then analyzed using repeated measures MANOVA. In the anteroposterior direction, the timing of the peak force values differed across conditions during walking (p=.041), while the magnitude of forces were modified across conditions for running (p=.047). Most significant differences were observed in the mediolateral direction, where generally force values were up to 390% and 530% (p<.001) larger during the cross-slope conditions compared to level for walking and running, respectively. The maximum force peak during running occurred earlier at IRU compared to the other conditions (p≤.031). For the normal axis a significant difference was observed in the first maximum force peak during walking (p=.049). The findings of this study showed that compared to level surfaces, functional adaptations are required to maintain forward progression and dynamic stability in stance during cross-slope walking and running. Copyright © 2011 Elsevier B.V. All rights reserved.

A Biomechanical Analysis of the Effects of Bouncing the Barbell in the Conventional Deadlift.

PubMed

Krajewski, Kellen; LeFavi, Robert; Riemann, Bryan

2018-02-27

The purpose of this study is to analyze biomechanical differences between the bounce and pause styles of deadlifting. Twenty physically active males performed deadlifts at their 75% one repetition maximum testing utilizing both pause and bounce techniques in a within-subjects randomized study design. The average peak height the barbell attained from the three bounce style repetitions was used to compute a compatible phase for analysis of the pause style repetitions. Net joint moment impulse (NJMI), work, average vertical ground reaction force (vGRF), vGRF impulse and phase time were computed for two phases, lift off to peak barbell height and the entire ascent. Additionally, the ankle, knee, hip, and trunk angles at the location of peak barbell height. During the lift off to peak barbell height phase, although each of the joints demonstrated significantly less NJMI and work during the bounce style, the hip joint was impacted the most. The average vGRF was greater for the bounce however the vGRF impulse was greater for the pause. The NJMI results for the ascent phase were similar to the lift off to peak barbell height phase, while work was significantly less for the bounce condition compared to the pause condition across all three joints. Strength and conditioning specialists utilizing the deadlift should be aware that the bounce technique does not allow the athlete to develop maximal force production in the early portion of the lift. Further analyses should focus on joint angles and potential vulnerability to injury when the barbell momentum generated from the bounce is lost.

[Case of cerebral venous thrombosis due to graves' disease with increased factor VIII activity].

PubMed

Kasuga, Kensaku; Naruse, Satoshi; Umeda, Maiko; Tanaka, Midori; Fujita, Nobuya

2006-04-01

A 39 year-old man was admitted to our hospital because of severe headache with fever continuing over two weeks. Three days after admission he developed aphasia and right hemiparesis, when his CT revealed subarachnoid hemorrhage at the left sylvian fissure. He was diagnosed as suffering from cerebral venous thrombosis because empty delta sign was positive on the enhanced brain CT. Suprasagittal sinus and bilateral transverse sinuses were not detected on the cerebral angiography. He was also diagnosed as having Graves' disease for the first time on the basis of free T3 13.56 pg/ml, free T4 4.65 ng/dl, TSH < 0.01 IU/ml, anti-TSH receptor antibody 4.3 IU/l, and thyroid stimulating antibody 224%. On the examination, homocystine and activities of antithrombin III, protein C, and protein S were normal. Antinculear, anti-DNA, anti-Sm, anticardiolipin beta2GP-I antibodies, and PR3ANCA were negative. Factor VIII activity, however, markedly increased over 300%, which has been known to increase in the cases of hyperthyroidism. He recovered well after the treatment with thiamazole in addition to warfarin followed by intravenous heparin. There are only six cases of cerebral venous thrombosis due to hyperthyroidism with increased factor VIII level. All of those cases were female, and 5 of them were taking oral contraceptives. This is a first Japanese male case.

Neuropeptide cycloprolylglycine increases the levels of brain-derived neurotrophic factor in neuronal cells.

PubMed

Gudasheva, T A; Koliasnikova, K N; Antipova, T A; Seredenin, S B

2016-07-01

It was shown for the first time that the endogenous cyclic dipeptide cycloprolylglycine (CPG) at concentrations of 10(-7) and 10(-3) M and piracetam at a concentration of 10(-3) M increased the content of brainderived neurotrophic factor (BDNF) in the culture of neuronal cells in normal state and under conditions of glutamate and 6-oxydopamine neurotoxicity. This may indicate the possible involvement of BDNF in the mechanism of action of neuropeptide CPG and piracetam.

Sound synthesis and evaluation of interactive footsteps and environmental sounds rendering for virtual reality applications.

PubMed

Nordahl, Rolf; Turchet, Luca; Serafin, Stefania

2011-09-01

We propose a system that affords real-time sound synthesis of footsteps on different materials. The system is based on microphones, which detect real footstep sounds from subjects, from which the ground reaction force (GRF) is estimated. Such GRF is used to control a sound synthesis engine based on physical models. Two experiments were conducted. In the first experiment, the ability of subjects to recognize the surface they were exposed to was assessed. In the second experiment, the sound synthesis engine was enhanced with environmental sounds. Results show that, in some conditions, adding a soundscape significantly improves the recognition of the simulated environment.

Fever as a risk factor for increased response to vitamin K antagonists: a review of the evidence and potential mechanisms.

PubMed

Self, Timothy H; Oliphant, Carrie S; Reaves, Anne B; Richardson, Amy M; Sands, Christopher W

2015-01-01

Numerous factors affect the response to vitamin K antagonists (VKA) including age, dietary vitamin K, other drugs, pharmacogenetics, and disease states. In antithrombotic guidelines, fever is mentioned as a factor that may increase response to VKA. The purpose of this article is to review the available evidence regarding the effect of fever on response to VKA, and to discuss possible mechanisms of this effect. We performed a search of the English literature from 1943 to June 2014, using the key words fever AND warfarin, acenocoumarol, phenprocoumon, coumarin anticoagulants and VKA; fever AND vitamin K dependent clotting factors II, VII, IX, and X. One animal investigation and 6 studies in humans suggest fever increases response to VKA, but one study did not find a significant effect. The magnitude of this effect is variable. Possible mechanisms for the increased effect of VKA associated with fever are increased catabolism of vitamin K dependent clotting factors, decreased vitamin K intake, and inhibition of VKA metabolism. More rigorous studies are needed to confirm that fever increases response to warfarin and other VKA. Copyright © 2014 Elsevier Ltd. All rights reserved.

Use of a tibial accelerometer to measure ground reaction force in running: A reliability and validity comparison with force plates.

PubMed

Raper, Damian P; Witchalls, Jeremy; Philips, Elissa J; Knight, Emma; Drew, Michael K; Waddington, Gordon

2018-01-01

The use of microsensor technologies to conduct research and implement interventions in sports and exercise medicine has increased recently. The objective of this paper was to determine the validity and reliability of the ViPerform as a measure of load compared to vertical ground reaction force (GRF) as measured by force plates. Absolute reliability assessment, with concurrent validity. 10 professional triathletes ran 10 trials over force plates with the ViPerform mounted on the mid portion of the medial tibia. Calculated vertical ground reaction force data from the ViPerform was matched to the same stride on the force plate. Bland-Altman (BA) plot of comparative measure of agreement was used to assess the relationship between the calculated load from the accelerometer and the force plates. Reliability was calculated by intra-class correlation coefficients (ICC) with 95% confidence intervals. BA plot indicates minimal agreement between the measures derived from the force plate and ViPerform, with variation at an individual participant plot level. Reliability was excellent (ICC=0.877; 95% CI=0.825-0.917) in calculating the same vertical GRF in a repeated trial. Standard error of measure (SEM) equalled 99.83 units (95% CI=82.10-119.09), which, in turn, gave a minimum detectable change (MDC) value of 276.72 units (95% CI=227.32-330.07). The ViPerform does not calculate absolute values of vertical GRF similar to those measured by a force plate. It does provide a valid and reliable calculation of an athlete's lower limb load at constant velocity. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

School-Level Factors Associated with Increased Fruit and Vegetable Consumption among Students in California Middle and High Schools

ERIC Educational Resources Information Center

Gosliner, Wendi

2014-01-01

Background: This study assessed associations between selective school-level factors and students' consumption of fruits and vegetables at school. Better understanding of school factors associated with increased produce consumption is especially important, as students are served more produce items at school. Methods: This cross-sectional study…

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion.

PubMed

Gorin, Caroline; Rochefort, Gael Y; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Muller, Laurent; Chaussain, Catherine; Germain, Stéphane

2016-03-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. ©AlphaMed Press.

Vascular endothelial growth factor increases fenestral permeability in hepatic sinusoidal endothelial cells.

PubMed

Yokomori, Hiroaki; Oda, Masaya; Yoshimura, Kazunori; Nagai, Toshihiro; Ogi, Mariko; Nomura, Masahiko; Ishii, Hiromasa

2003-12-01

Vascular endothelial growth factor (VEGF) is an important regulator of vasculogenesis and vascular permeability. Hepatic sinusoidal endothelial cells (SECs) possess sieve-like pores that form an anastomosing labyrinth structure by the deeply invaginated plasma membrane. Caveolin is the principal structural protein in caveolae. In this study, we examined the role of VEGF on the fenestration and permeability of SECs and the relation with caveolin-1. SECs isolated from rat livers by collagenase infusion method were cultured for 24 h with (10 or 100 ng/ml) or without VEGF. The cells were then examined by transmission and scanning electron microscopy (EM). The expression of caveolin was investigated by confocal immunofluorescence, immunogold EM, and Western blot. Endocytosis and intracellular traffic was studied using horseradish peroxidase (HRP) reaction as a marker of fluid phase transport in SECs. Both transmission and scanning EM showed an increased number of sinusoidal endothelial fenestrae (SEF) in SECs cultured with VEGF. By confocal immunofluorescence, SECs cultured with VEGF displayed prominent caveolin-l-positive aggregates in the cytoplasm, especially surrounding the nucleus region. Immunogold EM depicted increased caveolin-1 reactivity on vesicles and vacuoles of VEGF-treated SECs compared with VEGF-nontreated cells. However, there was no change in the level of caveolin-1 protein expression on Western blot. After HRP injection, an increase of electron-dense tracer filled the SEF in cells treated with VEGF. Our results suggested that VEGF induced fenestration in SECs, accompanied by an increased number of caveolae-like vesicles. Increased caveolin-1 might be associated with vesicle formation but not with fenestration. Increased fenestration may augment hepatic sinusoidal permeability and transendothelial transport.

The Influence of Sex and Maturation on Knee Mechanics during Side-Step Cutting

PubMed Central

Sigward, Susan M.; Pollard, Christine D.; Havens, Kathryn L.; Powers, Christopher M.

2012-01-01

Introduction Females have been reported to have a 3-5 times greater incidence of non-contact ACL injury when compared to their male counterparts. Previous research suggests that physical maturation is one factor that is associated with the development of potentially injurious lower extremity biomechanics in female athletes. Purpose To determine if lower extremity biomechanics differ between male and female soccer athletes during a cutting maneuver across different stages of maturational development. Methods One hundred and fifty six soccer players (76 male and 80 females) between the ages of 9 and 23 participated. Subjects were classified based on maturation as pre-pubertal, pubertal, post-pubertal or young adult. Lower extremity kinematics, kinetics and ground reaction forces (GRF) were obtained during a 45 degree side-step cutting maneuver. Differences between sex and maturation were assessed for peak knee valgus angle, knee adductor moments and GRF's (vertical, posterior and lateral) during weight acceptance using a 2 factor ANCOVA (controlling for approach velocity). Results No sex × maturation interactions were found for any variable of interest. On average, females exhibited greater knee abduction and adductor moments than males. Pre-pubertal athletes demonstrated greater knee adductor moments and GRFs than all other groups. Conclusion Biomechanical differences between males and females were evident across all stages of maturation. On average, less mature athletes exhibit biomechanical patterns during cutting that may place them at greater risk for injury than their more mature counterparts. PMID:22330027

Macrophage Control of Phagocytosed Mycobacteria Is Increased by Factors Secreted by Alveolar Epithelial Cells through Nitric Oxide Independent Mechanisms

PubMed Central

Freidl, Raphaela; Fernández, Carmen

2014-01-01

Tissue-resident macrophages are heterogeneous with tissue-specific and niche-specific functions. Thus, simplified models of macrophage activation do not explain the extent of heterogeneity seen in vivo. We focus here on the respiratory tract and ask whether factors secreted by alveolar epithelial cells (AEC) can influence the functionality of resident pulmonary macrophages (PuM). We have previously reported that factors secreted by AEC increase control of intracellular growth of BCG in macrophages. In the current study, we also aimed to investigate possible mechanisms by which AEC-derived factors increase intracellular control of BCG in both primary murine interstitial macrophages, and bone marrow-derived macrophages and characterize further the effect of these factors on macrophage differentiation. We show that; a) in contrast to other macrophage types, IFN-γ did not increase intracellular growth control of Mycobacterium bovis, Bacillus Calmette-Guérin (BCG) by interstitial pulmonary macrophages although the same macrophages could be activated by factors secreted by AEC; b) the lack of response of pulmonary macrophages to IFN-γ was apparently regulated by suppressor of cytokine signaling (SOCS)1; c) AEC-derived factors did not induce pro-inflammatory pathways induced by IFN-γ e.g. expression of inducible nitric oxide synthase (iNOS), secretion of nitric oxide (NO), or IL-12, d) in contrast to IFN-γ, intracellular bacterial destruction induced by AEC-derived factors was not dependent on iNOS transcription and NO production. Collectively, our data show that PuM were restricted in inflammatory responses mediated by IFN-γ through SOCS1 and that factors secreted by AEC- enhanced the microbicidal capacities of macrophages by iNOS independent mechanisms. PMID:25089618

Molecular stress-inducing compounds increase osteoclast formation in a heat shock factor 1 protein-dependent manner.

PubMed

Chai, Ryan C; Kouspou, Michelle M; Lang, Benjamin J; Nguyen, Chau H; van der Kraan, A Gabrielle J; Vieusseux, Jessica L; Lim, Reece C; Gillespie, Matthew T; Benjamin, Ivor J; Quinn, Julian M W; Price, John T

2014-05-09

Many anticancer therapeutic agents cause bone loss, which increases the risk of fractures that severely reduce quality of life. Thus, in drug development, it is critical to identify and understand such effects. Anticancer therapeutic and HSP90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) causes bone loss by increasing osteoclast formation, but the mechanism underlying this is not understood. 17-AAG activates heat shock factor 1 (Hsf1), the master transcriptional regulator of heat shock/cell stress responses, which may be involved in this negative action of 17-AAG upon bone. Using mouse bone marrow and RAW264.7 osteoclast differentiation models we found that HSP90 inhibitors that induced a heat shock response also enhanced osteoclast formation, whereas HSP90 inhibitors that did not (including coumermycin A1 and novobiocin) did not affect osteoclast formation. Pharmacological inhibition or shRNAmir knockdown of Hsf1 in RAW264.7 cells as well as the use of Hsf1 null mouse bone marrow cells demonstrated that 17-AAG-enhanced osteoclast formation was Hsf1-dependent. Moreover, ectopic overexpression of Hsf1 enhanced 17-AAG effects upon osteoclast formation. Consistent with these findings, protein levels of the essential osteoclast transcription factor microphthalmia-associated transcription factor were increased by 17-AAG in an Hsf1-dependent manner. In addition to HSP90 inhibitors, we also identified that other agents that induced cellular stress, such as ethanol, doxorubicin, and methotrexate, also directly increased osteoclast formation, potentially in an Hsf1-dependent manner. These results, therefore, indicate that cellular stress can enhance osteoclast differentiation via Hsf1-dependent mechanisms and may significantly contribute to pathological and therapeutic related bone loss.

Quadricep and hamstring activation during drop jumps with changes in drop height.

PubMed

Peng, Hsien-Te; Kernozek, Thomas W; Song, Chen-Yi

2011-08-01

Compare the muscle activation patterns of the quadricep-hamstring during drop jumps with increasing demands of drop heights. Observational. University biomechanics laboratory. Fifteen male and eight female college physical education students. Electromyographic activity of the rectus femoris (RF) and biceps femoris (BF) during the landing and takeoff phase of drop jumps from 20 to 60-cm heights. The ground contact time, vertical ground reaction force (vGRF), knee flexion angle during ground contact, and jump height after takeoff were also analyzed. The activation of RF was higher in the drop jump from 60-cm than that from 20- and 30-cm (comparing 107.0 ± 45.9 to 82.3 ± 30.8 and 88.9 ± 38.9 %MVIC, P<.05) during the landing phase. Activation of BF remained similar across all drop heights. Drop jump from 60-cm resulted in greater contact time during takeoff phase and peak vGRF, and resulted in greater maximum knee flexion but straighter knee at ground contact than from lower drop heights. At drop height of 60-cm, the altered knee muscular activation and movement patterns may diminish the effectiveness of plyometric training and increase the potential injury risk of knee. Copyright © 2010 Elsevier Ltd. All rights reserved.

Human factors dimensions in the evolution of increasingly automated control rooms for near-earth satellites

NASA Technical Reports Server (NTRS)

Mitchell, C. M.

1982-01-01

The NASA-Goddard Space Flight Center is responsible for the control and ground support for all of NASA's unmanned near-earth satellites. Traditionally, each satellite had its own dedicated mission operations room. In the mid-seventies, an integration of some of these dedicated facilities was begun with the primary objective to reduce costs. In this connection, the Multi-Satellite Operations Control Center (MSOCC) was designed. MSOCC represents currently a labor intensive operation. Recently, Goddard has become increasingly aware of human factors and human-machine interface issues. A summary is provided of some of the attempts to apply human factors considerations in the design of command and control environments. Current and future activities with respect to human factors and systems design are discussed, giving attention to the allocation of tasks between human and computer, and the interface for the human-computer dialogue.

Follicular fluid placental growth factor is increased in polycystic ovarian syndrome: correlation with ovarian stimulation.

PubMed

Tal, Reshef; Seifer, David B; Grazi, Richard V; Malter, Henry E

2014-08-20

Polycystic ovarian syndrome (PCOS) is characterized by increased ovarian angiogenesis and vascularity. Accumulating evidence indicates that vascular endothelial growth factor (VEGF) is increased in PCOS and may play an important role in these vascular changes and the pathogenesis of this disease. Placental growth factor (PlGF), a VEGF family member, has not been previously characterized in PCOS women. We investigated levels and temporal expression patterns of PlGF and its soluble receptor sFlt-1 (soluble Fms-like tyrosine kinase) in serum and follicular fluid (FF) of women with PCOS during controlled ovarian stimulation. This was a prospective cohort study of 14 PCOS women (Rotterdam criteria) and 14 matched controls undergoing controlled ovarian stimulation. Serum was collected on day 3, day of hCG and day of oocyte retrieval. FF was collected on retrieval day. PlGF, sFlt-1 and anti-mullerian hormone (AMH) protein concentrations were measured using ELISA. Since sFlt-1 binds free PlGF, preventing its signal transduction, we calculated PlGF bioavailability as PlGF/sFlt-1 ratio. Serum PlGF and sFlt-1 levels were constant throughout controlled ovarian stimulation, and no significant differences were observed in either factor in PCOS women compared with non-PCOS controls at all three measured time points. However, FF PlGF levels were increased 1.5-fold in PCOS women compared with controls (p < 0.01). Moreover, FF PlGF correlated positively with number of oocytes retrieved and the ovarian reserve marker anti-mullerian hormone (AMH) and negatively with age. In addition, FF sFlt-1 levels were decreased 1.4-fold in PCOS women compared to controls (p = 0.04). PlGF bioavailability in FF was significantly greater (2-fold) in PCOS women compared with non-PCOS controls (p < 0.01). These data provide evidence that FF PlGF correlates with ovarian stimulation and that its bioavailability is increased in women with PCOS undergoing controlled ovarian stimulation. This

Factors associated with opioid dose increases: a chart review of patients’ first year on long-term opioids

PubMed Central

Bautista, Christopher A.; Iosif, Ana-Maria; Wilsey, Barth L.; Melnikow, Joy A.; Crichlow, Althea; Henry, Stephen G.

2016-01-01

OBJECTIVE To examine encounter-level factors associated with opioid dose increases during patients’ first year on opioid therapy for chronic pain. DESIGN Case-control study analyzing all opioid prescriptions for patients with chronic pain during their first year after opioid initiation. Cases were patients who experienced an overall dose escalation of ≥30 mg morphine equivalents over the 1-year period; controls did not experience overall dose escalation. Main measures were encounter type; opioid dose change; documented prescribing rationale; documentation of guideline-concordant opioid prescribing practices. Two coders reviewed all encounters associated with opioid prescriptions. Analysis of factors associated with dose increases and provider documentation of prescribing rationale was conducted using multiple logistic regression. RESULTS 674 encounters were coded for 66 patients (22 cases, 44 controls). Fifty-three percent of opioid prescriptions were associated with telephone encounters; 13% were associated with email encounters. No prescribing rationale was documented for 43% of all opioid prescriptions and 25% of dose increases. Likelihood of dose increase and documentation of prescribing rationale did not significantly differ for cases versus controls. Compared to face-to-face encounters, dose increases were significantly less likely for telephone (OR 0.18, 95%CI 0.11 – 0.28) and email (OR 0.23, 95%CI 0.12 – 0.47) encounters; documentation of prescribing rationale was significantly more likely for email (OR 5.06, 95%CI 1.87–13.72) and less likely for telephone (OR 0.30, 95%CI 0.18–0.51) encounters. CONCLUSION Most opioid prescriptions were written without face-to-face encounters. One quarter of dose increases contained no documented prescribing rationale. Documented encounter-level factors were not significantly associated with overall opioid dose escalation. PMID:27477581

Stimulation of body weight increase and epiphyseal cartilage growth by insulin like growth factor

NASA Technical Reports Server (NTRS)

Ellis, S.

1981-01-01

The ability of insulin-like growth factor (IGF) to induce growth in hypophysectomized immature rats was tested by continuous infusion of the partially purified factor at daily doses of 6, 21, and 46 mU for an 8-day period. A dose-dependent growth of the proximal epiphyseal cartilage of the tibia and an associated stimulation of the primary spongiosa were produced by these amounts of IGF. The two highest doses of IGF also resulted in dose-dependent increases of body weight. Gel permeation of the sera at neutrality showed that the large-molecular-weight IGF binding protein was not induced by the infusion of IGF, whereas it ws generated in the sera of hypophysectomized rats that were infused with daily doses of 86 mU of human growth hormone.

Tissue factor deficiency increases alveolar hemorrhage and death in influenza A virus-infected mice.

PubMed

Antoniak, S; Tatsumi, K; Hisada, Y; Milner, J J; Neidich, S D; Shaver, C M; Pawlinski, R; Beck, M A; Bastarache, J A; Mackman, N

2016-06-01

Essentials H1N1 Influenza A virus (IAV) infection is a hemostatic challenge for the lung. Tissue factor (TF) on lung epithelial cells maintains lung hemostasis after IAV infection. Reduced TF-dependent activation of coagulation leads to alveolar hemorrhage. Anticoagulation might increase the risk for hemorrhages into the lung during severe IAV infection. Background Influenza A virus (IAV) infection is a common respiratory tract infection that causes considerable morbidity and mortality worldwide. Objective To investigate the effect of genetic deficiency of tissue factor (TF) in a mouse model of IAV infection. Methods Wild-type mice, low-TF (LTF) mice and mice with the TF gene deleted in different cell types were infected with a mouse-adapted A/Puerto Rico/8/34 H1N1 strain of IAV. TF expression was measured in the lungs, and bronchoalveolar lavage fluid (BALF) was collected to measure extracellular vesicle TF, activation of coagulation, alveolar hemorrhage, and inflammation. Results IAV infection of wild-type mice increased lung TF expression, activation of coagulation and inflammation in BALF, but also led to alveolar hemorrhage. LTF mice and mice with selective deficiency of TF in lung epithelial cells had low basal levels of TF and failed to increase TF expression after infection; these two strains of mice had more alveolar hemorrhage and death than controls. In contrast, deletion of TF in either myeloid cells or endothelial cells and hematopoietic cells did not increase alveolar hemorrhage or death after IAV infection. These results indicate that TF expression in the lung, particularly in epithelial cells, is required to maintain alveolar hemostasis after IAV infection. Conclusion Our study indicates that TF-dependent activation of coagulation is required to limit alveolar hemorrhage and death after IAV infection. © 2016 International Society on Thrombosis and Haemostasis.

Analysis of factors that increase motorcycle rider risk compared to car driver risk.

PubMed

Keall, Michael D; Newstead, Stuart

2012-11-01

As in other parts of the Western world, there is concern in New Zealand about increasing popularity of motorcycles because of potential increases in road trauma. This study sought to identify important factors associated with increased risk for motorcyclists to inform potential policy approaches to reduce motorcyclist injury, such as changes to motorcyclist licensing, training and education. Using data extracted from a register of all New Zealand licensed motor vehicles that were matched to crash data, statistical models were fitted to examine patterns of motorcycle risk in comparison with small cars. These showed generally elevated risks for motorcyclists compared to cars, but particularly elevated risks for motorcycle owners aged in their 20s or who lived in more urbanised settings. In crashes, motorcyclists have little protection from injury, putting the motorcyclist at high risk of injury. When comparing new motorcycles with new cars, the odds of fatal or serious injury to a motorcycle rider involved in an injury crash were almost eight times the odds for a car driver. Copyright © 2011 Elsevier Ltd. All rights reserved.

Increased expression of pro-angiogenic factors and vascularization in thyroid hyperfunctioning adenomas with and without TSH receptor activating mutations.

PubMed

Celano, Marilena; Sponziello, Marialuisa; Tallini, Giovanni; Maggisano, Valentina; Bruno, Rocco; Dima, Mariavittoria; Di Oto, Enrico; Redler, Adriano; Durante, Cosimo; Sacco, Rosario; Filetti, Sebastiano; Russo, Diego

2013-02-01

Autonomously functioning thyroid nodules (AFTN) are known to receive an increased blood influx necessary to sustain their high rate of growth and hormone production. Here, we investigated the expression of hematic and lymphatic vases in a series of 20 AFTN compared with the contralateral non-tumor tissues of the same patients, and the transcript levels of proteins involved in the control of vascular proliferation, including the vascular endothelial growth factor (VEGF) and platelet-derived growth factors (PDGF) and their receptors and the endothelial nitric oxide synthase (eNOS). In parallel, the expression of the differentiation markers sodium/iodide symporter (NIS), thyroperoxidase (TPO), thyroglobulin (Tg), and TSH receptor (TSHR) was also investigated. The data were further analyzed comparing subgroups of tumors with or without mutations in the TSHR gene. Analysis by means of CD31 and D2-40 immunostaining showed in AFTN an increased number of hematic, but not lymphatic, vessels in parallel with an enhanced proliferation rate shown by increased Ki67 staining. Quantitative RT-PCR analysis revealed an increase of VEGF, VEGFR1 and 2, PDGF-A, PDGF-B, and eNOS expression in tumor versus normal tissues. Also, higher transcript levels of NIS, TPO, and Tg were detected. Comparison of the two subgroups of samples revealed only few differences in the expression of the genes examined. In conclusion, these data demonstrate an increased expression of angiogenesis-related factors associated with an enhanced proliferation of hematic, but not lymphatic, vessels in AFTNs. In this context, the presence of TSHR mutations may only slightly influence the expression of pro-angiogenic growth factors.

Magnitude and Spatial Distribution of Impact Intensity Under the Foot Relates to Initial Foot Contact Pattern.

PubMed

Breine, Bastiaan; Malcolm, Philippe; Segers, Veerle; Gerlo, Joeri; Derie, Rud; Pataky, Todd; Frederick, Edward C; De Clercq, Dirk

2017-12-01

In running, foot contact patterns (rear-, mid-, or forefoot contact) influence impact intensity and initial ankle and foot kinematics. The aim of the study was to compare impact intensity and its spatial distribution under the foot between different foot contact patterns. Forty-nine subjects ran at 3.2 m·s -1 over a level runway while ground reaction forces (GRF) and shoe-surface pressures were recorded and foot contact pattern was determined. A 4-zone footmask (forefoot, midfoot, medial and lateral rearfoot) assessed the spatial distribution of the vertical GRF under the foot. We calculated peak vertical instantaneous loading rate of the GRF (VILR) per foot zone as the impact intensity measure. Midfoot contact patterns were shown to have the lowest, and atypical rearfoot contact patterns the highest impact intensities, respectively. The greatest local impact intensity was mainly situated under the rear- and midfoot for the typical rearfoot contact patterns, under the midfoot for the atypical rearfoot contact patterns, and under the mid- and forefoot for the midfoot contact patterns. These findings indicate that different foot contact patterns could benefit from cushioning in different shoe zones.

Factors Underlying the Temporal Increase in Maternal Mortality in the United States

PubMed Central

Joseph, K.S.; Lisonkova, Sarka; Muraca, Giulia M.; Razaz, Neda; Sabr, Yasser; Mehrabadi, Azar; Schisterman, Enrique F.

2016-01-01

OBJECTIVE To identify the factors underlying the recent increase in maternal mortality ratios (maternal deaths per 100,000 live births) in the United States. METHODS We carried out a retrospective study with data on maternal deaths and live births in the United States from 1993 to 2014 obtained from the birth and death files of the Centers for Disease Control and Prevention. Underlying causes of death were examined between 1999 and 2014 using International Classification of Diseases, Tenth Revision (ICD-10) codes. Poisson regression was used to estimate maternal mortality rate ratios (RR) and 95% confidence intervals (CI) after adjusting for the introduction of a separate pregnancy question and the standard pregnancy checkbox on death certificates, and adoption of ICD-10. RESULTS Maternal mortality ratios increased from 7.55 in 1993, to 9.88 in 1999 and to 21.5 per 100,000 live births in 2014 (RR 2014 vs 1993 2.84, 95% CI 2.49 to 3.24; RR 2014 vs 1999 2.17, 95% CI 1.93 to 2.45). The increase in maternal deaths from 1999 to 2014 was mainly due to increases in maternal deaths associated with two new ICD-10 codes (O26.8 i.e., primarily renal disease and O99 i.e., other maternal diseases classifiable elsewhere); exclusion of such deaths abolished the increase in mortality (RR 1.09, 95% CI 0.94 to 1.27). Regression adjustment for improvements in surveillance also abolished the temporal increase in maternal mortality ratios (adjusted maternal mortality ratios 7.55 in 1993, 8.00 per 100,000 live births in 2013; adjusted RR 2013 vs 1993 1.06, 95% CI 0.90 to 1.25). CONCLUSION Recent increases in maternal mortality ratios in the United States are likely an artifact of improvements in surveillance and highlight past underestimation of maternal death. Complete ascertainment of maternal death in populations remains a challenge even in countries with good systems for civil registration and vital statistics. PMID:27926651

Leptin Aggravates Reflux Esophagitis by Increasing Tissue Levels of Macrophage Migration Inhibitory Factor in Rats.

PubMed

Murata, Tsugihiro; Asanuma, Kiyotaka; Ara, Nobuyuki; Iijima, Katsunori; Hatta, Waku; Hamada, Shin; Asano, Naoki; Koike, Tomoyuki; Imatani, Akira; Masamune, Atsushi; Shimosegawa, Tooru

2018-05-01

Leptin, produced primarily by the adipose tissue, acts as a pro-inflammatory modulator, thereby contributing to the development of obesity-related disease. Although high levels of leptin in the obese are closely related to gastroesophageal reflux disease, the mechanism by which leptin influences esophageal inflammation remains unknown. Macrophage migration inhibitory factor (MIF) is produced by immune cells, such as T lymphocytes and macrophages, and MIF is known to induce the production of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6). We therefore investigated the mechanism whereby leptin aggravates reflux esophagitis, by focusing on esophageal tissue levels of MIF and CD3+ T lymphocytes, both of which are crucial for the reflux-induced epithelial damage. Esophageal inflammation was surgically induced in male Wistar rats by ligating the forestomach and narrowing the duodenum to facilitate gastroesophageal reflux, followed by administration of leptin or vehicle with an osmotic pump system for 1 week. We demonstrated that the administration of leptin exacerbated the reflux esophagitis with the apparent infiltration of CD3+ T lymphocytes and caused the significant increase in the esophageal tissue levels of MIF. Moreover, the leptin caused increases in the esophageal tissue levels of TNF-α, IL-1β and IL-6, downstream targets of MIF. Importantly, the increases in these pro-inflammatory cytokines were accompanied by increased protein levels of phospho-STAT3 and phospho-AKT, pivotal molecules of leptin signaling pathways. In conclusion, through enhancing the MIF-induced inflammatory signaling, leptin could contribute to the development of gastroesophageal reflux disease.

Time series of ground reaction forces following a single leg drop jump landing in elite youth soccer players consist of four distinct phases.

PubMed

Fransz, Duncan P; Huurnink, Arnold; de Boode, Vosse A; Kingma, Idsart; van Dieën, Jaap H

2016-10-01

The single leg drop jump landing test may assess dynamic and static balance abilities in different phases of the landing. However objective definitions of different phases following landing and associated reliability are lacking. Therefore, we determined the existence of possible distinct phases of single leg drop jump landing on a force plate in 82 elite youth soccer players. Three outcome measures were calculated over moving windows of five sizes: center of pressure (COP) speed, COP sway and horizontal ground reaction force (GRF). Per outcome measure, a Factor Analysis was employed with all windows as input variables. It showed that four factors (patterns of variance) largely (>75%) explained the variance across subjects/trials along the 12s time series. Each factor was highly associated with a distinct phase of the time series signal: dynamic (0.4-2.7s), late dynamic (2.5-5.0s), static 1 (5.0-8.3s) and static 2 (8.1-11.7s). Intra-class correlations (ICC) between trials were lower for the dynamic phases (0.45-0.68) than for the static phases (0.60-0.86). The COP speed showed higher ICC's (0.63-0.86) than COP sway (0.45-0.61) and GRF (0.57-0.71) for all four phases. In conclusion, following a drop jump landing unique information is available in four distinct phases. The COP speed is most reliable, with higher reliability in the static phases compared to the dynamic phases. Future studies should assess the sensitivity of information from dynamic, late dynamic and static phases. Copyright © 2016 Elsevier B.V. All rights reserved.

Increasing Children's Physical Activity: Individual, Social, and Environmental Factors Associated with Walking to and from School

ERIC Educational Resources Information Center

Trapp, Georgina S. A.; Giles-Corti, Billie; Christian, Hayley E.; Bulsara, Max; Timperio, Anna F.; McCormack, Gavin R.; Villaneuva, Karen P.

2012-01-01

Background. Efforts to increase the prevalence of children's active school transport require evidence to inform the development of comprehensive interventions. This study used a multilevel ecological framework to investigate individual, social, and environmental factors associated with walking to and from school among elementary school-aged…

Increased C3 production in human monocytes after stimulation with Candida albicans is suppressed by granulocyte-macrophage colony-stimulating factor.

PubMed Central

Høgåsen, A K; Abrahamsen, T G

1993-01-01

Activation of the complement system is an important part of host resistance against fungal infections. When human monocytes, cultured for 2 days or more, were treated in vitro with Candida albicans for 24 h, an enhancement of their biosynthesis of the complement components C3 and factor B was found. However, when C. albicans was administered to freshly isolated monocytes, a consistent stimulation of factor B biosynthesis occurred, while the C3 production was increased in about 50% of the donors. C. albicans also induced the release of granulocyte-macrophage colony-stimulating factor (GM-CSF) from the cultured cells, apparently in larger amounts in the donors in whom no stimulation of C3 production was found. An antibody to GM-CSF administered with the yeast at the initiation of the monocyte culture caused an increase in the C3 production. Furthermore, when monocytes were treated with recombinant human GM-CSF either at the same time as or 4 days prior to the addition of C. albicans, the increase in C3 production was suppressed or neutralized, while factor B biosynthesis was unaffected. Taken together, these results indicate that monocytes respond to C. albicans with an increased production of complement factors. This may be an important mechanism both for opsonization of the fungus and for initiation of an inflammatory reaction. At an inflammatory site, this complement response may be suppressed by locally produced GM-CSF. PMID:8478067

Increased expression of high mobility group box protein 1 and vascular endothelial growth factor in placenta previa.

PubMed

Xie, Han; Qiao, Ping; Lu, Yi; Li, Ying; Tang, Yuping; Huang, Yiying; Bao, Yirong; Ying, Hao

2017-12-01

Placenta previa is often associated with preterm delivery, reduced birth weight, a higher frequency of placental accreta and postpartum haemorrhage, and increased likelihood of blood transfusion. The present study aimed to examine the expression of high mobility group box protein 1 (HMGB1) in the placenta of women with or without placenta previa. The study group consisted of placental tissues obtained from women with or without placenta previa. The expression levels of HMGB1 and vascular endothelial growth factor (VEGF) were evaluated in the placental tissues using reverse transcription‑quantitative polymerase chain reaction, western blotting and immunohistochemistry. The mRNA expression levels of HMGB1 and VEGF were significantly increased in the placenta previa group compared with in the normal group. In addition, the placenta previa group exhibited increased HMGB1 and VEGF staining in vascular endothelial cells and trophoblasts. There were no significant differences in the expression of HMGB1 or VEGF between groups with or without placenta accreta or postpartum haemorrhage. The present study hypothesised that the increased expression of HMGB1 in the placenta may be associated with the pathogenesis of placenta previa by regulating the expression of the proangiogenic factor VEGF.

Genetic Factors That Increase Male Facial Masculinity Decrease Facial Attractiveness of Female Relatives

PubMed Central

Lee, Anthony J.; Mitchem, Dorian G.; Wright, Margaret J.; Martin, Nicholas G.; Keller, Matthew C.; Zietsch, Brendan P.

2014-01-01

For women, choosing a facially masculine man as a mate is thought to confer genetic benefits to offspring. Crucial assumptions of this hypothesis have not been adequately tested. It has been assumed that variation in facial masculinity is due to genetic variation and that genetic factors that increase male facial masculinity do not increase facial masculinity in female relatives. We objectively quantified the facial masculinity in photos of identical (n = 411) and nonidentical (n = 782) twins and their siblings (n = 106). Using biometrical modeling, we found that much of the variation in male and female facial masculinity is genetic. However, we also found that masculinity of male faces is unrelated to their attractiveness and that facially masculine men tend to have facially masculine, less-attractive sisters. These findings challenge the idea that facially masculine men provide net genetic benefits to offspring and call into question this popular theoretical framework. PMID:24379153

Genetic factors that increase male facial masculinity decrease facial attractiveness of female relatives.

PubMed

Lee, Anthony J; Mitchem, Dorian G; Wright, Margaret J; Martin, Nicholas G; Keller, Matthew C; Zietsch, Brendan P

2014-02-01

For women, choosing a facially masculine man as a mate is thought to confer genetic benefits to offspring. Crucial assumptions of this hypothesis have not been adequately tested. It has been assumed that variation in facial masculinity is due to genetic variation and that genetic factors that increase male facial masculinity do not increase facial masculinity in female relatives. We objectively quantified the facial masculinity in photos of identical (n = 411) and nonidentical (n = 782) twins and their siblings (n = 106). Using biometrical modeling, we found that much of the variation in male and female facial masculinity is genetic. However, we also found that masculinity of male faces is unrelated to their attractiveness and that facially masculine men tend to have facially masculine, less-attractive sisters. These findings challenge the idea that facially masculine men provide net genetic benefits to offspring and call into question this popular theoretical framework.

Honey Bee Venom (Apis mellifera) Contains Anticoagulation Factors and Increases the Blood-clotting Time

PubMed Central

Zolfagharian, Hossein; Mohajeri, Mohammad; Babaie, Mahdi

2015-01-01

Objectives: Bee venom (BV) is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera) on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50), and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Blood samples were obtained from 10 rabbits, and the prothrombin time (PT) and the partial thromboplastin time (PTT) tests were conducted. The approximate lethal dose (LD) values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs) = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa), respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2) and melittin, and that can increase the blood clotting times in vitro. PMID:26998384

Honey Bee Venom (Apis mellifera) Contains Anticoagulation Factors and Increases the Blood-clotting Time.

PubMed

Zolfagharian, Hossein; Mohajeri, Mohammad; Babaie, Mahdi

2015-12-01

Bee venom (BV) is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera) on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50), and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Blood samples were obtained from 10 rabbits, and the prothrombin time (PT) and the partial thromboplastin time (PTT) tests were conducted. The approximate lethal dose (LD) values of BV were determined. Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs) = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa), respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2) and melittin, and that can increase the blood clotting times in vitro.

Clostridium difficile colitis: increasing incidence, risk factors, and outcomes in solid organ transplant recipients.

PubMed

Boutros, Marylise; Al-Shaibi, Maha; Chan, Gabriel; Cantarovich, Marcelo; Rahme, Elham; Paraskevas, Steven; Deschenes, Marc; Ghali, Peter; Wong, Philip; Fernandez, Myriam; Giannetti, Nadia; Cecere, Renzo; Hassanain, Mazen; Chaudhury, Prosanto; Metrakos, Peter; Tchervenkov, Jean; Barkun, Jeffrey S

2012-05-27

Clostridium difficile-associated diarrhea (CDAD) is an increasingly important diagnosis in solid organ transplant recipients, with rising incidence and mortality. We describe the incidence, risk factors, and outcomes of colectomy for CDAD after solid organ transplantation. Patients with CDAD were identified from a prospective transplant database. Complicated Clostridium difficile colitis (CCDC) was defined as CDAD associated with graft loss, total colectomy, or death. From 1999 to 2010, we performed solid organ transplants for 1331 recipients at our institution. The incidence of CDAD was 12.4% (165 patients); it increased from 4.5% (1999) to 21.1% (2005) and finally 9.5% (2010). The peak frequency of CDAD was between 6 and 10 days posttransplantation. Age more than 55 years (hazard ratio [HR]: 1.47, 95% confidence interval [CI]=1.16-1.81), induction with antithymocyte globulin (HR: 1.43, 95% CI=1.075-1.94), and transplant other than kidney alone (liver, heart, pancreas, or combined kidney organ) (HR: 1.41, 95% CI=1.05-1.92) were significant independent risk factors for CDAD. CCDC occurred in 15.8% of CDAD cases. Independent predictors of CCDC were white blood cell count more than 25,000/μL (HR: 1.08, 95% CI=1.025-1.15) and evidence of pancolitis on computed tomography scan (HR: 2.52, 95% CI=1.195-5.35). Six patients with CCDC underwent colectomy with 83% patient survival and 20% graft loss. Of the medically treated patients with CCDC (n=20), the patient survival was 35% with 100% graft loss. We have identified significant risk factors for CDAD and predictors of progression to CCDC. Furthermore, we found that colectomy can be performed with excellent survival in selected patients.

Increased macrophage colony-stimulating factor levels in patients with Graves' disease.

PubMed

Morishita, Eriko; Sekiya, Akiko; Hayashi, Tomoe; Kadohira, Yasuko; Maekawa, Mio; Yamazaki, Masahide; Asakura, Hidesaku; Nakao, Shinji; Ohtake, Shigeki

2008-10-01

Previous studies have found markedly elevated serum concentrations of proinflammatory cytokines in patients with Graves' disease (GD). We investigated the role of macrophage colony-stimulating factor (M-CSF) in GD. We assayed concentrations of M-CSF in sera from 32 patients with GD (25 untreated; 7 receiving thiamazole therapy). We also studied 32 age-matched healthy subjects as controls. Relationships between serum M-CSF and both thyroid state and serum lipids were examined. Moreover, to examine the effect of thyroid hormone alone on serum M-CSF, T3 was administered orally to normal subjects. Serum concentrations of M-CSF in GD patients who were hyperthyroid were significantly increased compared with GD patients who were euthyroid (P < 0.05) and control subjects (P < 0.0001). Serum M-CSF concentrations correlated closely with T3 levels in patients (r = 0.51, P < 0.005). Serial measurement of five individual patients revealed that serum concentrations of M-CSF were significantly decreased (P < 0.05), reaching normal control values upon attainment of euthyroidism. Furthermore, oral T3 administered to 15 volunteers for 7 days produced significant increases in serum levels of M-CSF (P < 0.05). The close correlation between serum M-CSF and serum thyroid hormone levels suggests that high circulating levels of thyroid hormones may directly or indirectly potentiate the production of M-CSF in patients with GD.

A simple method of equine limb force vector analysis and its potential applications.

PubMed

Hobbs, Sarah Jane; Robinson, Mark A; Clayton, Hilary M

2018-01-01

Ground reaction forces (GRF) measured during equine gait analysis are typically evaluated by analyzing discrete values obtained from continuous force-time data for the vertical, longitudinal and transverse GRF components. This paper describes a simple, temporo-spatial method of displaying and analyzing sagittal plane GRF vectors. In addition, the application of statistical parametric mapping (SPM) is introduced to analyse differences between contra-lateral fore and hindlimb force-time curves throughout the stance phase. The overall aim of the study was to demonstrate alternative methods of evaluating functional (a)symmetry within horses. GRF and kinematic data were collected from 10 horses trotting over a series of four force plates (120 Hz). The kinematic data were used to determine clean hoof contacts. The stance phase of each hoof was determined using a 50 N threshold. Vertical and longitudinal GRF for each stance phase were plotted both as force-time curves and as force vector diagrams in which vectors originating at the centre of pressure on the force plate were drawn at intervals of 8.3 ms for the duration of stance. Visual evaluation was facilitated by overlay of the vector diagrams for different limbs. Summary vectors representing the magnitude (VecMag) and direction (VecAng) of the mean force over the entire stance phase were superimposed on the force vector diagram. Typical measurements extracted from the force-time curves (peak forces, impulses) were compared with VecMag and VecAng using partial correlation (controlling for speed). Paired samples t -tests (left v. right diagonal pair comparison and high v. low vertical force diagonal pair comparison) were performed on discrete and vector variables using traditional methods and Hotelling's T 2 tests on normalized stance phase data using SPM. Evidence from traditional statistical tests suggested that VecMag is more influenced by the vertical force and impulse, whereas VecAng is more influenced by the

A simple method of equine limb force vector analysis and its potential applications

PubMed Central

Robinson, Mark A.; Clayton, Hilary M.

2018-01-01

Background Ground reaction forces (GRF) measured during equine gait analysis are typically evaluated by analyzing discrete values obtained from continuous force-time data for the vertical, longitudinal and transverse GRF components. This paper describes a simple, temporo-spatial method of displaying and analyzing sagittal plane GRF vectors. In addition, the application of statistical parametric mapping (SPM) is introduced to analyse differences between contra-lateral fore and hindlimb force-time curves throughout the stance phase. The overall aim of the study was to demonstrate alternative methods of evaluating functional (a)symmetry within horses. Methods GRF and kinematic data were collected from 10 horses trotting over a series of four force plates (120 Hz). The kinematic data were used to determine clean hoof contacts. The stance phase of each hoof was determined using a 50 N threshold. Vertical and longitudinal GRF for each stance phase were plotted both as force-time curves and as force vector diagrams in which vectors originating at the centre of pressure on the force plate were drawn at intervals of 8.3 ms for the duration of stance. Visual evaluation was facilitated by overlay of the vector diagrams for different limbs. Summary vectors representing the magnitude (VecMag) and direction (VecAng) of the mean force over the entire stance phase were superimposed on the force vector diagram. Typical measurements extracted from the force-time curves (peak forces, impulses) were compared with VecMag and VecAng using partial correlation (controlling for speed). Paired samples t-tests (left v. right diagonal pair comparison and high v. low vertical force diagonal pair comparison) were performed on discrete and vector variables using traditional methods and Hotelling’s T2 tests on normalized stance phase data using SPM. Results Evidence from traditional statistical tests suggested that VecMag is more influenced by the vertical force and impulse, whereas VecAng is

Lifestyle Risk Factors Increase the Risk of Hospitalization for Sciatica: Findings of Four Prospective Cohort Studies.

PubMed

Shiri, Rahman; Euro, Ulla; Heliövaara, Markku; Hirvensalo, Mirja; Husgafvel-Pursiainen, Kirsti; Karppinen, Jaro; Lahti, Jouni; Rahkonen, Ossi; Raitakari, Olli T; Solovieva, Svetlana; Yang, Xiaolin; Viikari-Juntura, Eira; Lallukka, Tea

2017-12-01

The purpose of this study is to assess the effects of lifestyle risk factors on the risk of hospitalization for sciatica and to determine whether overweight or obesity modifies the effect of leisure-time physical activity on hospitalization for sciatica. We included 4 Finnish prospective cohort studies (Health 2000 Survey, Mobile Clinic Survey, Helsinki Health Study, and Young Finns Study) consisting of 34,589 participants and 1259 hospitalizations for sciatica during 12 to 30 years of follow-up. Sciatica was based on hospital discharge register data. We conducted a random-effects individual participant data meta-analysis. After adjustment for confounding factors, current smoking at baseline increased the risk of subsequent hospitalization for sciatica by 33% (95% confidence interval [CI], 13%-56%), whereas past smokers were no longer at increased risk. Obesity defined by body mass index increased the risk of hospitalization for sciatica by 36% (95% CI 7%-74%), and abdominal obesity defined by waist circumference increased the risk by 41% (95% CI 3%-93%). Walking or cycling to work reduced the risk of hospitalization for sciatica by 33% (95% CI 4%-53%), and the effect was independent of body weight and other leisure activities, while other types of leisure activities did not have a statistically significant effect. Smoking and obesity increase the risk of hospitalization for sciatica, whereas walking or cycling to work protects against hospitalization for sciatica. Walking and cycling can be recommended for the prevention of sciatica in the general population. Copyright © 2017 Elsevier Inc. All rights reserved.

Kinetic quantification of plyometric exercise intensity.

PubMed

Ebben, William P; Fauth, McKenzie L; Garceau, Luke R; Petushek, Erich J

2011-12-01

Ebben, WP, Fauth, ML, Garceau, LR, and Petushek, EJ. Kinetic quantification of plyometric exercise intensity. J Strength Cond Res 25(12): 3288-3298, 2011-Quantification of plyometric exercise intensity is necessary to understand the characteristics of these exercises and the proper progression of this mode of exercise. The purpose of this study was to assess the kinetic characteristics of a variety of plyometric exercises. This study also sought to assess gender differences in these variables. Twenty-six men and 23 women with previous experience in performing plyometric training served as subjects. The subjects performed a variety of plyometric exercises including line hops, 15.24-cm cone hops, squat jumps, tuck jumps, countermovement jumps (CMJs), loaded CMJs equal to 30% of 1 repetition maximum squat, depth jumps normalized to the subject's jump height (JH), and single leg jumps. All plyometric exercises were assessed with a force platform. Outcome variables associated with the takeoff, airborne, and landing phase of each plyometric exercise were evaluated. These variables included the peak vertical ground reaction force (GRF) during takeoff, the time to takeoff, flight time, JH, peak power, landing rate of force development, and peak vertical GRF during landing. A 2-way mixed analysis of variance with repeated measures for plyometric exercise type demonstrated main effects for exercise type and all outcome variables (p ≤ 0.05) and for the interaction between gender and peak vertical GRF during takeoff (p ≤ 0.05). Bonferroni-adjusted pairwise comparisons identified a number of differences between the plyometric exercises for the outcome variables assessed (p ≤ 0.05). These findings can be used to guide the progression of plyometric training by incorporating exercises of increasing intensity over the course of a program.

Increased and correlated expression of connective tissue growth factor and transforming growth factor beta 1 in surgically removed periodontal tissues with chronic periodontitis.

PubMed

Mize, T W; Sundararaj, K P; Leite, R S; Huang, Y

2015-06-01

Both gingival tissue destruction and regeneration are associated with chronic periodontitis, although the former overwhelms the latter. Studies have shown that transforming growth factor beta 1 (TGF-β1), a growth factor largely involved in tissue regeneration and remodeling, is upregulated in chronic periodontitis. However, the gingival expression of connective tissue growth factor (CTGF or CCN2), a TGF-β1-upregulated gene, in patients with periodontitis remains undetermined. Although both CTGF/CCN2 and TGF-b1 increase the production of extracellular matrix, they have many different biological functions. Therefore, it is important to delineate the impact of periodontitis on gingival CTGF/CCN2 expression. Periodontal tissue specimens were collected from seven individuals without periodontitis (group 1) and from 14 with periodontitis (group 2). The expression of CTGF and TGFβ1 mRNAs were quantified using real-time PCR. Analysis using the nonparametric Mann-Whitney U-test showed that the levels of expression of both CTGF/CCN2 and TGFβ1 mRNAs were significantly increased in individuals with periodontitis compared with individuals without periodontitis. Furthermore, analysis using a nonparametric correlation (Spearman r) test showed a positive correlation between TGFβ1 and CTGF/CCN2 mRNAs. The gingival expression levels of CTGF/CCN2 and TGFβ1 mRNAs in individuals with periodontitis are upregulated and correlated. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Structural factors that increase HIV/STI vulnerability among indigenous people in the Peruvian amazon.

PubMed

Orellana, E Roberto; Alva, Isaac E; Cárcamo, Cesar P; García, Patricia J

2013-09-01

We examined structural factors-social, political, economic, and environmental-that increase vulnerability to HIV among indigenous people in the Peruvian Amazon. Indigenous adults belonging to 12 different ethnic groups were purposively recruited in four Amazonian river ports and 16 indigenous villages. Qualitative data revealed a complex set of structural factors that give rise to environments of risk where health is constantly challenged. Ferryboats that cross Amazonian rivers are settings where unprotected sex-including transactional sex between passengers and boat crew and commercial sex work-often take place. Population mobility and mixing also occurs in settings like the river docks, mining sites, and other resource extraction camps, where heavy drinking and unprotected sex work are common. Multilevel, combination prevention strategies that integrate empirically based interventions with indigenous knowledge are urgently needed, not only to reduce vulnerability to HIV transmission, but also to eliminate the structural determinants of indigenous people's health.

Casein kinase 2 (CK2) increases survivin expression via enhanced β-catenin–T cell factor/lymphoid enhancer binding factor-dependent transcription

PubMed Central

Tapia, J. C.; Torres, V. A.; Rodriguez, D. A.; Leyton, L.; Quest, A. F. G.

2006-01-01

Increased expression of casein kinase 2 (CK2) is associated with hyperproliferation and suppression of apoptosis in cancer. Mutations in the tumor suppressor APC (adenomatous polyposis coli) are frequent in colon cancer and often augment β-catenin–T cell factor (Tcf)/lymphoid enhancer binding factor (Lef)-dependent transcription of genes such as c-myc and cyclin-D1. CK2 has also been implicated recently in the regulation of β-catenin stability. To identify mechanisms by which CK2 promotes survival, effects of the specific CK2 inhibitors 4,5,6,7-tetrabromobenzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole were assessed. TBB and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole significantly decreased proliferation and increased apoptosis of HT29(US) colon cancer cells. RT-PCR and immunoblot analysis revealed that both inhibitors decreased survivin mRNA and protein levels in HT29(US) cells. Similar effects were observed with TBB in human DLD-1 and SW-480 colorectal cells as well as ZR-75 breast cancer cells and HEK-293T embryonic kidney cells. Expression of GFP–CK2α in HEK-293T cells resulted in β-catenin–Tcf/Lef-dependent up-regulation of survivin and increased resistance to anticancer drugs. Augmented β-catenin–Tcf/Lef-dependent transcription and resistance to apoptosis observed upon GFP–CK2α expression were abolished by TBB. Alternatively, HEK-293T cells expressing GFP–survivin were resistant to TBB-induced apoptosis. Finally, siRNA-mediated down-regulation of CK2α in HEK-293T cells coincided with reduced β-catenin and survivin levels. Taken together, these results suggest that CK2 kinase activity promotes survival by increasing survivin expression via β-catenin–Tcf/Lef-mediated transcription. Hence, selective CK2 inhibition or down-regulation in tumors may provide an attractive opportunity for the development of novel cancer therapies. PMID:17005722

Effects of Prophylactic Ankle Supports on Vertical Ground Reaction Force During Landing: A Meta-Analysis.

PubMed

Niu, Wenxin; Feng, Tienan; Wang, Lejun; Jiang, Chenghua; Zhang, Ming

2016-03-01

There has been much debate on how prophylactic ankle supports (PASs) may influence the vertical ground reaction force (vGRF) during landing. Therefore, the primary aims of this meta-analysis were to systematically review and synthesize the effect of PASs on vGRF, and to understand how PASs affect vGRF peaks (F1, F2) and the time from initial contact to peak loading (T1, T2) during landing. Several key databases, including Scopus, Cochrane, Embase, PubMed, ProQuest, Medline, Ovid, Web of Science, and the Physical Activity Index, were used for identifying relevant studies published in English since inception to April 1, 2015. The computerized literature search and cross-referencing the citation list of the articles yielded 3,993 articles. Criteria for inclusion required that 1) the study was conducted on healthy adults; 2) the subject number and trial number were known; 3) the subjects performed landing with and without PAS; 4) the landing movement was in the sagittal plane; 5) the comparable vGRF parameters were reported; and 6) the F1 and F2 must be normalized to the subject's body weight. After the removal of duplicates and irrelevant articles, 6, 6, 15 and 11 studies were respectively pooled for outcomes of F1, T1, F2 and T2. This study found a significantly increased F2 (.03 BW, 95% CI: .001, .05) and decreased T1 (-1.24 ms, 95% CI: -1.77, -.71) and T2 (-3.74 ms, 95% CI: -4.83, -2.65) with the use of a PAS. F1 was not significantly influenced by the PAS. Heterogeneity was present in some results, but there was no evidence of publication bias for any outcome. These changes represented deterioration in the buffering characteristics of the joint. An ideal PAS design should limit the excessive joint motion of ankle inversion, while allowing a normal range of motion, especially in the sagittal plane. Key pointsPAS can effectively protect the ligamentous structure from spraining by providing mechanical support and cutaneous proprioceptive benefits.Using of PAS can

Increased urinary excretion of platelet activating factor in mice with lupus nephritis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macconi, D.; Noris, M.; Benfenati, E.

1991-01-01

Platelet activating factor (PAF) is present in urine from humans and experimental animals in normal conditions. Very little is known about changes in PAF urinary excretion under pathologic conditions and no data are available about the origin of PAF in the urine. In the present study we explored the possibility that immunologic renal disease is associated with an increase in PAF urinary excretion using gas chromatography-mass spectrometry technique. To clarify the renal or extrarenal origin of urinary PAF we evaluated whether exogenously administered PAF (1-(1{prime},2{prime}-{sup 3}H)alkyl) is filtered through the glomerulus and excreted in the urine. The results show that:more » (1) urine from mice with lupus nephritis in the early phase of the disease contained amounts of PAF comparable to those excreted in normal mouse urine, (2) PAF levels increased when animals started to develop high grade proteinuria, (3) after intravenous injection of ({sup 3}H) PAF In nephritic mice, a negligible amount of ({sup 3}H) ether lipid, corresponding to ({sup 3}H)1-alkyl -2-acyl-3-phosphocholine (alkyl-2-acyl-GPC), was recovered from the 24 h urine extract.« less

Burkholderia Diffusible Signal Factor Signals to Francisella novicida To Disperse Biofilm and Increase Siderophore Production

PubMed Central

Dean, Scott N.; Chung, Myung-Chul

2015-01-01

In many bacteria, the ability to modulate biofilm production relies on specific signaling molecules that are either self-produced or made by neighboring microbes within the ecological niche. We analyzed the potential interspecies signaling effect of the Burkholderia diffusible signal factor (BDSF) on Francisella novicida, a model organism for Francisella tularensis, and demonstrated that BDSF both inhibits the formation and causes the dispersion of Francisella biofilm. Specificity was demonstrated for the cis versus the trans form of BDSF. Using transcriptome sequencing, quantitative reverse transcription-PCR, and activity assays, we found that BDSF altered the expression of many F. novicida genes, including genes involved in biofilm formation, such as chitinases. Using a chitinase inhibitor, the antibiofilm activity of BDSF was also shown to be chitinase dependent. In addition, BDSF caused an increase in RelA expression and increased levels of (p)ppGpp, leading to decreased biofilm production. These results support our observation that exposure of F. novicida to BDSF causes biofilm dispersal. Furthermore, BDSF upregulated the genes involved in iron acquisition (figABCD), increasing siderophore production. Thus, this study provides evidence for a potential role and mechanism of diffusible signal factor (DSF) signaling in the genus Francisella and suggests the possibility of interspecies signaling between Francisella and other bacteria. Overall, this study suggests that in response to the interspecies DSF signal, F. novicida can alter its gene expression and regulate its biofilm formation. PMID:26231649

Increased platelet factor 4 and aberrant permeability of follicular fluid in PCOS.

PubMed

Huang, Chu-Chun; Chou, Chia-Hung; Chen, Shee-Uan; Ho, Hong-Nerng; Yang, Yu-Shih; Chen, Mei-Jou

2018-05-17

Abnormal folliculogenesis is one of the cardinal presentations of polycystic ovarian syndrome (PCOS) and permeability of follicular wall has been proposed to be involved in the normal follicular growth. However, whether or not there is a change in intrafollicular permeability underlies PCOS is unknown. This was a tertiary center-based case-control study. From 2014 to 2015, thirteen patients with PCOS who underwent in vitro fertilization-embryo transfer (IVF-ET) were enrolled. Eleven normo-ovulatory patients who underwent IVF-ET due to male factor and/or tubal factor infertility were enrolled as the control group. The influence of ovarian follicular fluid (FF) on endothelial cell permeability was evaluated using a human umbilical vein endothelial cell monolayer permeability assay. The intrafollicular expression profiles of angiogenesis-related proteins were analyzed using a Human Angiogenesis Protein Array Kit. The FF from PCOS patients caused significantly poorer endothelial cell permeability comparing with the effect of FF from the control group (46% ± 12% vs. 58% ± 9%, P = 0.023). Among the 55 angiogenesis-related proteins tested, there was a significantly higher level of intrafollicular platelet factor 4 (PF4) and PF4/IL-8 complex in the PCOS group (p = 0.004). The anti-permeability effect of PF4 was related to the decrease in the intercellular gaps and antagonistic binding with IL-8. Our study provides the first evidence of the pathophysiologic contribution of the well-known angiostatic protein, PF4, on human reproductive biology. The increase of the intrafollicular PF4 and its anti-permeability effect might affect the formation of FF and folliculogenesis in PCOS. Copyright © 2018. Published by Elsevier B.V.

Increased Serum Levels of Epidermal Growth Factor in Children with Autism

ERIC Educational Resources Information Center

Iseri, Elvan; Guney, Esra; Ceylan, Mehmet F.; Yucel, Aysegul; Aral, Arzu; Bodur, Sahin; Sener, Sahnur

2011-01-01

The etiology of autism is unclear, however autism is considered as a multifactorial disorder that is influenced by neurological, environmental, immunological and genetic factors. Growth factors, including epidermal growth factor (EGF), play an important role in the celluler proliferation and the differentiation of the central and peripheral…

A compendium of transcription factor and Transcriptionally active protein coding gene families in cowpea (Vigna unguiculata L.).

PubMed

Misra, Vikram A; Wang, Yu; Timko, Michael P

2017-11-22

Cowpea (Vigna unguiculata (L.) Walp.) is the most important food and forage legume in the semi-arid tropics of sub-Saharan Africa where approximately 80% of worldwide production takes place primarily on low-input, subsistence farm sites. Among the major goals of cowpea breeding and improvement programs are the rapid manipulation of agronomic traits for seed size and quality and improved resistance to abiotic and biotic stresses to enhance productivity. Knowing the suite of transcription factors (TFs) and transcriptionally active proteins (TAPs) that control various critical plant cellular processes would contribute tremendously to these improvement aims. We used a computational approach that employed three different predictive pipelines to data mine the cowpea genome and identified over 4400 genes representing 136 different TF and TAP families. We compare the information content of cowpea to two evolutionarily close species common bean (Phaseolus vulgaris), and soybean (Glycine max) to gauge the relative informational content. Our data indicate that correcting for genome size cowpea has fewer TF and TAP genes than common bean (4408 / 5291) and soybean (4408/ 11,065). Members of the GROWTH-REGULATING FACTOR (GRF) and Auxin/indole-3-acetic acid (Aux/IAA) gene families appear to be over-represented in the genome relative to common bean and soybean, whereas members of the MADS (Minichromosome maintenance deficient 1 (MCM1), AGAMOUS, DEFICIENS, and serum response factor (SRF)) and C2C2-YABBY appear to be under-represented. Analysis of the AP2-EREBP APETALA2-Ethylene Responsive Element Binding Protein (AP2-EREBP), NAC (NAM (no apical meristem), ATAF1, 2 (Arabidopsis transcription activation factor), CUC (cup-shaped cotyledon)), and WRKY families, known to be important in defense signaling, revealed changes and phylogenetic rearrangements relative to common bean and soybean that suggest these groups may have evolved different functions. The availability of detailed

Dietary L-glutamine supplementation increases Pasteurella multocida burden and the expression of its major virulence factors in mice.

PubMed

Ren, Wenkai; Liu, Shuping; Chen, Shuai; Zhang, Fengmei; Li, Nengzhang; Yin, Jie; Peng, Yuanyi; Wu, Li; Liu, Gang; Yin, Yulong; Wu, Guoyao

2013-10-01

This study was conducted to determine the effects of graded doses of L-glutamine supplementation on the replication and distribution of Pasteurella multocida, and the expression of its major virulence factors in mouse model. Mice were randomly assigned to the basal diet supplemented with 0, 0.5, 1.0 or 2.0 % glutamine. Pasteurella multocida burden was detected in the heart, liver, spleen, lung and kidney after 12 h of P. multocida infection. The expression of major virulence factors, toll-like receptors (TLRs), proinflammatory cytokines (interleukin-1 beta, interleukin-6, and tumor necrosis factor alpha) and anti-oxidative factors (GPX1 and CuZnSOD) was analyzed in the lung and spleen. Dietary 0.5 % glutamine supplementation has little significant effect on these parameters, compared to those with basal diet. However, results showed that a high dose of glutamine supplementation increased the P. multocida burden (P < 0.001) and the expression of its major virulence factors (P < 0.05) as compared to those with a lower dose of supplementation. In the lung, high dose of glutamine supplementation inhibited the proinflammatory responses (P < 0.05) and TLRs signaling (P < 0.05). In the spleen, the effect of glutamine supplementation on different components in TLR signaling depends on glutamine concentration, and high dose of glutamine supplementation activated the proinflammatory response. In conclusion, glutamine supplementation increased P. multocida burden and the expression of its major virulence factors, while affecting the functions of the lung and spleen.

THE EFFECTS OF DIFFERENT TRUNK INCLINATIONS ON BILATERAL TRUNK MUSCULAR ACTIVITIES, CENTRE OF PRESSURE AND FORCE EXERTIONS IN STATIC PUSHING POSTURES.

PubMed

Sanjaya, Kadek Heri; Lee, Soomin; Sriwarno, Andar Bagus; Shimomura, Yoshihito; Katsuura, Tetsuo

2014-06-01

In order to reconcile contradictory results from previous studies on manual pushing, a study was conducted to examine the effect of trunk inclination on muscular activities, centre of pressure (COP) and force exertion during static pushing. Ten subjects pushed at 0 degrees, 15 degrees, 30 degrees, and 45 degrees body inclinations in parallel and staggered feet stances. Wall and ground force plates measured pushing force, wall COP, vertical ground reaction force (GRF) and ground COP. Electromyogram data were recorded at 10 trunk muscle sites. Pushing force was found to increase with body inclination. GRF peaked at 15 degrees and reached its lowest level at the 45 degrees inclination. The lowest wall force plate standard deviation of COP displacement was found at the 30 degrees inclination. The lowest low back muscular activity was found at the 15 degrees and 30 degrees inclinations. Based on force exertion, muscular load, and stability, the 30 degrees body inclination was found to be the best posture for static pushing. This study also showed asymmetry in muscular activity and force exertion which has been received less attention in manual pushing studies. These findings will require further study.

Proper motion of the Draco dwarf galaxy based on Hubble space telescope imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pryor, Carlton; Piatek, Slawomir; Olszewski, Edward W., E-mail: pryor@physics.rutgers.edu, E-mail: piatek@physics.rutgers.edu, E-mail: eolszewski@as.arizona.edu

2015-02-01

We have measured the proper motion of the Draco dwarf galaxy using images at two epochs with a time baseline of about two years taken with the Hubble Space Telescope Advanced Camera for Surveys. Wide Field Channels 1 and 2 provide two adjacent fields, each containing a known QSO. The zero point for the proper motion is determined using both background galaxies and the QSOs and the two methods produce consistent measurements within each field. Averaging the results from the two fields gives a proper motion in the equatorial coordinate system of (μ{sub α},μ{sub δ})=(17.7±6.3,−22.1±6.3) mas century{sup −1} and inmore » the Galactic coordinate system of (μ{sub ℓ},μ{sub b})=(−23.1±6.3,−16.3±6.3) mas century{sup −1}. Removing the contributions of the motion of the Sun and of the LSR to the measured proper motion yields a Galactic rest-frame proper motion of (μ{sub α}{sup Grf},μ{sub δ}{sup Grf})=(51.4±6.3,−18.7±6.3) mas century{sup −1} and (μ{sub ℓ}{sup Grf},μ{sub b}{sup Grf})=(−21.8±6.3,−50.1±6.3) mas century{sup −1}. The implied space velocity with respect to the Galactic center is (Π,Θ,Z)=(27±14,89±25,−212±20) km s{sup −1}. This velocity implies that the orbital inclination is 70{sup ∘}, with a 95% confidence interval of (59{sup ∘},80{sup ∘}), and that the plane of the orbit is consistent with that of the vast polar structure (VPOS) of Galactic satellite galaxies.« less

Factors that affect the postnatal increase in superior mesenteric artery blood flow velocity in very low birth weight preterm infants.

PubMed

Havranek, Thomas; Miladinovic, Branko; Wadhawan, Rajan; Carver, Jane D

2012-04-15

To identify factors related to the postnatal increase in superior mesenteric artery blood flow velocity (SMA BFV). SMA BFV was measured in 35 infants (birth weight 1047±246 g) on day of life (DOL) 1, 3, 5, 7 10 and 14. Latent curve modeling (LCM) was used to measure the longitudinal change in BFV for each subject, and the correlation between changes in BFV and baseline values. Non-parametric correlations were calculated between BFV and variables previously reported to be related to SMA BFV. There was significant variability in SMA BFV on DOL 1, a significant increase from DOL 1-14, and significant variability in the postnatal increase. Infants with higher enteral feeding volumes had greater increases, while infants receiving positive pressure ventilation or hyperalimentation had lower increases. Several clinical factors affect the postnatal increase in SMA BFV. The use of LCM is useful in longitudinal studies of very low birth weight (VLBW) infants, who are clinically and demographically heterogeneous.

Body armour: the effect of load, exercise and distraction on landing forces.

PubMed

Dempsey, Paddy C; Handcock, Phil J; Rehrer, Nancy J

2014-01-01

We investigated the effect of added load and intense exercise on jump and landing performance and ground reaction force (GRF) during landings where attentional demand was varied. Fifty-two males (37 ± 9.2 years, 180.7 ± 6.1 cm, 90.2 ± 11.6 kg, maximal aerobic fitness (VO(₂max)) 50 ± 8.5 ml (.) kg(-1 .) min(-1), BMI 27.6 ± 3.1, mean ± s) completed a VO(₂max) test. Experimental sessions were completed (≥4 days in between) in a randomised counterbalanced order, one while wearing body armour and appointments (loaded) and one without load (unloaded). A vertical jump, a drop landing concentrating on safe touchdown, a drop jump and a drop landing with an attentional distraction were performed. These were repeated 1 min after a 5-min treadmill run. Mean jump height decreased by 12% (P < 0.001) with loading and a further by 6% following the running task. Peak GRFs were increased by 13-19% with loading (P < 0.001) depending on the landing task demands and a further by 4-9% following intense exercise. The distracted drop landing had significantly higher GRFs compared to all other landings. Results demonstrate that added load impacts on jumping and landing performance, an effect that is amplified by prior intense exercise, and distraction during landing. Such increases in GRF apply to police officer performance in their duties and may increase the risk of injury.

The influence of different lower seat height on the muscular stress during squatting for a ground level job.

PubMed

Sriwarno, Andar Bagus; Shimomura, Yoshihiro; Iwanaga, Koichi; Katsuura, Tetsuo

2007-06-01

Work requiring extremely body flexion is strongly associated with a high incidence of musculoskeletal injuries often reported during adopting squatting. In this study, the influence of different lower seat heights on the muscular stress in squatting on a stool (SS) were examined in comparison with fully squatting (FS). Fourteen healthy Indonesian males were recruited in the experiment. Two-dimensional body kinematics, ground reaction force (GRF) and electromyography (EMG) data were collected as subjects performed forward movement under four squatting height conditions which were FS and SS at 10 cm, 15 cm and 20 cm seat height. The results demonstrated that the change from FS to SS primarily affected the segmental angular flexions and muscular activities in the upper and lower limbs. GRF data showed that the SS conditions delivered 24% body weight onto the seat. The change of FS to SS showed significantly decrease in muscular load of the rectus femoris and tibialis anterior. In contrast, the soleus and gastrocnemius increased the activities as the seat height increased. The type of task that required the hand to handle the object on the ground level affected the trunk to be more flexed as the seat height increased. The findings of this study suggest that the use of a lower seat stool of a proper height seems to be a sub-optimal solution considering the change of muscular load associated with the discomfort in a squatting posture.

Cost of bariatric surgery and factors associated with increased cost: an analysis of national inpatient sample.

PubMed

Khorgami, Zhamak; Aminian, Ali; Shoar, Saeed; Andalib, Amin; Saber, Alan A; Schauer, Philip R; Brethauer, Stacy A; Sclabas, Guido M

2017-08-01

In the current healthcare environment, bariatric surgery centers need to be cost-effective while maintaining quality. The aim of this study was to evaluate national cost of bariatric surgery to identify the factors associated with a higher cost. A retrospective analysis of 2012-2013 Healthcare Cost and Utilization Project - Nationwide Inpatient Sample (HCUP-NIS). We included all patients with a diagnosis of morbid obesity (ICD9 278.01) and a Diagnosis Related Group code related to procedures for obesity, who underwent Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), or adjustable gastric banding (AGB) as their primary procedure. We converted "hospital charges" to "cost," using hospital specific cost-to-charge ratio. Inflation was adjusted using the annual consumer price index. Increased cost was defined as the top 20th percentile of the expenditure and its associated factors were analyzed using the logistic regression multivariate analysis. A total of 45,219 patients (20,966 RYGBs, 22,380 SGs, and 1,873 AGBs) were included. The median (interquartile range) calculated costs for RYGB, SG, and AGB were $12,543 ($9,970-$15,857), $10,531 ($8,248-$13,527), and $9,219 ($7,545-$12,106), respectively (P<.001). Robotic-assisted procedures had the highest impact on the cost (odds ratio 3.6, 95% confidence interval 3.2-4). Hospital cost of RYGB and SG increased linearly with the length of hospital stay and almost doubled after 7 days. Furthermore, multivariate analysis showed that certain co-morbidities and concurrent procedures were associated with an increased cost. Factors contributing to the cost variation of bariatric procedures include co-morbidities, robotic platform, complexity of surgery, and hospital length of stay. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Lower limb mechanics during moderate high-heel jogging and running in different experienced wearers.

PubMed

Fu, Fengqin; Zhang, Yan; Shu, Yang; Ruan, Guoqing; Sun, Jianjun; Baker, Julien S; Gu, Yaodong

2016-08-01

The aim of this study is to investigate the differences in lower limb kinematics and kinetics between experienced (EW) and inexperienced (IEW) moderate high-heel wearers during jogging and running. Eleven experienced female wearers of moderate high-heel shoes and eleven matched controls participated in jogging and running tests. A Vicon motion analysis system was used to capture kinematic data and a Kistler force platform was used to collect ground reaction force (GRF). There were no significant differences in jogging and running speed respectively. Compared with IEW, EW adopted larger stride length (SL) with lower stride frequency (SF) at each corresponding speed. During running, EW enlarged SL significantly while IEW increased both SL and SF significantly. Kinematic data showed that IEW had generally larger joint range of motion (ROM) and peak angles during stance phase. Speed effect was not obvious within IEW. EW exhibited a significantly increased maximal vertical GRF (Fz2) and vertical average loading rate (VALR) during running, which was potentially caused by overlong stride. These suggest that both EW and IEW are at high risk of joint injuries when running on moderate high heels. For wearers who have to do some running on moderate high heels, it is crucial to control joint stability and balance SL and SF consciously. Copyright © 2016 Elsevier B.V. All rights reserved.

Insulin and insulin-like growth factor-1 increased in preterm neonates following massage therapy.

PubMed

Field, Tiffany; Diego, Miguel; Hernandez-Reif, Maria; Dieter, John N I; Kumar, Adarsh M; Schanberg, Saul; Kuhn, Cynthia

2008-12-01

To determine if massage therapy increased serum insulin and insulin-like growth factor-1 (IGF-1) in preterm neonates. Forty-two preterm neonates who averaged 34.6 weeks (M = 29.5 wk gestational age; M birth weight = 1237 g) and were in the "grower" (step-down) nursery were randomly assigned to a massage therapy group (body stroking and passive limb movements for three, 15-minute periods per day for 5 days) or a control group that received the standard nursery care without massage therapy. On Days 1 and 5, the serum collected by clinical heelsticks was also assayed for insulin and IGF-1, and weight gain and kilocalories consumed were recorded daily. Despite similar formula intake, the massaged preterm neonates showed greater increases during the 5-day period in (1) weight gain; (2) serum levels of insulin; and (3) IGF-1. Increased weight gain was significantly correlated with insulin and IGF-1. Previous data suggested that preterm infant weight gain following massage therapy related to increased vagal activity, which suggests decreased stress and gastric motility, which may contribute to more efficient food absorption. The data from this study suggest for the first time that weight gain was also related to increased serum insulin and IGF-1 levels following massage therapy. Preterm infants who received massage therapy not only showed greater weight gain but also a greater increase in serum insulin and IGF-1 levels, suggesting that massage therapy might be prescribed for all growing neonates.

Milk consumption during pregnancy increases birth weight, a risk factor for the development of diseases of civilization.

PubMed

Melnik, Bodo C; John, Swen Malte; Schmitz, Gerd

2015-01-16

Antenatal dietary lifestyle intervention and nutrition during pregnancy and early postnatal life are important for appropriate lifelong metabolic programming. Epidemiological evidence underlines the crucial role of increased birth weight as a risk factor for the development of chronic diseases of civilization such as obesity, diabetes and cancer. Obstetricians and general practitioners usually recommend milk consumption during pregnancy as a nutrient enriched in valuable proteins and calcium for bone growth. However, milk is not just a simple nutrient, but has been recognized to function as an endocrine signaling system promoting anabolism and postnatal growth by activating the nutrient-sensitive kinase mTORC1. Moreover, pasteurized cow's milk transfers biologically active exosomal microRNAs into the systemic circulation of the milk consumer apparently affecting more than 11,000 human genes including the mTORC1-signaling pathway. This review provides literature evidence and evidence derived from translational research that milk consumption during pregnancy increases gestational, placental, fetal and birth weight. Increased birth weight is a risk factor for the development of diseases of civilization thus involving key disciplines of medicine. With regard to the presented evidence we suggest that dietary recommendations promoting milk consumption during pregnancy have to be re-evaluated.

Ankle taping can reduce external ankle joint moments during drop landings on a tilted surface.

PubMed

Sato, Nahoko; Nunome, Hiroyuki; Hopper, Luke S; Ikegami, Yasuo

2017-09-20

Ankle taping is commonly used to prevent ankle sprains. However, kinematic assessments investigating the biomechanical effects of ankle taping have provided inconclusive results. This study aimed to determine the effect of ankle taping on the external ankle joint moments during a drop landing on a tilted surface at 25°. Twenty-five participants performed landings on a tilted force platform that caused ankle inversion with and without ankle taping. Landing kinematics were captured using a motion capture system. External ankle inversion moment, the angular impulse due to the medio-lateral and vertical components of ground reaction force (GRF) and their moment arm lengths about the ankle joint were analysed. The foot plantar inclination relative to the ground was assessed. In the taping condition, the foot plantar inclination and ankle inversion angular impulse were reduced significantly compared to that of the control. The only component of the external inversion moment to change significantly in the taped condition was a shortened medio-lateral GRF moment arm length. It can be assumed that the ankle taping altered the foot plantar inclination relative to the ground, thereby shortening the moment arm of medio-lateral GRF that resulted in the reduced ankle inversion angular impulse.

Musculoskeletal loading during the round-off in female gymnastics: the effect of hand position.

PubMed

Farana, Roman; Jandacka, Daniel; Uchytil, Jaroslav; Zahradnik, David; Irwin, Gareth

2014-06-01

Chronic elbow injuries from tumbling in female gymnastics present a serious problem for performers. This research examined how the biomechanical characteristics of impact loading and elbow kinematics and kinetics change as a function of technique selection. Seven international-level female gymnasts performed 10 trials of the round-off from a hurdle step to flic-flac with 'parallel' and 'T-shape' hand positions. Synchronized kinematic (3D-automated motion analysis system; 247 Hz) and kinetic (two force plates; 1,235 Hz) data were collected for each trial. Wilcoxon non-parametric test and effect-size statistics determined differences between the hand positions examined in this study. Significant differences (p < 0.05) and large effect sizes (ES > 0.8) were observed for peak vertical ground reaction force (GRF), anterior-posterior GRF, resultant GRF, loading rates of these forces and elbow joint angles, and internal moments of force in sagittal, transverse, and frontal planes. In conclusion, the T-shape hand position reduces vertical, anterior-posterior, and resultant contact forces and has a decreased loading rate indicating a safer technique for the round-off. Significant differences observed in joint elbow moments highlighted that the T-shape position may prevent overloading of the joint complex and consequently reduce the potential for elbow injury.

Metabolic syndrome is a significant and independent risk factor for increased arterial stiffness in Japanese subjects.

PubMed

Satoh, Hiroki; Kishi, Reiko; Tsutsui, Hiroyuki

2009-12-01

Metabolic syndrome (MetS) has been recognized as a risk factor for cardiovascular disease; however, the impact of MetS on arterial stiffness has not been fully established in the general Japanese population. We analyzed the relationship between MetS and the severity of arterial stiffness using brachial-ankle pulse wave velocity (baPWV) in 2744 male and 358 female subjects aged 38-62 years, adjusted for conventional risk factors and C-reactive protein. The prevalence rates of MetS identified by Japanese criteria were 22.7% (n=624) and 7.8% (n=28) in male and female subjects, respectively. The subjects with MetS had significantly greater mean values of baPWV than those without MetS among both male and female subjects (1444+/-209 vs. 1294+/-165 cm/s in male subjects, P<0.001; 1379+/-151 vs. 1220+/-171 cm/s in female subjects, P<0.001). After adjustment for atherosclerotic variables such as age, smoking habits, total cholesterol and C-reactive protein, the odds ratio (OR) of MetS for increased baPWV was 3.65 in male subjects (95% confidence interval (CI): 2.99-4.47, P<0.001) and 8.02 in female subjects (95% CI: 3.18-20.25 P<0.001). In conclusion, MetS was identified as a significant and independent risk factor for increased arterial stiffness in both the male and female general population in Japan.

Increased metastatic potential of tumor cells in von Willebrand factor-deficient mice.

PubMed

Terraube, V; Pendu, R; Baruch, D; Gebbink, M F B G; Meyer, D; Lenting, P J; Denis, C V

2006-03-01

The key role played by von Willebrand factor (VWF) in platelet adhesion suggests a potential implication in various pathologies, where this process is involved. In cancer metastasis development, tumor cells interact with platelets and the vessel wall to extravasate from the circulation. As a potential mediator of platelet-tumor cell interactions, VWF could influence this early step of tumor spread and therefore play a role in cancer metastasis. To investigate whether VWF is involved in metastasis development. In a first step, we characterized the interaction between murine melanoma cells B16-BL6 and VWF in vitro. In a second step, an experimental metastasis model was used to compare the formation of pulmonary metastatic foci in C57BL/6 wild-type and VWF-null mice following the injection of B16-BL6 cells or Lewis lung carcinoma cells. In vitro adhesion assays revealed that VWF is able to promote a dose-dependent adhesion of B16-BL6 cells via its Arg-Gly-Asp (RGD) sequence. In the experimental metastasis model, we found a significant increase in the number of pulmonary metastatic foci in VWF-null mice compared with the wild-type mice, a phenotype that could be corrected by restoring VWF plasma levels. We also showed that increased survival of the tumor cells in the lungs during the first 24 h in the absence of VWF was the cause of this increased metastasis. These findings suggest that VWF plays a protective role against tumor cell dissemination in vivo. Underlying mechanisms remain to be investigated.

[Evaluation of the increasing serum lactate dehydrogenase caused by recombinant human granulocyte-colony stimulating factor].

PubMed

Sawa, Toshiyuki; Yoshida, Tsutomu; Ikoma, Tetsuroh; Toyoda, Miki; Ohno, Yasushi; Fujiwara, Hisayoshi

2003-01-01

Increasing serum lactate dehydrogenase (LDH) is often caused by granulocyte-colony stimulating factor (G-CSF) for leukopenia following chemotherapy in patients with lung cancer. To evaluate the increase in LDH, we investigated the significance of its elevation and LDH isozyme during chemotherapy supported by recombinant human G-CSF (rhG-CSF). To exclude effects of liver diseases and chemotherapy-induced liver dysfunction, only patients in whom laboratory findings concerning liver function were within normal range were entered in this study. If leukocyte or neutrophil counts were less than grade 3, subcutaneous injection of 50 micrograms/m2 of filgrastim was given daily until leukocyte counts increased to more than 10,000/mm3. Sixty patients with unresectable lung cancer were enrolled in this study and the LDH isozyme was evaluable in 54 patients. Increasing LDH was observed in 38 patients(70.4%), and LDH isozyme was measured in these 38 patients. Increases in granulocytes and LDH isozymes were found to have a positive correlation. LDH2, LDH3, LDH4 and LDH5 increased significantly after rhG-CSF administration, although LDH 1 did not increase. It was found that a rapid increase in leukocytes by rhG-CSF induced an increase in LDH, especially LDH 3.4. Considering the results of principal component analysis and the distribution ratio of LDH isozymes in neutrophils, it is thought that elevation of LDH is reflected in the rapid production and consumption of neutrophils.

Striatal increase of neurotrophic factors as a mechanism of nicotine protection in experimental parkinsonism.

PubMed

Maggio, R; Riva, M; Vaglini, F; Fornai, F; Racagni, G; Corsini, G U

1997-01-01

The repeated finding of an apparent protective effect of cigarette smoking on the risk of Parkinson's disease is one of the few consistent results in the epidemiology of this disorder. Among the innumerous substances that originate from tobacco smoke, nicotine is by far the most widely studied, and the most likely candidate for a protective effect against neuronal degeneration in Parkinson's disease. Nicotine is a natural alkaloid that has considerable stimulatory effects on the central nervous system (CNS). Its effects on the CNS are mediated by the activation of neuronal heteromeric acetylcholine-gated ion channel receptors (nAChR, also termed nicotinic acetylcholine receptors). In the present study, we describe the neuroprotective effects of (-)nicotine in two animal models of parkinsonism: the diethyldithiocarbamate (DDC)-induced enhancement of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in mice, and the methamphetamine-induced neurotoxicity in rats and mice. In parallel experiments, we found that (-)nicotine induces the basic fibroblast growth factor (FGF-2) and the brain-derived neurotrophic factor (BDNF) in rat striatum. As FGF-2 and BDNF have been reported to be neuroprotective for dopaminergic cells, our data indicate that the increase in neurotrophic factors is a possible mechanism by which (-)nicotine protects from experimental parkinsonisms. Moreover, they suggest that nAChR agonists could be of potential benefit in the progression of Parkinson's disease.

Changes in the Width of the Tibiofibular Syndesmosis Related to Lower Extremity Joint Dynamics and Neuromuscular Coordination on Drop Landing During the Menstrual Cycle.

PubMed

Okazaki, Michie; Kaneko, Masaaki; Ishida, Yukisato; Murase, Norio; Katsumura, Toshihito

2017-09-01

Many injuries of the lower extremities, especially the knee and ankle, occur during sports activity, and the incidence rate is higher in women than in men. The hypothesis was that phases of the menstrual cycle affect the width of the tibiofibular syndesmosis during drop landing in healthy young women and that such changes at the tibiofibular joint also affect the dynamics and neuromuscular coordination of the lower extremities. Descriptive laboratory study. Participants included 28 healthy young women (mean age, 21.0 ± 0.8 years). Blood samples were collected to determine plasma levels of estradiol and progesterone immediately before the performance of the task: drop landing on a single leg from a 30-cm platform. Using ultrasonography, the distance between the tibia and the distal end of the fibula, regarded as the width of the tibiofibular syndesmosis, was measured in an upright position without flexion of the ankle. The peak ground-reaction force (GRF) on landing was measured using a force platform. The time to peak GRF (Tp-GRF) was measured as the time from initial ground contact to the peak GRF. Hip, knee, and ankle joint angles during the single-leg landing were calculated using a 3-dimensional motion analysis system. Muscle activities of the lower extremities were measured using surface electromyography. The width of the tibiofibular syndesmosis was significantly greater in the luteal phase when compared with the menstrual, follicular, and ovulation phases (by 5%-8% of control). Also, during the luteal phase, the Tp-GRF was significantly shorter than in the follicular phase (by 6%); hip internal rotation and knee valgus were significantly greater than in the menstrual phase (by 43% and 34%, respectively); knee flexion was significantly less than in the menstrual and follicular phases (by 7%-9%); ankle dorsiflection was significantly less than in the follicular phase (by 11%); ankle adduction and eversion were significantly greater than in the menstrual and

Increased actin polymerization reduces the inhibition of serum response factor activity by Yin Yang 1.

PubMed Central

Ellis, Peter D; Martin, Karen M; Rickman, Colin; Metcalfe, James C; Kemp, Paul R

2002-01-01

Recent evidence has implicated CC(A/T(richG))GG (CArG) boxes, binding sites for serum response factor (SRF), in the regulation of expression of a number of genes in response to changes in the actin cytoskeleton. In many cases, the activity of SRF at CArG boxes is modulated by transcription factors binding to overlapping (e.g. Yin Yang 1, YY1) or adjacent (e.g. ets) binding sites. However, the mechanisms by which SRF activity is regulated by the cytoskeleton have not been determined. To investigate these mechanisms, we screened for cells that did or did not increase the activity of a fragment of the promoter for a smooth-muscle (SM)-specific gene SM22alpha, in response to changes in actin cytoskeletal polymerization induced by LIM kinase. These experiments showed that vascular SM cells (VSMCs) and C2C12 cells increased the activity of promoters containing at least one of the SM22alpha CArG boxes (CArG near) in response to LIM kinase, whereas P19 cells did not. Bandshift assays using a probe to CArG near showed that P19 cells lacked detectable YY1 DNA binding to the CArG box in contrast with the other two cell types. Expression of YY1 in P19 cells inhibited SM22alpha promoter activity and conferred responsiveness to LIM kinase. Mutation of the CArG box to inhibit YY1 or SRF binding indicated that both factors were required for the LIM kinase response in VSMCs and C2C12 cells. The data indicate that changes in the actin cytoskeletal organization modify SRF activity at CArG boxes by modulating YY1-dependent inhibition. PMID:12023898

Clinical and Surgical Factors Associated With Increased Epilepsy Risk in Children With Hydrocephalus.

PubMed

Tully, Hannah M; Kukull, Walter A; Mueller, Beth A

2016-06-01

Children with hydrocephalus are at risk for epilepsy both due to their underlying condition and as a consequence of surgical treatment; however, the relative contributions of these factors remain unknown. The authors sought to characterize epilepsy among children with infancy-onset hydrocephalus and to examine the risks of epilepsy associated with hydrocephalus subtype and with factors related to surgical treatment. We conducted a longitudinal cohort study of all children with infancy-onset hydrocephalus treated at a major regional children's hospital during 2002 to 2012, with follow-up to ascertain risk factors and epilepsy outcome through April 2015. Poisson regression was used to calculate adjusted risk ratios and 95% confidence intervals for associations. Among 379 children with hydrocephalus, 86 (23%) developed epilepsy (mean onset age = 2.7 years), almost one fifth of whom had a history of infantile spasms. Relative to spina bifida-associated hydrocephalus, children with other major hydrocephalus subtypes had fourfold higher risks of developing epilepsy. Among children who underwent surgery, surgical infection doubled the risk of epilepsy (risk ratio = 2.0, 95% confidence interval = 1.4 to 3.0). Epilepsy was associated with surgical failure for intracranial reasons but not extracranial reasons (risk ratio = 1.7, 95% confidence interval = 1.1 to 2.7; risk ratio = 1.1, 95% confidence interval = 0.7 to 1.9, respectively). Epilepsy is common among children with hydrocephalus. Compared with children with spina bifida-associated hydrocephalus, children with other major hydrocephalus subtypes have a markedly increased risk of epilepsy. Surgical infection doubles the risk of epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.

ICSI does not increase the cumulative live birth rate in non-male factor infertility.

PubMed

Li, Z; Wang, A Y; Bowman, M; Hammarberg, K; Farquhar, C; Johnson, L; Safi, N; Sullivan, E A

2018-06-12

What is the cumulative live birth rate following ICSI cycles compared with IVF cycles for couples with non-male factor infertility? ICSI resulted in a similar cumulative live birth rate compared with IVF for couples with non-male factor infertility. The ICSI procedure was developed for couples with male factor infertility. There has been an increased use of ICSI regardless of the cause of infertility. Cycle-based statistics show that there is no difference in pregnancy rates between ICSI and IVF in couples with non-male factor infertility. However, evidence indicates that ICSI is associated with an increased risk of adverse perinatal outcomes. A population-based cohort of 14 693 women, who had their first ever stimulated cycle with fertilization performed for at least one oocyte by either IVF or ICSI between July 2009 and June 2014 in Victoria, Australia was evaluated retrospectively. The pregnancy and birth outcomes following IVF or ICSI were recorded for the first oocyte retrieval (fresh stimulated cycle and associated thaw cycles) until 30 June 2016, or until a live birth was achieved, or until all embryos from the first oocyte retrieval had been used. Demographic, treatment characteristics and resulting outcome data were obtained from the Victorian Assisted Reproductive Treatment Authority. Data items in the VARTA dataset were collected from all fertility clinics in Victoria. Women were grouped by whether they had undergone IVF or ICSI. The primary outcome was the cumulative live birth rate, which was defined as live deliveries (at least one live birth) per woman after the first oocyte retrieval. A discrete-time survival model was used to evaluate the cumulative live birth rate following IVF and ICSI. The adjustment was made for year of treatment in which fertilization occurred, the woman's and male partner's age at first stimulated cycle, parity and the number of oocytes retrieved in the first stimulated cycle. A total of 4993 women undergoing IVF and 8470

Transgenic mice expressing human fibroblast growth factor-19 display increased metabolic rate and decreased adiposity.

PubMed

Tomlinson, Elizabeth; Fu, Ling; John, Linu; Hultgren, Bruce; Huang, Xiaojian; Renz, Mark; Stephan, Jean Philippe; Tsai, Saio Ping; Powell-Braxton, Lyn; French, Dorothy; Stewart, Timothy A

2002-05-01

The fibroblast growth factors (FGFs), and the corresponding receptors, are implicated in more than just the regulation of epithelial cell proliferation and differentiation. Specifically, FGF23 is a regulator of serum inorganic phosphate levels, and mice deficient in FGF receptor-4 have altered cholesterol metabolism. The recently described FGF19 is unusual in that it is nonmitogenic and appears to interact only with FGF receptor-4. Here, we report that FGF19 transgenic mice had a significant and specific reduction in fat mass that resulted from an increase in energy expenditure. Further, the FGF19 transgenic mice did not become obese or diabetic on a high fat diet. The FGF19 transgenic mice had increased brown adipose tissue mass and decreased liver expression of acetyl coenzyme A carboxylase 2, providing two mechanisms by which FGF19 may increase energy expenditure. Consistent with the reduction in expression of acetyl CoA carboxylase 2, liver triglyceride levels were reduced.

Real-time feedback on knee abduction moment does not improve frontal-plane knee mechanics during jump landings.

PubMed

Beaulieu, M L; Palmieri-Smith, R M

2014-08-01

Excessive knee abduction loading is a contributing factor to anterior cruciate ligament (ACL) injury risk. The purpose of this study was to determine whether a double-leg landing training program with real-time visual feedback improves frontal-plane mechanics during double- and single-leg landings. Knee abduction angles and moments and vertical ground reaction forces (GRF) of 21 recreationally active women were quantified for double- and single-leg landings before and after the training program. This program consisted of two sessions of double-leg jump landings with real-time visual feedback on knee abduction moments for the experimental group and without real-time feedback for the control group. No significant differences were found between training groups. In comparison with pre-training data, peak knee abduction moments decreased 12% post-training for both double- and single-leg landings; whereas peak vertical GRF decreased 8% post-training for double-leg landings only, irrespective of training group. Real-time feedback on knee abduction moments, therefore, did not significantly improve frontal-plane knee mechanics during landings. The effect of the training program on knee abduction moments, however, transferred from the double-leg landings (simple task) to single-leg landings (more complex task). Consequently, ACL injury prevention efforts may not need to focus on complex tasks during which injury occurs. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bisphenol A exposure induces increased microglia and microglial related factors in the murine embryonic dorsal telencephalon and hypothalamus.

PubMed

Takahashi, Mifumi; Komada, Munekazu; Miyazawa, Ken; Goto, Shigemi; Ikeda, Yayoi

2018-03-01

Bisphenol A (BPA) is a widely used compound in the food packaging industry. Prenatal exposure to BPA induces histological abnormalities in the neocortex and hypothalamus in association with abnormal behaviors. Yet, the molecular and cellular neurodevelopmental toxicological mechanisms of BPA are incompletely characterized on neuroinflammatory-related endopoints. To evaluate the neurodevelopmental effects of BPA exposure in mouse embryos, we examined microglial numbers as well as the expression of microglial-related factors in the E15.5 embryonic brain. BPA-exposed embryos exhibited significant increases in Iba1-immunoreactive microglial numbers in the dorsal telencephalon and the hypothalamus compared to control embryos. Further, the expression levels of microglial markers (Iba1, CD16, iNOS, and CD206), inflammatory factors (TNFα and IL4), signal transducing molecules (Cx3Cr1 and Cx3Cl1), and neurotrophic factor (IGF1) were altered in BPA-exposed embryos. These findings suggest that BPA exposure increases microglial numbers in the brain and alters the neuroinflammatory status at a transcriptional level. Together, these changes may represent a novel target for neurodevelopmental toxicity assessment after BPA exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

Factors associated with increased academic productivity among US academic radiation oncology faculty.

PubMed

Zhang, Catherine; Murata, Stephen; Murata, Mark; Fuller, Clifton David; Thomas, Charles R; Choi, Mehee; Holliday, Emma B

Publication productivity metrics can help evaluate academic faculty for hiring, promotion, grants, and awards; however, limited benchmarking data exist, which makes intra- and interdepartmental comparisons difficult. Therefore, we sought to evaluate the scholarly activity of physician faculty at academic radiation oncology (RO) departments and establish factors associated with increased academic productivity. Citation database searches were performed for all physician-faculty in US residency-affiliated academic RO departments. Demographics, National Institutes of Health (NIH) funding, and bibliometrics (number of publications, Hirsch-[h]-index, and m-index [Hirsch index divided by the number of years since first publication]) were collected and stratified by academic rank. Senior academic rank was defined as full professor, professor, and/or chair. Junior academic rank was defined as all others. Logistic regression was performed to determine the association of academic rank and other factors with h- and m-indices. A total of 1191 academic RO physician faculty from 75 institutions were included in the analysis. The mean (standard deviation) number of publications and h- and m-indices were 48.2 (71.2), 14.5 (15), and 0.86 (0.83), respectively. The median (interquartile range) number of publications and h- and m-indices were 20 (6-61), 9 (4-20), and 0.69 (0.38-1.10), respectively. Recursive partitioning analysis revealed a statistically significant numeric h-index threshold of 21 between junior and senior faculty (LogWorth 114; receiver operating characteristic, 0.828). Senior faculty status, receipt of NIH funding, and a larger department size were associated with increased h- and m-indices. Current academic RO departments have relatively high objective metrics of scholastic productivity compared with prior benchmarking analyses of RO departments and compared with published metrics from other academic medicine subspecialties. An h-index of 21 or greater was

INCREASED PRODUCTION OF NERVE GROWTH FACTOR, NEUROTROPHIN-3, AND NEUROTROPHIN-4 IN A PENICILLIUM CHRYSOGENUM -INDUCED ALLERGIC ASTHMA MODEL IN MICE

EPA Science Inventory

Increased levels of neurotrophins (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], neurotrophin [NT]-3, and/or NT-4) have been associated with asthmatics and in animal models of allergic asthma. In our mouse model for fungal allergic asthma, repeated pulmona...

Vacuum-assisted closure therapy increases local interleukin-8 and vascular endothelial growth factor levels in traumatic wounds.

PubMed

Labler, Ludwig; Rancan, Mario; Mica, Ladislav; Härter, Luc; Mihic-Probst, Daniela; Keel, Marius

2009-03-01

Clinical observations are suggesting accelerated granulation tissue formation in traumatic wounds treated with vacuum-assisted closure (VAC). Aim of this study was to determine the impact of VAC therapy versus alternative Epigard application on local inflammation and neovascularization in traumatic soft tissue wounds. Thirty-two patients with traumatic wounds requiring temporary coverage (VAC n = 16; Epigard n = 16) were included. At each change of dressing, samples of wound fluid and serum were collected (n = 80). The cytokines interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF), and fibroblast growth factor-2 were measured by ELISA. Wound biopsies were examined histologically for inflammatory cells and degree of neovascularization present. All cytokines were found to be elevated in wound fluids during both VAC and Epigard treatment, whereas serum concentrations were negligible or not detectable. In wound fluids, significantly higher IL-8 (p < 0.001) and VEGF (p < 0.05) levels were detected during VAC therapy. Furthermore, histologic examination revealed increased neovascularization (p < 0.05) illustrated by CD31 and von Willebrand factor immunohistochemistry in wound biopsies of VAC treatment. In addition, there was an accumulation of neutrophils as well as an augmented expression of VEGF (p < 0.005) in VAC wound biopsies. This study suggests that VAC therapy of traumatic wounds leads to increased local IL-8 and VEGF concentrations, which may trigger accumulation of neutrophils and angiogenesis and thus, accelerate neovascularization.

Modeling genetic and environmental factors to increase heritability and ease the identification of candidate genes for birth weight: a twin study.

PubMed

Gielen, M; Lindsey, P J; Derom, C; Smeets, H J M; Souren, N Y; Paulussen, A D C; Derom, R; Nijhuis, J G

2008-01-01

Heritability estimates of birth weight have been inconsistent. Possible explanations are heritability changes during gestational age or the influence of covariates (e.g. chorionicity). The aim of this study was to model birth weights of twins across gestational age and to quantify the genetic and environmental components. We intended to reduce the common environmental variance to increase heritability and thereby the chance of identifying candidate genes influencing the genetic variance of birth weight. Perinatal data were obtained from 4232 live-born twin pairs from the East Flanders Prospective Twin Survey, Belgium. Heritability of birth weights across gestational ages was estimated using a non-linear multivariate Gaussian regression with covariates in the means model and in covariance structure. Maternal, twin-specific, and placental factors were considered as covariates. Heritability of birth weight decreased during gestation from 25 to 42 weeks. However, adjusting for covariates increased the heritability over this time period, with the highest heritability for first-born twins of multipara with separate placentas, who were staying alive (from 52% at 25 weeks to 30% at 42 weeks). Twin-specific factors revealed latent genetic components, whereas placental factors explained common and unique environmental factors. The number of placentas and site of the insertion of the umbilical cord masked the effect of chorionicity. Modeling genetic and environmental factors leads to a better estimate of their role in growth during gestation. For birth weight, mainly environmental factors were explained, resulting in an increase of the heritability and thereby the chance of finding genes influencing birth weight in linkage and association studies.

Repeated injections of nicergoline increase the nerve growth factor level in the aged rat brain.

PubMed

Nishio, T; Sunohara, N; Furukawa, S; Akiguchi, I; Kudo, Y

1998-03-01

We studied whether nicergoline, clinically active in chronic cerebrovascular insufficiency, influences nerve growth factor (NGF) levels in the rat brain. In young Fischer rats, repeated intraperitoneal injections of nicergoline (0.3 and 1.0 mg/kg body weight) did not show any effects on frontal NGF contents determined by a highly sensitive enzyme immunoassay. In aged rats, 22-month-old, however, repeated injections of nicergoline (1.0 mg/kg body weight) induced a significant increase in the NGF level in the frontal region.

Human extrahepatic portal vein obstruction correlates with decreased factor VII and protein C transcription but increased hepatocyte proliferation.

PubMed

Chiu, Bill; Melin-Aldana, Hector; Superina, Riccardo A

2007-10-01

A 3-year-old girl developed extrahepatic portal vein obstruction (EHPVO) after a liver transplant. She had sequelae of portal hypertension that required another transplantation. The circumstances allowed for comparison of liver-dependent coagulation factor production between the second donor liver and the explanted liver with EHPVO. Liver samples from the explanted first graft and the second transplant were obtained. Fresh tissue was used to perform reverse transcription-polymerase chain reaction with primers against factors V, VII, as well as VIII, protein C, and paraffin-embedded sections for hepatocyte proliferation using Ki-67 antibody as well as for apoptosis using TUNEL assay. The transcription of factor VII and that of protein C were decreased in the explant as compared with the newly transplanted liver (factor VII, 77% of the donor; protein C, 88% of the donor). The transcription of factor V and that of factor VIII were unchanged. The explant had a greater percentage of proliferating hepatocytes than the new organ (0.85% +/- 0.75% vs 0.11% +/- 0.21%). The percentage of apoptotic cells was similar between the 2 livers (0.09% +/- 0.13% vs 0.09% +/- 0.13%). Idiopathic EHPVO is associated with a reduction in liver-dependent coagulation factor transcription and an increase in hepatocyte proliferation. Portal blood flow deprivation alters hepatic homeostasis and initiates mechanisms that attempt to restore liver-dependent coagulation factors.

Vitamin D Supplementation increases fibroblast growth factor-23 in HIV-infected youth treated with tenofovir disoproxil fumarate

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Tenofovir (TDF) is associated with phosphaturia and elevated 1,25 dihydroxy vitamin D (1,25-OH(2)D). Fibroblast growth factor 23 (FGF23) causes phosphaturia and increases in response to elevated 1,25-OH(2)D. Vitamin D binding protein (VDBP) binds to 1,25-OH(2)D, decreasing its biologic...

Biomechanical Analysis of T2 Exercise

NASA Technical Reports Server (NTRS)

DeWitt, John K.; Ploutz-Snyder, Lori; Everett, Meghan; Newby, Nathaniel; Scott-Pandorf, Melissa; Guilliams, Mark E.

2010-01-01

Crewmembers regularly perform treadmill exercise on the ISS. With the implementation of T2 on ISS, there is now the capacity to obtain ground reaction force (GRF) data GRF data combined with video motion data allows biomechanical analyses to occur that generate joint torque estimates from exercise conditions. Knowledge of how speed and load influence joint torque will provide quantitative information on which exercise prescriptions can be based. The objective is to determine the joint kinematics, ground reaction forces, and joint kinetics associated with treadmill exercise on the ISS. This study will: 1) Determine if specific exercise speed and harness load combinations are superior to others in exercise benefit; and 2) Aid in the design of exercise prescriptions that will be most beneficial in maintaining crewmember health.

Experimental alteration of limb posture in the chicken (Gallus gallus) and its bearing on the use of birds as analogs for dinosaur locomotion.

PubMed

Carrano, M T; Biewener, A A

1999-06-01

Extant birds represent the only diverse living bipeds, and can be informative for investigations into the life-history parameters of their extinct dinosaurian relatives. However, morphological changes that occurred during early avian evolution, including the unique adoption of a nearly horizontal femoral orientation associated with a shift in center of mass (CM), suggest that caution is warranted in the use of birds as analogs for nonavian dinosaur locomotion. In this study, we fitted a group of white leghorn chickens (Gallus gallus) with a weight suspended posterior to the hip in order to examine the effects on loading and morphology. This caused a CM shift that necessitated a change in femoral posture (by 35 degrees towards the horizontal, P < 0.001), and resulted in reorientation of the ground reaction force (GRF) vector relative to the femur (from 41 degrees to 82 degrees, P < 0.001). Despite similar strain magnitudes, an overall increase in torsion relative to bending (from 1.70 to 1.95 times bending, P < 0.001) was observed, which was weakly associated with a tendency for increased femoral cross-sectional dimensions (P = 0.1). We suggest that a relative increase in torsion is consistent with a change in femoral posture towards the horizontal, since this change increases the degree to which the bone axis and the GRF vector produce mediolateral long-axis rotation of the bone. These results support the hypothesis that a postural change during early avian evolution could underlie the allometric differences seen between bird and nonavian dinosaur femora by requiring more robust femoral dimensions in birds due to an increase in torsion.

Risk factor management in a contemporary Australian population at increased cardiovascular disease risk.

PubMed

Campbell, D J; Coller, J M; Gong, F F; McGrady, M; Prior, D L; Boffa, U; Shiel, L; Liew, D; Wolfe, R; Owen, A J; Krum, H; Reid, C M

2017-11-14

Effective management of cardiovascular and chronic kidney disease risk factors offers longer, healthier lives and savings in health care. We examined risk factor management in participants of the SCReening Evaluation of the Evolution of New Heart Failure (SCREEN-HF) study, a self-selected population at increased cardiovascular disease risk recruited from members of a health insurance fund in Melbourne and Shepparton, Australia. Inclusion criteria were age ≥60 years with one or more of self-reported ischaemic or other heart disease, irregular or rapid heart rhythm, cerebrovascular disease, renal impairment, or treatment for hypertension or diabetes for ≥2 years. Exclusion criteria were known heart failure or cardiac abnormality on echocardiography or other imaging. Medical history, clinical examination, full blood examination and biochemistry (without lipids and HbA1c) were performed for 3847 participants on enrolment, and blood pressure, lipids and HbA1c were measured 1-2 years after enrolment for 3202 participants. Despite 99% of 3294 participants with hypertension receiving antihypertensive medication, half had blood pressures >140/90 mmHg. Approximately 77% of participants were overweight or obese, with one third obese. Additionally, 74% of participants at high cardiovascular disease risk had low density lipoprotein cholesterol levels ≥2 mmol/l, one third of diabetic participants had HbA1c >7%, 22% had estimated glomerular filtration rate <60 ml/min/1.73m 2 , and substantial proportions had under-utilisation of antiplatelet therapy, anticoagulation for atrial fibrillation, and were physically inactive. This population demonstrated substantial potential to reduce cardiovascular and renal morbidity and mortality and health care costs through more effective management of modifiable risk factors. This article is protected by copyright. All rights reserved.

Asymmetric dimethylarginine (ADMA) as an important risk factor for the increased cardiovascular diseases and heart failure in chronic kidney disease.

PubMed

Liu, Xiaohong; Xu, Xin; Shang, Ruru; Chen, Yingjie

2018-06-19

Patients with chronic kidney disease have an increased cardiovascular morbidity and mortality. It has been recognized that the traditional cardiovascular risk factors could only partially explain the increased cardiovascular morbidity and mortality in patients with chronic kidney disease. Asymmetric dimethylarginine (ADMA) and N-monomethy l-arginine (L-NMMA) are endogenous inhibitors of nitric oxide synthases that attenuate nitric oxide production and enhance reactive oxidative specie generation. Increased plasma ADMA and/or L-NMMA are strong and independent risk factor for chronic kidney disease, and various cardiovascular diseases such as hypertension, coronary artery disease, atherosclerosis, diabetes, and heart failure. Both ADMA and L-NMMA are also eliminated from the body through either degradation by dimethylarginine dimethylaminohydrolase-1 (DDAH1) or urine excretion. This short review will exam the literature of ADMA and L-NMMA degradation and urine excretion, and the role of chronic kidney diseases in ADMA and L-NMMA accumulation and the increased cardiovascular disease risk. Based on all available data, it appears that the increased cardiovascular morbidity in chronic kidney disease may relate to the dramatic increase of systemic ADMA and L-NMMA after kidney failure. Copyright © 2018 Elsevier Inc. All rights reserved.

Exponentially increasing incidences of cutaneous malignant melanoma in Europe correlate with low personal annual UV doses and suggests 2 major risk factors.

PubMed

Merrill, Stephen J; Ashrafi, Samira; Subramanian, Madhan; Godar, Dianne E

2015-01-01

For several decades the incidence of cutaneous malignant melanoma (CMM) steadily increased in fair-skinned, indoor-working people around the world. Scientists think poor tanning ability resulting in sunburns initiate CMM, but they do not understand why the incidence continues to increase despite the increased use of sunscreens and formulations offering more protection. This paradox, along with lower incidences of CMM in outdoor workers, although they have significantly higher annual UV doses than indoor workers have, perplexes scientists. We found a temporal exponential increase in the CMM incidence indicating second-order reaction kinetics revealing the existence of 2 major risk factors. From epidemiology studies, we know one major risk factor for getting CMM is poor tanning ability and we now propose the other major risk factor may be the Human Papilloma Virus (HPV) because clinicians find β HPVs in over half the biopsies. Moreover, we uncovered yet another paradox; the increasing CMM incidences significantly correlate with decreasing personal annual UV dose, a proxy for low vitamin D3 levels. We also discovered the incidence of CMM significantly increased with decreasing personal annual UV dose from 1960, when it was almost insignificant, to 2000. UV and other DNA-damaging agents can activate viruses, and UV-induced cytokines can hide HPV from immune surveillance, which may explain why CMM also occurs in anatomical locations where the sun does not shine. Thus, we propose the 2 major risk factors for getting CMM are intermittent UV exposures that result in low cutaneous levels of vitamin D3 and possibly viral infection.

Exponentially increasing incidences of cutaneous malignant melanoma in Europe correlate with low personal annual UV doses and suggests 2 major risk factors

PubMed Central

Merrill, Stephen J; Ashrafi, Samira; Subramanian, Madhan; Godar, Dianne E

2015-01-01

For several decades the incidence of cutaneous malignant melanoma (CMM) steadily increased in fair-skinned, indoor-working people around the world. Scientists think poor tanning ability resulting in sunburns initiate CMM, but they do not understand why the incidence continues to increase despite the increased use of sunscreens and formulations offering more protection. This paradox, along with lower incidences of CMM in outdoor workers, although they have significantly higher annual UV doses than indoor workers have, perplexes scientists. We found a temporal exponential increase in the CMM incidence indicating second-order reaction kinetics revealing the existence of 2 major risk factors. From epidemiology studies, we know one major risk factor for getting CMM is poor tanning ability and we now propose the other major risk factor may be the Human Papilloma Virus (HPV) because clinicians find β HPVs in over half the biopsies. Moreover, we uncovered yet another paradox; the increasing CMM incidences significantly correlate with decreasing personal annual UV dose, a proxy for low vitamin D3 levels. We also discovered the incidence of CMM significantly increased with decreasing personal annual UV dose from 1960, when it was almost insignificant, to 2000. UV and other DNA-damaging agents can activate viruses, and UV-induced cytokines can hide HPV from immune surveillance, which may explain why CMM also occurs in anatomical locations where the sun does not shine. Thus, we propose the 2 major risk factors for getting CMM are intermittent UV exposures that result in low cutaneous levels of vitamin D3 and possibly viral infection. PMID:26413188

Increasing Risk Factors for Imported and Domestic Gnathostomiasis in the United States.

PubMed

Diaz, James H

2015-01-01

Gnathostomiasis is a foodborne zoonotic helminthic infection, commonly described in Asia and Latin America, which may follow the consumption of raw fish, eels, amphibians, and reptiles infected with muscle-encysted larvae of Gnathostoma species nematodes. After an inoculum of as little as one infective larva and an incubation period of months to years, most infections are characterized by intermittent migratory swellings due to subdermal larval migration. Less commonly, larval migration to the central nervous system may result in radiculomyelopathy or eosinophilic meningoencephalitis with high fatality rates; or larval migration to the eye with resulting blindness in untreated cases. Since the US now supports a zoonosis of Gnathostoma species with infective larvae encysted in imported and domestic fish and eels that may be consumed raw as exotic ethnic dishes, the objectives of this review were to describe the biology and life cycle of Gnathostoma nematodes and the behavioral risk factors for gnathostomiasis; and to describe the clinical manifestations, diagnosis, management, and prevention of human gnathostomiasis. Since the eradication of gnathostomiasis is very unlikely given the global distribution of Gnathostoma nematodes and the increasingly exotic culinary tastes of US residents and travelers to endemic regions, the only effective strategies for gnathostomiasis include: (1) educating citizens in the US and travelers abroad in endemic areas that fish, eels, frogs, snakes, and chicken must be cooked thoroughly first and not eaten raw or marinated; and (2) seeking medical care immediately for evaluation of migratory subcutaneous swellings. The combination of international travel and increased immigration from Asia and Latin America to the US has resulted in greater popularity of exotic ethnic cuisine, especially raw seafood dishes. The ethnic cuisine industry is supported by domestic aquaculture that produces fish-farmed tilapia and trout, and by increased

Risk factors and outcome of increased red blood cell transfusion in cardiac surgical patients aged 65 years and older.

PubMed

Isil, Canan Tulay; Yazici, Pinar; Bakir, Ihsan

2015-02-01

The use of blood products is not uncommon during cardiac surgery in elderly patients. We conducted this study to investigate the risk factors and adverse outcomes of increased red blood cell (RBC) transfusion in the patients aged ≥ 65 years undergoing cardiac surgery. During 1 year period, 288 patients (197 male/91 female) aged ≥ 65 years who underwent coronary and/or valvular surgery were retrospectively reviewed. Patients were stratified into groups on the basis of the number of transfusions received (< 4 and ≥ 4 U) which was classified as increased transfusion. Univariate analysis and multivariate logistic regression were used to identify risk factors for increased transfusion. The mean unit of RBC transfusion was 4.5 ± 3.1 and 55.9% (n = 161) of patients received ≥ 4 U RBC. The overall postoperative complication rate was 36% and significantly higher in those with ≥ 4 U) RBC transfusion (p < 0.01). Risk factors including age, EuroSCORE, and low body surface were significantly higher in patient with ≥ 4 U RBC transfusion. Besides, preoperative anemia, postoperative drainage volume, and fresh frozen plasma (FFP) transfusion during hospital stay were found to be significantly associated with increased transfusion requirements. No difference was observed in mortality (p = 0.13). These results suggest that improvement in blood transfusion policy in elderly patients undergoing cardiac surgery requires elimination of preoperative anemia, careful attention to surgical hemostasis, and FFP use. Georg Thieme Verlag KG Stuttgart · New York.

Increasing numbers of nonaneurysmal subarachnoid hemorrhage in the last 15 years: antithrombotic medication as reason and prognostic factor?

PubMed

Konczalla, Juergen; Kashefiolasl, Sepide; Brawanski, Nina; Senft, Christian; Seifert, Volker; Platz, Johannes

2016-06-01

OBJECT Subarachnoid hemorrhage (SAH) is usually caused by a ruptured intracranial aneurysm, but in some patients no source of hemorrhage can be detected. More recent data showed increasing numbers of cases of spontaneous nonaneurysmal SAH (NASAH). The aim of this study was to analyze factors, especially the use of antithrombotic medications such as systemic anticoagulation or antiplatelet agents (aCPs), influencing the increasing numbers of cases of NASAH and the clinical outcome. METHODS Between 1999 and 2013, 214 patients who were admitted to the authors' institution suffered from NASAH, 14% of all patients with SAH. Outcome was assessed according to the modified Rankin Scale (mRS) at 6 months. Risk factors were identified based on the outcome. RESULTS The number of patients with NASAH increased significantly in the last 15 years of the study period. There was a statistically significant increase in the rate of nonperimesencephalic (NPM)-SAH occurrence and aCP use, while the proportion of elderly patients remained stable. Favorable outcome (mRS 0-2) was achieved in 85% of cases, but patients treated with aCPs had a significantly higher risk for an unfavorable outcome. Further analysis showed that elderly patients, and especially the subgroup with a Fisher Grade 3 bleeding pattern, had a high risk for an unfavorable outcome, whereas the subgroup of NPM-SAH without a Fisher Grade 3 bleeding pattern had a favorable outcome, similar to perimesencephalic (PM)-SAH. CONCLUSIONS Over the years, a significant increase in the number of patients with NASAH has been observed. Also, the rate of aCP use has increased significantly. Risk factors for an unfavorable outcome were age > 65 years, Fisher Grade 3 bleeding pattern, and aCP use. Both "PM-SAH" and "NPM-SAH without a Fisher Grade 3 bleeding pattern" had excellent outcomes. Patients with NASAH and a Fisher Grade 3 bleeding pattern had a significantly higher risk for an unfavorable outcome and death. Therefore, for further

The increased concentration of macrophage migration inhibitory factor in serum and cerebrospinal fluid of patients with tick-borne encephalitis.

PubMed

Grygorczuk, Sambor; Parczewski, Miłosz; Świerzbińska, Renata; Czupryna, Piotr; Moniuszko, Anna; Dunaj, Justyna; Kondrusik, Maciej; Pancewicz, Sławomir

2017-06-24

Host factors determining the clinical presentation of tick-borne encephalitis (TBE) are not fully elucidated. The peripheral inflammatory response to TBE virus is hypothesized to facilitate its entry into central nervous system by disrupting the blood-brain barrier with the involvement of a signaling route including Toll-like receptor 3 (TLR3) and pro-inflammatory cytokines macrophage migration inhibitory factor (MIF), tumor necrosis factor-α (TNFα), and interleukin-1 beta (IL-1β). Concentrations of MIF, TNFα, and IL-1β were measured with commercial ELISA in serum and cerebrospinal fluid (CSF) from 36 hospitalized TBE patients, 7 patients with non-TBE meningitis, and 6 controls. The CSF albumin quotient (AQ) was used as a marker of blood-brain barrier permeability. Single nucleotide polymorphisms rs3775291, rs5743305 (associated with TLR3 expression), and rs755622 (associated with MIF expression) were assessed in blood samples from 108 TBE patients and 72 non-TBE controls. The data were analyzed with non-parametric tests, and p < 0.05 was considered significant. The median serum and CSF concentrations of MIF and IL-1β were significantly increased in TBE group compared to controls. MIF concentration in serum tended to correlate with AQ in TBE, but not in non-TBE meningitis. The serum concentration of TNFα was increased in TBE patients bearing a high-expression TLR3 rs5743305 TT genotype, which also associated with the increased risk of TBE. The low-expression rs3775291 TLR3 genotype TT associated with a prolonged increase of CSF protein concentration. The high-expression MIF rs755622 genotype CC tended to correlate with an increased risk of TBE, and within TBE group, it was associated with a mild presentation. The results point to the signaling route involving TLR3, MIF, and TNFα being active in TBE virus infection and contributing to the risk of an overt neuroinvasive disease. The same factors may play a protective role intrathecally contributing to the

Mortality risk factor analysis in colonic perforation: would retroperitoneal contamination increase mortality in colonic perforation?

PubMed

Yoo, Ri Na; Kye, Bong-Hyeon; Kim, Gun; Kim, Hyung Jin; Cho, Hyeon-Min

2017-10-01

Colonic perforation is a lethal condition presenting high morbidity and mortality in spite of urgent surgical treatment. This study investigated the surgical outcome of patients with colonic perforation associated with retroperitoneal contamination. Retrospective analysis was performed for 30 patients diagnosed with colonic perforation caused by either inflammation or ischemia who underwent urgent surgical treatment in our facility from January 2005 to December 2014. Patient characteristics were analyzed to find risk factors correlated with increased postoperative mortality. Using the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) audit system, the mortality and morbidity rates were estimated to verify the surgical outcomes. Patients with retroperitoneal contamination, defined by the presence of retroperitoneal air in the preoperative abdominopelvic CT, were compared to those without retroperitoneal contamination. Eight out of 30 patients (26.7%) with colonic perforation had died after urgent surgical treatment. Factors associated with mortality included age, American Society of Anesthesiologists (ASA) physical status classification, and the ischemic cause of colonic perforation. Three out of 6 patients (50%) who presented retroperitoneal contamination were deceased. Although the patients with retroperitoneal contamination did not show significant increase in the mortality rate, they showed significantly higher ASA physical status classification than those without retroperitoneal contamination. The mortality rate predicted from Portsmouth POSSUM was higher in the patients with retroperitoneal contamination. Patients presenting colonic perforation along with retroperitoneal contamination demonstrated severe comorbidity. However, retroperitoneal contamination was not found to be correlated with the mortality rate.

Cuprophane but not synthetic membrane induces increases in serum tumor necrosis factor-alpha levels during hemodialysis.

PubMed

Canivet, E; Lavaud, S; Wong, T; Guenounou, M; Willemin, J C; Potron, G; Chanard, J

1994-01-01

Cytokine synthesis and secretion by blood mononuclear cells is a well-documented phenomenon in hemodialyzed patients. The present study was conducted in 17 chronically hemodialyzed patients to test the relative effect of uremic toxicity, membrane biocompatibility, dialysate composition, and the risk of endotoxinemia on the serum level of tumor necrosis factor-alpha (TNF-alpha). The only significant parameter that influenced circulating TNF-alpha was the chemical characteristics of the dialyzer membrane. Tumor necrosis factor-alpha levels significantly increased during the session with cuprophane, whereas they decreased with AN69. The TNF-alpha increase was documented whatever the dialysate buffer and the presence or absence (negative Limulus amoebocyte lysate test) of endotoxin in the dialysate. In the subgroup of patients treated with a contaminated dialysate and AN69, none had clinical symptoms and the central body temperature remained constant throughout the session. In these patients, serum TNF-alpha levels did not change after priming the dialyzer with sterile saline. In conclusion, the serum TNF-alpha level during hemodialysis appears to be modulated by biocompatibility, permeability, and binding properties of dialysis membrane rather than dialysate composition. Endotoxin in the dialysate did not result in positive TNF-alpha balance no matter what its possible priming effect on mononucleated blood cells.

Association Between the Duration of Periodontitis and Increased Cardiometabolic Risk Factors: A 9-Year Cohort Study.

PubMed

Morita, Toyoko; Yamazaki, Yoji; Fujiharu, Chika; Ishii, Takanori; Seto, Misae; Nishinoue, Norihide; Sasaki, Yoshiyuki; Nakai, Kumiko; Tanaka, Hideki; Kawato, Takayuki; Maeno, Masao

2016-12-01

Epidemiological studies have reported that periodontitis and cardiometabolic disease such as cardiovascular disease and type 2 diabetes are associated; however, there have been very few prospective cohort studies on this topic. Therefore, we conducted a 9-year follow-up study to examine the relationship between the duration of periodontitis and cardiometabolic risk factors, including hypertension, hyperglycemia, dyslipidemia, and obesity. The study participants comprised 572 adult industrial workers (417 men and 155 women; mean age, 37.4 years) who had undergone annual medical and dental health examinations from 2003 to 2012; the evaluation of the four cardiometabolic risk factors in 2003 revealed normal values in all the participants. We investigated the relationship between the cumulative duration of the presence of periodontal pockets, which is a major symptom of periodontitis, and the presence of cardiometabolic risk factors after 9 years using multiple logistic regression analysis. The odds ratio (OR) for the presence of ≥1 cardiometabolic risk factor in participants with a cumulative duration of periodontal pockets for ≥6 years was significantly higher than that in participants without pockets. The ORs for the onset of obesity, hypertension, dyslipidemia, and hyperglycemia were higher in participants with a cumulative duration of periodontal pockets for ≥6 years than those in participants without pockets or in participants with a cumulative duration of periodontal pockets for ≤5 years, and all the differences, except dyslipidemia, were significant. Chronic periodontitis was significantly associated with having cardiometabolic risk factors during the 9-year observation period, suggesting that the risk of cardiometabolic disease might increase in people who have untreated periodontitis.

Prenatal stress-induced increases in hippocampal von Willebrand factor expression are prevented by concurrent prenatal escitalopram

PubMed Central

Neigh, Gretchen N.; Nemeth, Christina L; Kelly, Sean D.; Hardy, Emily E.; Bourke, Chase; Stowe, Zachary N.; Owens, Michael J.

2016-01-01

Prenatal stress has been linked to deficits in neurological function including deficient social behavior, alterations in learning and memory, impaired stress regulation, and susceptibility to adult disease. In addition, prenatal environment is known to alter cardiovascular health; however, limited information is available regarding the cerebrovascular consequences of prenatal stress exposure. Vascular disturbances late in life may lead to cerebral hypoperfusion which is linked to a variety of neurodegenerative and psychiatric diseases. The known impact of cerebrovascular compromise on neuronal function and behavior highlights the importance of characterizing the impact of stress on not just neurons and glia, but also cerebrovasculature. Von Willebrand factor has previously been shown to be impacted by prenatal stress and is predictive of cerebrovascular health. Here we assess the impact of prenatal stress on von Willebrand factor and related angiogenic factors. Furthermore, we assess the potential protective effects of concurrent anti-depressant treatment during in utero stress exposure on the assessed cerebrovascular endpoints. Prenatal stress augmented expression of von Willebrand factor which was prevented by concurrent in utero escitalopram treatment. The functional implications of this increase in von Willebrand factor remain elusive, but the presented data demonstrate that although prenatal stress did not independently impact total vascularization, exposure to chronic stress in adulthood decreased blood vessel length. In addition, the current study demonstrates that production of reactive oxygen species in the hippocampus is decreased by prenatal exposure to escitalopram. Collectively, these findings demonstrate that the prenatal experience can cause complex changes in adult cerebral vascular structure and function. PMID:27422674

Is increased antidepressant exposure a contributory factor to the obesity pandemic?

PubMed Central

Lee, S H; Paz-Filho, G; Mastronardi, C; Licinio, J; Wong, M-L

2016-01-01

of stress and antidepressants followed by long-term high-fat diet results, long after discontinuation of antidepressant treatment, in markedly increased weight, in excess of what is caused by high-fat diet alone. On the basis of existing epidemiological, clinical and preclinical data, we have generated the testable hypothesis that escalating use of antidepressants, resulting in high rates of antidepressant exposure, might be a contributory factor to the obesity epidemic. PMID:26978741

Fibroblast growth factor 19 increases metabolic rate and reverses dietary and leptin-deficient diabetes.

PubMed

Fu, Ling; John, Linu M; Adams, Sean H; Yu, Xing Xian; Tomlinson, Elizabeth; Renz, Mark; Williams, P Mickey; Soriano, Robert; Corpuz, Racquel; Moffat, Barbara; Vandlen, Richard; Simmons, Laura; Foster, Jessica; Stephan, Jean-Philippe; Tsai, Siao Ping; Stewart, Timothy A

2004-06-01

Hormonal control of metabolic rate can be important in regulating the imbalance between energy intake and expenditure that underlies the development of obesity. In mice fed a high-fat diet, human fibroblast growth factor 19 (FGF19) increased metabolic rate [1.53 +/- 0.06 liters O(2)/h.kg(0.75) (vehicle) vs. 1.93 +/- 0.05 liters O(2)/h.kg(0.75) (FGF19); P < 0.001] and decreased respiratory quotient [0.82 +/- 0.01 (vehicle) vs. 0.80 +/- 0.01 (FGF19); P < 0.05]. In contrast to the vehicle-treated mice that gained weight (0.14 +/- 0.05 g/mouse.d), FGF19-treated mice lost weight (-0.13 +/- 0.03 g/mouse.d; P < 0.001) without a significant change in food intake. Furthermore, in addition to a reduction in weight gain, treatment with FGF19 prevented or reversed the diabetes that develops in mice made obese by genetic ablation of brown adipose tissue or genetic absence of leptin. To explore the mechanisms underlying the FGF19-mediated increase in metabolic rate, we profiled the FGF19-induced gene expression changes in the liver and brown fat. In brown adipose tissue, chronic exposure to FGF19 led to a gene expression profile that is consistent with activation of this tissue. We also found that FGF19 acutely increased liver expression of the leptin receptor (1.8-fold; P < 0.05) and decreased the expression of acetyl coenzyme A carboxylase 2 (0.6-fold; P < 0.05). The gene expression changes were consistent with the experimentally determined increase in fat oxidation and decrease in liver triglycerides. Thus, FGF19 is able to increase metabolic rate concurrently with an increase in fatty acid oxidation.

Frontal plane landing mechanics in high-arched compared with low-arched female athletes.

PubMed

Powell, Douglas W; Hanson, Nicholas J; Long, Benjamin; Williams, D S Blaise

2012-09-01

To examine ground reaction forces (GRFs); frontal plane hip, knee, and ankle joint angles; and moments in high-arched (HA) and low-arched (LA) athletes during landing. Experimental study. Controlled research laboratory. Twenty healthy female recreational athletes (10 HA and 10 LA). Athletes performed 5 barefoot drop landings from a height of 30 cm. Frontal plane ankle, knee, and hip joint angles (in degrees) at initial contact, peak vertical GRF, and peak knee flexion; peak ankle, knee, and hip joint moments in the frontal plane. Vertical GRF profiles were similar between HA and LA athletes (P = 0.78). The HA athletes exhibited significantly smaller peak ankle inversion angles than the LA athletes (P = 0.01) at initial contact. At peak vertical GRF, HA athletes had significantly greater peak knee (P = 0.01) and hip abduction angles than LA athletes (P = 0.02). There were no significant differences between HA and LA athletes in peak joint moments (hip: P = 0.68; knee: P = 0.71; ankle: P = 0.15). These findings demonstrate that foot type is associated with altered landing mechanics, which may underlie lower extremity injuries. The ankle-driven strategy previously reported in female athletes suggests that foot function may have a greater relationship with lower extremity injury than that in male athletes. Future research should address the interaction of foot type and gender during landing tasks.

Atrial natriuretic factor increases splenic microvascular pressure and fluid extravasation in the rat.

PubMed

Sultanian, R; Deng, Y; Kaufman, S

2001-05-15

The spleen is an important site of atrial natriuretic factor (ANF)-induced fluid extravasation into the systemic lymphatic system. The mechanism underlying this process was studied in a blood-perfused (1 ml min(-1)) rat spleen using the double occlusion technique. To ensure that our observations were spleen specific, a similar protocol was repeated in the hindquarters. Rat ANF(1-28), infused into the splenic artery of anaesthetized male rats, caused a dose-dependent (0.3-59 pmol min(-1)) increase in microvascular pressure from 11.3 +/- 0.7 to 14.9 +/- 0.5 mmHg and in post-capillary resistance from 7.2 +/- 0.6 to 10.1 +/- 1.1 mmHg ml(-1). ANF elicited no change in splenic pre-capillary resistance or in hindquarter haemodynamics. Intrasplenic ANF (6.5 pmol min(-1)) caused a sustained increase in intrasplenic fluid efflux from 0.1 +/- 0.1 to 0.3 +/- 0.1 ml min(-1), and in capillary filtration coefficient (Kf) from 1.2 +/- 0.5 to 2.4 +/- 0.6 ml mmHg-1 min-1 (100 g tissue)-1. Mechanical elevation of splenic intravascular pressure (from 11.3 +/- 0.7 to 22.4 +/- 0.2 mmHg) significantly increased intrasplenic fluid extravasation (from 0.4 +/- 0.3 to 1.4 +/- 0.3 ml min(-1)). The natriuretic peptide receptor-C (NPRC)-specific agonist C-ANF(4-23) (12.5 and 125 pmol min(-1)) did not alter splenic intravascular pressure or pre-/post-capillary resistance. The ANF antagonist A71915 (8.3 and 83 pmol min-1), which blocks ANF-stimulated cGMP production via natriuretic peptide receptor-A (NPRA), inhibited the ANF-induced changes in splenic microvascular pressure and post-capillary resistance. It is concluded that ANF enhances the extravasation of isoncotic fluid from the splenic vasculature both by raising intrasplenic microvascular pressure (increased post-capillary resistance) and by increasing filtration area. The constrictive activity of ANF on the splenic vasculature is mediated through NPRA.

M-CSF increases proliferation and phagocytosis while modulating receptor and transcription factor expression in adult human microglia

PubMed Central

2013-01-01

Background Microglia are the primary immune cells of the brain whose phenotype largely depends on their surrounding micro-environment. Microglia respond to a multitude of soluble molecules produced by a variety of brain cells. Macrophage colony-stimulating factor (M-CSF) is a cytokine found in the brain whose receptor is expressed by microglia. Previous studies suggest a critical role for M-CSF in brain development and normal functioning as well as in several disease processes involving neuroinflammation. Methods Using biopsy tissue from patients with intractable temporal epilepsy and autopsy tissue, we cultured primary adult human microglia to investigate their response to M-CSF. Mixed glial cultures were treated with 25 ng/ml M-CSF for 96 hours. Proliferation and phagocytosis assays, and high through-put immunocytochemistry, microscopy and image analysis were performed to investigate microglial phenotype and function. Results We found that the phenotype of primary adult human microglia was markedly changed following exposure to M-CSF. A greater number of microglia were present in the M-CSF- treated cultures as the percentage of proliferating (BrdU and Ki67-positive) microglia was greatly increased. A number of changes in protein expression occurred following M-CSF treatment, including increased transcription factors PU.1 and C/EBPβ, increased DAP12 adaptor protein, increased M-CSF receptor (CSF-1R) and IGF-1 receptor, and reduced HLA-DP, DQ, DR antigen presentation protein. Furthermore, a distinct morphological change was observed with elongation of microglial processes. These changes in phenotype were accompanied by a functional increase in phagocytosis of Aβ1-42 peptide. Conclusions We show here that the cytokine M-CSF dramatically influences the phenotype of adult human microglia. These results pave the way for future investigation of M-CSF-related targets for human therapeutic benefit. PMID:23866312

Endothelial Cell Permeability during Hantavirus Infection Involves Factor XII-Dependent Increased Activation of the Kallikrein-Kinin System

PubMed Central

Taylor, Shannon L.; Wahl-Jensen, Victoria; Copeland, Anna Maria; Jahrling, Peter B.; Schmaljohn, Connie S.

2013-01-01

Hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) are diseases caused by hantavirus infections and are characterized by vascular leakage due to alterations of the endothelial barrier. Hantavirus-infected endothelial cells (EC) display no overt cytopathology; consequently, pathogenesis models have focused either on the influx of immune cells and release of cytokines or on increased degradation of the adherens junction protein, vascular endothelial (VE)-cadherin, due to hantavirus-mediated hypersensitization of EC to vascular endothelial growth factor (VEGF). To examine endothelial leakage in a relevant in vitro system, we co-cultured endothelial and vascular smooth muscle cells (vSMC) to generate capillary blood vessel-like structures. In contrast to results obtained in monolayers of cultured EC, we found that despite viral replication in both cell types as well as the presence of VEGF, infected in vitro vessels neither lost integrity nor displayed evidence of VE-cadherin degradation. Here, we present evidence for a novel mechanism of hantavirus-induced vascular leakage involving activation of the plasma kallikrein-kinin system (KKS). We show that incubation of factor XII (FXII), prekallikrein (PK), and high molecular weight kininogen (HK) plasma proteins with hantavirus-infected EC results in increased cleavage of HK, higher enzymatic activities of FXIIa/kallikrein (KAL) and increased liberation of bradykinin (BK). Measuring cell permeability in real-time using electric cell-substrate impedance sensing (ECIS), we identified dramatic increases in endothelial cell permeability after KKS activation and liberation of BK. Furthermore, the alterations in permeability could be prevented using inhibitors that directly block BK binding, the activity of FXIIa, or the activity of KAL. Lastly, FXII binding and autoactivation is increased on the surface of hantavirus-infected EC. These data are the first to demonstrate KKS activation during

Brain-derived neurotrophic factor transgenic mice exhibit passive avoidance deficits, increased seizure severity and in vitro hyperexcitability in the hippocampus and entorhinal cortex.

PubMed

Croll, S D; Suri, C; Compton, D L; Simmons, M V; Yancopoulos, G D; Lindsay, R M; Wiegand, S J; Rudge, J S; Scharfman, H E

1999-01-01

Transgenic mice overexpressing brain-derived neurotrophic factor from the beta-actin promoter were tested for behavioral, gross anatomical and physiological abnormalities. Brain-derived neurotrophic factor messenger RNA overexpression was widespread throughout brain. Overexpression declined with age, such that levels of overexpression decreased sharply by nine months. Brain-derived neurotrophic factor transgenic mice had no gross deformities or behavioral abnormalities. However, they showed a significant passive avoidance deficit. This deficit was dependent on continued overexpression, and resolved with age as brain-derived neurotrophic factor transcripts decreased. In addition, the brain-derived neurotrophic factor transgenic mice showed increased seizure severity in response to kainic acid. Hippocampal slices from brain-derived neurotrophic factor transgenic mice showed hyperexcitability in area CA3 and entorhinal cortex, but not in dentate gyrus. Finally, area CA1 long-term potentiation was disrupted, indicating abnormal plasticity. Our data suggest that overexpression of brain-derived neurotrophic factor in the brain can interfere with normal brain function by causing learning impairments and increased excitability. The results also support the hypothesis that excess brain-derived neurotrophic factor could be pro-convulsant in the limbic system.

PPAR-alpha agonist treatment increases trefoil factor family-3 expression and attenuates apoptosis in the liver tissue of bile duct-ligated rats.

PubMed

Karakan, Tarkan; Kerem, Mustafa; Cindoruk, Mehmet; Engin, Doruk; Alper, Murat; Akın, Okan

2013-01-01

Peroxisome proliferators-activated receptor alpha activation modulates cholesterol metabolism and suppresses bile acid synthesis. The trefoil factor family comprises mucin-associated proteins that increase the viscosity of mucins and help protect epithelial linings from insults. We evaluated the effect of short-term administration of fenofibrate, a peroxisome proliferators activated receptor alpha agonist, on trefoil factor family-3 expression, degree of apoptosis, generation of free radicals, and levels of proinflammatory cytokines in the liver tissue of bile duct-ligated rats. Forty male Wistar rats were randomly divided into four groups: 1 = sham operated, 2 = bile duct ligation, 3 = bile duct-ligated + vehicle (gum Arabic), and 4 = bile duct-ligated + fenofibrate (100 mg/kg/day). All rats were sacrificed on the 7 th day after obtaining blood samples and liver tissue. Liver function tests, tumor necrosis factor-alpha and interleukin 1 beta in serum, and trefoil factor family-3 mRNA expression, degree of apoptosis (TUNEL) and tissue malondialdehyde (malondialdehyde, end-product of lipid peroxidation by reactive oxygen species) in liver tissue were evaluated. Fenofibrate administration significantly reduced serum total bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and tumor necrosis factor-alpha and interleukin-1β levels. Apoptosis and malondialdehyde were significantly reduced in the fenofibrate group. Trefoil factor family-3 expression increased with fenofibrate treatment in bile duct-ligated rats. The peroxisome proliferators-activated receptor alpha agonist fenofibrate significantly increased trefoil factor family-3 expression and decreased apoptosis and lipid peroxidation in the liver and attenuated serum levels of proinflammatory cytokines in bile duct-ligated rats. Further studies are needed to determine the protective role of fenofibrate in human cholestatic disorders.

Factors associated with increased incidence of severe toxicities following yttrium-90 resin microspheres in the treatment of hepatic malignancies.

PubMed

Roberson Ii, John D; McDonald, Andrew M; Baden, Craig J; Lin, Chee Paul; Jacob, Rojymon; Burnett Iii, Omer L

2016-03-14

To further define variables associated with increased incidences of severe toxicities following administration of yttrium-90 ((90)Y) microspheres. Fifty-eight patients undergoing 79 treatments were retrospectively assessed for development of clinical and laboratory toxicity incidence following (90)Y administration. Severe toxicity events were defined using Common Terminology Criteria for Adverse Events version 4.03 and defined as grade ≥ 3. Univariate logistic regression analyses were used to evaluate the effect of different factors on the incidence of severe toxicity events. Multicollinearity was assessed for all factors with P < 0.1 using Pearson correlation matrices. All factors not excluded due to multicollinearity were included in a multivariate logistic regression model for each measurement of severe toxicity. Severe (grade ≥ 3) toxicities occurred following 21.5% of the 79 treatments included in our analysis. The most common severe laboratory toxicities were severe alkaline phosphatase (17.7%), albumin (12.7%), and total bilirubin (10.1%) toxicities. Decreased pre-treatment albumin (OR = 26.2, P = 0.010) and increased pre-treatment international normalized ratio (INR) (OR = 17.7, P = 0.048) were associated with development of severe hepatic toxicity. Increased pre-treatment aspartate aminotransferase (AST; OR = 7.4, P = 0.025) and decreased pre-treatment hemoglobin (OR = 12.5, P = 0.025) were associated with severe albumin toxicity. Increasing pre-treatment model for end-stage liver disease (MELD) score (OR = 1.8, P = 0.033) was associated with severe total bilirubin toxicity. Colorectal adenocarcinoma histology was associated with severe alkaline phosphatase toxicity (OR = 5.4, P = 0.043). Clinicians should carefully consider pre-treatment albumin, INR, AST, hemoglobin, MELD, and colorectal histology when choosing appropriate candidates for (90)Y microsphere therapy.

Is Fibroblast growth factor 23 the leading cause of increased mortality among chronic kidney disease patients? A narrative review.

PubMed

Sharaf El Din, Usama A; Salem, Mona M; Abdulazim, Dina O

2017-05-01

The death rate among chronic kidney disease patients is the highest compared to other chronic diseases. 60% of these fatalities are cardiovascular. Cardiovascular calcifications and chronic inflammation affect almost all chronic kidney disease patients and are associated with cardiovascular mortality. Fibroblast growth factor 23 is associated with vascular calcification. Systemic inflammation in chronic kidney disease patients is multifactorial. The role of systemic inflammation in the pathogenesis of vascular calcification was recently reappraised. Fibroblast growth factor 23 was accused as a direct stimulus of left ventricular hypertrophy, uremic inflammation, and impaired neutrophil function. This review will discuss the underlying mechanisms that underlie the link between Fibroblast growth factor 23 and increased mortality encountered among chronic kidney disease patients.

Single-leg drop landing movement strategies 6 months following first-time acute lateral ankle sprain injury.

PubMed

Doherty, C; Bleakley, C; Hertel, J; Caulfield, B; Ryan, J; Delahunt, E

2015-12-01

No research exists predicating a link between acute ankle sprain injury-affiliated movement patterns and those of chronic ankle instability (CAI) populations. The aim of the current study was to perform a biomechanical analysis of participants, 6 months after they sustained a first-time acute lateral ankle sprain (LAS) injury to establish this link. Fifty-seven participants with a 6-month history of first-time LAS and 20 noninjured participants completed a single-leg drop landing task on both limbs. Three-dimensional kinematic (angular displacement) and sagittal plane kinetic (moment of force) data were acquired for the joints of the lower extremity, from 200 ms pre-initial contact (IC) to 200 ms post-IC. Individual joint stiffnesses and the peak magnitude of the vertical component of the ground reaction force (GRF) were also computed. LAS participants displayed increases in hip flexion and ankle inversion on their injured limb (P < 0.05); this coincided with a reduction in the net flexion-extension moment at the hip joint, with an increase in its stiffness (P < 0.05). There was no difference in the magnitude of the peak vertical GRF for either limb compared with controls. These results demonstrate that altered movement strategies persist in participants, 6 months following acute LAS, which may precipitate the onset of CAI. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Terrestrial ecosystems, increased solar ultraviolet radiation, and interactions with other climate change factors.

PubMed

Caldwell, M M; Bornman, J F; Ballaré, C L; Flint, S D; Kulandaivelu, G

2007-03-01

, such as diminished growth, acclimation responses of plants to UV-B radiation and interactions of plants with consumer organisms such as insects and plant pathogens. The response to UV-B radiation involves both the initial stimulus by solar radiation and transmission of signals within the plants. Resulting changes in gene expression induced by these signals may have elements in common with those elicited by other environmental factors, and generate overlapping functional (including acclimation) responses. Concurrent responses of terrestrial systems to the combination of enhanced UV-B radiation and other global change factors (increased temperature, CO2, available nitrogen and altered precipitation) are less well understood. Studies of individual plant responses to combinations of factors indicate that plant growth can be augmented by higher CO2 levels, yet many of the effects of UV-B radiation are usually not ameliorated by the elevated CO2. UV-B radiation often increases both plant frost tolerance and survival under extreme high temperature conditions. Conversely, extreme temperatures sometimes influence the UV-B radiation sensitivity of plants directly. Plants that endure water deficit stress effectively are also likely to be tolerant of high UV-B flux. Biologically available nitrogen is exceeding historical levels in many regions due to human activities. Studies show that plants well supplied with nitrogen are generally more sensitive to UV-B radiation. Technical issues concerning the use of biological spectral weighting functions (BSWFs) have been further elucidated. The BSWFs, which are multiplication factors assigned to different wavelengths giving an indication of their relative biological effectiveness, are critical to the proper conduct and interpretation of experiments in which organisms are exposed to UV radiation, both in the field and in controlled environment facilities. The characteristics of BSWFs vary considerably among different plant processes, such

Chronic high-sucrose diet increases fibroblast growth factor 21 production and energy expenditure in mice.

PubMed

Maekawa, Ryuya; Seino, Yusuke; Ogata, Hidetada; Murase, Masatoshi; Iida, Atsushi; Hosokawa, Kaori; Joo, Erina; Harada, Norio; Tsunekawa, Shin; Hamada, Yoji; Oiso, Yutaka; Inagaki, Nobuya; Hayashi, Yoshitaka; Arima, Hiroshi

2017-11-01

Excess carbohydrate intake causes obesity in humans. On the other hand, acute administration of fructose, glucose or sucrose in experimental animals has been shown to increase the plasma concentration of anti-obesity hormones such as glucagon-like peptide 1 (GLP-1) and Fibroblast growth factor 21 (FGF21), which contribute to reducing body weight. However, the secretion and action of GLP-1 and FGF21 in mice chronically fed a high-sucrose diet has not been investigated. To address the role of anti-obesity hormones in response to increased sucrose intake, we analyzed mice fed a high-sucrose diet, a high-starch diet or a normal diet for 15 weeks. Mice fed a high-sucrose diet showed resistance to body weight gain, in comparison with mice fed a high-starch diet or control diet, due to increased energy expenditure. Plasma FGF21 levels were highest among the three groups in mice fed a high-sucrose diet, whereas no significant difference in GLP-1 levels was observed. Expression levels of uncoupling protein 1 (UCP-1), FGF receptor 1c (FGFR1c) and β-klotho (KLB) mRNA in brown adipose tissue were significantly increased in high sucrose-fed mice, suggesting increases in FGF21 sensitivity and energy expenditure. Expression of carbohydrate responsive element binding protein (ChREBP) mRNA in liver and brown adipose tissue was also increased in high sucrose-fed mice. These results indicate that FGF21 production in liver and brown adipose tissue is increased in high-sucrose diet and participates in resistance to weight gain. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Factors Associated With Persistent Increase in Level of Alanine Aminotransferase in Patients With Chronic Hepatitis B Receiving Oral Antiviral Therapy.

PubMed

Jacobson, Ira M; Washington, Mary K; Buti, Maria; Thompson, Alexander; Afdhal, Nezam; Flisiak, Robert; Akarca, Ulus Salih; Tchernev, Konstantin G; Flaherty, John F; Aguilar Schall, Raul; Myers, Robert P; Subramanian, G Mani; McHutchison, John G; Younossi, Zobair; Marcellin, Patrick; Patel, Keyur

2017-07-01

Despite complete suppression of viral DNA with antiviral agents, in some patients with chronic hepatitis B (CHB), serum levels of alanine aminotransferase (ALT) do not normalize. We investigated factors associated with persistent increases in ALT level in patients with CHB given long-term tenofovir disoproxil fumarate. We analyzed data from 471 hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients with CHB participating in 2 phase 3 trials. We identified patients with an increased level of ALT (above the upper limit of normal range) after 5 years (240 weeks) of tenofovir disoproxil fumarate therapy. We analyzed findings from liver biopsy specimens collected from 467 patients (99%) at baseline and 339 patients (72%) at year 5 of treatment; biopsy specimens were evaluated by an independent pathologist. We performed stepwise, forward, multivariate regression analyses of specified baseline characteristics and on-treatment response parameters to identify factors associated with persistent increases in ALT level. Of the 471 patients, 87 (18%) still had an increased ALT level at year 5 of treatment. Factors associated significantly with a persistent increase in ALT level were a steatosis score of 5% or greater (grade 1 or more) at baseline (odds ratio [OR], 2.236; 95% confidence interval [CI], 1.031-4.852; P = .042) and at year 5 (OR, 3.392; 95% CI, 1.560 ≥ 7.375; P = .002), HBeAg seropositivity at baseline (OR, 3.297; 95% CI, 1.653-6.576; P < .001), and age 40 years or older (OR, 2.099; 95% CI, 1.014-4.342; P = .046). Of the 42 HBeAg-positive patients with steatosis at baseline, 21 (50%) had an increased ALT level at year 5 of treatment. Patients with persistent increases in ALT level were more likely to have an increase in steatosis at year 5 than those with a normal ALT level. HBeAg seropositivity and hepatic steatosis contribute to persistent increases in ALT level in patients with CHB receiving suppressive antiviral treatment. Clinical

Perinatal risk factors increase the risk of being affected by both type 1 diabetes and coeliac disease.

PubMed

Adlercreutz, Emma H; Wingren, Carl Johan; Vincente, Raquel P; Merlo, Juan; Agardh, Daniel

2015-02-01

This study investigated whether perinatal factors influenced the risk of a double diagnosis of type 1 diabetes and coeliac disease. We used multinomial logistic regression models to study the associations between perinatal factors, gender, mode of delivery, season of birth and the risk of type 1 diabetes, coeliac disease or both, in Swedish-born singleton children. We found that 4327 of the 768 395 children (0.6%) had been diagnosed with type 1 diabetes, 3817 (0.5%) had been diagnosed with coeliac disease and 191 (0.02%) were affected by both diseases. If the children already had type 1 diabetes (n = 4518), the absolute risk of being affected by coeliac disease increased to 4.2% (n = 191). Children with both type 1 diabetes and coeliac disease were more likely to be female (OR = 1.48, 95% CI = 1.01-1.97), delivered by Caesarean section (OR = 1.60, 95% CI = 1.07-2.39), have native-born Swedish mothers (OR = 4.84, 95% CI = 1.96-11.97) or be born during the summer months (OR = 1.43, 95% CI = 1.07-1.92). The increased risk of being affected by a double diagnosis of type 1 diabetes and coeliac disease was modulated by perinatal risk factors. This suggests that early life events are important when it comes to children with type 1 diabetes also developing coeliac disease. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

The variance needed to accurately describe jump height from vertical ground reaction force data.

PubMed

Richter, Chris; McGuinness, Kevin; O'Connor, Noel E; Moran, Kieran

2014-12-01

In functional principal component analysis (fPCA) a threshold is chosen to define the number of retained principal components, which corresponds to the amount of preserved information. A variety of thresholds have been used in previous studies and the chosen threshold is often not evaluated. The aim of this study is to identify the optimal threshold that preserves the information needed to describe a jump height accurately utilizing vertical ground reaction force (vGRF) curves. To find an optimal threshold, a neural network was used to predict jump height from vGRF curve measures generated using different fPCA thresholds. The findings indicate that a threshold from 99% to 99.9% (6-11 principal components) is optimal for describing jump height, as these thresholds generated significantly lower jump height prediction errors than other thresholds.

A wheat CCAAT box-binding transcription factor increases the grain yield of wheat with less fertilizer input.

PubMed

Qu, Baoyuan; He, Xue; Wang, Jing; Zhao, Yanyan; Teng, Wan; Shao, An; Zhao, Xueqiang; Ma, Wenying; Wang, Junyi; Li, Bin; Li, Zhensheng; Tong, Yiping

2015-02-01

Increasing fertilizer consumption has led to low fertilizer use efficiency and environmental problems. Identifying nutrient-efficient genes will facilitate the breeding of crops with improved fertilizer use efficiency. This research performed a genome-wide sequence analysis of the A (NFYA), B (NFYB), and C (NFYC) subunits of Nuclear Factor Y (NF-Y) in wheat (Triticum aestivum) and further investigated their responses to nitrogen and phosphorus availability in wheat seedlings. Sequence mining together with gene cloning identified 18 NFYAs, 34 NFYBs, and 28 NFYCs. The expression of most NFYAs positively responded to low nitrogen and phosphorus availability. In contrast, microRNA169 negatively responded to low nitrogen and phosphorus availability and degraded NFYAs. Overexpressing TaNFYA-B1, a low-nitrogen- and low-phosphorus-inducible NFYA transcript factor on chromosome 6B, significantly increased both nitrogen and phosphorus uptake and grain yield under differing nitrogen and phosphorus supply levels in a field experiment. The increased nitrogen and phosphorus uptake may have resulted from the fact that that overexpressing TaNFYA-B1 stimulated root development and up-regulated the expression of both nitrate and phosphate transporters in roots. Our results suggest that TaNFYA-B1 plays essential roles in root development and in nitrogen and phosphorus usage in wheat. Furthermore, our results provide new knowledge and valuable gene resources that should be useful in efforts to breed crops targeting high yield with less fertilizer input. © 2015 American Society of Plant Biologists. All Rights Reserved.

Unhealthy lifestyle and sleep problems as risk factors for increased direct employers' cost of short-term sickness absence.

PubMed

Kanerva, Noora; Pietiläinen, Olli; Lallukka, Tea; Rahkonen, Ossi; Lahti, Jouni

2018-03-01

Objectives Unhealthy lifestyle (eg, smoking) as well as sleep problems are associated with increased risk of sickness absence, but the financial impact of these associations beyond risk ratios is not well known. We aimed to estimate the additive contribution of lifestyle and sleep problems (risk factors) to direct costs of short-term (<15 days) sickness absence. Methods The Helsinki Health Study is a longitudinal cohort of employees of the City of Helsinki, Finland (N=8960, response rate 67%). During 2000-2002 the participants were mailed a survey questionnaire that gathered information on their lifestyle and sleep. A sum of the risk factors was calculated: participants received one point for being a smoker; high alcohol user (>7 servings/week for women and >14 servings/week for men); physically inactive [<14 metabolic equivalents (MET) hours/week]; having low fruit and vegetable consumption (<1 times/day); or suffering from frequent insomnia symptoms. Sickness absence, salary, and time of employment were followed through the employer's register between 2002-2016. Individual salary data were used to calculate the direct costs of short-term sickness absence. Data were analyzed using a two-part model. Results Direct costs of short-term sickness absences were on average €9057 (standard deviation €11 858) per employee over the follow-up. Those with ≥3 risk factors had €3266 [95% confidence interval (95% CI) €2114-4417] higher direct costs for the employer over the follow-up compared to those without any risk factors. Conclusions Unhealthy lifestyle and sleep problems may increase the costs of short-term sickness absence to the employer by 10-30%. Consequently, programs addressing lifestyle and sleep may yield to significant savings.

Vitamin D3 supplementation increases fibroblast growth factor-23 in HIV-infected youth treated with tenofovir disoproxil fumarate

USDA-ARS?s Scientific Manuscript database

Tenofovir (TDF) is associated with phosphaturia and elevated 1,25 dihydroxy vitamin D (1,25-OH(2)D). Fibroblast growth factor-23 causes phosphaturia and increases in response to elevated 1,25-OH(2)D. Vitamin D binding proetin (VDBP) binds to 1,25-OH(2)D, decreasing biologic activity, and is elevated...

Factors related to increasing safety belt use in states with safety belt use laws : second annual report to Congress

DOT National Transportation Integrated Search

1989-01-01

This report is the second in a series of four annual reports to the Congress on provisions of state safety belt use laws and other programmatic factors related to increasing safety belt use levels. The first Congressional Report reviewed what was kno...

Identifying Factors That Increase the Likelihood for Alcohol-Induced Blackouts in the Prepartying Context

PubMed Central

LaBrie, Joseph W.; Hummer, Justin; Kenney, Shannon; Lac, Andrew; Pedersen, Eric

2015-01-01

The present study examined risk factors related to “blacking out” (e.g., temporary periods of memory loss during drinking) during preparty drinking events (i.e., pregaming, predrinking). Participants were students from two universities on the West Coast who reported past month prepartying (N = 2,546) in online surveys administered in the fall of 2008. Among these students, 25% (n = 636) reported blacking out during at least one occasion in which they prepartied in the past month. A logistic regression model underscored that Greek student affiliation, family history of alcohol abuse, frequency of prepartying, and both playing drinking games and consuming shots of liquor while prepartying increased the likelihood of blacking out. Limitations and implications for future research and collegiate prevention strategies are discussed. PMID:21222521

An increase in serum tumour necrosis factor-α during anti-tumour necrosis factor-α therapy for Crohn's disease - A paradox or a predictive index?

PubMed

Eder, Piotr; Korybalska, Katarzyna; Łykowska-Szuber, Liliana; Stawczyk-Eder, Kamila; Krela-Kaźmierczak, Iwona; Łuczak, Joanna; Czepulis, Natasza; Linke, Krzysztof; Witowski, Janusz

2016-10-01

Soluble tumour necrosis factor-α (sTNF-α) has been reported to increase in the course of anti-TNF-α therapy for rheumatoid and skin diseases. To assess changes in sTNF-α and clinical efficacy of anti-TNF-α agents in Crohn's disease (CD). Sixty-four patients on infliximab or adalimumab were analyzed. Clinical outcomes were assessed by using CD Activity Index after the induction therapy and at week 52. sTNF-α was measured before and after the induction therapy with high-sensitivity immunoassay. In the majority of patients, sTNF-α increased significantly. Those with the greatest increase were more likely to experience long-term response, were more often treated with infliximab, had less frequently isolated small bowel CD, and tended to have sTNF-α levels at baseline that correlated with C-reactive protein. Neutralization of sTNF-α does not seem to be critical for the efficacy of anti-TNF-α therapy in CD. Paradoxically - an increase in sTNF-α may reflect an ongoing process that is beneficial for the clinical outcome. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

A Consensus Network of Gene Regulatory Factors in the Human Frontal Lobe

PubMed Central

Berto, Stefano; Perdomo-Sabogal, Alvaro; Gerighausen, Daniel; Qin, Jing; Nowick, Katja

2016-01-01

Cognitive abilities, such as memory, learning, language, problem solving, and planning, involve the frontal lobe and other brain areas. Not much is known yet about the molecular basis of cognitive abilities, but it seems clear that cognitive abilities are determined by the interplay of many genes. One approach for analyzing the genetic networks involved in cognitive functions is to study the coexpression networks of genes with known importance for proper cognitive functions, such as genes that have been associated with cognitive disorders like intellectual disability (ID) or autism spectrum disorders (ASD). Because many of these genes are gene regulatory factors (GRFs) we aimed to provide insights into the gene regulatory networks active in the human frontal lobe. Using genome wide human frontal lobe expression data from 10 independent data sets, we first derived 10 individual coexpression networks for all GRFs including their potential target genes. We observed a high level of variability among these 10 independently derived networks, pointing out that relying on results from a single study can only provide limited biological insights. To instead focus on the most confident information from these 10 networks we developed a method for integrating such independently derived networks into a consensus network. This consensus network revealed robust GRF interactions that are conserved across the frontal lobes of different healthy human individuals. Within this network, we detected a strong central module that is enriched for 166 GRFs known to be involved in brain development and/or cognitive disorders. Interestingly, several hubs of the consensus network encode for GRFs that have not yet been associated with brain functions. Their central role in the network suggests them as excellent new candidates for playing an essential role in the regulatory network of the human frontal lobe, which should be investigated in future studies. PMID:27014338

Oral contraceptives increase insulin-like growth factor binding protein-1 concentration in women with polycystic ovarian disease.

PubMed

Suikkari, A M; Tiitinen, A; Stenman, U H; Seppälä, M; Laatikainen, T

1991-05-01

Insulin-like growth factor-I (IGF-I) stimulates ovarian androgen production. Insulin-like growth factor binding protein-1 (IGFBP-1) inhibits IGF actions in vitro. To investigate the effect of oral contraceptive (OC) pills, given for 3 months, on serum gonadotropin, androgen, IGF-I, and IGFBP-1 concentrations, and glucose tolerance in seven women with polycystic ovarian disease (PCOD) and in five healthy control subjects. Seven women with PCOD and five healthy control subjects. An oral glucose tolerance test (OGTT) was performed before and after treatment with OC. After treatment with OC, serum luteinizing hormone, androstenedione, and free testosterone levels decreased, and sex hormone-binding globulin concentration increased in the women with PCOD as well as in the control subjects. The cumulative response of serum insulin to OGTT was larger in the women with PCOD than in the control subjects both before and after treatment. Serum IGF-I concentration, which was unchanged during OGTT, decreased from basal level of 326 +/- 70 micrograms/L to 199 +/- 28 micrograms/L after treatment with OC in the women with PCOD, whereas no change was found in the control subjects (from 235 +/- 11 micrograms/L to 226 +/- 11 micrograms/L). Treatment with OC caused an increase of the mean basal IGFBP-1 concentration from 24 +/- 7 micrograms/L to 73 +/- 14 micrograms/L in the women with PCOD. This increase was constant during the OGTT. In the control subjects, treatment with OC did not result in any significant change in IGFBP-1 concentrations (from 44 +/- 11 micrograms/L to 61 +/- 9 micrograms/L). The combination of decreased total IGF-I concentration and increased IGFBP-1 concentration induced by OC may decrease ovarian androgen production in PCOD.

Technology advancement: a factor in increasing resource use

USGS Publications Warehouse

Wilburn, David R.; Goonan, Thomas G.; Bleiwas, Donald I.

2001-01-01

The specter of mineral resource scarcity has been repeatedly raised as a concern because ever-growing populations with seemingly insatiable appetites for minerals place claims against a finite resource endowment. This report analyzes how technology has helped to ease resource constraints, and uses case studies of aluminum, copper, potash, and sulfur minerals to identify the effects of technology on resource supply. In spite of heightened demand for and increased loss of resources to environmental policy and urbanization, mineral producers historically have been able to continually expand production and lower costs. Specific production increases for the years 1900-98 were: aluminum (3,250 percent), copper (2,465 percent), potash (3,770 percent), and sulfur (6,000 percent). For the same period, constant-dollar (1998) prices decreased: aluminum (90 percent), copper (75 percent), potash (94 percent), and sulfur (89 percent). The application of technology has made available mineral deposits that were previously overlooked or considered non-viable. Using technology, producers can meet the demand for stronger, energy-efficient, more environmentally safe products with less physical material. Technologies have been developed to increase the amount of materials recycled and remanufactured. Technology development can occur in breakthroughs, but most often advances incrementally. Technological development is driven by the profit motive.

Risk Factors for Increased ED Utilization in a Multinational Cohort of Children with Sickle Cell Disease

PubMed Central

Glassberg, Jeffrey A.; Wang, Jason; Cohen, Robyn; Richardson, Lynne D.; DeBaun, Michael R.

2012-01-01

Objectives To identify clinical, social, and environmental risk factors for increased emergency department (ED) use in children with sickle cell disease (SCD). Methods This study was a secondary analysis of ED utilization data from the international multicenter Silent Cerebral Infarct Transfusion (SIT) trial. Between December 2004 and June 2010, baseline demographic, clinical, and laboratory data were collected from children with SCD participating in the trial. The primary outcome was the frequency of ED visits for pain. A secondary outcome was the frequency of ED visits for acute chest syndrome. Results The sample included 985 children from the US, Canada, England, and France, for a total of 2,955 patient-years of data. There were 0.74 ED visits for pain per patient-year. A past medical history of asthma was associated with an increased risk of ED utilization for both pain (RR = 1.28, 95% CI = 1.04 to 1.58) and acute chest syndrome (RR = 1.60, 95% CI = 1.03 to 2.49). Exposure to environmental tobacco smoke in the home was associated with 73% more ED visits for acute chest syndrome (RR 1.73, 95% CI = 1.09 to 2.74). Each $10,000 increase in household income was associated with 5% fewer ED visits for pain (RR 0.95, 95% CI = 0.91 to 1.00, p = 0.05). The association between low income and ED utilization was not significantly different in the USA vs. countries with universal health care (p = 0.51). Conclusions Asthma and exposure to environmental tobacco smoke are potentially modifiable risk factors for greater ED use in children with SCD. Low income is associated with greater ED use for SCD pain in countries with and without universal health care. PMID:22687181

Global increasing of mean sea level and erroneous treatment of a role of thermal factors

NASA Astrophysics Data System (ADS)

Barkin, Yu. V.

2009-04-01

in the northern hemisphere. At averaging of measurements over all ocean surface (mainly located in a southern hemisphere where it occupies about 80 % of the areas) there will be an effect of apparent additional increase of the sea level. Therefore this ("apparent") velocity of increase of the sea level accepts the greater value (about 2.4 mm / year) in comparison with coastal determinations of this velocity that is rather close to the data of satellite observations. The additional effect in increase of the sea level is brought by deformation of the ocean bottom. The both mentioned phenomena: the secular drift of the center of mass of the Earth and the secular expansion of southern hemisphere of the Earth have been predicted by author [2], [3] and have obtained confirmations by space geodesy methods. The offered explanation has the extremely - important value for studying a possible role of thermal and climatic factors which can not apply any more for a big component attributed to it in change of the sea level. The account of fictitious component of this velocity results practically in real value of variation of the average sea level about 1.3-1.6 mm / yr, that completely coordinate positions of researchers of ocean by coastal and altimetry (satellite) methods. Moreover, the given work opens a direct opportunity for an explanation of increase of the sea level as result of deformation of the ocean bottom. This deformation is a major factor of change of the average sea level. Water superseded in a southern hemisphere gives the significant contribution to observably value of velocity of sea level rise up to 0.8-1.2 mm / yr [3, 4]. The work fulfilled at financial support of Russian projects of RFBR: N 07-05-00939 and N 06-02-16665. This abstract (without what or changes) has been accepted to EGU GA 2008 Session IS48 "75th Anniversary of the PSML"(Convener: Woodworth P.) but was not included in its program. References. [1] Nerem R.S., Leuliette E.W., Chambers D.P. (2005

Physical therapy intervention (PTI) increases plasma brain-derived neurotrophic factor (BDNF) levels in non-frail and pre-frail elderly women.

PubMed

Coelho, F M; Pereira, D S; Lustosa, L P; Silva, J P; Dias, J M D; Dias, R C D; Queiroz, B Z; Teixeira, A L; Teixeira, M M; Pereira, L S M

2012-01-01

Biomarkers are important factors in the identification of the frail elderly (higher risk of developing disease) and in assessing the impact of PTI. On the other hand, BDNF has been related to neuroprotection in a series of central nervous system diseases in older age. The levels of BDNF in groups of elderly women classified according to Fried phenotype (non-frail and pre-frail) were compared. We assessed the impact of a PTI on BDNF levels. A convenience sample of 48 elderly women was randomly selected. The PTI group was composed by 20 elderly women selected from this group. Plasma neurotrophic factors, such as BDNF, glial-derived neutrophic factor (GDNF), and nerve growth factor (NGF) were measured by enzyme-linked immunosorbent assay (ELISA). Timed-up-and-go (TUG) test, hand-grip and work/body weight were evaluated before and after the intervention. Plasma concentrations of BDNF were significantly higher in non-frail in comparison to pre-frail elderly women. After the PTI, higher levels of BDNF were found in elderly women (before 351±68 pg/ml and after 593±79 pg/ml; p<0.001). Both groups had an increase in BDNF levels after the PTI. The low levels of BDNF in pre-frail elderly women suggest that this neurotrophic factor may be a key pathophysiological mediator in the syndrome of frailty. The fact that PTI increased BDNF levels in both groups suggests that it may be possible to modify this phenotype. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Factors influencing success of marine protected areas in the Visayas, Philippines as related to increasing protected area coverage.

PubMed

Pollnac, Richard; Seara, Tarsila

2011-04-01

Throughout the world there is a general consensus among environmentalists that there should be an increase in the amount of marine area that should be reserved in marine protected areas (MPAs). In fact, the 1998 Philippines Fishery Code indicates a need for designation of at least 15% of municipal waters for fish refuges or sanctuaries. Such an increase in area would take productive fishing areas away from fishing communities that can ill-afford the loss. The larger the protected area, there will be a greater number of people impacted. This article examines the relationship between factors that influence the success of Community Based MPA (CBMPA) performance in the Visayas, Philippines and their significance in efforts to increase the size of protected areas.

Obesity does not increase External Mechanical Work per kilogram body mass during Walking

PubMed Central

Browning, Raymond C.; McGowan, Craig P.; Kram, Rodger

2009-01-01

Walking is the most common type of physical activity prescribed for the treatment of obesity. The net metabolic rate during level walking (Watts/kg) is ~10% greater in obese vs. normal weight adults. External mechanical work (Wext) is one of the primary determinants of the metabolic cost of walking, but the effects of obesity on Wext have not been clearly established. The purpose of this study was to compare Wext between obese and normal weight adults across a range of walking speeds. We hypothesized that Wext (J/step) would be greater in obese adults but Wext normalized to body mass would be similar in obese and normal weight adults. We collected right leg three-dimensional ground reaction forces (GRF) while twenty adults (10 obese, BMI=35.6 kg/m2 and 10 normal weight, BMI=22.1 kg/m2) walked on a level, dual-belt force measuring treadmill at six speeds (0.50–1.75 m/s). We used the individual limb method (ILM) to calculate external work done on the center of mass. Absolute Wext (J/step) was greater in obese vs. normal weight adults at each walking speed, but relative Wext (J/step/kg) was similar between the groups. Step frequencies were not different. These results suggest that Wext is not responsible for the greater metabolic cost of walking (W/kg) in moderately obese adults. PMID:19646701

Factor structure of the happiness-increasing strategies scales (H-ISS): activities and coping strategies in relation to positive and negative affect.

PubMed

Al Nima, Ali; Garcia, Danilo

2015-01-01

Background. Previous research (Tkach & Lyubomirsky, 2006) shows that there are eight general happiness-increasing strategies: social affiliation, partying, mental control, goal pursuit, passive leisure, active leisure, religion, and direct attempts. The present study investigates the factor structure of the happiness-increasing strategies scales (H-ISS) and their relationship to positive and negative affect. Method. The present study used participants' (N = 1,050 and age mean = 34.21 sd = 12.73) responses to the H-ISS in structural equation modeling analyses. Affect was measured using the Positive Affect Negative Affect Schedule. Results. After small modifications we obtained a good model that contains the original eight factors/scales. Moreover, we found that women tend to use social affiliation, mental control, passive leisure, religion, and direct attempts more than men, while men preferred to engage in partying and clubbing more than women. The H-ISS explained significantly the variance of positive affect (R (2) = .41) and the variance of negative affect (R (2) = .27). Conclusions. Our study is an addition to previous research showing that the factor structure of the happiness-increasing strategies is valid and reliable. However, due to the model fitting issues that arise in the present study, we give some suggestions for improving the instrument.

Depletion of mitochondrial fission factor DRP1 causes increased apoptosis in human colon cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inoue-Yamauchi, Akane, E-mail: ainoyama@research.twmu.ac.jp; Oda, Hideaki

2012-04-27

Highlights: Black-Right-Pointing-Pointer DRP1 is required for mitochondrial fission in colon cancer cells. Black-Right-Pointing-Pointer DRP1 participates in inhibition of colon cancer cell apoptosis. Black-Right-Pointing-Pointer DRP1 can inhibit apoptosis through the regulation of cytochrome c release. -- Abstract: Mitochondria play a critical role in regulation of apoptosis, a form of programmed cell death, by releasing apoptogenic factors including cytochrome c. Growing evidence suggests that dynamic changes in mitochondrial morphology are involved in cellular apoptotic response. However, whether DRP1-mediated mitochondrial fission is required for induction of apoptosis remains speculative. Here, we show that siRNA-mediated DRP1 knockdown promoted accumulation of elongated mitochondria in HCT116more » and SW480 human colon cancer cells. Surprisingly, DRP1 down-regulation led to decreased proliferation and increased apoptosis of these cells. A higher rate of cytochrome c release and reductions in mitochondrial membrane potential were also revealed in DRP1-depleted cells. Taken together, our present findings suggest that mitochondrial fission factor DRP1 inhibits colon cancer cell apoptosis through the regulation of cytochrome c release and mitochondrial membrane integrity.« less

Increased circulating procoagulant and anticoagulant factors as TF and TFPI according to severity or infecting serotypes in human dengue infection.

PubMed

Leal de Azeredo, Elzinandes; Solórzano, Victor Edgar Fiestas; de Oliveira, Débora Batista; Marinho, Cintia Ferreira; de Souza, Luiz José; da Cunha, Rivaldo Venâncio; Damasco, Paulo Vieira; Kubelka, Claire Fernandes; de-Oliveira-Pinto, Luzia Maria

2017-01-01

Tissue Factor (TF) is the initiator of coagulation and Tissue Factor Inhibitor (TFPI) is the physiological inhibitor of the TF/FVIIa complex. Circulating levels of TF and TFPI were quantified in dengue patients and the relationships with disease severity and infecting serotype analysed. A significant decrease in TF and TPFI plasma levels was observed in mild DF patients compared with severe dengue. Furthermore, both factors were associated with haemorrhagic manifestations. Finally, TF levels were significantly increased in DENV-1/2 infected patients as compared with DENV-4. These findings suggest that activation of TF-pathway is an important component of DENV -related coagulation disorders. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

NZ-GMP Approved Serum Improve hDPSC Osteogenic Commitment and Increase Angiogenic Factor Expression.

PubMed

Spina, Anna; Montella, Roberta; Liccardo, Davide; De Rosa, Alfredo; Laino, Luigi; Mitsiadis, Thimios A; La Noce, Marcella

2016-01-01

Human dental pulp stem cells (hDPSCs), selected from the stromal-vascular fraction of dental pulp, are ecto-mesenchymal stem cells deriving from neural crests, successfully used in human bone tissue engineering. For their use in human therapy GMP procedures are required. For instance, the use of fetal bovine serum (FBS) is strongly discouraged in clinical practice due to its high risk of prions and other infections for human health. Alternatively, clinical grade sera have been suggested, including the New Zealand FBS (NZ-FBS). Therefore, the aim of this study was to evaluate the behavior of hDPSCs expanded in culture medium containing NZ-FBS. Since it was widely demonstrated hDPSCs display relevant capabilities to differentiate into osteogenic and angiogenic lineages, we performed a comparative study to assess if these features are also retained by cultivating the cells with a safer serum never tested on this cell line. hDPSCs were grown using NZ-FBS and conventional (C-FBS) for 7, 14, and 21 days, in both 2D and 3D cultures. Growth curves, expression of bone-related markers, calcification and angiogenesis were evaluated. NZ-FBS induced significant cell growth with respect to C-FBS and promoted an earlier increase expression of osteogenic markers, in particular of those involved in the formation of mineralized matrix (BSP and OPN) within 14 days. In addition, hDPSCs cultured in presence of NZ-FBS were found to produce higher mRNA levels of the angiogenic factors, such as VEGF and PDGFA. Taken together, our results highlight that hDPSCs proliferate, enhance their osteogenic commitment and increase angiogenic factors in NZ-FBS containing medium. These features have also been found when hDPSC were seeded on the clinical-grade collagen I scaffold (Bio-Gide®), leading to the conclusion that for human therapy some procedures and above all the use of GMP-approved materials have no negative impact.

DOSE-DEPENDENT INCREASE IN THE PRODUCTION OF NERVE GROWTH FACTOR, NEUROTROPHIN-3, AND NEUROTROPHIN-4 IN A PENICILLIUM CHRYSOGENUM-INDUCED ALLERGIC ASTHMA MODEL

EPA Science Inventory

Increased levels of neurotrophins (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], neurotrophin [NT]-3, and/or NT-4) have been associated with asthma as well as in animal models of allergic asthma. In our mouse model for fungal allergic asthma, repeated ...

Exercise increases serum brain-derived neurotrophic factor in patients with major depressive disorder.

PubMed

Kerling, A; Kück, M; Tegtbur, U; Grams, L; Weber-Spickschen, S; Hanke, A; Stubbs, B; Kahl, K G

2017-06-01

Brain derived neurotrophic factor (BDNF) has been implicated in the pathogenesis of major depressive disorder (MDD). Existing data on exercise treatment in people with MDD are inconsistent concerning the effect of exercise on BDNF pointing either to increased or unaltered BDNF concentrations. However, studies in non-depressed persons demonstrated a significant effect on resting peripheral BDNF concentrations in aerobic training interventions. Given the lack of clarity mentioned above, the current study aimed at examining the effect of adjunctive exercise on serum BDNF levels in guideline based treated patients with MDD. 42 depressed inpatients were included, and randomized either to a 6 week structured and supervised exercise intervention plus treatment as usual (EXERCISE, n=22), or to treatment as usual (TAU, n=20). BDNF serum concentrations were assessed before and after the intervention in both study groups with established immunoassays. Serum BDNF slightly decreased in the TAU group, whilst there was an increase in BDNF levels in the exercise group. There was a significant time x group effect concerning sBDNF (p=0.030) with repeated ANOVA measures with age and BMI as covariates, suggesting an increase in BDNF concentrations in the EXERCISE group compared to TAU. Though there was no statistic difference in the antidepressant medication between EXERCISE and TAU potential interactions between exercise and medication on the effects of exercise in BDNF cannot be excluded. Gender was not considered as a covariate in ANOVA due to the small number of objects. Exercise training given as adjunct to standard guideline based treatment appears to have additional effects on BDNF serum concentrations in people with MDD. Our results add further evidence to the beneficial effects of exercise in the treatment of MDD. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Repeated variate stress in male rats induces increased voiding frequency, somatic sensitivity, and urinary bladder nerve growth factor expression

PubMed Central

Merrill, Liana; Malley, Susan

2013-01-01

Stress exacerbates symptoms of functional lower urinary tract disorders including interstitial cystitis (IC)/bladder pain syndrome (BPS) and overactive bladder (OAB) in humans, but mechanisms contributing to symptom worsening are unknown. These studies address stress-induced changes in the structure and function of the micturition reflex using an animal model of stress in male rats. Rats were exposed to 7 days of repeated variate stress (RVS). Target organ (urinary bladder, thymus, adrenal gland) tissues were collected and weighed following RVS. Evans blue (EB) concentration and histamine, myeloperoxidase (MPO), nerve growth factor (NGF), brain-derived neurotropic factor (BDNF), and CXCL12 protein content (ELISA) were measured in the urinary bladder, and somatic sensitivity of the hindpaw and pelvic regions was determined following RVS. Bladder function was evaluated using continuous, open outlet intravesical infusion of saline in conscious rats. Increases in body weight gain were significantly (P ≤ 0.01) attenuated by day 5 of RVS, and adrenal weight was significantly (P ≤ 0.05) increased. Histamine, MPO, NGF, and CXCL12 protein expression was significantly (P ≤ 0.01) increased in the urinary bladder after RVS. Somatic sensitivity of the hindpaw and pelvic regions was significantly (P ≤ 0.01) increased at all monofilament forces tested (0.1–4 g) after RVS. Intercontraction interval, infused volume, and void volume were significantly (P ≤ 0.01) decreased after RVS. These studies demonstrate increased voiding frequency, histamine, MPO, NGF, and CXCL12 bladder content and somatic sensitivity after RVS suggesting an inflammatory component to stress-induced changes in bladder function and somatic sensitivity. PMID:23657640

Hypoxia Increases Sirtuin 1 Expression in a Hypoxia-inducible Factor-dependent Manner*

PubMed Central

Chen, Rui; Dioum, Elhadji M.; Hogg, Richard T.; Gerard, Robert D.; Garcia, Joseph A.

2011-01-01

Hypoxia-inducible factors (HIFs) are stress-responsive transcriptional regulators of cellular and physiological processes involved in oxygen metabolism. Although much is understood about the molecular machinery that confers HIF responsiveness to oxygen, far less is known about HIF isoform-specific mechanisms of regulation, despite the fact that HIF-1 and HIF-2 exhibit distinct biological roles. We recently determined that the stress-responsive genetic regulator sirtuin 1 (Sirt1) selectively augments HIF-2 signaling during hypoxia. However, the mechanism by which Sirt1 maintains activity during hypoxia is unknown. In this report, we demonstrate that Sirt1 gene expression increases in a HIF-dependent manner during hypoxia in Hep3B and in HT1080 cells. Impairment of HIF signaling affects Sirt1 deacetylase activity as decreased HIF-1 signaling results in the appearance of acetylated HIF-2α, which is detected without pharmacological inhibition of Sirt1. We also find that Sirt1 augments HIF-2 mediated, but not HIF-1 mediated, transcriptional activation of the isolated Sirt1 promoter. These data in summary reveal a bidirectional link of HIF and Sirt1 signaling during hypoxia. PMID:21345792

Variability of vertical ground reaction forces collected with one and two force plates in healthy dogs.

PubMed

Stejskal, M; Torres, B T; Sandberg, G S; Sapora, J A; Dover, R K; Budsberg, S C

2015-01-01

To compare peak vertical force (PVF) and vertical impulse (VI) data collected with one and two force plates during the same collection time period in healthy dogs at a trot. Seventeen healthy client-owned adult dogs. Vertical ground reaction force (GRF) data were collected in a crossover study design, with four sessions on two consecutive days, and then two weeks apart (days 1, 2, 15, and 16) using both one and two force plates collection methods. A repeated measures model analysis of variance (ANOVA) was used to test for differences in force plate PVF, VI, and average time per trial (ATT) between days, weeks, and systems (1 plate versus 2 plates). Coefficients of variation for PVF and VI were also calculated separately by forelimbs and hindlimbs, plates, day, and week. The time required to obtain a valid trial was significantly longer using a single force plate when compared with two force plates. Comparing GRF data for all dogs, significant differences in PVF data were found between one and two force plates, however, these differences were diminutive in absolute magnitude, and of unknown clinical importance. Examination of the coefficients of variation for PVF and VI during the different collection periods yielded similar results. Use of two force plates decreased trial repetition and collection time. Vertical GRF data had a similar coefficient of variation with either one or two force plates collection techniques in healthy dogs.

Gravitational Effects upon Locomotion Posture

NASA Technical Reports Server (NTRS)

DeWitt, John K.; Bentley, Jason R.; Edwards, W. Brent; Perusek, Gail P.; Samorezov, Sergey

2008-01-01

Researchers use actual microgravity (AM) during parabolic flight and simulated microgravity (SM) obtained with horizontal suspension analogs to better understand the effect of gravity upon gait. In both environments, the gravitational force is replaced by an external load (EL) that returns the subject to the treadmill. However, when compared to normal gravity (N), researchers consistently find reduced ground reaction forces (GRF) and subtle kinematic differences (Schaffner et al., 2005). On the International Space Station, the EL is applied by elastic bungees attached to a waist and shoulder harness. While bungees can provide EL approaching body weight (BW), their force-length characteristics coupled with vertical oscillations of the body during gait result in a variable load. However, during locomotion in N, the EL is consistently equal to 100% body weight. Comparisons between AM and N have shown that during running, GRF are decreased in AM (Schaffner et al, 2005). Kinematic evaluations in the past have focussed on joint range of motion rather than joint posture at specific instances of the gait cycle. The reduced GRF in microgravity may be a result of differing hip, knee, and ankle positions during contact. The purpose of this investigation was to compare joint angles of the lower extremities during walking and running in AM, SM, and N. We hypothesized that in AM and SM, joints would be more flexed at heel strike (HS), mid-stance (MS) and toe-off (TO) than in N.

Discrete sensors distribution for accurate plantar pressure analyses.

PubMed

Claverie, Laetitia; Ille, Anne; Moretto, Pierre

2016-12-01

The aim of this study was to determine the distribution of discrete sensors under the footprint for accurate plantar pressure analyses. For this purpose, two different sensor layouts have been tested and compared, to determine which was the most accurate to monitor plantar pressure with wireless devices in research and/or clinical practice. Ten healthy volunteers participated in the study (age range: 23-58 years). The barycenter of pressures (BoP) determined from the plantar pressure system (W-inshoe®) was compared to the center of pressures (CoP) determined from a force platform (AMTI) in the medial-lateral (ML) and anterior-posterior (AP) directions. Then, the vertical ground reaction force (vGRF) obtained from both W-inshoe® and force platform was compared for both layouts for each subject. The BoP and vGRF determined from the plantar pressure system data showed good correlation (SCC) with those determined from the force platform data, notably for the second sensor organization (ML SCC= 0.95; AP SCC=0.99; vGRF SCC=0.91). The study demonstrates that an adjusted placement of removable sensors is key to accurate plantar pressure analyses. These results are promising for a plantar pressure recording outside clinical or laboratory settings, for long time monitoring, real time feedback or for whatever activity requiring a low-cost system. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Hoof accelerations and ground reaction forces of Thoroughbred racehorses measured on dirt, synthetic, and turf track surfaces.

PubMed

Setterbo, Jacob J; Garcia, Tanya C; Campbell, Ian P; Reese, Jennifer L; Morgan, Jessica M; Kim, Sun Y; Hubbard, Mont; Stover, Susan M

2009-10-01

To compare hoof acceleration and ground reaction force (GRF) data among dirt, synthetic, and turf surfaces in Thoroughbred racehorses. 3 healthy Thoroughbred racehorses. Forelimb hoof accelerations and GRFs were measured with an accelerometer and a dynamometric horseshoe during trot and canter on dirt, synthetic, and turf track surfaces at a racecourse. Maxima, minima, temporal components, and a measure of vibration were extracted from the data. Acceleration and GRF variables were compared statistically among surfaces. The synthetic surface often had the lowest peak accelerations, mean vibration, and peak GRFs. Peak acceleration during hoof landing was significantly smaller for the synthetic surface (mean + or - SE, 28.5g + or - 2.9g) than for the turf surface (42.9g + or - 3.8g). Hoof vibrations during hoof landing for the synthetic surface were < 70% of those for the dirt and turf surfaces. Peak GRF for the synthetic surface (11.5 + or - 0.4 N/kg) was 83% and 71% of those for the dirt (13.8 + or - 0.3 N/kg) and turf surfaces (16.1 + or - 0.7 N/kg), respectively. The relatively low hoof accelerations, vibrations, and peak GRFs associated with the synthetic surface evaluated in the present study indicated that synthetic surfaces have potential for injury reduction in Thoroughbred racehorses. However, because of the unique material properties and different nature of individual dirt, synthetic, and turf racetrack surfaces, extending the results of this study to encompass all track surfaces should be done with caution.

Micro-level social and structural factors act synergistically to increase HIV risk among Nepalese female sex workers.

PubMed

Deuba, Keshab; Anderson, Sarah; Ekström, Anna Mia; Pandey, Satish Raj; Shrestha, Rachana; Karki, Deepak Kumar; Marrone, Gaetano

2016-08-01

Sex workers face stigma, discrimination, and violence across the globe and are almost 14 times more likely to be HIV-infected than other women in low- and middle-income countries. In Asia, condom campaigns at brothels have been effective in some settings, but for preventive interventions to be sustainable, it is important to understand micro-level social and structural factors that influence sexual behaviours of sex workers. This study assessed the syndemic effects of micro-level social and structural factors of unprotected sex and the prevalence of HIV among female sex workers (FSWs) in Nepal. This quantitative study included 610 FSWs who were recruited using two-stage cluster sampling from September to November 2012 in 22 Terai Highway districts of Nepal. Rapid HIV tests and face-to-face interviews were conducted to collect biological and behavioural information. A count of physical (sexual violence and other undesirable events), social (poor social support and condom negotiation skills), and economic (unprotected sex to make more money) factors that operate at the micro-level was calculated to test the additive relationship to unprotected sex. The HIV prevalence was 1%; this is presumably representative, with a large sample of FSWs in Nepal. The prevalence of unprotected sex with clients was high (24%). For each additional adverse physical, social, and economic condition, the probability of non-use of condoms with clients increased substantially: one problem = 12% (p<0.005), two problems = 19% (p<0.001), and three to five problems = 38% (p<0.001). Interactions between two or more adverse conditions linked to physical, social, and economic environments increased the risk of unprotected sex among Nepalese FSWs. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Factors related to increasing safety belt use in states with safety belt use laws : second annual report to Congress, 1988.

DOT National Transportation Integrated Search

1989-01-01

This report. is the second in a series of four annual reports to the : Congress on provisions of state safety belt use laws and other : programmatic factors related to increasing safety belt use levels. : The first Congressional Report reviewed what ...

What factors are associated with increased risk for prolonged postoperative opioid usage after colorectal surgery?

PubMed

Stafford, Caitlin; Francone, Todd; Roberts, Patricia L; Ricciardi, Rocco

2018-02-06

Opioid-related deaths have increased substantially over the last 10 years placing clinician's prescription practices under intense scrutiny. Given the substantial risk of opioid dependency after colorectal surgery, we sought to analyze risk of postoperative prolonged opioid use after colorectal resections. Between 2008 and 2014, patients undergoing abdominopelvic procedure with intestinal resection at a tertiary care facility were retrospectively identified. Patient's postoperative narcotic usage including their prescriptions on discharge and their total opioid medication use was recorded. Patient variables such as demographics, surgical characteristics, and prescription use were evaluated. Finally, we developed multivariate models to identify risk factors for prolonged opioid use (> 30 days after incident surgical procedure). We identified 9423 recorded procedures of which 2173 consisted of abdominopelvic procedures with intestinal resection and survived > 1 year. Of these, 91% (n = 1981) were discharged on opioids, and 98% (n = 1955) of those patients filled only one prescription. A total of 92 (4%) patients remained on opioids beyond 30 days, and from this group, 25% (n = 23 patients) remained at 90 days. We found no association between postoperative complications, stoma formation, and patient's sex with risk of prolonged opioid use. However, younger age and history of chronic pain were associated with an increased risk of prolonged opioid use. The use of minimally invasive techniques also attenuated the risk of prolonged opioid use (Table 2). A small but considerable proportion of patients remain on opioids beyond 30 days. Predictors of opioid use for greater than 30 days include a history of chronic pain and younger age. The use of minimally invasive techniques reduced the risk of prolonged opioid use. We identified several immutable risk factors that predicted prolonged postoperative opioid use; however, surgeons may be able to attenuate

Gait strategy changes with acceleration to accommodate the biomechanical constraint on push-off propulsion.

PubMed

Oh, Keonyoung; Baek, Juhyun; Park, Sukyung

2012-11-15

To maintain steady and level walking, push-off propulsion during the double support phase compensates for the energy loss through heel strike collisions in an energetically optimal manner. However, a large portion of daily gait activities also contains transient gait responses, such as acceleration or deceleration, during which the observed dominance of the push-off work or the energy optimality may not hold. In this study, we examined whether the push-off propulsion during the double support phase served as a major energy source for gait acceleration, and we also studied the energetic optimality of accelerated gait using a simple bipedal walking model. Seven healthy young subjects participated in the over-ground walking experiments. The subjects walked at four different constant gait speeds ranging from a self-selected speed to a maximum gait speed, and then they accelerated their gait from zero to the maximum gait speed using a self-selected acceleration ratio. We measured the ground reaction force (GRF) of three consecutive steps and the corresponding leg configuration using force platforms and an optical marker system, respectively, and we compared the mechanical work performed by the GRF during each single and double support phase. In contrast to the model prediction of an increase in the push-off propulsion that is proportional to the acceleration and minimizes the mechanical energy cost, the push-off propulsion was slightly increased, and a significant increase in the mechanical work during the single support phase was observed. The results suggest that gait acceleration occurs while accommodating a feasible push-off propulsion constraint. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effect of tibiotalar alignment on coronal plane mechanics following total ankle replacement.

PubMed

Grier, A Jordan; Schmitt, Abigail C; Adams, Samuel B; Queen, Robin M

2016-07-01

Gait mechanics following total ankle replacement (TAR) have reported improved ankle motion following surgery. However, no studies have addressed the impact of preoperative radiographic tibiotalar alignment on post-TAR gait mechanics. We therefore investigated whether preoperative tibiotalar alignment (varus, valgus, or neutral) resulted in significantly different coronal plane mechanics or ground reaction forces post-TAR. We conducted a non-randomized study of 93 consecutive end-stage ankle arthritis patients. Standard weight-bearing radiographs were obtained preoperatively to categorize patients as having neutral (±4°), varus (≥5° of varus), or valgus (≥5° of valgus) coronal plane tibiotalar alignment. All patients underwent a standard walking assessment including three-dimensional lower extremity kinetics and kinematics preoperatively, 12 and 24 months postoperatively. A significant group by time interaction was observed for the propulsive vertical ground reaction force (vGRF), coronal plane hip range of motion (ROM) and the peak hip abduction moment. The valgus group demonstrated an increase in the peak knee adduction angle and knee adduction angle at heel strike when compared to the other groups. Coronal plane ankle ROM, knee and hip angles at heel strike, and the peak hip angle exhibited significant increases across time. Peak ankle inversion moment, peak knee abduction moment and the weight acceptance vGRF also exhibited significant increases across time. Neutral ankle alignment was achieved for all patients by 2 years following TAR. Restoration of neutral ankle alignment at the time of TAR in patients with preoperative varus or valgus tibiotalar alignment resulted in biomechanics similar to those of patients with neutral preoperative tibiotalar alignment by 24-month follow-up. Copyright © 2016 Elsevier B.V. All rights reserved.

Increased Energy Expenditure, Ucp1 Expression, and Resistance to Diet-induced Obesity in Mice Lacking Nuclear Factor-Erythroid-2-related Transcription Factor-2 (Nrf2).

PubMed

Schneider, Kevin; Valdez, Joshua; Nguyen, Janice; Vawter, Marquis; Galke, Brandi; Kurtz, Theodore W; Chan, Jefferson Y

2016-04-01

The NRF2 (also known as NFE2L2) transcription factor is a critical regulator of genes involved in defense against oxidative stress. Previous studies suggest thatNrf2plays a role in adipogenesisin vitro, and deletion of theNrf2gene protects against diet-induced obesity in mice. Here, we demonstrate that resistance to diet-induced obesity inNrf2(-/-)mice is associated with a 20-30% increase in energy expenditure. Analysis of bioenergetics revealed thatNrf2(-/-)white adipose tissues exhibit greater oxygen consumption. White adipose tissue showed a >2-fold increase inUcp1gene expression. Oxygen consumption is also increased nearly 2.5-fold inNrf2-deficient fibroblasts. Oxidative stress induced by glucose oxidase resulted in increasedUcp1expression. Conversely, antioxidant chemicals (such asN-acetylcysteine and Mn(III)tetrakis(4-benzoic acid)porphyrin chloride) and SB203580 (a known suppressor ofUcp1expression) decreasedUcp1and oxygen consumption inNrf2-deficient fibroblasts. These findings suggest that increasing oxidative stress by limitingNrf2function in white adipocytes may be a novel means to modulate energy balance as a treatment of obesity and related clinical disorders. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

High levels of serum fibroblast growth factor (FGF)-23 are associated with increased mortality in long haemodialysis patients.

PubMed

Jean, Guillaume; Terrat, Jean-Claude; Vanel, Thierry; Hurot, Jean-Marc; Lorriaux, Christie; Mayor, Brice; Chazot, Charles

2009-09-01

Fibroblast growth factor (FGF)-23, a novel bone-derived phosphaturic factor involved in mineral metabolism, is increased in chronic kidney disease (CKD); in dialysis patients, it has been linked to increased mortality rates and vascular calcification (VC). The present investigation aimed to study the factors associated with elevated serum FGF-23 levels in patients treated with long haemodialysis (LHD) sessions and to determine whether a relationship exists between serum FGF-23 levels and patient survival. All patients treated in one haemodialysis centre from September 2006 were included in the study. Standard laboratory values, medical history, cardiovascular events and risk factors, medication and FGF-23 levels [ELISA (C-Term) Immutopics] were recorded. Patients received haemodialysis three times a week, on a 5- to 8-h schedule. Patient data were analysed according to FGF-23 quartiles. The effect of FGF-23 on the 2-year survival rate was assessed using the Cox proportional hazard model, adjusted for confounding variables and according to the serum phosphate tertiles. The study included 219 patients. Serum FGF-23 levels were high: 7060 +/- 13 500 RU/mL (median, 2740 RU/mL). In logistical regressions, only calcaemia (P = 0.002), phosphataemia (P = 0.008) and warfarin use (P = 0.04) were associated with the highest FGF-23 quartile. In the subgroup of patients with an estimated VC score, the third and fourth quartiles of the FGF-23 levels were associated with more severe VC. In multivariate linear regressions, only phosphataemia remained significantly correlated with FGF-23 (P = 0.04). The 2-year mortality rate was significantly higher for haemodialysis patients with serum FGF-23 levels in the higher quartile [P = 0.007; hazard ratio, 2.5 (1.3-5)] than in the first quartile, whereas within the phosphataemia tertiles, the lowest serum FGF-23 quartile was associated with lowered mortality. This study demonstrated a high level of circulating FGF-23 in LHD patients

Comprehensive Geriatric Assessment (CGA) based risk factors for increased caregiver burden among elderly Asian patients with cancer.

PubMed

Rajasekaran, Tanujaa; Tan, Tira; Ong, Whee Sze; Koo, Khai Nee; Chan, Lili; Poon, Donald; Roy Chowdhury, Anupama; Krishna, Lalit; Kanesvaran, Ravindran

2016-05-01

This study aims to identify Comprehensive Geriatric Assessment (CGA) based risk factors to help predict caregiver burden among elderly patients with cancer. The study evaluated 249 patients newly diagnosed with cancer, aged 70years and above, who attended the geriatric oncology clinic at the National Cancer Centre Singapore between 2007 and 2010. Out of 249 patients, 244 patients had information available on family caregiver burden and were analysed. On univariate analysis, ADL dependence, lower IADL scores, ECOG performance status of 3-4, higher fall risk, lower scores in dominant hand grip strength test and mini mental state examination, polypharmacy, higher nutritional risk, haemoglobin <12g/dL and presence of geriatric syndromes were significantly associated with mild to severe caregiver burden. On multivariate analysis, only ECOG performance status of 3-4 (odds ratio [OR], 4.47; 95% confidence interval [CI], 2.27-8.80) and haemoglobin <12g/dL (OR, 2.38; 95% CI, 1.14-4.99) were associated with an increased probability of mild to severe caregiver burden. The model achieved a good fit (Hosmer-Lemeshow's p=0.196) and discrimination (area under the curve [AUC]=0.742; bias-corrected AUC=0.737). Based on this, patients were stratified into 3 risk groups with different proportion of patients with increased caregiver burden (low risk: 3.9% vs intermediate risk: 18.8% vs high risk: 39.6%; p<0.001). ECOG performance status and haemoglobin were associated with increased caregiver burden among elderly patients with cancer. Using these two factors in the clinic may help clinicians identify caregivers at risk and take preventive action to mitigate that. Copyright © 2016 Elsevier Inc. All rights reserved.

Arsenite induces endothelial cell permeability increase through a reactive oxygen species-vascular endothelial growth factor pathway.

PubMed

Bao, Lingzhi; Shi, Honglian

2010-11-15

As a potent environmental oxidative stressor, arsenic exposure has been reported to exacerbate cardiovascular diseases and increase vascular endothelial cell monolayer permeability. However, the underlying mechanism of this effect is not well understood. In this paper, we test our hypothesis that reactive oxygen species (ROS)-induced vascular endothelial growth factor (VEGF) expression may play an important role in an arsenic-caused increase of endothelial cell monolayer permeability. The mouse brain vascular endothelial cell bEnd3 monolayer was exposed to arsenite for 1, 3, and 6 days. The monolayer permeability, VEGF protein release, and ROS generation were determined. In addition, VE-cadherin and zonula occludens-1 (ZO-1), two membrane structure proteins, were immunostained to elucidate the effects of arsenite on the cell-cell junction. The roles of ROS and VEGF in arsenite-induced permeability was determined by inhibiting ROS with antioxidants and immuno-depleting VEGF with a VEGF antibody. We observed that arsenite increased bEnd3 monolayer permeability, elevated the production of cellular ROS, and increased VEGF release. VE-cadherin and ZO-1 disruptions were also found in cells treated with arsenite. Furthermore, both antioxidant (N-acetyl cysteine and tempol) and the VEGF antibody treatments significantly lowered the arsenite-induced permeability of the bEnd3 monolayer as well as VEGF expression. VE-cadherin and ZO-1 disruptions were also diminished by N-acetyl cysteine and the VEGF antibody. Our data suggest that the increase in VEGF expression caused by ROS may play an important role in the arsenite-induced increase in endothelial cell permeability.

A Wheat CCAAT Box-Binding Transcription Factor Increases the Grain Yield of Wheat with Less Fertilizer Input1

PubMed Central

Qu, Baoyuan; He, Xue; Wang, Jing; Zhao, Yanyan; Teng, Wan; Shao, An; Zhao, Xueqiang; Ma, Wenying; Wang, Junyi; Li, Bin; Li, Zhensheng; Tong, Yiping

2015-01-01

Increasing fertilizer consumption has led to low fertilizer use efficiency and environmental problems. Identifying nutrient-efficient genes will facilitate the breeding of crops with improved fertilizer use efficiency. This research performed a genome-wide sequence analysis of the A (NFYA), B (NFYB), and C (NFYC) subunits of Nuclear Factor Y (NF-Y) in wheat (Triticum aestivum) and further investigated their responses to nitrogen and phosphorus availability in wheat seedlings. Sequence mining together with gene cloning identified 18 NFYAs, 34 NFYBs, and 28 NFYCs. The expression of most NFYAs positively responded to low nitrogen and phosphorus availability. In contrast, microRNA169 negatively responded to low nitrogen and phosphorus availability and degraded NFYAs. Overexpressing TaNFYA-B1, a low-nitrogen- and low-phosphorus-inducible NFYA transcript factor on chromosome 6B, significantly increased both nitrogen and phosphorus uptake and grain yield under differing nitrogen and phosphorus supply levels in a field experiment. The increased nitrogen and phosphorus uptake may have resulted from the fact that that overexpressing TaNFYA-B1 stimulated root development and up-regulated the expression of both nitrate and phosphate transporters in roots. Our results suggest that TaNFYA-B1 plays essential roles in root development and in nitrogen and phosphorus usage in wheat. Furthermore, our results provide new knowledge and valuable gene resources that should be useful in efforts to breed crops targeting high yield with less fertilizer input. PMID:25489021

Increased fructose intake as a risk factor for dementia.

PubMed

Stephan, B C M; Wells, J C K; Brayne, C; Albanese, E; Siervo, M

2010-08-01

The transition in the world age demographic toward older age is associated with an increased risk of neurodegenerative diseases, such as Alzheimer's disease. Risk profiles for dementia may also be changing. Obesity and type 2 diabetes have increased in prevalence in the last half-century and have been associated with increased dementia risk. Specific changes in nutrition may also represent a direct risk. A diet transition in the United States has occurred in the intake of refined sugar, particularly high-fructose corn syrup (HFCS) from a yearly estimate of 8.1 kg/person at the beginning of the XIX century to a current estimate of 65 kg/person. This article considers the association between refined sugar intake, markers of cardiovascular disease risk, and the possible promotion of the development of dementia.

Fibroblast growth factor-23 increases mouse PGE2 production in vivo and in vitro.

PubMed

Syal, Ashu; Schiavi, Susan; Chakravarty, Sumana; Dwarakanath, Vangipuram; Quigley, Raymond; Baum, Michel

2006-02-01

Fibroblast growth factor-23 (FGF-23) has been implicated in the renal phosphate wasting in X-linked hypophosphatemia, tumor-induced osteomalacia, and autosomal dominant hypophosphatemic rickets. Recently, we demonstrated that Hyp mice have greater urinary PGE2 levels compared with C57/B6 mice and that indomethacin administration in vivo and in vitro ameliorates the phosphate transport defect in Hyp mice. To determine further whether altered prostaglandin metabolism plays a role in the renal phosphate transport defect in Hyp mice, we incubated renal proximal tubules with arachidonic acid. We find that PGE2 production was higher in Hyp mice than in C57/B6 mice. Incubation of C57/B6 mouse renal proximal tubules with FGF-23R176Q, an active mutant form of FGR23, increased tubular PGE2 production, an effect that was inhibited by 50 microM PD-98059 and 10 microM SB-203580, inhibitors of the MAP kinase pathway. C57/B6 mice injected with FGF-23R176Q had a approximately 10-fold increase in PGE2 excretion 24 h after intraperitoneal injection of FGF-23R176Q compared with vehicle-treated controls. Finally, we show that PGE2 inhibited both phosphate and volume absorption in mouse proximal convoluted tubules perfused in vitro and reduced brush-border membrane vesicle NaPi-2a protein abundance from renal cortex incubated in vitro with PGE2. In conclusion, FGF-23 increases urinary and renal tubular PGE2 production via the MAP kinase pathway and PGE2 inhibits proximal tubule phosphate transport.

Fibroblast growth factor-23 increases mouse PGE2 production in vivo and in vitro

PubMed Central

Syal, Ashu; Schiavi, Susan; Chakravarty, Sumana; Dwarakanath, Vangipuram; Quigley, Raymond; Baum, Michel

2014-01-01

Fibroblast growth factor-23 (FGF-23) has been implicated in the renal phosphate wasting in X-linked hypophosphatemia, tumor-induced osteomalacia, and autosomal dominant hypophosphatemic rickets. Recently, we demonstrated that Hyp mice have greater urinary PGE2 levels compared with C57/B6 mice and that indomethacin administration in vivo and in vitro ameliorates the phosphate transport defect in Hyp mice. To determine further whether altered prostaglandin metabolism plays a role in the renal phosphate transport defect in Hyp mice, we incubated renal proximal tubules with arachidonic acid. We find that PGE2 production was higher in Hyp mice than in C57/B6 mice. Incubation of C57/B6 mouse renal proximal tubules with FGF-23R176Q, an active mutant form of FGR23, increased tubular PGE2 production, an effect that was inhibited by 50 μM PD-98059 and 10 μM SB-203580, inhibitors of the MAP kinase pathway. C57/B6 mice injected with FGF-23R176Q had a ~10-fold increase in PGE2 excretion 24 h after intraperitoneal injection of FGF-23R176Q compared with vehicle-treated controls. Finally, we show that PGE2 inhibited both phosphate and volume absorption in mouse proximal convoluted tubules perfused in vitro and reduced brush-border membrane vesicle NaPi-2a protein abundance from renal cortex incubated in vitro with PGE2. In conclusion, FGF-23 increases urinary and renal tubular PGE2 production via the MAP kinase pathway and PGE2 inhibits proximal tubule phosphate transport. PMID:16144964

Solar radiation increases suicide rate after adjusting for other climate factors in South Korea.

PubMed

Jee, Hee-Jung; Cho, Chul-Hyun; Lee, Yu Jin; Choi, Nari; An, Hyonggin; Lee, Heon-Jeong

2017-03-01

Previous studies have indicated that suicide rates have significant seasonal variations. There is seasonal discordance between temperature and solar radiation due to the monsoon season in South Korea. We investigated the seasonality of suicide and assessed its association with climate variables in South Korea. Suicide rates were obtained from the National Statistical Office of South Korea, and climatic data were obtained from the Korea Meteorological Administration for the period of 1992-2010. We conducted analyses using a generalized additive model (GAM). First, we explored the seasonality of suicide and climate variables such as mean temperature, daily temperature range, solar radiation, and relative humidity. Next, we identified confounding climate variables associated with suicide rate. To estimate the adjusted effect of solar radiation on the suicide rate, we investigated the confounding variables using a multivariable GAM. Suicide rate showed seasonality with a pattern similar to that of solar radiation. We found that the suicide rate increased 1.008 times when solar radiation increased by 1 MJ/m 2 after adjusting for other confounding climate factors (P < 0.001). Solar radiation has a significant linear relationship with suicide after adjusting for region, other climate variables, and time trends. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

trans-Resveratrol Protects Ischemic PC12 Cells by Inhibiting the Hypoxia Associated Transcription Factors and Increasing the Levels of Antioxidant Defense Enzymes

PubMed Central

2012-01-01

An in vitro model of ischemic cerebral stroke [oxygen-glucose deprivation (OGD) for 6 h followed by 24 h reoxygenation (R)] with PC12 cells increases Ca2+ influx by upregulating native L-type Ca2+ channels and reactive oxygen species (ROS) generation. This reactive oxygen species generation and increase in intracellular Ca2+ triggers the expression of hypoxic homeostasis transcription factors such as hypoxia induced factor-1 alpha (HIF-1α), Cav-beta 3 (Cav β3), signal transducer and activator of transcription 3 (STAT3), heat shock protein 27 (hsp-27), and cationic channel transient receptor potential melastatin 7 (TRPM7). OGD insulted PC12 cells were subjected to biologically safe doses (5, 10, and 25 μM) of trans-resveratrol in three different treatment groups: 24 h prior to OGD (pre-treatment); 24 h post OGD (post-treatment); and from 24 h before OGD to end of reoxygenation period (whole-treatment). Here, we demonstrated that OGD-R-induced neuronal injury/death is by reactive oxygen species generation, increase in intracellular calcium levels, and decrease in antioxidant defense enzymes. trans-Resveratrol increases the viability of OGD-R insulted PC12 cells, which was assessed by using MTT, NRU, and LDH release assay. In addition, trans-resveratrol significantly decreases reactive oxygen species generation, intracellular Ca2+ levels, and hypoxia associated transcription factors and also increases the level of antioxidant defense enzymes. Our data shows that the whole-treatment group of trans-resveratrol is most efficient in decreasing hypoxia induced cell death through its antioxidant properties. PMID:23421680

Utilizing a Human Factors Nursing Worksystem Improvement Framework to Increase Nurses' Time at the Bedside and Enhance Safety.

PubMed

Probst, C Adam; Carter, Megan; Cadigan, Caton; Dalcour, Cortney; Cassity, Cindy; Quinn, Penny; Williams, Tiana; Montgomery, Donna Cook; Wilder, Claudia; Xiao, Yan

2017-02-01

The aim of this study is to increase nurses' time for direct patient care and improve safety via a novel human factors framework for nursing worksystem improvement. Time available for direct patient care influences outcomes, yet worksystem barriers prevent nurses adequate time at the bedside. A novel human factors framework was developed for worksystem improvement in 3 units at 2 facilities. Objectives included improving nurse efficiency as measured by time-and-motion studies, reducing missing medications and subsequent trips to medication rooms and improving medication safety. Worksystem improvement resulted in time savings of 16% to 32% per nurse per 12-hour shift. Requests for missing medications dropped from 3.2 to 1.3 per day. Nurse medication room trips were reduced by 30% and nurse-reported medication errors fell from a range of 1.2 to 0.8 and 6.3 to 4.0 per month. An innovative human factors framework for nursing worksystem improvement provided practical and high priority targets for interventions that significantly improved the nursing worksystem.

Artemin growth factor increases nicotinic cholinergic receptor subunit expression and activity in nociceptive sensory neurons.

PubMed

Albers, Kathryn M; Zhang, Xiu Lin; Diges, Charlotte M; Schwartz, Erica S; Yang, Charles I; Davis, Brian M; Gold, Michael S

2014-05-22

Artemin (Artn), a member of the glial cell line-derived growth factor (GDNF) family, supports the development and function of a subpopulation of peptidergic, TRPV1-positive sensory neurons. Artn (enovin, neublastin) is elevated in inflamed tissue and its injection in skin causes transient thermal hyperalgesia. A genome wide expression analysis of trigeminal ganglia of mice that overexpress Artn in the skin (ART-OE mice) showed elevation in nicotinic acetylcholine receptor (nAChR) subunits, suggesting these ion channels contribute to Artn-induced sensitivity. Here we have used gene expression, immunolabeling, patch clamp electrophysiology and behavioral testing assays to investigate the link between Artn, nicotinic subunit expression and thermal hypersensitivity. Reverse transcriptase-PCR validation showed increased levels of mRNAs encoding the nAChR subunits α3 (13.3-fold), β3 (4-fold) and β4 (7.7-fold) in trigeminal ganglia and α3 (4-fold) and β4 (2.8-fold) in dorsal root ganglia (DRG) of ART-OE mice. Sensory ganglia of ART-OE mice had increased immunoreactivity for nAChRα3 and exhibited increased overlap in labeling with GFRα3-positive neurons. Patch clamp analysis of back-labeled cutaneous afferents showed that while the majority of nicotine-evoked currents in DRG neurons had biophysical and pharmacological properties of α7-subunit containing nAChRs, the Artn-induced increase in α3 and β4 subunits resulted in functional channels. Behavioral analysis of ART-OE and wildtype mice showed that Artn-induced thermal hyperalgesia can be blocked by mecamylamine or hexamethonium. Complete Freund's adjuvant (CFA) inflammation of paw skin, which causes an increase in Artn in the skin, also increased the level of nAChR mRNAs in DRG. Finally, the increase in nAChRs transcription was not dependent on the Artn-induced increase in TRPV1 or TRPA1 in ART-OE mice since nAChRs were elevated in ganglia of TRPV1/TRPA1 double knockout mice. These findings suggest that Artn

Factors Which Increase Acid Production in Milk by Lactobacilli

PubMed Central

Huhtanen, C. N.; Williams, W. L.

1963-01-01

The stimulation by yeast extract of acid production in milk by various lactobacilli was studied. It was found that supplementing milk with purine and pyrimidine bases and amino acids allowed nearly maximal acid production by Lactobacillus bulgaricus strain 7994, L. acidophilus 4796, 4356, and 4357, and L. leichmannii 326 and 327. Further supplementation with deoxyribotides allowed maximal acid production by L. acidophilus 204, but L. acidophilus 207 required adenosine or adenylic acid. L. casei strain 7469 showed no appreciable response to the amino acids or purine and pyrimidine bases, and is presumed to require an unidentified factor in corn steep liquor. PMID:13955610

An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 2: Functional Performance Tests Correlate With Return-to-Sport Outcomes.

PubMed

McGrath, Timothy M; Waddington, Gordon; Scarvell, Jennie M; Ball, Nick; Creer, Rob; Woods, Kevin; Smith, Damian; Adams, Roger

2017-02-01

Additional high-quality prospective studies are needed to better define the objective criteria used in relation to return-to-sport decisions after anterior cruciate ligament (ACL) reconstruction in active populations. To investigate prospectively the relationship between functional performance test results at 24 weeks postoperative and return-to-sport activity (Tegner activity score) at 12 and 24 months, respectively, after synthetic (ligament advanced reinforcement system [LARS]) and autograft (doubled semitendinosus/gracilis [2ST/2GR]) ACL reconstructions. Case series; Level of evidence, 4. A total of 64 patients who underwent ACL reconstruction (32 LARS, 32 2ST/2GR autograft; mean age, 27.9 years; body mass index [BMI], 24.9 kg/m 2 ) were assessed preoperatively and at staged intervals postoperatively up to 24 weeks for isokinetic testing of quadriceps and hamstring average power per repetition at 60 deg/s and 180 deg/s, a battery of hop tests, peak vertical ground-reaction force (vGRF), and time to peak vGRF (in seconds) during a step- and jump-down task onto a force platform and peak speed (m/s) using a global positioning system (GPS unit) during a running task. A cohort of 32 healthy matched participants (mean age, 26.31 years; BMI, 25.7 kg/m 2 ) were also tested to act as reference. Pearson correlation was calculated to assess correlation of each performance measure at 24 weeks postoperative with activity outcomes (Tegner score) at 12 and 24 months. The strongest correlation between physical performance tests and return-to-sport outcomes was observed with peak speed during running. Large correlations were also observed for hamstring isokinetic power and hop test for distance. Moderate correlations were observed for timed hop, peak vGRF during a jump-down task, and quadriceps isokinetic power. No statistical correlations were observed for time to peak vGRF during a step-down and jump-down task as well as peak vGRF during a step-down task. When the performance

Microgravity and Signaling Molecules in Rat Osteoblasts: Downstream of Receptor Tyrosine Kinase, G-Protein-Coupled Receptor, and Small GTP-Binding Proteins

NASA Technical Reports Server (NTRS)

Kumel, Yasuhiro; Shimokawa, Hitoyata; Morita, Sadao; Katano, Hisako; Akiyama, Hideo; Hirano, Masahiko; Ohya, Keiichi; Sams, Clarence F.; Whitson, Peggy A.

2005-01-01

Rat osteoblasts were cultured for 4 and 5 days aboard Space Shuttle and solubilized on board. The mRNA levels of the post-receptor signaling molecules were analyzed by quantitative RT-PCR. The G-protein alpha subunit G(alpha)q mRNA levels were elevated 3-fold by microgravity. G(alpha)q stimulates PLC(beta), and then PKC. PKC(delta) and PKC(theta) mRNA levels were increased 2- to 5-fold by microgravity The mRNA levels of SOS and Ras GRF were increased 4 to 5-fold by microgravity, while Ras GAP was not altered. Spaceflight-induced bone loss might be attributed to microgravity modulation of the signaling pathway in osteoblasts.

Does high sugar consumption exacerbate cardiometabolic risk factors and increase the risk of type 2 diabetes and cardiovascular disease?

PubMed Central

Sonestedt, Emily; Øverby, Nina Cecilie; Laaksonen, David E.; Birgisdottir, Bryndis Eva

2012-01-01

Consumption of sugar has been relatively high in the Nordic countries; the impact of sugar intake on metabolic risk factors and related diseases has been debated. The objectives were to assess the effect of sugar intake (sugar-sweetened beverages, sucrose and fructose) on association with type 2 diabetes, cardiovascular disease and related metabolic risk factors (impaired glucose tolerance, insulin sensitivity, dyslipidemia, blood pressure, uric acid, inflammation markers), and on all-cause mortality, through a systematic review of prospective cohort studies and randomised controlled intervention studies published between January 2000 and search dates. The methods adopted were as follows: the first search was run in PubMed in October 2010. A second search with uric acid as risk marker was run in April 2011. The total search strategy was rerun in April 2011 in SveMed+. An update was run in PubMed in January 2012. Two authors independently selected studies for inclusion from the 2,743 abstracts according to predefined eligibility criteria. The outcome was that out of the 17 studies extracted, 15 were prospective cohort studies and two were randomised controlled crossover trials. All of the studies included only adults. With respect to incident type 2 diabetes (nine studies), four of six prospective cohort studies found a significant positive association for sugar-sweetened beverage intake. In general, larger cohort studies with longer follow-up more often reported positive associations, and BMI seemed to mediate part of the increased risk. For other metabolic or cardiovascular risk factors or outcomes, too few studies have been published to draw conclusions. In conclusion, data from prospective cohort studies published in the years 2000–2011 suggest that sugar-sweetened beverages probably increase the risk of type 2 diabetes. For related metabolic risk factors, cardiovascular disease or all-cause mortality and other types of sugars, too few studies were available

Reduced intestinal brain-derived neurotrophic factor increases vagal sensory innervation of the intestine and enhances satiation.

PubMed

Biddinger, Jessica E; Fox, Edward A

2014-07-30

Brain-derived neurotrophic factor (BDNF) is produced by developing and mature gastrointestinal (GI) tissues that are heavily innervated by autonomic neurons and may therefore control their development or function. To begin investigating this hypothesis, we compared the morphology, distribution, and density of intraganglionic laminar endings (IGLEs), the predominant vagal GI afferent, in mice with reduced intestinal BDNF (INT-BDNF(-/-)) and controls. Contrary to expectations of reduced development, IGLE density and longitudinal axon bundle number in the intestine of INT-BDNF(-/-) mice were increased, but stomach IGLEs were normal. INT-BDNF(-/-) mice also exhibited increased vagal sensory neuron numbers, suggesting that their survival was enhanced. To determine whether increased intestinal IGLE density or other changes to gut innervation in INT-BDNF(-/-) mice altered feeding behavior, meal pattern and microstructural analyses were performed. INT-BDNF(-/-) mice ate meals of much shorter duration than controls, resulting in reduced meal size. Increased suppression of feeding in INT-BDNF(-/-) mice during the late phase of a scheduled meal suggested that increased satiation signaling contributed to reduced meal duration and size. Furthermore, INT-BDNF(-/-) mice demonstrated increases in total daily intermeal interval and satiety ratio, suggesting that satiety signaling was augmented. Compensatory responses maintained normal daily food intake and body weight in INT-BDNF(-/-) mice. These findings suggest a target organ-derived neurotrophin suppresses development of that organ's sensory innervation and sensory neuron survival and demonstrate a role for BDNF produced by peripheral tissues in short-term controls of feeding, likely through its regulation of development or function of gut innervation, possibly including augmented intestinal IGLE innervation. Copyright © 2014 the authors 0270-6474/14/3410379-15$15.00/0.

Insulin-Like Growth Factor Binding Proteins Increase Intracellular Calcium Levels in Two Different Cell Lines

PubMed Central

Seurin, Danielle; Lombet, Alain; Babajko, Sylvie; Godeau, François; Ricort, Jean-Marc

2013-01-01

Background Insulin-like growth factor binding proteins (IGFBPs) are six related secreted proteins that share IGF-dependent and -independent functions. If the former functions begin to be well described, the latter are somewhat more difficult to investigate and to characterize. At the cellular level, IGFBPs were shown to modulate numerous processes including cell growth, differentiation and apoptosis. However, the molecular mechanisms implicated remain largely unknown. We previously demonstrated that IGFBP-3, but not IGFBP-1 or IGFBP-5, increase intracellular calcium concentration in MCF-7 cells (Ricort J-M et al. (2002) FEBS lett 527: 293–297). Methodology/Principal Findings We perform a global analysis in which we studied, by two different approaches, the binding of each IGFBP isoform (i.e., IGFBP-1 to -6) to the surface of two different cellular models, MCF-7 breast adenocarcinoma cells and C2 myoblast proliferative cells, as well as the IGFBP-induced increase of intracellular calcium concentration. Using both confocal fluorescence microscopy and flow cytometry analysis, we showed that all IGFBPs bind to MCF-7 cell surface. By contrast, only four IGFBPs can bind to C2 cell surface since neither IGFBP-2 nor IGFBP-4 were detected. Among the six IGFBPs tested, only IGFBP-1 did not increased intracellular calcium concentration whatever the cellular model studied. By contrast, IGFBP-2, -3, -4 and -6, in MCF-7 cells, and IGFBP-3, -5 and -6, in C2 proliferative cells, induce a rapid and transient increase in intracellular free calcium concentration. Moreover, IGFBP-2 and -3 (in MCF-7 cells) and IGFBP-5 (in C2 cells) increase intracellular free calcium concentration by a pertussis toxin sensitive signaling pathway. Conclusions Our results demonstrate that IGFBPs are able to bind to cell surface and increase intracellular calcium concentration. By characterizing the IGFBPs-induced cell responses and intracellular couplings, we highlight the cellular specificity and

Exercise reduces diet-induced cognitive decline and increases hippocampal brain-derived neurotrophic factor in CA3 neurons

PubMed Central

Noble, Emily E.; Mavanji, Vijayakumar; Little, Morgan R.; Billington, Charles J.; Kotz, Catherine M.; Wang, ChuanFeng

2014-01-01

Background Previous studies have shown that a western diet impairs, whereas physical exercise enhances hippocampus-dependent learning and memory. Both diet and exercise influence expression of hippocampal brain-derived neurotrophic factor (BDNF), which is associated with improved cognition. We hypothesized that exercise reverses diet-induced cognitive decline while increasing hippocampal BDNF. Methods To test the effects of exercise on hippocampal-dependent memory, we compared cognitive scores of Sprague-Dawley rats exercised by voluntary running wheel (RW) access or forced treadmill (TM) to sedentary (Sed) animals. Memory was tested by two-way active avoidance test (TWAA), in which animals are exposed to a brief shock in a specific chamber area. When an animal avoids, escapes or has reduced latency to do either, this is considered a measure of memory. In a second experiment, rats were fed either a high-fat diet or control diet for 16 weeks, then randomly assigned to running wheel access or sedentary condition, and TWAA memory was tested once a week for seven weeks of exercise intervention. Results Both groups of exercised animals had improved memory as indicated by reduced latency to avoid and escape shock, and increased avoid and escape episodes (p<0.05). Exposure to a high-fat diet resulted in poor performance during both the acquisition and retrieval phases of the memory test as compared to controls. Exercise reversed high-fat diet-induced memory impairment, and increased brain-derived neurotrophic factor (BDNF) in neurons of the hippocampal CA3 region. Conclusions These data suggest that exercise improves memory retrieval, particularly with respect to avoiding aversive stimuli, and may be beneficial in protecting against diet induced cognitive decline, likely via elevated BDNF in neurons of the CA3 region. PMID:24755094

Exercise reduces diet-induced cognitive decline and increases hippocampal brain-derived neurotrophic factor in CA3 neurons.

PubMed

Noble, Emily E; Mavanji, Vijayakumar; Little, Morgan R; Billington, Charles J; Kotz, Catherine M; Wang, ChuanFeng

2014-10-01

Previous studies have shown that a western diet impairs, whereas physical exercise enhances hippocampus-dependent learning and memory. Both diet and exercise influence expression of hippocampal brain-derived neurotrophic factor (BDNF), which is associated with improved cognition. We hypothesized that exercise reverses diet-induced cognitive decline while increasing hippocampal BDNF. To test the effects of exercise on hippocampal-dependent memory, we compared cognitive scores of Sprague-Dawley rats exercised by voluntary running wheel (RW) access or forced treadmill (TM) to sedentary (Sed) animals. Memory was tested by two-way active avoidance test (TWAA), in which animals are exposed to a brief shock in a specific chamber area. When an animal avoids, escapes or has reduced latency to do either, this is considered a measure of memory. In a second experiment, rats were fed either a high-fat diet or control diet for 16 weeks, then randomly assigned to running wheel access or sedentary condition, and TWAA memory was tested once a week for 7 weeks of exercise intervention. Both groups of exercised animals had improved memory as indicated by reduced latency to avoid and escape shock, and increased avoid and escape episodes (p<0.05). Exposure to a high-fat diet resulted in poor performance during both the acquisition and retrieval phases of the memory test as compared to controls. Exercise reversed high-fat diet-induced memory impairment, and increased brain-derived neurotrophic factor (BDNF) in neurons of the hippocampal CA3 region. These data suggest that exercise improves memory retrieval, particularly with respect to avoiding aversive stimuli, and may be beneficial in protecting against diet induced cognitive decline, likely via elevated BDNF in neurons of the CA3 region. Published by Elsevier Inc.

Role of insulin-like growth factor-I in the regulation of skeletal muscle adaptation to increased loading

NASA Technical Reports Server (NTRS)

Adams, G. R.

1998-01-01

Adaptations in muscle mass stimulated by changes in muscle loading state entail alternations in the synthesis and degradation of myofiber proteins and the modulation of myonuclear number such that the ratio between the number of myonuclei and the size of the myofibers remains relatively constant. As depicted schematically in Figure 2.6, the literature regarding the role of IGF-in mediating muscle adaptation to alterations in loading state suggests the following conclusions: During periods of increased loading, myofibers upregulate the expression and secretion of IGF-I. Acting as an autocrine and/or paracrine growth factor, IGF-I stimulates myofiber anabolic processes. Acting as a paracrine growth factor, IGF-I also stimulates adjacent satellite cells to enter the cell cycle and proliferate. Continued myofiber production of IGF-I stimulates some satellite cells to differentiate and then fuse with myofibers, thus providing additional myonuclei in order to maintain or reestablish the myonucleus to myofiber size ratios of the enlarged myofibers.

Copper-2 Ingestion, Plus Increased Meat Eating Leading to Increased Copper Absorption, Are Major Factors Behind the Current Epidemic of Alzheimer's Disease.

PubMed

Brewer, George J

2015-12-02

It has become clear that copper toxicity is playing a major role in Alzheimer's disease; but why is the brain copper toxicity with cognition loss in Alzheimer's disease so much different clinically than brain copper toxicity in Wilson's disease, which results in a movement disorder? Furthermore, why is the inorganic copper of supplement pills and in drinking water so much more damaging to cognition than the organic copper in food? A recent paper, which shows that almost all food copper is copper-1, that is the copper-2 of foods reverts to the reduced copper-1 form at death or harvest, gives new insight into these questions. The body has an intestinal transport system for copper-1, Ctr1, which channels copper-1 through the liver and into safe channels. Ctr1 cannot absorb copper-2, and some copper-2 bypasses the liver, ends up in the blood quickly, and is toxic to cognition. Humans evolved to handle copper-1 safely, but not copper-2. Alzheimer's is at least in part, a copper-2 toxicity disease, while Wilson's is a general copper overload disease. In this review, we will show that the epidemiology of the Alzheimer's epidemic occurring in developed, but not undeveloped countries, fits with the epidemiology of exposure to copper-2 ingestion leached from copper plumbing and from copper supplement pill ingestion. Increased meat eating in developed countries is also a factor, because it increases copper absorption, and thus over all copper exposure.

Intermittent hypoxia causes histological kidney damage and increases growth factor expression in a mouse model of obstructive sleep apnea

PubMed Central

Ayas, Najib T.

2018-01-01

increased glomerular area (by 1.13 fold, p< 0.001) and expansion of mesangial matrix (by 1.8 fold, p< 0.01). Moreover, the glomerular expressions of TGF-β1, CTGF and VEGF-A proteins were 2.7, 2.2 and 3.8-fold higher in mice exposed to IH (p< 0.05 for all). Furthermore, western blotting protein analysis demonstrates that IH-exposed mice express higher levels of TGF-β1, CTGF and VEGF-A proteins by 1.9, 4.0 and 1.6-fold (p< 0.05 for all) respectively. Renal cellular apoptosis was greater in the IH group as shown by an increased cortical Bax/Bcl-2 protein ratio (p< 0.01) and higher fluorometric TUNEL staining (p< 0.001). Finally, 24-hr urinary albumin levels were higher in mice exposed to IH (43.4 μg vs 9.7 μg, p< 0.01), while there were no differences in serum creatinine levels between the two groups. We conclude that IH causes kidney injury that is accompanied by glomerular hypertrophy, mesangial matrix expansion, increased expression of glomerular growth factors and an increased cellular apoptosis. PMID:29389945

Teleseismic P-wave polarization analysis at the Gräfenberg array

NASA Astrophysics Data System (ADS)

Cristiano, L.; Meier, T.; Krüger, F.; Keers, H.; Weidle, C.

2016-12-01

P-wave polarization at the Gräfenberg array (GRF) in southern Germany is analysed in terms of azimuthal deviations and deviations in the vertical polarization using 20 yr of broad-band recordings. An automated procedure for estimating P-wave polarization parameters is suggested, based on the definition of a characteristic function, which evaluates the polarization angles and their time variability as well as the amplitude, linearity and the signal-to-noise ratio of the P wave. P-wave polarization at the GRF array is shown to depend mainly on frequency and backazimuth and only slightly on epicentral distance indicating depth-dependent local anisotropy and lateral heterogeneity. A harmonic analysis is applied to the azimuthal anomalies to analyse their periodicity as a function of backazimuth. The dominant periods are 180° and 360°. At low frequencies, between 0.03 and 0.1 Hz, the observed fast directions of azimuthal anisotropy inferred from the 180° periodicity are similar across the array. The average fast direction of azimuthal anisotropy at these frequencies is N20°E with an uncertainty of about 8° and is consistent with fast directions of Pn-wave propagation. Lateral velocity gradients determined for the low-frequency band are compatible with the Moho topography of the area. A more complex pattern in the horizontal fast axis orientation beneath the GRF array is observed in the high-frequency band between 0.1 and 0.5 Hz, and is attributed to anisotropy in the upper crust. A remarkable rotation of the horizontal fast axis orientation across the suture between the geological units Moldanubicum and Saxothuringicum is observed. In contrast, the 360° periodicity at high frequencies is rather consistent across the array and may either point to lower velocities in the upper crust towards the Bohemian Massif and/or to anisotropy dipping predominantly in the NE-SW direction. Altogether, P-wave polarization analysis indicates the presence of layered lithospheric

Factor V Leiden is associated with increased sperm count.

PubMed

van Mens, T E; Joensen, U N; Bochdanovits, Z; Takizawa, A; Peter, J; Jørgensen, N; Szecsi, P B; Meijers, J C M; Weiler, H; Rajpert-De Meyts, E; Repping, S; Middeldorp, S

2017-11-01

Is the thrombophilia mutation factor V Leiden (FVL) associated with an increased total sperm count? Carriers of FVL have a higher total sperm count than non-FVL-carriers, which could not be explained by genetic linkage or by observations in a FVL-mouse model. FVL has a high prevalence in Caucasians despite detrimental health effects. Carriers have been shown to have higher fecundity, which might partly explain this evolutionary paradox. We determined FVL status in two cohorts (Dutch, n = 627; Danish, n = 854) of consecutively included men without known causes for spermatogenic failure, and performed an individual patient data meta-analysis of these two cohorts together with one previously published (Dutch, n = 908) cohort. We explored possible biological underpinnings for the relation between sperm count and FVL, by use of a FVL-mouse model and investigations of genetic linkage. Participants were male partners of subfertile couples (two Dutch cohorts) and young men from the general population (Danish cohort): FVL carrier rate was 4.0%, 4.6% and 7.3%, respectively. There were differences in smoking, abstinence time and age between the cohorts. We corrected for these in the primary analysis, which consisted of a mixed linear effects model, also incorporating unobjectified population differences. In public haplotype data from subjects of European descent, we explored linkage disequilibrium of FVL with all known single nucleotide polymorphisms in a 1.5 MB region around the F5 gene with an R2 cutoff of 0.8. We sequenced exons of four candidate genes hypothesized to be linked to FVL in a subgroup of FVL carriers with extreme sperm count values. The animal studies consisted of never mated 15-18-week-old C57BL/J6 mice heterozygous and homozygous for FVL and wild-type mice. We compared spermatogenesis parameters (normalized internal genitalia weights, epididymis sperm content and sperm motility) between FVL and wild-type mice. Human FVL carriers have a higher total sperm

Increasing diversity in radiologic technology.

PubMed

Carwile, Laura

2003-01-01

Diversity is increasingly important in the radiologic technology workplace. For significant changes to occur in work force diversity, educators must first recruit and retain students from a wide variety of backgrounds. This article examines personality, race and gender as factors affecting career choice and how educators can use these factors to increase diversity in their programs. An overview of the ASRT's efforts to improve diversity within the profession is presented, along with suggestions for developing effective recruitment and retention plans to increase diversity.

Low-fat diet with omega-3 fatty acids increases plasma insulin-like growth factor concentration in healthy postmenopausal women.

PubMed

Young, Lindsay R; Kurzer, Mindy S; Thomas, William; Redmon, J Bruce; Raatz, Susan K

2013-07-01

The insulin-like growth factor pathway plays a central role in the normal and abnormal growth of tissues; however, nutritional determinants of insulin-like growth factor I (IGF-I) and its binding proteins in healthy individuals are not well defined. Three test diets-high-fat diet (40% energy as fat), low-fat diet (LF; 20% energy as fat), and a diet with low fat and high omega-3 fatty acid (LFn3; 23% energy as fat)--were tested in a randomized crossover designed controlled feeding trial in healthy postmenopausal women. Plasma IGF-I, IGF binding protein-3 (IGFBP-3), insulin, glucose, and ratio of IGF-I/IGFBP-3 concentrations were measured in response to diets. Insulin sensitivity was calculated using the homeostatic model assessment of insulin resistance We hypothesized that IGF-I, insulin, and glucose concentrations would decrease and IGFBP-3 concentration would increase in response to the low-fat diets. Eight weeks of the LFn3 diet increased circulating IGF-I (P < .001) and IGFBP-3 (P = .01) and the LF diet increased IGFBP-3 (P = .04), resulting in trends toward an increased IGF-I/IGFBP-3 ratio with the LFn3 diet and a decreased IGF-I/IGFBP-3 ratio with the LF diet (P = .13 for both comparisons). No statistically significant differences were detected between treatments at baseline or 8 weeks for IGF-1, IGFBP-3, or the ratio of IGF-1/IGFBP-3. Insulin, glucose, and the homeostatic model assessment of insulin resistance were not altered by the interventions. Low-fat diet with high n-3 fatty acids may increase circulating IGF-I concentrations without adversely affecting insulin sensitivity in healthy individuals. Published by Elsevier Inc.

Increasing maternal percentage body fat in early second trimester: a risk factor for preeclampsia.

PubMed

Wang, Yanxia; Qiu, Jie; Zhou, Min; Wang, Youjie; Du, Yukai

2015-02-01

To determine if maternal percentage body fat (PBF) or fat free mass (FFM) in the early second trimester of pregnancy influenced the development of preeclampsia. A matched nested case-control study was conducted from a cohort study of 1668 women at Gansu provincial maternal and child care hospital from July 2007 to August 2011 in China. Maternal PBF and FFM were assessed by bioelectrical impedance analysis during 12th-16th gestational week. The demographic characteristics were all chart abstracted. After childbirth, 70 cases of preeclampsia were matched by race/age with 140 uncomplicated pregnancies women. Multivariate logistic regression analysis was performed to determine the associated risk factors. Pre-pregnancy body mass index were higher in women who subsequently developed preeclampsia compared with controls (p < 0.001). During 12th-16th gestational week, there were nearly 7-fold increase in the odds of preeclampsia (adjusted OR: 6.84, 95% CI: 4.15-41.60) among women with PBF ≥ 40% versus women with PBF < 40%. But FFM were not at further increased risk of the development of preeclampsia (adjusted OR, 1.02; 95% CI, 0.6-3.6). Maternal PBF but not FFM is a predictor of preeclampsia in the early second trimester. Excessive adipose tissue possibly played an important role in developing of preeclampsia.

Simvastatin mitigates increases in risk factors for and the occurrence of cardiac disease following 10 Gy total body irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lenarczyk, Marek; Su, Jidong; Haworth, Steven T.

The ability of simvastatin to mitigate the increases in risk factors for and the occurrence of cardiac disease after 10 Gy total body irradiation (TBI) was determined. This radiation dose is relevant to conditioning for stem cell transplantation and threats from radiological terrorism. Male rats received single dose TBI of 10 Gy. Age-matched, sham-irradiated rats served as controls. Lipid profile, heart and liver morphology and cardiac mechanical function were determined for up to 120 days after irradiation. TBI resulted in a sustained increase in total- and LDL-cholesterol (low-density lipoprotein-cholesterol), and triglycerides. Simvastatin (10 mg/kg body weight/day) administered continuously from 9more » days after irradiation mitigated TBI-induced increases in total- and LDL-cholesterol and triglycerides, as well as liver injury. TBI resulted in cellular peri-arterial fibrosis, whereas control hearts had less collagen and fibrosis. Simvastatin mitigated these morphological injuries. TBI resulted in cardiac mechanical dysfunction. Simvastatin mitigated cardiac mechanical dysfunction 20–120 days following TBI. To determine whether simvastatin affects the ability of the heart to withstand stress after TBI, injury from myocardial ischemia/reperfusion was determined in vitro. TBI increased the severity of an induced myocardial infarction at 20 and 80 days after irradiation. Simvastatin mitigated the severity of this myocardial infarction at 20 and 80 days following TBI. It is concluded simvastatin mitigated the increases in risk factors for cardiac disease and the extent of cardiac disease following TBI. This statin may be developed as a medical countermeasure for the mitigation of radiation-induced cardiac disease.« less

Simvastatin mitigates increases in risk factors for and the occurrence of cardiac disease following 10 Gy total body irradiation

DOE PAGES

Lenarczyk, Marek; Su, Jidong; Haworth, Steven T.; ...

2015-06-01

The ability of simvastatin to mitigate the increases in risk factors for and the occurrence of cardiac disease after 10 Gy total body irradiation (TBI) was determined. This radiation dose is relevant to conditioning for stem cell transplantation and threats from radiological terrorism. Male rats received single dose TBI of 10 Gy. Age-matched, sham-irradiated rats served as controls. Lipid profile, heart and liver morphology and cardiac mechanical function were determined for up to 120 days after irradiation. TBI resulted in a sustained increase in total- and LDL-cholesterol (low-density lipoprotein-cholesterol), and triglycerides. Simvastatin (10 mg/kg body weight/day) administered continuously from 9more » days after irradiation mitigated TBI-induced increases in total- and LDL-cholesterol and triglycerides, as well as liver injury. TBI resulted in cellular peri-arterial fibrosis, whereas control hearts had less collagen and fibrosis. Simvastatin mitigated these morphological injuries. TBI resulted in cardiac mechanical dysfunction. Simvastatin mitigated cardiac mechanical dysfunction 20–120 days following TBI. To determine whether simvastatin affects the ability of the heart to withstand stress after TBI, injury from myocardial ischemia/reperfusion was determined in vitro. TBI increased the severity of an induced myocardial infarction at 20 and 80 days after irradiation. Simvastatin mitigated the severity of this myocardial infarction at 20 and 80 days following TBI. It is concluded simvastatin mitigated the increases in risk factors for cardiac disease and the extent of cardiac disease following TBI. This statin may be developed as a medical countermeasure for the mitigation of radiation-induced cardiac disease.« less

Factors affecting acceptability of an email-based intervention to increase fruit and vegetable consumption.

PubMed

Kothe, Emily J; Mullan, Barbara A

2014-09-30

Fresh Facts is a 30-day email-delivered intervention designed to increase the fruit and vegetable consumption of Australian young adults. This study investigated the extent to which the program was acceptable to members of the target audience and examined the relationships between participant and intervention characteristics, attrition, effectiveness, and acceptability ratings. Young adults were randomised to two levels of message frequency: high-frequency (n = 102), low-frequency (n = 173). Individuals in the high-frequency group received daily emails while individuals in the low-frequency group received an email every 3 days. Individuals in the high-frequency group were more likely to indicate that they received too many emails than individuals in the low-frequency group. No other differences in acceptability were observed. Baseline beliefs about fruit and vegetables were an important predictor of intervention acceptability. In turn, acceptability was associated with a number of indicators of intervention success, including change in fruit and vegetable consumption. The findings highlight the importance of considering the relationship between these intervention and participant factors and acceptability in intervention design and evaluation. Results support the ongoing use of email-based interventions to target fruit and vegetable consumption within young adults. However, the relationships between beliefs about fruit and vegetable consumption and acceptability suggest that this intervention may be differentially effective depending on individual's existing beliefs about fruit and vegetable consumption. As such, there is a pressing need to consider these factors in future research in order to minimize attrition and maximize intervention effectiveness when interventions are implemented outside of a research context.

Regulation of Ras Exchange Factors and Cellular Localization of Ras Activation by Lipid Messengers in T Cells

PubMed Central

Jun, Jesse E.; Rubio, Ignacio; Roose, Jeroen P.

2013-01-01

The Ras-MAPK signaling pathway is highly conserved throughout evolution and is activated downstream of a wide range of receptor stimuli. Ras guanine nucleotide exchange factors (RasGEFs) catalyze GTP loading of Ras and play a pivotal role in regulating receptor-ligand induced Ras activity. In T cells, three families of functionally important RasGEFs are expressed: RasGRF, RasGRP, and Son of Sevenless (SOS)-family GEFs. Early on it was recognized that Ras activation is critical for T cell development and that the RasGEFs play an important role herein. More recent work has revealed that nuances in Ras activation appear to significantly impact T cell development and selection. These nuances include distinct biochemical patterns of analog versus digital Ras activation, differences in cellular localization of Ras activation, and intricate interplays between the RasGEFs during distinct T cell developmental stages as revealed by various new mouse models. In many instances, the exact nature of these nuances in Ras activation or how these may result from fine-tuning of the RasGEFs is not understood. One large group of biomolecules critically involved in the control of RasGEFs functions are lipid second messengers. Multiple, yet distinct lipid products are generated following T cell receptor (TCR) stimulation and bind to different domains in the RasGRP and SOS RasGEFs to facilitate the activation of the membrane-anchored Ras GTPases. In this review we highlight how different lipid-based elements are generated by various enzymes downstream of the TCR and other receptors and how these dynamic and interrelated lipid products may fine-tune Ras activation by RasGEFs in developing T cells. PMID:24027568

Cardiovascular Risk Factors Increase the Risks of Diabetic Peripheral Neuropathy in Patients With Type 2 Diabetes Mellitus

PubMed Central

Yang, Chun-Pai; Lin, Cheng-Chieh; Li, Chia-Ing; Liu, Chiu-Shong; Lin, Wen-Yuan; Hwang, Kai-Lin; Yang, Sing-Yu; Chen, Hsuan-Ju; Li, Tsai-Chung

2015-01-01

Abstract This study aimed to examine whether poor glycemic control, measured by glycated hemoglobin A1C (HbA1c) and other cardiovascular risk factors, can predict diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (DM). Patients aged ≥30 years with type 2 DM, enrolled in the National Diabetes Care Management Program, and free of DPN (n = 37,375) in the period 2002 to 2004 were included and followed up until 2011. The related factors were analyzed using Cox proportional hazards regression models. For an average follow-up of 7.00 years, 8379 cases of DPN were identified, with a crude incidence rate of 32.04/1000 person-years. After multivariate adjustment, patients with HbA1c levels 7 to 8%, 8 to 9%, 9 to 10%, and ≥10% exhibited higher risk of DPN (adjusted HR: 1.11 [1.04–1.20], 1.30 [1.21–1.40], 1.32 [1.22–1.43], and 1.62 [1.51–1.74], respectively) compared with patients with HbA1c level 6 to 7%. There was a significant linear trend in DPN incidence with increasing HbA1c (P < 0.001) and significant HRs of DPN for patients with HbA1c level ≥7%, blood pressure ≥130/85 mm Hg, triglycerides (TG) ≥150 mg/dL, high density of lipoprotein-cholesterol (HDL-C) <40 mg/dL in males and <50 mg/dL in females, low density of lipoprotein-cholesterol (LDL-C) ≥100 mg/dL, and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Patients with type 2 DM and HbA1c ≥7.0% exhibit increased risk of DPN, demonstrating a linear relationship. The incidence of DPN is also associated with poor glucose control and cardiovascular risk factors like hypertension, hyper-triglyceridemia, low HDL-C, high LDL-C, and decreased eGFR. PMID:26496307

The use of an electric field in increasing the resistance of plants to the action of unfavorable space flight factors

NASA Astrophysics Data System (ADS)

Nechitailo, G.; Gordeev, A.

The key role in increasing the resistance of plants to unfavorable space flight factors is assigned to biomembranes of root cells. It is these biomembranes on which numerous biochemical and biophysical processes determining the adaptive capacity of plant organisms occur. In the initial period of exposure to unfavorable space flight factors the adaptational reactions of the plant organism undoubtedly increase its resistance. But the intensification of removal of H+ ions through the plasmalemma with an increase of the external influence sharply raises the quantity of cations leaving the cell, which leads to the accumu lation of a considerable quantity of intracellular negative charges. These charges together with negative charges built in the membrane force protons to concentrate on the external surface of the membrane. Since protons have a very strong electric field, they form such a charge of which the electric field is about from several to hundreds of V/cm. The concentration of positive charges of protons entails the formation of a double electric field which extremely impedes the diffusion of other ions. Thus, a proton barrier is formed. Its length can be very considerable due to which the whole process of transmembrane energy and mass-transfer is disturbed. The proton barrier is easily destroyed by a weak electric field created in the root zone. In experiment on electrostimulation of different plants under space flight conditions at the orbital station MIR the absorption of nutrient elements by the root system increased to the optimal level, the ratio of physiologically active substances in the rhizosphere was normalized, the content of chlorophyll, carotin, and ascorbic acid in leaves corresponded to the ground-based control. Understanding of the mechanism of formation of a proton barrier on the plasmalemma of root cells as a result of the response of plants to the negative action of external factors (microgravity) is of great importance. It allows the

The use of an electric field in increasing the resistance of plants to the action of unfavorable space flight factors

NASA Astrophysics Data System (ADS)

Nechitailo, G.; Gordeev, A.

2004-01-01

The key role in increasing the resistance of plants to unfavorable space flight factors is assigned to biomembranes of root cells. It is these biomembranes in which numerous biochemical and biophysical processes determining the adaptive capacity of plant organisms occur. In the initial period of exposure to unfavorable space flight factors the adaptation reactions of the plant organism undoubtedly increase its resistance. But the intensification of removal of H + ions through the plasmalemma with an increase of the external influence sharply raises the quantity of cations leaving the cell, which leads to the accumulation of a considerable quantity of intracellular negative charges. These charges together with negative charges built in the membrane force protons to concentrate on the external surface of the membrane. Since protons have a very strong electric field, they form such a charge of which the electric field is about from several to hundreds of V/cm. The concentration of positive charges of protons entails the formation of a double electric field which extremely impedes the diffusion of other ions. Thus, a proton barrier is formed. Its length can be very considerable due to which the whole process of transmembrane energy and mass-transfer is disturbed. The proton barrier is easily destroyed by a weak electric field created in the root zone. In experiments on electrostimulation of different plants under space flight conditions at the orbital station MIR the absorption of nutrient elements by the root system increased to the optimal level, the ratio of physiologically active substances in the rhizosphere was normalized, the content of chlorophyll, carotin, and ascorbic acid in leaves corresponded to the ground-based control. Understanding of the mechanism of formation of a proton barrier on the plasmalemma of root cells as a result of the response of plants to the negative action of external factors (microgravity) is of great importance. It allows the

Treatment of X-Linked Hypophosphatemia with Calcitriol and Phosphate Increases Circulating Fibroblast Growth Factor 23 Concentrations

PubMed Central

Imel, Erik A.; DiMeglio, Linda A.; Hui, Siu L.; Carpenter, Thomas O.; Econs, Michael J.

2010-01-01

Context: X-Linked hypophosphatemia (XLH) is characterized by renal phosphate wasting, with inappropriately low or normal serum 1,25-dihydroxyvitamin D concentrations causing rickets and osteomalacia. Mutations in PHEX result in increased fibroblast growth factor 23 (FGF23) expression, elevating circulating FGF23 concentrations. Treating XLH with phosphate and calcitriol may further increase FGF23 concentrations, based on in vitro and in vivo models. Objective: The aim of the study was to investigate whether current standard XLH therapies increase circulating FGF23 concentrations. Design and Setting: We conducted a prospective observational study of XLH subjects during routine clinical management at two tertiary referral centers. Patients: The study included 10 XLH patients (seven children, three adults; age, 2–30 yr) initiating therapy and five XLH patients (age, 18–41 yr) electing not to undergo therapy. Intervention(s): Oral calcitriol and phosphate were administered. Main Outcome Measures: We measured circulating intact FGF23 concentrations. Results: Baseline circulating FGF23 concentrations were elevated in 14 of 15 subjects, increasing after treatment in most subjects. Follow-up was 14.4 ± 11.7 months (treatment cohort) and 25 ± 32 months (nontreatment cohort). FGF23 concentrations increased 132.7 ± 202.4% from pretreatment to peak during therapy but did not change significantly over time in the nontreatment cohort. FGF23 concentrations were related to phosphate doses (P = 0.04) and nonsignificantly to calcitriol doses (P = 0.06). Conclusions: Treating XLH with phosphate and calcitriol was associated with concurrent increases in circulating FGF23 concentrations, which may diminish therapeutic effect or contribute to complications of therapy. Because it is unknown whether the degree of FGF23 elevation correlates with disease severity in XLH, further study is needed to determine whether adjusting therapy to minimize effects on FGF23 concentration is

Expression of connective tissue growth factor (CTGF/CCN2) in breast cancer cells is associated with increased migration and angiogenesis.

PubMed

Chien, Wenwen; O'Kelly, James; Lu, Daning; Leiter, Amanda; Sohn, Julia; Yin, Dong; Karlan, Beth; Vadgama, Jay; Lyons, Karen M; Koeffler, H Phillip

2011-06-01

Connective tissue growth factor (CTGF/CCN2) belongs to the CCN family of matricellular proteins, comprising Cyr61, CTGF, NovH and WISP1-3. The CCN proteins contain an N-terminal signal peptide followed by four conserved domains sharing sequence similarities with the insulin-like growth factor binding proteins, von Willebrand factor type C repeat, thrombospondin type 1 repeat, and a C-terminal growth factor cysteine knot domain. To investigate the role of CCN2 in breast cancer, we transfected MCF-7 cells with full-length CCN2, and with four mutant constructs in which one of the domains had been deleted. MCF-7 cells stably expressing full-length CCN2 demonstrated reduced cell proliferation, increased migration in Boyden chamber assays and promoted angiogenesis in chorioallantoic membrane assays compared to control cells. Deletion of the C-terminal cysteine knot domain, but not of any other domain-deleted mutants, abolished activities mediated by full-length CCN2. We have dissected the role of CCN2 in breast tumorigenesis on a structural basis.

Ankle and knee kinetics between strike patterns at common training speeds in competitive male runners.

PubMed

Kuhman, Daniel; Melcher, Daniel; Paquette, Max R

2016-01-01

The purpose of this study was to investigate the interaction of foot strike and common speeds on sagittal plane ankle and knee joint kinetics in competitive rear foot strike (RFS) runners when running with a RFS pattern and an imposed forefoot strike (FFS) pattern. Sixteen competitive habitual male RFS runners ran at two different speeds (i.e. 8 and 6 min mile(-1)) using their habitual RFS and an imposed FFS pattern. A repeated measures analysis of variance was used to assess a potential interaction between strike pattern and speed for selected ground reaction force (GRF) variables and, sagittal plane ankle and knee kinematic and kinetic variables. No foot strike and speed interaction was observed for any of the kinetic variables. Habitual RFS yielded a greater loading rate of the vertical GRF, peak ankle dorsiflexor moment, peak knee extensor moment, peak knee eccentric extensor power, peak dorsiflexion and sagittal plane knee range of motion compared to imposed FFS. Imposed FFS yielded greater maximum vertical GRF, peak ankle plantarflexor moment, peak ankle eccentric plantarflexor power and sagittal plane ankle ROM compared to habitual RFS. Consistent with previous literature, imposed FFS in habitual RFS reduces eccentric knee extensor and ankle dorsiflexor involvement but produce greater eccentric ankle plantarflexor action compared to RFS. These acute differences between strike patterns were independent of running speeds equivalent to typical easy and hard training runs in competitive male runners. Current findings along with previous literature suggest differences in lower extremity kinetics between habitual RFS and imposed FFS running are consistent among a variety of runner populations.

Effect of impeded medial longitudinal arch drop on vertical ground reaction force and center of pressure during static loading.

PubMed

Chen, Shing-Jye; Gielo-Perczak, Krystyna

2011-01-01

Arch supports commonly used to alleviate foot pain can impede the normal drop of medial longitudinal arch (MLA) thereby altering its function. The purpose of the study was to examine the effect of using arch supports on vertical ground reaction force (GRF) and center of pressure (COP) during simulated midstance while the foot was statically loaded. Ten healthy young subjects were recruited. Two dimensional (2D) analysis of the MLA was captured for both barefoot (BF) and arch support conditions before and after loading via a custom made weight loading apparatus. The foot was loaded and positioned to simulate the midstance phase of walking. Two-dimensional reflective markers demarcated the MLA and captured with the loaded foot on a force platform. The impeded MLA drop was compared between the unloaded BF, loaded BF and loaded arch support conditions. The vertical GRF, the anterior-posterior and the medial-lateral COP displacements were also measured in response to the impeded MLA by the arch supports. The arch supports impeded the MLA drop (p<0.05) and shifted the COP toward the medial side (p<0.05), specifically for the rearfoot (calcaneal segment region), but no changes were determined for the vertical GRF (p>0.05). The impedance of MLA drop by the arch support altered the pattern of the ML COP shift in the rearfoot region. The use of arch supports may not relieve painful foot conditions that are associated with excessive calcaneal eversion indicated by altering COP shifts in localized foot regions.

Immersive virtual reality improves movement patterns in patients after ACL reconstruction: implications for enhanced criteria-based return-to-sport rehabilitation.

PubMed

Gokeler, Alli; Bisschop, Marsha; Myer, Gregory D; Benjaminse, Anne; Dijkstra, Pieter U; van Keeken, Helco G; van Raay, Jos J A M; Burgerhof, Johannes G M; Otten, Egbert

2016-07-01

The purpose of this study was to evaluate the influence of immersion in a virtual reality environment on knee biomechanics in patients after ACL reconstruction (ACLR). It was hypothesized that virtual reality techniques aimed to change attentional focus would influence altered knee flexion angle, knee extension moment and peak vertical ground reaction force (vGRF) in patients following ACLR. Twenty athletes following ACLR and 20 healthy controls (CTRL) performed a step-down task in both a non-virtual reality environment and a virtual reality environment displaying a pedestrian traffic scene. A motion analysis system and force plates were used to measure kinematics and kinetics during a step-down task to analyse each single-leg landing. A significant main effect was found for environment for knee flexion excursion (P = n.s.). Significant interaction differences were found between environment and groups for vGRF (P = 0.004), knee moment (P < 0.001), knee angle at peak vGRF (P = 0.01) and knee flexion excursion (P = 0.03). There was larger effect of virtual reality environment on knee biomechanics in patients after ACLR compared with controls. Patients after ACLR immersed in virtual reality environment demonstrated knee joint biomechanics that approximate those of CTRL. The results of this study indicate that a realistic virtual reality scenario may distract patients after ACLR from conscious motor control. Application of clinically available technology may aid in current rehabilitation programmes to target altered movement patterns after ACLR. Diagnostic study, Level III.

Prophylactic Ankle Braces and the Kinematics and Kinetics of Half-Squat Parachute Landing.

PubMed

Wu, Di; Zheng, Chao; Wu, Ji; Hu, Tan; Huang, Rongrong; Wang, Lizhen; Fan, Yubo

2018-02-01

The objective of the study was to investigate the effects of dropping heights and prophylactic ankle braces on ankle joint biomechanics during half-squat parachute landing from two different heights. There were 30 male elite paratroopers with formal parachute landing training and more than 2 yr of parachute jumping experience who were recruited for this study. The subjects tested three different ankle brace conditions (no-brace, elastic brace, semirigid brace). Each subject was instructed to jump off a platform from two different heights of 0.4 m and 0.8 m, and land on a force plate in a half-squat posture. The Vicon 3D motion capture system and force plate were used to record and calculate kinematic and kinetic data. Dropping height had a significant effect on peak vertical ground reaction force (vGRF), maximum ankle angular displacement, and time to vGRF. As compared with the no-brace group, use of an elastic ankle brace significantly reduced peak vGRF by 18.57% and both braces significantly reduced the maximal angular displacements of dorsiflexion. The semirigid brace provided greater restriction against maximal angular displacement of inversion. The elastic and semirigid ankle braces both effectively restricted motion stability of the ankle joint in the sagittal plane, and the semirigid ankle brace prevented excessive inversion, although the comfort of this device should be improved overall.Wu D, Zheng C, Wu J, Hu T, Huang R, Wang L, Fan Y. Prophylactic ankle braces and the kinematics and kinetics of half-squat parachute landing. Aerosp Med Hum Perform. 2018; 89(2):141-146.

Concurrent validity and reliability of using ground reaction force and center of pressure parameters in the determination of leg movement initiation during single leg lift.

PubMed

Aldabe, Daniela; de Castro, Marcelo Peduzzi; Milosavljevic, Stephan; Bussey, Melanie Dawn

2016-09-01

Postural adjustment evaluations during single leg lift requires the initiation of heel lift (T1) identification. T1 measured by means of motion analyses system is the most reliable approach. However, this method involves considerable workspace, expensive cameras, and time processing data and setting up laboratory. The use of ground reaction forces (GRF) and centre of pressure (COP) data is an alternative method as its data processing and setting up is less time consuming. Further, kinetic data is normally collected using frequency samples higher than 1000Hz whereas kinematic data are commonly captured using 50-200Hz. This study describes the concurrent-validity and reliability of GRF and COP measurements in determining T1, using a motion analysis system as reference standard. Kinematic and kinetic data during single leg lift were collected from ten participants. GRF and COP data were collected using one and two force plates. Displacement of a single heel marker was captured by means of ten Vicon(©) cameras. Kinetic and kinematic data were collected using a sample frequency of 1000Hz. Data were analysed in two stages: identification of key events in the kinetic data, and assessing concurrent validity of T1 based on the chosen key events with T1 provided by the kinematic data. The key event presenting the least systematic bias, along with a narrow 95% CI and limits of agreement against the reference standard T1, was the Baseline COPy event. Baseline COPy event was obtained using one force plate and presented excellent between-tester reliability. Copyright © 2016 Elsevier B.V. All rights reserved.

Using Dynamic Walking Models to Identify Factors that Contribute to Increased Risk of Falling in Older Adults

PubMed Central

Roos, Paulien E.; Dingwell, Jonathan B.

2013-01-01

Falls are common in older adults. The most common cause of falls is tripping while walking. Simulation studies demonstrated that older adults may be restricted by lower limb strength and movement speed to regain balance after a trip. This review examines how modeling approaches can be used to determine how different measures predict actual fall risk and what some of the causal mechanisms of fall risk are. Although increased gait variability predicts increased fall risk experimentally, it is not clear which variability measures could best be used, or what magnitude of change corresponded with increased fall risk. With a simulation study we showed that the increase in fall risk with a certain increase in gait variability was greatly influenced by the initial level of variability. Gait variability can therefore not easily be used to predict fall risk. We therefore explored other measures that may be related to fall risk and investigated the relationship between stability measures such as Floquet multipliers and local divergence exponents and actual fall risk in a dynamic walking model. We demonstrated that short-term local divergence exponents were a good early predictor for fall risk. Neuronal noise increases with age. It has however not been fully understood if increased neuronal noise would cause an increased fall risk. With our dynamic walking model we showed that increased neuronal noise caused increased fall risk. Although people who are at increased risk of falling reduce their walking speed it had been questioned whether this slower speed would actually cause a reduced fall risk. With our model we demonstrated that a reduced walking speed caused a reduction in fall risk. This may be due to the decreased kinematic variability as a result of the reduced signal-dependent noise of the smaller muscle forces that are required for slower. These insights may be used in the development of fall prevention programs in order to better identify those at increased risk of

Using dynamic walking models to identify factors that contribute to increased risk of falling in older adults.

PubMed

Roos, Paulien E; Dingwell, Jonathan B

2013-10-01

Falls are common in older adults. The most common cause of falls is tripping while walking. Simulation studies demonstrated that older adults may be restricted by lower limb strength and movement speed to regain balance after a trip. This review examines how modeling approaches can be used to determine how different measures predict actual fall risk and what some of the causal mechanisms of fall risk are. Although increased gait variability predicts increased fall risk experimentally, it is not clear which variability measures could best be used, or what magnitude of change corresponded with increased fall risk. With a simulation study we showed that the increase in fall risk with a certain increase in gait variability was greatly influenced by the initial level of variability. Gait variability can therefore not easily be used to predict fall risk. We therefore explored other measures that may be related to fall risk and investigated the relationship between stability measures such as Floquet multipliers and local divergence exponents and actual fall risk in a dynamic walking model. We demonstrated that short-term local divergence exponents were a good early predictor for fall risk. Neuronal noise increases with age. It has however not been fully understood if increased neuronal noise would cause an increased fall risk. With our dynamic walking model we showed that increased neuronal noise caused increased fall risk. Although people who are at increased risk of falling reduce their walking speed it had been questioned whether this slower speed would actually cause a reduced fall risk. With our model we demonstrated that a reduced walking speed caused a reduction in fall risk. This may be due to the decreased kinematic variability as a result of the reduced signal-dependent noise of the smaller muscle forces that are required for slower. These insights may be used in the development of fall prevention programs in order to better identify those at increased risk of

Heparanase enhances the generation of activated factor X in the presence of tissue factor and activated factor VII.

PubMed

Nadir, Yona; Brenner, Benjamin; Fux, Liat; Shafat, Itay; Attias, Judith; Vlodavsky, Israel

2010-11-01

Heparanase is an endo-β-D-glucuronidase dominantly involved in tumor metastasis and angiogenesis. Recently, we demonstrated that heparanase is involved in the regulation of the hemostatic system. Our hypothesis was that heparanase is directly involved in activation of the coagulation cascade. Activated factor X and thrombin were studied using chromogenic assays, immunoblotting and thromboelastography. Heparanase levels were measured by enzyme-linked immunosorbent assay. A potential direct interaction between tissue factor and heparanase was studied by co-immunoprecipitation and far-western assays. Interestingly, addition of heparanase to tissue factor and activated factor VII resulted in a 3- to 4-fold increase in activation of the coagulation cascade as shown by increased activated factor X and thrombin production. Culture medium of human embryonic kidney 293 cells over-expressing heparanase and its derivatives increased activated factor X levels in a non-enzymatic manner. When heparanase was added to pooled normal plasma, a 7- to 8-fold increase in activated factor X level was observed. Subsequently, we searched for clinical data supporting this newly identified role of heparanase. Plasma samples from 35 patients with acute leukemia at presentation and 20 healthy donors were studied for heparanase and activated factor X levels. A strong positive correlation was found between plasma heparanase and activated factor X levels (r=0.735, P=0.001). Unfractionated heparin and an inhibitor of activated factor X abolished the effect of heparanase, while tissue factor pathway inhibitor and tissue factor pathway inhibitor-2 only attenuated the procoagulant effect. Using co-immunoprecipitation and far-western analyses it was shown that heparanase interacts directly with tissue factor. Overall, our results support the notion that heparanase is a potential modulator of blood hemostasis, and suggest a novel mechanism by which heparanase increases the generation of activated

Microparticles released by vascular endothelial cells increase hypoxia inducible factor expression in human proximal tubular HK-2 cells.

PubMed

Fernandez-Martínez, Ana Belen; Torija, Ana Valdehita; Carracedo, Julia; Ramirez, Rafael; de Lucio-Cazaña, Francisco Javier

2014-08-01

Microparticles are produced by vesiculation of the cell plasma membrane and serve as vectors of cell-to-cell communication. Co-culture experiments have shown that hypoxia-inducible factor-α (HIF-α)-regulated-genes are up-regulated in human renal proximal tubular HK-2 cells by endothelial cell factors which might be transported inside endothelial microparticles (EMP). Here we aimed to study in HK-2 cells the effect of EMP, produced by activated endothelial cells, on HIF-α and HIF-α-regulated vascular endothelial growth factor-A (VEGF-A). EMP, at a concentration much lower than that found in plasma, increased the expression of HIF-α/VEGF-A in a COX-2/EP2 receptor dependent manner. Since the EMP/cells ratio was ∼1/1000, we hypothesized that paracrine mediators produced by HK-2 cells amplified the initial signal. This hypothesis was confirmed by two facts which also suggested that the mediators were conveyed by particles released by HK-2 cells: (i) HIF-α was up-regulated in HK-2 cells treated with the pellet obtained from the conditioned medium of the EMP-treated HK-2 cells. (ii) In transwell experiments, EMP-treated cells increased the expression of HIF-α in untreated HK-2 cells. Interestingly, we detected these cells, particles that were released by EMP-treated HK-2 cells. Depending on the pathological context, activation of HIF-α and VEGF-A signaling in renal tissue/cells may have either beneficial or harmful effects. Therefore, our results suggest that their presence in the urinary space of EMP produced by activated endothelial cells may influence the outcome of a number of renal diseases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Structural Factors That Increase HIV/STI Vulnerability Among Indigenous People in the Peruvian Amazon

PubMed Central

Orellana, E. Roberto; Alva, Isaac E.; Cárcamo, Cesar P.; García, Patricia J.

2015-01-01

We examined structural factors—social, political, economic, and environmental—that increase vulnerability to HIV among indigenous people in the Peruvian Amazon. Indigenous adults belonging to 12 different ethnic groups were purposively recruited in four Amazonian river ports and 16 indigenous villages. Qualitative data revealed a complex set of structural factors that give rise to environments of risk where health is constantly challenged. Ferryboats that cross Amazonian rivers are settings where unprotected sex—including transactional sex between passengers and boat crew and commercial sex work—often take place. Population mobility and mixing also occurs in settings like the river docks, mining sites, and other resource extraction camps, where heavy drinking and unprotected sex work are common. Multilevel, combination prevention strategies that integrate empirically based interventions with indigenous knowledge are urgently needed, not only to reduce vulnerability to HIV transmission, but also to eliminate the structural determinants of indigenous people’s health. PMID:23925407

Resveratrol Reactivates Latent HIV through Increasing Histone Acetylation and Activating Heat Shock Factor 1.

PubMed

Zeng, Xiaoyun; Pan, Xiaoyan; Xu, Xinfeng; Lin, Jian; Que, Fuchang; Tian, Yuanxin; Li, Lin; Liu, Shuwen

2017-06-07

The persistence of latent HIV reservoirs presents a significant challenge to viral eradication. Effective latency reversing agents (LRAs) based on "shock and kill" strategy are urgently needed. The natural phytoalexin resveratrol has been demonstrated to enhance HIV gene expression, although its mechanism remains unclear. In this study, we demonstrated that resveratrol was able to reactivate latent HIV without global T cell activation in vitro. Mode of action studies showed resveratrol-mediated reactivation from latency did not involve the activation of silent mating type information regulation 2 homologue 1 (SIRT1), which belonged to class-3 histone deacetylase (HDAC). However, latent HIV was reactivated by resveratrol mediated through increasing histone acetylation and activation of heat shock factor 1 (HSF1). Additionally, synergistic activation of the latent HIV reservoirs was observed under cotreatment with resveratrol and conventional LRAs. Collectively, this research reveals that resveratrol is a natural LRA and shows promise for HIV therapy.

The predictive factors of α1-D/A adrenoceptor antagonist, naftopidil, dose increase therapy for male lower urinary tract symptoms caused by benign prostatic hyperplasia: INFORM study.

PubMed

Tanuma, Yasushi; Tanaka, Yoshinori; Takeyama, Ko; Okamoto, Tomoshi

2017-01-01

We evaluated the predictive factors which affect the efficacy of naftopidil 50 mg/day therapy and dose increase therapy to administration of 75 mg/day after an initial dose of 50 mg/day. A total of 92 patients with male lower urinary tract symptoms/benign prostatic hyperplasia were administrated naftopidil 50 mg/day for 4 weeks (50 mg therapy). At week 4, the patients were divided into an effective and an ineffective group (Group E and Group I, respectively). For further 4 weeks, the dosage of naftopidil was increased to 75 mg/day in all patients. At week 8, the patients of Group E and Group I were divided into an effective and an ineffective group (Group EE, Group EI, Group IE, and Group II, respectively). Postvoid residual (PVR) urine volume at baseline was a predictive factor for efficacy of 50 mg therapy. In Group E, change in International Prostate Symptom Score storage symptoms subscore from baseline to week 4 was a predictive factor for efficacy of this dose increase therapy. In Group I, change in maximum flow rate from baseline to week 4 was a predictive factor for efficacy of this dose increase therapy. The short term of naftopidil 50 mg therapy was ineffective for the patients who had large PVR. The predictive factor of this dose increase therapy might be a dynamic variable in 50 mg/day of dose period, but not a baseline variable at the time of 75 mg/day dosage starts.

Cardiovascular risk factors are associated with increased lesion burden and brain atrophy in multiple sclerosis.

PubMed

Kappus, Natalie; Weinstock-Guttman, Bianca; Hagemeier, Jesper; Kennedy, Cheryl; Melia, Rebecca; Carl, Ellen; Ramasamy, Deepa P; Cherneva, Mariya; Durfee, Jacqueline; Bergsland, Niels; Dwyer, Michael G; Kolb, Channa; Hojnacki, David; Ramanathan, Murali; Zivadinov, Robert

2016-02-01

Cardiovascular (CV) risk factors have been associated with changes in clinical outcomes in patients with multiple sclerosis (MS). To investigate the frequency of CV risks in patients with MS and their association with MRI outcomes. In a prospective study, 326 patients with relapsing-remitting MS and 163 patients with progressive MS, 61 patients with clinically isolated syndrome (CIS) and 175 healthy controls (HCs) were screened for CV risks and scanned on a 3T MRI scanner. Examined CV risks included hypertension, heart disease, smoking, overweight/obesity and type 1 diabetes. MRI measures assessed lesion volumes (LVs) and brain atrophy. Association between individual or multiple CV risks and MRI outcomes was examined adjusting for age, sex, race, disease duration and treatment status. Patients with MS showed increased frequency of smoking (51.7% vs 36.5%, p = 0.001) and hypertension (33.9% vs 24.7%, p=0.035) compared with HCs. In total, 49.9% of patients with MS and 36% of HCs showed ≥ 2 CV risks (p = 0.003), while the frequency of ≥ 3 CV risks was 18.8% in the MS group and 8.6% in the HCs group (p = 0.002). In patients with MS, hypertension and heart disease were associated with decreased grey matter (GM) and cortical volumes (p < 0.05), while overweight/obesity was associated with increased T1-LV (p < 0.39) and smoking with decreased whole brain volume (p = 0.049). Increased lateral ventricle volume was associated with heart disease (p = 0.029) in CIS. Patients with MS with one or more CV risks showed increased lesion burden and more advanced brain atrophy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Simvastatin mitigates increases in risk factors for and the occurrence of cardiac disease following 10 Gy total body irradiation.

PubMed

Lenarczyk, Marek; Su, Jidong; Haworth, Steven T; Komorowski, Richard; Fish, Brian L; Migrino, Raymond Q; Harmann, Leanne; Hopewell, John W; Kronenberg, Amy; Patel, Shailendra; Moulder, John E; Baker, John E

2015-06-01

The ability of simvastatin to mitigate the increases in risk factors for and the occurrence of cardiac disease after 10 Gy total body irradiation (TBI) was determined. This radiation dose is relevant to conditioning for stem cell transplantation and threats from radiological terrorism. Male rats received single dose TBI of 10 Gy. Age-matched, sham-irradiated rats served as controls. Lipid profile, heart and liver morphology and cardiac mechanical function were determined for up to 120 days after irradiation. TBI resulted in a sustained increase in total- and LDL-cholesterol (low-density lipoprotein-cholesterol), and triglycerides. Simvastatin (10 mg/kg body weight/day) administered continuously from 9 days after irradiation mitigated TBI-induced increases in total- and LDL-cholesterol and triglycerides, as well as liver injury. TBI resulted in cellular peri-arterial fibrosis, whereas control hearts had less collagen and fibrosis. Simvastatin mitigated these morphological injuries. TBI resulted in cardiac mechanical dysfunction. Simvastatin mitigated cardiac mechanical dysfunction 20-120 days following TBI. To determine whether simvastatin affects the ability of the heart to withstand stress after TBI, injury from myocardial ischemia/reperfusion was determined in vitro. TBI increased the severity of an induced myocardial infarction at 20 and 80 days after irradiation. Simvastatin mitigated the severity of this myocardial infarction at 20 and 80 days following TBI. It is concluded simvastatin mitigated the increases in risk factors for cardiac disease and the extent of cardiac disease following TBI. This statin may be developed as a medical countermeasure for the mitigation of radiation-induced cardiac disease.

High-Intensity Locomotor Exercise Increases Brain-Derived Neurotrophic Factor in Individuals with Incomplete Spinal Cord Injury.

PubMed

Leech, Kristan A; Hornby, T George

2017-03-15

High-intensity locomotor exercise is suggested to contribute to improved recovery of locomotor function after neurological injury. This may be secondary to exercise-intensity-dependent increases in neurotrophin expression demonstrated previously in control subjects. However, rigorous examination of intensity-dependent changes in neurotrophin levels is lacking in individuals with motor incomplete spinal cord injury (SCI). Therefore, the primary aim of this study was to evaluate the effect of locomotor exercise intensity on peripheral levels of brain-derived neurotrophic factor (BDNF) in individuals with incomplete SCI. We also explored the impact of the Val66Met single-nucleotide polymorphism (SNP) on the BDNF gene on intensity-dependent changes. Serum concentrations of BDNF and insulin-like growth factor-1 (IGF-1), as well as measures of cardiorespiratory dynamics, were evaluated across different levels of exercise intensity achieved during a graded-intensity, locomotor exercise paradigm in 11 individuals with incomplete SCI. Our results demonstrate a significant increase in serum BDNF at high, as compared to moderate, exercise intensities (p = 0.01) and 15 and 30 min post-exercise (p < 0.01 for both), with comparison to changes at low intensity approaching significance (p = 0.05). Serum IGF-1 demonstrated no intensity-dependent changes. Significant correlations were observed between changes in BDNF and specific indicators of exercise intensity (e.g., rating of perceived exertion; R = 0.43; p = 0.02). Additionally, the data suggest that Val66Met SNP carriers may not exhibit intensity-dependent changes in serum BDNF concentration. Given the known role of BDNF in experience-dependent neuroplasticity, these preliminary results suggest that exercise intensity modulates serum BDNF concentrations and may be an important parameter of physical rehabilitation interventions after neurological injury.

High-Intensity Locomotor Exercise Increases Brain-Derived Neurotrophic Factor in Individuals with Incomplete Spinal Cord Injury

PubMed Central

Leech, Kristan A.

2017-01-01

Abstract High-intensity locomotor exercise is suggested to contribute to improved recovery of locomotor function after neurological injury. This may be secondary to exercise-intensity–dependent increases in neurotrophin expression demonstrated previously in control subjects. However, rigorous examination of intensity-dependent changes in neurotrophin levels is lacking in individuals with motor incomplete spinal cord injury (SCI). Therefore, the primary aim of this study was to evaluate the effect of locomotor exercise intensity on peripheral levels of brain-derived neurotrophic factor (BDNF) in individuals with incomplete SCI. We also explored the impact of the Val66Met single-nucleotide polymorphism (SNP) on the BDNF gene on intensity-dependent changes. Serum concentrations of BDNF and insulin-like growth factor-1 (IGF-1), as well as measures of cardiorespiratory dynamics, were evaluated across different levels of exercise intensity achieved during a graded-intensity, locomotor exercise paradigm in 11 individuals with incomplete SCI. Our results demonstrate a significant increase in serum BDNF at high, as compared to moderate, exercise intensities (p = 0.01) and 15 and 30 min post-exercise (p < 0.01 for both), with comparison to changes at low intensity approaching significance (p = 0.05). Serum IGF-1 demonstrated no intensity-dependent changes. Significant correlations were observed between changes in BDNF and specific indicators of exercise intensity (e.g., rating of perceived exertion; R = 0.43; p = 0.02). Additionally, the data suggest that Val66Met SNP carriers may not exhibit intensity-dependent changes in serum BDNF concentration. Given the known role of BDNF in experience-dependent neuroplasticity, these preliminary results suggest that exercise intensity modulates serum BDNF concentrations and may be an important parameter of physical rehabilitation interventions after neurological injury. PMID:27526567

Factors increasing the risk of inactivity among administrative, technical, and manual workers in Warszawa public institutions.

PubMed

Biernat, Elżbieta

2015-01-01

The research aims to assess the level of physical activity among administrative, technical, and manual workers employed in Warszawa public institutions and to analyze the factors that increase the risk of failing to meet World Health Organization (WHO) recommendations. The study comprised 373 employees of randomly selected institutions. A short version of International Physical Activity Questionnaire (IPAQ) was applied. The correlation between the mean values of duration, days, MET-min/week of efforts, gender, and type of work was analyzed using the Tukey's honest significant difference (HSD) test, while the correlation between the level of physical activity and the socio-demographic characteristics was assessed with the Chi² test. The strength of the relationship between socio-demographic characteristics and fulfilment of WHO standards was expressed by the odds ratio (OR) and 95% confidence interval (95% CI). The significance level was p = 0.05. High levels of physical activity were declared by 41.8% of the manual workers, 14.7% of the administration staff, and 7.3% of the technicians; 19%, 31.5% and 54.5%, respectively, reported low levels of physical activity. Factors determining the fulfilment of the WHO recommendations include: the nature of work (p = 0.003), education (p = 0.004), and income (p = 0.003). The risk of being inactive nearly doubles in the case of administration staff (31.5%) and increases more than 4 times in the case of technicians (54.5%). Respondents with secondary school education (31.6%) are exposed to a 3-fold higher risk of inactivity, while in respondents with higher education (37.2%), the level of the risk is 4-fold higher. Compared to those in the highest income group (23.4%), people who earn less (34.1%) are inactive almost twice as often. Urgent intervention is necessary in all studied groups: increased energy expenditure for recreation and locomotion, educational offers of employers to promote healthy lifestyle

Explaining the Rapid Increase in Nigeria's Sex Ratio at Birth: Factors and Implications.

PubMed

Kaba, Amadu J

2015-06-01

This paper examines the rapid increase in Nigeria's sex ratio at birth from 1.03 boys born for every 1 girl born in each year from 1996-2008 to 1.06 in each year from 2009-2014, second only to Tunisia in Africa at 1.07. The average sex ratio at birth in the world in 2014 was 1.07. In most Black African nations or Black majority nations, it is 1.03 or less. Among the factors presented for this development are: historical fluctuations of sex ratio at birth; geography and ethnicity; male preference/chasing a son; Age of parents; high death rates of male infants and males in general; and wealth/socioeconomic status. Among the potential implications are: young and poor men in Nigeria may not be able to find brides and form families due to a potential shortage of females; emigration of young and poor Nigerian men to West (Africa) and elsewhere to seek brides and form families; immigration of marriage age women from West (Africa) and around the world to Nigeria to seek husbands; and low contraceptive use and high fertility rates in Nigeria.

Premature atherosclerosis in pediatric systemic lupus erythematosus: risk factors for increased carotid intima-media thickness in the atherosclerosis prevention in pediatric lupus erythematosus cohort.

PubMed

Schanberg, Laura E; Sandborg, Christy; Barnhart, Huiman X; Ardoin, Stacy P; Yow, Eric; Evans, Gregory W; Mieszkalski, Kelly L; Ilowite, Norman T; Eberhard, Anne; Levy, Deborah M; Kimura, Yukiko; von Scheven, Emily; Silverman, Earl; Bowyer, Suzanne L; Punaro, Lynn; Singer, Nora G; Sherry, David D; McCurdy, Deborah; Klein-Gitelman, Marissa; Wallace, Carol; Silver, Richard; Wagner-Weiner, Linda; Higgins, Gloria C; Brunner, Hermine I; Jung, Lawrence; Soep, Jennifer B; Reed, Ann

2009-05-01

To evaluate risk factors for subclinical atherosclerosis in a population of patients with pediatric systemic lupus erythematosus (SLE). In a prospective multicenter study, a cohort of 221 patients underwent baseline measurements of carotid intima-media thickness (CIMT) as part of the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) trial. SLE disease measures, medications, and traditional risk factors for atherosclerosis were assessed. A standardized protocol was used to assess the thickness of the bilateral common carotid arteries and the mean maximal IMT of 12 segments. Univariable analysis identified potential associations with CIMT, which were examined in multivariable linear regression modeling. Based on the mean-mean common or the mean-max CIMT as the dependent variable, univariable analysis showed significant associations of the following variables with increased CIMT: increasing age, longer SLE duration, minority status, higher body mass index (BMI), male sex, increased creatinine clearance, higher lipoprotein(a) level, proteinuria, azathioprine treatment, and prednisone dose. In multivariable modeling, both azathioprine use (P=0.005 for the mean-mean model and P=0.102 for the mean-max model) and male sex (P<0.001) were associated with increases in the mean-max CIMT. A moderate dosage of prednisone (0.15-0.4 mg/kg/day) was associated with decreases in the mean-max CIMT (P=0.024), while high-dose and low-dose prednisone were associated with increases in the mean-mean common CIMT (P=0.021) and the mean-max CIMT (P=0.064), respectively. BMI (P<0.001) and creatinine clearance (P=0.031) remained associated with increased mean-mean common CIMT, while increasing age (P<0.001) and increasing lipoprotein(a) level (P=0.005) were associated with increased mean-max CIMT. Traditional as well as nontraditional risk factors were associated with increased CIMT in this cohort of patients in the APPLE trial. Azathioprine treatment was associated with

Tumor necrosis factor-308 polymorphism increases the embryo implantation rate in women undergoing in vitro fertilization.

PubMed

Vialard, F; El Sirkasi, M; Tronchon, V; Boudjenah, R; Molina-Gomes, D; Bergere, M; Mauduit, C; Wainer, R; Selva, J; Benahmed, M

2013-10-01

Do TNF-308 and -238 polymorphisms impact the embryo implantation rate after in vitro fertilization (IVF) in women without female infertility factor? The presence of the TNF-308A allele is associated with high implantation and multiple pregnancy rates in women without known infertility factors after ovarian hyperstimulation with exogenous FSH. Multiple pregnancies are frequent after the use of Assisted Reproductive Technologies. Single embryo transfer (SET) has been proposed as a simple way to prevent these risks. However, the extension of SET indications to patients not selected based on specific criteria is controversial because of reduced pregnancy rates. To date, the predictive value of the parameters used for SET (age, gynecological history of the patient and uterine characteristics) allows a pregnancy rate of ~30%. The potential predictive value of TNF polymorphisms (-308, rs1800629 and -238, rs361525) on implantation rate was evaluated in 424 women requiring IVF due to male fertility factors. This cohort retrospective study was conducted over 4 years in University-affiliated hospitals. The entire patient group included 424 women undergoing intracytoplasmic sperm injection (ICSI) due to male fertility factors without the contribution of any female factor. From among this group, a selected patient group included 120 women with a normal karyotype, age under 38 years, serum follicle-stimulating hormone (Day-3 FSH) levels below 10 IU/l, a long agonist desensitization protocol associated with recombinant FSH treatment and a Caucasian background. The TNF-238 polymorphism was not associated with implantation rate. In contrast, the presence of the TNF-308A allele was associated with increased Day 3-E2 levels as well as higher implantation and multiple pregnancy rates after fresh embryo transfer in women from the entire and selected patient groups. Moreover, in the selected patient group, the presence of the TNF-308A allele was also associated with a decrease in the

Kinematic and Kinetic Profiles of Trunk and Lower Limbs during Baseball Pitching in Collegiate Pitchers

PubMed Central

Kageyama, Masahiro; Sugiyama, Takashi; Takai, Yohei; Kanehisa, Hiroaki; Maeda, Akira

2014-01-01

The purpose of this study was to clarify differences in the kinematic and kinetic profiles of the trunk and lower extremities during baseball pitching in collegiate baseball pitchers, in relation to differences in the pitched ball velocity. The subjects were 30 collegiate baseball pitchers aged 18 to 22 yrs, who were assigned to high- (HG, 37.4 ± 0.8 m·s-1) and low-pitched-ball-velocity groups (LG, 33.3 ± 0.8 m·s-1). Three-dimensional motion analysis with a comprehensive lower-extremity model was used to evaluate kinematic and kinetic parameters during baseball pitching. The ground-reaction forces (GRF) of the pivot and stride legs during pitching were determined using two multicomponent force plates. The joint torques of hip, knee, and ankle were calculated using inverse-dynamics computation of a musculoskeletal human model. To eliminate any effect of variation in body size, kinetic and GRF data were normalized by dividing them by body mass. The maxima and minima of GRF (Fy, Fz, and resultant forces) on the pivot and stride leg were significantly greater in the HG than in the LG (p < 0.05). Furthermore, Fy, Fz, and resultant forces on the stride leg at maximum shoulder external rotation and ball release were significantly greater in the HG than in the LG (p < 0.05). The hip abduction, hip internal rotation and knee extension torques of the pivot leg and the hip adduction torque of the stride leg when it contacted the ground were significantly greater in the HG than in the LG (p < 0.05). These results indicate that, compared with low-ball-velocity pitchers, high-ball-velocity pitchers can generate greater momentum of the lower limbs during baseball pitching. Key points High-ball-velocity pitchers are characterized by greater momentum of the lower limbs during pitching motion. For high-pitched-ball velocity, stabilizing lower limbs during pitching plays an important role in order to increase the rotation and forward motion of the trunk. Computation of the lower

Factors influencing increased expertise for a sustainable workforce at a research centre in South Africa

PubMed Central

Draper, H. R.; Enarson, D. A.; Beyers, N.; Claassens, M.

2014-01-01

Setting: The Desmond Tutu Tuberculosis (TB) Centre (DTTC), Stellenbosch University, South Africa. Objectives: 1) To determine whether access to designated funding is associated with the development of expertise in employees, and 2) which other factors are associated with the development of expertise in employees. Design: This was a retrospective study. The target population consisted of all employees at the DTTC during the period 1 January 2004 to 31 December 2011. Improvement in expertise during employment was the primary outcome; the secondary outcome was an increase in educational level linked to the National Qualifications Framework. Results: There was no association between access to funding and expertise development, but an association between the number of months employed and improvement of expertise during employment was observed (OR 1.03, 95%CI 1.02–1.04, P < 0.001), controlling for age at appointment, sex, access to designated funding and education level. Conclusion: The study shows that almost a third of employees increased their expertise, more than 90% had access to designated funding and personnel employed for a longer duration were more likely to experience improvements in expertise. We encourage research organisations in low- and middle-income countries to implement strategies to retain employees in order to build their expertise. PMID:26400709

Melanogenesis-inducing effect of cirsimaritin through increases in microphthalmia-associated transcription factor and tyrosinase expression.

PubMed

Kim, Hyo Jung; Kim, Il Soon; Dong, Yin; Lee, Ik-Soo; Kim, Jin Sook; Kim, Jong-Sang; Woo, Je-Tae; Cha, Byung-Yoon

2015-04-20

The melanin-inducing properties of cirsimaritin were investigated in murine B16F10 cells. Cirsimaritin is an active flavone with methoxy groups, which is isolated from the branches of Lithocarpus dealbatus. Tyrosinase activity and melanin content in murine B16F10 melanoma cells were increased by cirsimaritin in a dose-dependent manner. Western blot analysis revealed that tyrosinase, tyrosinase-related protein (TRP) 1, TRP2 protein levels were enhanced after treatment with cirsimaritin for 48 h. Cirsimaritin also upregulated the expression of microphthalmia-associated transcription factor (MITF) after 24 h of treatment. Furthermore, cirsimaritin induced phosphorylation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in a dose-dependent manner after treatment for 15 min. The cirsimaritin-mediated increase of tyrosinase activity was significantly attenuated by H89, a cAMP-dependent protein kinase A inhibitor. These findings indicate that cirsimaritin stimulates melanogenesis in B16F10 cells by activation of CREB as well as upregulation of MITF and tyrosinase expression, which was activated by cAMP signaling. Finally, the melanogenic effect of cirsimaritin was confirmed in human epidermal melanocytes. These results support the putative application of cirsimaritin in ultraviolet photoprotection and hair coloration treatments.

Changes in biomechanical properties during drop jumps of incremental height.

PubMed

Peng, Hsien-Te

2011-09-01

The purpose of this study was to investigate changing biomechanical properties with increasing drop jump height. Sixteen physically active college students participated in this study and performed drop jumps from heights of 20, 30, 40, 50, and 60 cm (DJ20-DJ60). Kinematic and kinetic data were collected using 11 Eagle cameras and 2 force platforms. Data pertaining to the dominant leg for each of 3 trials for each drop height were recorded and analyzed. Statistical comparisons of vertical ground reaction force (vGRF), impulse, moment, power, work, and stiffness were made between different drop jump heights. The peak vGRF of the dominant leg exceeded 3 times the body weight during DJ50 and DJ60; these values were significantly greater than those for DJ20, DJ30, and DJ40 (all p < 0.004). The height jumped during DJ60 was significantly less than that during DJ20 and DJ30 (both p = 0.010). Both the landing impulse and total impulse during the contact phase were significantly different between each drop height (all p < 0.036) and significantly increased with drop height. There were no significant differences in the takeoff impulse. Peak and mean power absorption and negative work at the knee and ankle joints during DJ40, DJ50, and DJ60 were significantly greater than those during DJ20 and DJ30 (all p < 0.049). Leg, knee, and ankle stiffness during DJ60 were significantly less than during DJ20, DJ30, and DJ40 (all p < 0.037). The results demonstrated that drop jumps from heights >40 cm offered no advantages in terms of mechanical efficiency (SSC power output) and stiffness. Drop jumps from heights in excess of 60 cm are not recommended because of the lack of biomechanical efficiency and the potentially increased risk of injury.

Reduction of the neuroprotective transcription factor Npas4 results in increased neuronal necrosis, inflammation and brain lesion size following ischaemia

PubMed Central

Choy, Fong Chan; Klarić, Thomas S; Leong, Wai Khay; Koblar, Simon A

2015-01-01

Stroke is the second leading cause of death and the most frequent cause of adult disability. Neuronal Per-Arnt-Sim domain protein 4 (Npas4) is an activity-dependent transcription factor whose expression is induced in various brain insults, including cerebral ischaemia. Although previous studies have demonstrated that Npas4 plays a critical role in protecting neurons against neurodegenerative insults, the neuroprotective effect of Npas4 in response to ischaemic brain injury remains unknown. In this study, we used a loss-of-function approach to examine the neuroprotective potential of Npas4 in the context of ischaemic damage. Using oxygen and glucose deprivation, we demonstrated that the knockdown of Npas4 in mouse cortical neurons resulted in increased susceptibility to cell death. The protective effect of Npas4 was further investigated in vivo using a photochemically-induced stroke model in mice. We found a significantly larger lesion size and increased neurodegeneration in Npas4 knockout mice as compared to wild-type mice. Moreover, we also showed that ablation of Npas4 caused an increase in activated astrocytes and microglia, pro-inflammatory cytokines interleukin-6 and tumour necrosis factor alpha levels and a switch from apoptotic to necrotic cell death. Taken together, these data suggest that Npas4 plays a neuroprotective role in ischaemic stroke by limiting progressive neurodegeneration and neuroinflammation. PMID:26661154

Brain-derived neurotrophic factor modulates angiotensin signaling in the hypothalamus to increase blood pressure in rats

PubMed Central

Backes, Iara; McCowan, Michael L.; Hayward, Linda F.; Scheuer, Deborah A.

2015-01-01

Brain-derived neurotrophic factor (BDNF) expression increases in the paraventricular nucleus of the hypothalamus (PVN) in response to hypertensive stimuli including stress and hyperosmolarity. However, it is unclear whether BDNF in the PVN contributes to increases in blood pressure (BP). We tested the hypothesis that increased BDNF levels within the PVN would elevate baseline BP and heart rate (HR) and cardiovascular stress responses by altering central angiotensin signaling. BP was recorded using radiotelemetry in male Sprague-Dawley rats after bilateral PVN injections of adeno-associated viral vectors expressing green fluorescent protein (GFP) or myc epitope-tagged BDNF fusion protein. Cardiovascular responses to acute stress were evaluated 3 to 4 wk after injections. Additional GFP and BDNF-treated animals were equipped with osmotic pumps for intracerebroventricular infusion of saline or the angiotensin type-1 receptor (AT1R) inhibitor losartan (15 μg·0.5 μl−1·h−1). BDNF treatment significantly increased baseline BP (121 ± 3 mmHg vs. 99 ± 2 mmHg in GFP), HR (394 ± 9 beats/min vs. 314 ± 4 beats/min in GFP), and sympathetic tone indicated by HR- and BP-variability analysis and adrenomedullary tyrosine hydroxylase protein expression. In contrast, body weight and BP elevations to acute stressors decreased. BDNF upregulated AT1R mRNA by ∼80% and downregulated Mas receptor mRNA by ∼50% in the PVN, and losartan infusion partially inhibited weight loss and increases in BP and HR in BDNF-treated animals without any effect in GFP rats. Our results demonstrate that BDNF overexpression in the PVN results in sympathoexcitation, BP and HR elevations, and weight loss that are mediated, at least in part, by modulating angiotensin signaling in the PVN. PMID:25576628

An increase in circulating B cell-activating factor in childhood-onset ocular myasthenia gravis.

PubMed

Motobayashi, Mitsuo; Inaba, Yuji; Nishimura, Takafumi; Kobayashi, Norimoto; Nakazawa, Yozo; Koike, Kenichi

2015-04-01

Myasthenia gravis is a B cell-mediated autoimmune disorder. The pathophysiology of childhood-onset ocular myasthenia gravis remains unclear. We investigated serum B cell-activating factor levels and other immunological parameters in child patients with ocular myasthenia gravis. Blood samples were obtained from 9 children with ocular myasthenia gravis and 20 age-matched controls. We assayed serum concentrations of B cell-activating factor, anti-acetylcholine receptor antibody titers, 7 types of cytokines (interleukins-2, -4, -6, -10, and -17A; interferon-γ; tumor necrosis factor-α) as well as the percentages of peripheral blood CD4+, CD8+, and CD19+ cells. Serum B cell-activating factor levels were significantly higher before immunosuppressive therapy in patients with childhood-onset ocular myasthenia gravis than in controls and decreased after immunosuppressive therapy. A significant positive correlation was observed between serum B cell-activating factor levels and anti-acetylcholine receptor antibody titers in patients with myasthenia gravis. Serum B cell-activating factor concentrations did not correlate with the percentages of CD4+, CD8+, and CD19+ cells or the CD4+/CD8+ ratio. No significant differences were observed in the levels of the 7 different types of cytokines examined, including interleukin-17A, between preimmunosuppressive therapy myasthenia gravis patients and controls. Circulating B cell-activating factor may play a key role in the pathophysiology of childhood-onset ocular myasthenia gravis. Copyright © 2015 Elsevier Inc. All rights reserved.

Prenatal exposure to common environmental factors affects brain lipids and increases risk of developing autism spectrum disorders.

PubMed

Wong, Christine T; Wais, Joshua; Crawford, Dorota A

2015-11-01

The prevalence of autism spectrum disorders (ASDs) has been on the rise over recent years. The presence of diverse subsets of candidate genes in each individual with an ASD and the vast variability of phenotypical differences suggest that the interference of an exogenous environmental component may greatly contribute to the development of ASDs. The lipid mediator prostaglandin E2 (PGE2 ) is released from phospholipids of cell membranes, and is important in brain development and function; PGE2 is involved in differentiation, synaptic plasticity and calcium regulation. The previous review already described extrinsic factors, including deficient dietary supplementation, and exposure to oxidative stress, infections and inflammation that can disrupt signaling of the PGE2 pathway and contribute to ASDs. In this review, the structure and establishment of two key protective barriers for the brain during early development are described: the blood-brain barrier; and the placental barrier. Then, the first comprehensive summary of other environmental factors, such as exposure to chemicals in air pollution, pesticides and consumer products, which can also disturb PGE2 signaling and increase the risk for developing ASDs is provided. Also, how these exogenous agents are capable of crossing the protective barriers of the brain during critical developmental periods when barrier components are still being formed is described. This review underlines the importance of avoiding or limiting exposure to these factors during vulnerable periods in development. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Pregnancy-induced hypertension is associated with an increase in the prevalence of cardiovascular disease risk factors in Japanese women.

PubMed

Watanabe, Kazushi; Kimura, Chiharu; Iwasaki, Ai; Mori, Toshitaka; Matsushita, Hiroshi; Shinohara, Koichi; Wakatsuki, Akihiko; Gosho, Masahiko; Miyano, Ichiro

2015-06-01

This study assessed whether pregnancy-induced hypertension (PIH) affects the prevalence of cardiovascular disease (CVD) risk factors in later life among Japanese women. Study participants were 1,185 women (mean [SD] age, 46.5 [5.6] y; range, 38-73 y) aged 40 years or older who underwent a health checkup at a periodic health examination facility between January 2012 and December 2013 and had experienced giving birth. Questionnaires were sent to potential participants, and they were encouraged to provide their Maternal and Child Health Handbook (handbook). We recruited 101 women with a history of PIH (PIH group) and 1,084 women with uncomplicated pregnancy at delivery (control group). Groupings were based on information from the handbook. We assessed the association between PIH and CVD in later life among Japanese women by focusing on hypertension, diabetes mellitus, and dyslipidemia as risk factors for CVD. Odds ratios (ORs) for the use of antihypertensive, diabetes mellitus, and dyslipidemic medications in the PIH group were determined. Women with PIH had increased risk of antihypertensive medication use compared with women without PIH (2.9% vs 13.9%; OR, 4.28; 95% CI, 2.14-8.57). Triglycerides were significantly higher and high-density lipoprotein cholesterol was significantly lower in the PIH group than in the control group. The OR for dyslipidemic medication use in the PIH group relative to the control group was 3.20 (95% CI, 1.42-7.22). Our findings suggest that a history of PIH may be associated with an increased risk of hypertension (a risk factor for CVD) in later life among Japanese women.

In-Shoe Plantar Pressures and Ground Reaction Forces during Overweight Adults' Overground Walking

ERIC Educational Resources Information Center

de Castro, Marcelo P.; Abreu, Sofia C.; Sousa, Helena; Machado, Leandro; Santos, Rubim; Vilas-Boas, João Paulo

2014-01-01

Purpose: Because walking is highly recommended for prevention and treatment of obesity and some of its biomechanical aspects are not clearly understood for overweight people, we compared the absolute and normalized ground reaction forces (GRF), plantar pressures, and temporal parameters of normal-weight and overweight participants during…

The role of biomechanics in maximising distance and accuracy of golf shots.

PubMed

Hume, Patria A; Keogh, Justin; Reid, Duncan

2005-01-01

Golf biomechanics applies the principles and technique of mechanics to the structure and function of the golfer in an effort to improve golf technique and performance. A common recommendation for technical correction is maintaining a single fixed centre hub of rotation with a two-lever one-hinge moment arm to impart force on the ball. The primary and secondary spinal angles are important for conservation of angular momentum using the kinetic link principle to generate high club-head velocity. When the golfer wants to maximise the distance of their drives, relatively large ground reaction forces (GRF) need to be produced. However, during the backswing, a greater proportion of the GRF will be observed on the back foot, with transfer of the GRF on to the front foot during the downswing/acceleration phase. Rapidly stretching hip, trunk and upper limb muscles during the backswing, maximising the X-factor early in the downswing, and uncocking the wrists when the lead arm is about 30 degrees below the horizontal will take advantage of the summation of force principle. This will help generate large angular velocity of the club head, and ultimately ball displacement. Physical conditioning will help to recruit the muscles in the correct sequence and to optimum effect. To maximise the accuracy of chipping and putting shots, the golfer should produce a lower grip on the club and a slower/shorter backswing. Consistent patterns of shoulder and wrist movements and temporal patterning result in successful chip shots. Qualitative and quantitative methods are used to biomechanically assess golf techniques. Two- and three-dimensional videography, force plate analysis and electromyography techniques have been employed. The common golf biomechanics principles necessary to understand golf technique are stability, Newton's laws of motion (inertia, acceleration, action reaction), lever arms, conservation of angular momentum, projectiles, the kinetic link principle and the stretch

Post-fusion treatment with MG132 increases transcription factor expression in somatic cell nuclear transfer embryos in pigs.

PubMed

You, Jinyoung; Lee, Joohyeong; Kim, Jinyoung; Park, Junhong; Lee, Eunsong

2010-02-01

The objective of this study was to examine the effect of post-fusion treatment of somatic cell nuclear transfer (SCNT) oocytes with the proteasomal inhibitor MG132 on maturation promoting factor (MPF) activity, nuclear remodeling, embryonic development, and gene expression of cloned pig embryos. Immediately after electrofusion, SCNT oocytes were treated with MG132 and/or caffeine for 2 hr, vanadate for 0.5 hr, or vanadate for 0.5 hr followed by MG132 for 1.5 hr. Of the MG132 concentrations tested (0-5 microM), the 1 microM concentration showed a higher rate of blastocyst formation (25.9%) than 0 (14.2%), 0.5 (16.9%), and 5 microM (16.9%). Post-fusion treatment with MG132, caffeine, and both MG132 and caffeine improved blastocyst formation (22.1%, 21.4%, and 24.4%, respectively), whereas vanadate treatment inhibited blastocyst formation (6.5%) compared to the control (11.1%). When examined 2 hr after fusion and 1 hr after activation, MPF activity remained at a higher (P < 0.05) level in SCNT oocytes that were treated post-fusion with caffeine and/or MG132, but it was decreased by vanadate. The rate of oocytes showing premature chromosome condensation was not altered by MG132 but was decreased by vanadate treatment. In addition, formation of single pronuclei was increased by MG132 compared to control and vanadate treatment. MG132-treated embryos showed increased expression of POU5F1, DPPA2, DPPA3, DPPA5, and NDP52l1 genes compared to control embryos. Our results demonstrate that post-fusion treatment of SCNT oocytes with MG132 prevents MPF degradation and increases expression of transcription factors in SCNT embryos, which are necessary for normal development of SCNT embryos. (c) 2009 Wiley-Liss, Inc.

Lower-extremity ground reaction forces in collegiate baseball pitchers.

PubMed

Guido, John A; Werner, Sherry L

2012-07-01

The purpose of this study was to investigate ground reaction forces (GRF) in collegiate baseball pitchers and their relationship to pitching mechanics. Fourteen healthy collegiate baseball pitchers participated in this study. High-speed video and force plate data were collected for fastballs from each pitcher. The average ball speed was 35 ± 3 m/sec (78 ± 7 mph). Peak GRFs of 245 ± 20% body weight (BW) were generated in an anterior or braking direction to control descent. Horizontal GRFs tended to occur in a laterally directed fashion, reaching a peak of 45 ± 63% BW. The maximum vertical GRF averaged 202 ± 43% BW approximately 45 milliseconds after stride foot contact. A correlation between braking force and ball velocity was evident. Because of the downward inclination and rotation of the pitching motion, in addition to volume, shear forces may occur in the musculoskeletal tissues of the stride limb leading to many of the lower-extremity injuries seen in this athletic population.

Three-Axis Ground Reaction Force Distribution during Straight Walking.

PubMed

Hori, Masataka; Nakai, Akihito; Shimoyama, Isao

2017-10-24

We measured the three-axis ground reaction force (GRF) distribution during straight walking. Small three-axis force sensors composed of rubber and sensor chips were fabricated and calibrated. After sensor calibration, 16 force sensors were attached to the left shoe. The three-axis force distribution during straight walking was measured, and the local features of the three-axis force under the sole of the shoe were analyzed. The heel area played a role in receiving the braking force, the base area of the fourth and fifth toes applied little vertical or shear force, the base area of the second and third toes generated a portion of the propulsive force and received a large vertical force, and the base area of the big toe helped move the body's center of mass to the other foot. The results demonstrate that measuring the three-axis GRF distribution is useful for a detailed analysis of bipedal locomotion.

Spin-orbit coupling in ultracold Fermi gases of 173Yb atoms

NASA Astrophysics Data System (ADS)

Song, Bo; He, Chengdong; Hajiyev, Elnur; Ren, Zejian; Seo, Bojeong; Cai, Geyue; Amanov, Dovran; Zhang, Shanchao; Jo, Gyu-Boong

2017-04-01

Synthetic spin-orbit coupling (SOC) in cold atoms opens an intriguing new way to probe nontrivial topological orders beyond natural conditions. Here, we report the realization of the SOC physics both in a bulk system and in an optical lattice. First, we demonstrate two hallmarks induced from SOC in a bulk system, spin dephasing in the Rabi oscillation and asymmetric atomic distribution in the momentum space respectively. Then we describe the observation of non-trivial spin textures and the determination of the topological phase transition in a spin-dependent optical lattice dressed by the periodic Raman field. Furthermore, we discuss the quench dynamics between topological and trivial states by suddenly changing the band topology. Our work paves a new way to study non-equilibrium topological states in a controlled manner. Funded by Croucher Foundation and Research Grants Council (RGC) of Hong Kong (Project ECS26300014, GRF16300215, GRF16311516, and Croucher Innovation Grants).

Observation of topological states in an optical Raman lattice with ultracold fermions

NASA Astrophysics Data System (ADS)

Song, Bo; He, Chengdong; Zhang, Long; Poon, Ting Fung Jeffrey; Hajiyev, Elnur; Ren, Zejian; Seo, Bojeong; Zhang, Shanchao; Liu, Xiong-Jun; Jo, Gyu-Boong

2017-04-01

The spin-orbit coupling with cold atoms, especially in optical lattices, provides a versatile platform to investigate the intriguing topological matters. In this talk, we will present the realization of one-dimensional spin-dependent lattice dressed by the periodic Raman field. Ultracold 173Yb fermions loaded into an optical Raman lattice reveal non-trivial spin textures due to the band topology, by which we measured topological invariants and determined a topological phase transition. In addition, we explored the non-equilibrium quench dynamics between the topological and the trivial states by suddenly changing the band topology of the optical Raman lattice. The optical Raman lattice demonstrated here opens a new avenue to study the spin-orbit coupling physics and furthermore to realize novel quantum matters such as symmetry-protected topological states. Funded by Croucher Foundation and Research Grants Council (RGC) of Hong Kong (Project ECS26300014, GRF16300215, GRF16311516, and Croucher Innovation Grants); MOST (Grant No. 2016YFA0301604) and NSFC (No. 11574008).

Applying human factors principles to alert design increases efficiency and reduces prescribing errors in a scenario-based simulation

PubMed Central

Russ, Alissa L; Zillich, Alan J; Melton, Brittany L; Russell, Scott A; Chen, Siying; Spina, Jeffrey R; Weiner, Michael; Johnson, Elizabette G; Daggy, Joanne K; McManus, M Sue; Hawsey, Jason M; Puleo, Anthony G; Doebbeling, Bradley N; Saleem, Jason J

2014-01-01

Objective To apply human factors engineering principles to improve alert interface design. We hypothesized that incorporating human factors principles into alerts would improve usability, reduce workload for prescribers, and reduce prescribing errors. Materials and methods We performed a scenario-based simulation study using a counterbalanced, crossover design with 20 Veterans Affairs prescribers to compare original versus redesigned alerts. We redesigned drug–allergy, drug–drug interaction, and drug–disease alerts based upon human factors principles. We assessed usability (learnability of redesign, efficiency, satisfaction, and usability errors), perceived workload, and prescribing errors. Results Although prescribers received no training on the design changes, prescribers were able to resolve redesigned alerts more efficiently (median (IQR): 56 (47) s) compared to the original alerts (85 (71) s; p=0.015). In addition, prescribers rated redesigned alerts significantly higher than original alerts across several dimensions of satisfaction. Redesigned alerts led to a modest but significant reduction in workload (p=0.042) and significantly reduced the number of prescribing errors per prescriber (median (range): 2 (1–5) compared to original alerts: 4 (1–7); p=0.024). Discussion Aspects of the redesigned alerts that likely contributed to better prescribing include design modifications that reduced usability-related errors, providing clinical data closer to the point of decision, and displaying alert text in a tabular format. Displaying alert text in a tabular format may help prescribers extract information quickly and thereby increase responsiveness to alerts. Conclusions This simulation study provides evidence that applying human factors design principles to medication alerts can improve usability and prescribing outcomes. PMID:24668841

A neuromechanics-based powered ankle exoskeleton to assist walking post-stroke: a feasibility study.

PubMed

Takahashi, Kota Z; Lewek, Michael D; Sawicki, Gregory S

2015-02-25

In persons post-stroke, diminished ankle joint function can contribute to inadequate gait propulsion. To target paretic ankle impairments, we developed a neuromechanics-based powered ankle exoskeleton. Specifically, this exoskeleton supplies plantarflexion assistance that is proportional to the user's paretic soleus electromyography (EMG) amplitude only during a phase of gait when the stance limb is subjected to an anteriorly directed ground reaction force (GRF). The purpose of this feasibility study was to examine the short-term effects of the powered ankle exoskeleton on the mechanics and energetics of gait. Five subjects with stroke walked with a powered ankle exoskeleton on the paretic limb for three 5 minute sessions. We analyzed the peak paretic ankle plantarflexion moment, paretic ankle positive work, symmetry of GRF propulsion impulse, and net metabolic power. The exoskeleton increased the paretic plantarflexion moment by 16% during the powered walking trials relative to unassisted walking condition (p < .05). Despite this enhanced paretic ankle moment, there was no significant increase in paretic ankle positive work, or changes in any other mechanical variables with the powered assistance. The exoskeleton assistance appeared to reduce the net metabolic power gradually with each 5 minute repetition, though no statistical significance was found. In three of the subjects, the paretic soleus activation during the propulsion phase of stance was reduced during the powered assistance compared to unassisted walking (35% reduction in the integrated EMG amplitude during the third powered session). This feasibility study demonstrated that the exoskeleton can enhance paretic ankle moment. Future studies with greater sample size and prolonged sessions are warranted to evaluate the effects of the powered ankle exoskeleton on overall gait outcomes in persons post-stroke.

Definitive surgical closure of enterocutaneous fistula: outcome and factors predictive of increased postoperative morbidity.

PubMed

Ravindran, P; Ansari, N; Young, C J; Solomon, M J

2014-03-01

Enterocutaneous fistula (ECF) presents a complex management problem with significant mortality and morbidity. The aim of this study was to assess the outcome of patients undergoing surgical cure for ECF and to predict factors that might relate to increased postoperative morbidity. Medical records of all patients who underwent definitive surgery for cure of an ECF within our colorectal surgery unit between 2000 and 2010 were reviewed. Forty-one patients (18 male) were identified, in whom 44 definitive procedures were performed. The median age was 54 (17-81) years. The median postoperative length of stay in hospital was 14 (2-213) days. Half (50%) of the ECFs occurred as a postoperative complication followed by spontaneous fistulation in Crohn's disease (36%). The interval to definitive surgery was influenced by the aetiology of the fistula. The median time to surgery after formation of postoperative fistula was 240 days (7.9 months). There was no 30-day postoperative mortality. There were two (4.5%) recurrences at 3 months. Thirty-eight (86%) patients suffered postoperative morbidity as defined by the Clavien-Dindo classification. High-grade morbidity occurred in 32% of patients. On univariate analysis, factors identified as being significantly associated with high-grade morbidity included a fistula output of > 500 ml/day (P = 0.004) in patients with postoperative ECF, malnutrition at presentation (P = 0.04) and a serum albumin value of < 30 g/l (P = 0.02) in patients with spontaneous ECF due to Crohn's disease. The majority of persistent complex ECFs can be cured surgically with low mortality and recurrence in a multidisciplinary setting. Postoperative morbidity, however, remains a significant burden. Colorectal Disease © 2013 The Association of Coloproctology of Great Britain and Ireland.

Four weeks of training in a sledge jump system improved the jump pattern to almost natural reactive jumps.

PubMed

Kramer, Andreas; Ritzmann, Ramona; Gruber, Markus; Gollhofer, Albert

2012-01-01

In spite of extensive training regimens during long-term space missions with existing training devices, astronauts suffer from muscle and bone loss. It has been suggested that reactive jumps inducing high forces in the muscles-consequently exposing the bones to high strains-help to counteract these degradations. In a previous study, a new sledge jump system (SJS) was found to allow fairly natural reactive jumps. The aim of the present study was to evaluate if training in the SJS would further reduce the differences between jumps in the SJS and normal jumps, particularly with respect to ground reaction forces (GRF) and rate of force development (RFD). Sixteen participants in a training group (TG) and 16 in a control group (CON) were tested before and after the TGs four-week hopping training in the SJS. During the tests, kinetic, kinematic and electromyographic data were compared between hops on the ground and in the SJS. After the training period, the GRF, the RFD and the leg stiffness in the SJS significantly increased for the TG (but not for CON) by 10, 35 and 38%, respectively. The kinematic and electromyographic data showed no significant changes. A short training regimen in the SJS reduced the differences between jumps in the SJS and normal jumps. Considering that a natural movement that exposes the muscles and thus also the bones to high loads is regarded as important for the preservation of muscle and bone, the SJS seems to be a promising countermeasure.

Kinetics of cross-slope running.

PubMed

Willwacher, Steffen; Fischer, Katina Mira; Benker, Rita; Dill, Stephan; Brüggemann, Gert-Peter

2013-11-15

The purpose of the present study was to identify kinetic responses to running on mediolaterally elevated (cross-sloped) running surfaces. Ground reaction forces (GRFs), GRF lever arms and joint moment characteristics of 19 male runners were analyzed when running at 3.5m/s on a custom-made, tiltable runway. Tilt angles of 3° and 6° for medial and lateral elevation were analyzed using a 10 camera Vicon Nexus system and a force platform. The point of force application of the GRF showed a systematic shift in the order of 1-1.5cm to either the lateral or medial aspect of the foot for lateral or medial inclinations, respectively. Consequently, the strongest significant effects of tilt orientation and level on joint kinetics and ground reaction force lever arms were identified at the ankle, knee and hip joint in the frontal plane of movement. External eversion moments at the ankle were significantly increased by 35% for 6° of lateral elevation and decreased by 16% for 6° of medial elevation. Altering the cross-slope of the running surface changed the pattern of ankle joint moments in the transversal plane. Effect sizes were on average larger for laterally elevated conditions, indicating a higher sensitivity of kinetic parameters to this kind of surface tilt. These alterations in joint kinetics should be considered in the choice of the running environment, especially for specific risk groups, like runners in rehabilitation processes. © 2013 Elsevier Ltd. All rights reserved.

Single-leg drop landing motor control strategies following acute ankle sprain injury.

PubMed

Doherty, C; Bleakley, C; Hertel, J; Caulfield, B; Ryan, J; Delahunt, E

2015-08-01

No research currently exists investigating the effect of acute injury on single-limb landing strategies. The aim of the current study was to analyze the coordination strategies of participants in the acute phase of lateral ankle sprain (LAS) injury. Thirty-seven participants with acute, first-time LAS and 19 uninjured participants completed a single-leg drop landing task on both limbs. Three-dimensional kinematic (angular displacement) and sagittal plane kinetic (moment-of-force) data were acquired for the joints of the lower extremity from 200 ms pre-initial contact (IC) to 200 ms post-IC. The peak magnitude of the vertical component of the ground reaction force (GRF) was also computed. Injured participants displayed a bilateral increase in hip flexion, with altered transverse plane kinematic profiles at the knee and ankle for both limbs (P < 0.05). This coincided with a reduction in the net-supporting flexor moment of the lower extremity (P < 0.05) and magnitude of the peak vertical GRF for the injured limb (21.82 ± 2.44 N/kg vs 24.09 ± 2.77 N/kg; P = 0.013) in injured participants compared to control participants. These results demonstrate that compensatory movement strategies are utilized by participants with acute LAS to successfully reduce the impact forces of landing. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Resources–tasks imbalance: Experiences of nurses from factors influencing workload to increase

PubMed Central

Khademi, Mojgan; Mohammadi, Easa; Vanaki, Zohreh

2015-01-01

Background: While nursing workload is a worldwide challenge, less attention has been given to the determining factors. Understanding these factors is important and could help nursing managers to provide suitable working environment and to manage the adverse outcomes of nursing workload. The aim of this study was to discover nurses’ experiences of determinant factors of their workload. Materials and Methods: In this qualitative study, the participants included 15 nurses working in two hospitals in Tehran, Iran. The data were collected through 26 unstructured interviews and were analyzed using conventional content analysis. The rigor has been guaranteed with prolonged engagement, maximum variance sampling, member check, and audit trail. Results: Resource–task imbalance was the main theme of nurses’ experiences. It means that there was an imbalance between necessary elements to meet patients’ needs in comparison with expectation and responsibility. Resource–task imbalance included lack of resource, assignment without preparation, assigning non-care tasks, and patients’ and families’ needs/expectations. Conclusions: A deep and comprehensive imbalance between recourses and tasks and expectations has been perceived by the participants to be the main source of work overload. Paying more attention to resource allocation, education of quality workforce, and job description by managers is necessary. PMID:26257804