Displaying publications 421 - 440 of 4601 in total

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  1. Pai YJ, Abdullah NL, Mohd-Zin SW, Mohammed RS, Rolo A, Greene ND, et al.
    PMID: 22945349 DOI: 10.1002/bdra.23072
    Adhesion and fusion of epithelial sheets marks the completion of many morphogenetic events during embryogenesis. Neural tube closure involves an epithelial fusion sequence in which the apposing neural folds adhere initially via cellular protrusions, proceed to a more stable union, and subsequently undergo remodeling of the epithelial structures to yield a separate neural tube roof plate and overlying nonneural ectoderm. Cellular protrusions comprise lamellipodia and filopodia, and studies in several different systems emphasize the critical role of RhoGTPases in their regulation. How epithelia establish initial adhesion is poorly understood but, in neurulation, may involve interactions between EphA receptors and their ephrinA ligands. Epithelial remodeling is spatially and temporally correlated with apoptosis in the dorsal neural tube midline, but experimental inhibition of this cell death does not prevent fusion and remodeling. A variety of molecular signaling systems have been implicated in the late events of morphogenesis, but genetic redundancy, for example among the integrins and laminins, makes identification of the critical players challenging. An improved understanding of epithelial fusion can provide insights into normal developmental processes and may also indicate the mode of origin of clinically important birth defects.
    Matched MeSH terms: Cell Adhesion/physiology; Epithelial Cells/physiology*; Morphogenesis/physiology*; Apoptosis/physiology; Neural Tube/physiology; Neurulation/physiology
  2. Poznanski RR
    J Integr Neurosci, 2010 Sep;9(3):299-335.
    PMID: 21064220
    Optical imaging of dendritic calcium signals provided evidence of starburst amacrine cells exhibiting calcium bias to somatofugal motion. In contrast, it has been impractical to use a dual-patch clamp technique to record membrane potentials from both proximal dendrites and distal varicosities of starburst amacrine cells in order to unequivocally prove that they are directionally sensitive to voltage, as was first suggested almost two decades ago. This paper aims to extend the passive cable model to an active cable model of a starburst amacrine cell that is intrinsically dependent on the electrical properties of starburst amacrine cells, whose various macroscopic currents are described quantitatively. The coupling between voltage and calcium just below the membrane results in a voltage-calcium system of coupled nonlinear Volterra integral equations whose solutions must be integrated into a prescribed model for example, for a synaptic couplet of starburst amacrine cells. Networks of starburst amacrine cells play a fundamental role in the retinal circuitry underlying directional selectivity. It is suggested that the dendritic plexus of starburst amacrine cells provides the substrate for the property of directional selectivity, while directional selectivity is a property of the exclusive layerings and confinement of their interconnections within the sublaminae of the inner plexiform layer involving cone bipolar cells and directionally selective ganglion cells.
    Matched MeSH terms: Dendrites/physiology*; Membrane Potentials/physiology; Nerve Net/physiology; Neural Inhibition/physiology*; Calcium Signaling/physiology; Amacrine Cells/physiology*
  3. Heikal MY, Aminuddin BS, Jeevanan J, Chen HC, Sharifah S, Ruszymah BH
    Med J Malaysia, 2008 Jul;63 Suppl A:34.
    PMID: 19024970
    Normal tracheal mucociliary clearance is the key to maintaining the health and defense of respiratory airway. Therefore the present of cilia and mucous blanket are important for tracheal epithelium to function effectively. In the present study, we prepared a tissue engineered respiratory epithelium construct (TEREC) made of autologous respiratory epithelium cells, fibroblast and fibrin from sheep owns blood which replaced a created tracheal mucosal defect. Scanning electron microscopy (SEM) showed encouraging result where immature cilia were present on the surface of TEREC. This result indicates that engineered respiratory epithelium was able to function as normal tissue.
    Matched MeSH terms: Cilia/physiology; Epithelial Cells/physiology*; Epithelium/physiology*; Fibrin/physiology; Fibroblasts/physiology; Trachea/physiology
  4. Ewers RM, Boyle MJ, Gleave RA, Plowman NS, Benedick S, Bernard H, et al.
    Nat Commun, 2015 Apr 13;6:6836.
    PMID: 25865801 DOI: 10.1038/ncomms7836
    Invertebrates are dominant species in primary tropical rainforests, where their abundance and diversity contributes to the functioning and resilience of these globally important ecosystems. However, more than one-third of tropical forests have been logged, with dramatic impacts on rainforest biodiversity that may disrupt key ecosystem processes. We find that the contribution of invertebrates to three ecosystem processes operating at three trophic levels (litter decomposition, seed predation and removal, and invertebrate predation) is reduced by up to one-half following logging. These changes are associated with decreased abundance of key functional groups of termites, ants, beetles and earthworms, and an increase in the abundance of small mammals, amphibians and insectivorous birds in logged relative to primary forest. Our results suggest that ecosystem processes themselves have considerable resilience to logging, but the consistent decline of invertebrate functional importance is indicative of a human-induced shift in how these ecological processes operate in tropical rainforests.
    Matched MeSH terms: Amphibians/physiology; Birds/physiology; Invertebrates/physiology*; Mammals/physiology; Trees/physiology*; Plant Dispersal/physiology*
  5. Meimandipour A, Hair-Bejo M, Shuhaimi M, Azhar K, Soleimani AF, Rasti B, et al.
    Br Poult Sci, 2010 Feb;51(1):52-9.
    PMID: 20390569 DOI: 10.1080/00071660903394455
    1. An experiment was conducted to determine the effects of supposedly unpleasant physical treatment on broiler performance, small intestinal development and ameliorating role of probiotics. 2. The following treatments were applied from day one: (1) chicks exposed to normal human contact fed basal diet (control); (2) chicks were exposed to unpleasant physical treatment and fed basal diet (UPT-BD); and (3) chicks were exposed to unpleasant physical treatment and fed basal diet supplemented with Lactobacillus (UPT-BDL). Chicks were exposed to UPT from days 1 to 21. Different segments of gastrointestinal tract were sampled at 14, 28, 35 and 42 d of age. 3. Broilers of UPT-BD had lower feed consumption compared with control group at 7 d of age. Overall, UPT-BDL birds showed higher body weight gain (BWG) and better feed conversion ratio (FCR) over the course of the experiment. 4. Birds of UPT-BD had lower concentrations of lactic, propionic and butyric acids in the caecum as compared with other groups at 14 d of age. Acetic acid concentration was profoundly decreased in both UPT groups compared to the control. 5. Duodenal villus height of UPT-BD broilers showed a slight reduction compared to the control and UPT-BDL birds at 14 d of age. Afterwards until day 42, UPT-BDL birds showed the highest villus height among treatments in different parts of the small intestine. 6. The results suggested that, even though UPT did not have significant inhibitory effects on the development of the small intestine and broiler performance, it negatively affected bacterial metabolic end products in the caecum, which could be ameliorated by the addition of Lactobacillus.
    Matched MeSH terms: Body Weight/physiology; Chickens/physiology*; Eating/physiology*; Fear/physiology*; Lactobacillus/physiology*; Gastrointestinal Tract/physiology
  6. Chan SC, Mok SY, Ng DW, Goh SY
    Biol Cybern, 2017 Dec;111(5-6):459-472.
    PMID: 29128889 DOI: 10.1007/s00422-017-0740-z
    Ultra-slow cortical oscillatory activity of 1-100 mHz has been recorded in human by electroencephalography and in dissociated cultures of cortical rat neurons, but the underlying mechanisms remain to be elucidated. This study presents a computational model of ultra-slow oscillatory activity based on the interaction between neurons and astrocytes. We predict that the frequency of these oscillations closely depends on activation of astrocytes in the network, which is reflected by oscillations of their intracellular calcium concentrations with periods between tens of seconds and minutes. An increase of intracellular calcium in astrocytes triggers the release of adenosine triphosphate from these cells which may alter transmission at nearby synapses by increasing or decreasing neurotransmitter release. These results provide theoretical support for the emerging awareness of astrocytes as active players in the regulation of neural activity and identify neuron-astrocyte interactions as a potential primary mechanism for the emergence of ultra-slow cortical oscillations.
    Matched MeSH terms: Action Potentials/physiology*; Cell Communication/physiology*; Nerve Net/physiology; Neuroglia/physiology*; Neurons/physiology*; Synapses/physiology*
  7. Kondo T, Nishimura S, Tani N, Ng KK, Lee SL, Muhammad N, et al.
    Am J Bot, 2016 Nov;103(11):1912-1920.
    PMID: 27797714
    PREMISE OF THE STUDY: In tropical rainforests of Southeast Asia, a highly fecund thrips (Thrips spp.) responds rapidly to the mass flowering at multiple-year intervals characteristic of certain species such as the canopy tree studied here, Shorea acuminata, by feeding on flower resources. However, past DNA analyses of pollen adherent to thrips bodies revealed that the thrips promoted a very high level of self-pollination. Here, we identified the pollinator that contributes to cross-pollination and discuss ways that the pollination system has adapted to mass flowering.

    METHODS: By comparing the patterns of floral visitation and levels of genetic diversity in adherent pollen loads among floral visitors, we evaluated the contribution of each flower visitor to pollination.

    KEY RESULTS: The big-eyed bug, Geocoris sp., a major thrips predator, was an inadvertent pollinator, and importantly contributed to cross-pollination. The total outcross pollen adhering to thrips was approximately 30% that on the big-eyed bugs. Similarly, 63% of alleles examined in S. acuminata seeds and seedlings occurred in pollen adhering to big-eyed bugs; about 30% was shared with pollen from thrips.

    CONCLUSIONS: During mass flowering, big-eyed bugs likely travel among flowering S. acuminata trees, attracted by the abundant thrips. Floral visitation patterns of big-eyed bugs vs. other insects suggest that these bugs can maintain their population size between flowering by preying upon another thrips (Haplothrips sp.) that inhabits stipules of S. acuminata throughout the year and quickly respond to mass flowering. Thus, thrips and big-eyed bugs are essential components in the pollination of S. acuminata.

    Matched MeSH terms: Pollen/physiology; Seeds/physiology; Flowers/physiology; Seedlings/physiology; Dipterocarpaceae/physiology*; Thysanoptera/physiology*
  8. Kamakura M, Kosugi Y, Takanashi S, Uemura A, Utsugi H, Kassim AR
    Tree Physiol, 2015 Jan;35(1):61-70.
    PMID: 25595752 DOI: 10.1093/treephys/tpu109
    In this study, we demonstrated the occurrence of stomatal patchiness and its spatial scale in leaves from various sizes of trees grown in a lowland dipterocarp forest in Peninsular Malaysia. To evaluate the patterns of stomatal behavior, we used three techniques simultaneously to analyze heterobaric or homobaric leaves from five tree species ranging from 0.6 to 31 m in height: (i) diurnal changes in chlorophyll fluorescence imaging, (ii) observation and simulation of leaf gas-exchange rates and (iii) a pressure-infiltration method. Measurements were performed in situ with 1000 or 500 μmol m(-2) s(-1) photosynthetic photon flux density. Diurnal patterns in the spatial distribution of photosynthetic electron transport rate (J) mapped from chlorophyll fluorescence images, a comparison of observed and simulated leaf gas-exchange rates, and the spatial distribution of stomatal apertures obtained from the acid-fuchsin-infiltrated area showed that patchy stomatal closure coupled with severe midday depression of photosynthesis occurred in Neobalanocarpus heimii (King) Ashton, a higher canopy tree with heterobaric leaves due to the higher leaf temperature and vapor pressure deficit. However, subcanopy or understory trees showed uniform stomatal behavior throughout the day, although they also have heterobaric leaves. These results suggest that the occurrence of stomatal patchiness is determined by tree size and/or environmental conditions. The analysis of spatial scale by chlorophyll fluorescence imaging showed that several adjacent anatomical patches (lamina areas bounded by bundle-sheath extensions within the lamina) may co-operate for the distributed patterns of J and stomatal apertures.
    Matched MeSH terms: Trees/physiology*; Plant Leaves/physiology; Euphorbiaceae/physiology; Rubiaceae/physiology; Dipterocarpaceae/physiology; Plant Stomata/physiology
  9. Huat TJ, Khan AA, Pati S, Mustafa Z, Abdullah JM, Jaafar H
    BMC Neurosci, 2014;15:91.
    PMID: 25047045 DOI: 10.1186/1471-2202-15-91
    There has been increasing interest recently in the plasticity of mesenchymal stem cells (MSCs) and their potential to differentiate into neural lineages. To unravel the roles and effects of different growth factors in the differentiation of MSCs into neural lineages, we have differentiated MSCs into neural lineages using different combinations of growth factors. Based on previous studies of the roles of insulin-like growth factor 1 (IGF-1) in neural stem cell isolation in the laboratory, we hypothesized that IGF-1 can enhance proliferation and reduce apoptosis in neural progenitor-like cells (NPCs) during differentiation of MSCs into NCPs.We induced MSCs differentiation under four different combinations of growth factors: (A) EGF + bFGF, (B) EGF + bFGF + IGF-1, (C) EGF + bFGF + LIF, (D) EGF + bFGF + BDNF, and (E) without growth factors, as a negative control. The neurospheres formed were characterized by immunofluorescence staining against nestin, and the expression was measured by flow cytometry. Cell proliferation and apoptosis were also studied by MTS and Annexin V assay, respectively, at three different time intervals (24 hr, 3 days, and 5 days). The neurospheres formed in the four groups were then terminally differentiated into neuron and glial cells.
    Matched MeSH terms: Cell Survival/physiology; Neuroglia/physiology; Neurons/physiology; Apoptosis/physiology; Cell Proliferation/physiology; Neurogenesis/physiology*; Neural Stem Cells/physiology*; Mesenchymal Stromal Cells/physiology*
  10. Yaakub H, Masnindah M, Shanthi G, Sukardi S, Alimon AR
    Anim. Reprod. Sci., 2009 Oct;115(1-4):182-8.
    PMID: 19167847 DOI: 10.1016/j.anireprosci.2008.12.006
    Testes from nine male Malin x Santa-Ines rams with an average body weight of 43.1+/-3.53 kg, were used to study the effects of palm kernel cake (PKC) based diet on spermatogenic cells and to assess copper (Cu) levels in liver, testis and plasma in sheep. Animals were divided into three groups and randomly assigned three dietary treatments using restricted randomization of body weight in completely randomized design. The dietary treatments were 60% palm kernel cake plus 40% oil palm frond (PKC), 60% palm kernel cake plus 40% oil palm frond supplemented with 23 mg/kg dry matter of molybdenum as ammonium molybdate [(NH(4))(6)Mo(7)O(24).4H(2)O] and 600 mg/kg dry matter of sulphate as sodium sulphate [Na(2)SO(4)] (PKC-MS) and 60% concentrate of corn-soybean mix+40% oil palm frond (Control), the concentrate was mixed in a ratio of 79% corn, 20% soybean meal and 1% standard mineral mix. The results obtained showed that the number of spermatogonia, spermatocytes, spermatids and Leydig cells were not significantly different among the three treatment groups. However, spermatozoa, Sertoli cells and degenerated cells showed significant changes, which, may be probably due to the Cu content in PKC. Liver and testis Cu levels in the rams under PKC diet was found to be significantly higher (P<0.05) than rams in Control and PKC-MS diets. Plasma Cu levels showed a significant increase (P<0.05) at the end of the experiment as compared to at the beginning of the experiment for PKC and Control. In conclusion, spermatogenesis is normal in rams fed the diet without PKC and PKC supplemented with Mo and S. However spermatogenesis was altered in the PKC based diet probably due to the toxic effects of Cu and the significant changes in organs and plasma. Thus, Mo and S play a major role in reducing the accumulation of Cu in organs.
    Matched MeSH terms: Leydig Cells/physiology; Sertoli Cells/physiology; Spermatids/physiology; Spermatocytes/physiology; Spermatogenesis/physiology*; Spermatogonia/physiology; Spermatozoa/physiology; Testis/physiology*
  11. Mazlyzam AL, Aminuddin BS, Saim L, Ruszymah BH
    Med J Malaysia, 2008 Jul;63 Suppl A:32-3.
    PMID: 19024969
    The angiogenic potential of native skin (NS), keratinocytes single skin equivalent (SSE-K), fibroblasts single skin equivalent (SSE-F) and bilayered skin equivalent secreting angiogenic growth factors such as transforming growth factor beta1 (TGF-beta1), vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF) in the in vitro systems at 24, 48, 72 hours and 7 days was compared using Enzyme-Linked Immunosorbent Assay (ELISA). Bilayered skin equivalent exhibit highest release of growth factors within 24 hours to 7 days of culture compared to NS, SSE-K and SSE-F. This proved the potential of bilayered skin equivalent in producing and sustaining growth factors release to enhance angiogenesis, fibroblasts proliferation, matrix deposition, migration and growth of keratinocytes.
    Matched MeSH terms: Fibroblasts/physiology*; Wound Healing/physiology*; Keratinocytes/physiology*; Fibroblast Growth Factor 2/physiology*; Neovascularization, Physiologic/physiology*; Vascular Endothelial Growth Factor A/physiology*; Fibroblast Growth Factor 7/physiology*; Transforming Growth Factor beta1/physiology*
  12. Freiria-Oliveira AH, Blanch GT, Pedrino GR, Cravo SL, Murphy D, Menani JV, et al.
    Am J Physiol Regul Integr Comp Physiol, 2015 Nov 01;309(9):R1082-91.
    PMID: 26333788 DOI: 10.1152/ajpregu.00432.2014
    Noradrenergic A2 neurons of the nucleus of the solitary tract (NTS) have been suggested to contribute to body fluid homeostasis and cardiovascular regulation. In the present study, we investigated the effects of lesions of A2 neurons of the commissural NTS (cNTS) on the c-Fos expression in neurons of the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, arterial pressure, water intake, and urinary excretion in rats with plasma hyperosmolality produced by intragastric 2 M NaCl (2 ml/rat). Male Holtzman rats (280-320 g) received an injection of anti-dopamine-β-hydroxylase-saporin (12.6 ng/60 nl; cNTS/A2-lesion, n = 28) or immunoglobulin G (IgG)-saporin (12.6 ng/60 nl; sham, n = 24) into the cNTS. The cNTS/A2 lesions increased the number of neurons expressing c-Fos in the magnocellular PVN in rats treated with hypertonic NaCl (90 ± 13, vs. sham: 47 ± 20; n = 4), without changing the number of neurons expressing c-Fos in the parvocellular PVN or in the SON. Contrary to sham rats, intragastric 2 M NaCl also increased arterial pressure in cNTS/A2-lesioned rats (16 ± 3, vs. sham: 2 ± 2 mmHg 60 min after the intragastric load; n = 9), an effect blocked by the pretreatment with the vasopressin antagonist Manning compound (0 ± 3 mmHg; n = 10). In addition, cNTS/A2 lesions enhanced hyperosmolality-induced water intake (10.5 ± 1.4, vs. sham: 7.7 ± 0.8 ml/60 min; n = 8-10), without changing renal responses to hyperosmolality. The results suggest that inhibitory mechanisms dependent on cNTS/A2 neurons reduce water intake and vasopressin-dependent pressor response to an acute increase in plasma osmolality.
    Matched MeSH terms: Neurovascular Coupling/physiology; Appetite Regulation/physiology; Blood Pressure/physiology*; Vasoconstriction/physiology; Water-Electrolyte Balance/physiology*; Solitary Nucleus/physiology*; Adrenergic Neurons/physiology*; Osmoregulation/physiology
  13. Makinejad MD, Abu Osman NA, Abu Bakar Wan Abas W, Bayat M
    Clinics (Sao Paulo), 2013 Sep;68(9):1180-8.
    PMID: 24141832 DOI: 10.6061/clinics/2013(09)02
    This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height.
    Matched MeSH terms: Biomechanical Phenomena/physiology; Femur/physiology; Knee Joint/physiology*; Movement/physiology*; Tibia/physiology; Range of Motion, Articular/physiology; Anterior Cruciate Ligament/physiology; Weight-Bearing/physiology
  14. Sculthorpe-Petley L, Liu C, Hajra SG, Parvar H, Satel J, Trappenberg TP, et al.
    J Neurosci Methods, 2015 Apr 30;245:64-72.
    PMID: 25701685 DOI: 10.1016/j.jneumeth.2015.02.008
    Event-related potentials (ERPs) may provide a non-invasive index of brain function for a range of clinical applications. However, as a lab-based technique, ERPs are limited by technical challenges that prevent full integration into clinical settings.
    Matched MeSH terms: Brain/physiology*; Consciousness/physiology*; Evoked Potentials/physiology*; Reaction Time/physiology
  15. Hong YH, Betik AC, McConell GK
    Exp Physiol, 2014 Dec 1;99(12):1569-73.
    PMID: 25192731 DOI: 10.1113/expphysiol.2014.079202
    Nitric oxide is produced within skeletal muscle fibres and has various functions in skeletal muscle. There is evidence that NO may be essential for normal increases in skeletal muscle glucose uptake during contraction/exercise. Although there have been some discrepant results, it has been consistently demonstrated that inhibition of NO synthase (NOS) attenuates the increase in skeletal muscle glucose uptake during contraction in mouse and rat muscle ex vivo, during in situ contraction in rats and during exercise in humans. The NO-mediated increase in skeletal muscle glucose uptake during contraction/exercise is probably due to the modulation of intramuscular signalling that ultimately increases glucose transporter 4 (GLUT4) translocation and is, surprisingly, independent of blood flow. In this review, we discuss the evidence for and against a role of NO in regulating skeletal muscle glucose uptake during contraction/exercise and outline the possible mechanism(s) involved. Emerging findings regarding the role of neuronal NOS mu (nNOSμ) in this process are also discussed.
    Matched MeSH terms: Biological Transport/physiology; Muscle Contraction/physiology*; Physical Conditioning, Animal/physiology*; Exercise/physiology*
  16. Cacha LA, Poznanski RR
    J Integr Neurosci, 2014 Jun;13(2):253-92.
    PMID: 25012712 DOI: 10.1142/S0219635214400081
    A theoretical framework is developed based on the premise that brains evolved into sufficiently complex adaptive systems capable of instantiating genomic consciousness through self-awareness and complex interactions that recognize qualitatively the controlling factors of biological processes. Furthermore, our hypothesis assumes that the collective interactions in neurons yield macroergic effects, which can produce sufficiently strong electric energy fields for electronic excitations to take place on the surface of endogenous structures via alpha-helical integral proteins as electro-solitons. Specifically the process of radiative relaxation of the electro-solitons allows for the transfer of energy via interactions with deoxyribonucleic acid (DNA) molecules to induce conformational changes in DNA molecules producing an ultra weak non-thermal spontaneous emission of coherent biophotons through a quantum effect. The instantiation of coherent biophotons confined in spaces of DNA molecules guides the biophoton field to be instantaneously conducted along the axonal and neuronal arbors and in-between neurons and throughout the cerebral cortex (cortico-thalamic system) and subcortical areas (e.g., midbrain and hindbrain). Thus providing an informational character of the electric coherence of the brain - referred to as quantum coherence. The biophoton field is realized as a conscious field upon the re-absorption of biophotons by exciplex states of DNA molecules. Such quantum phenomenon brings about self-awareness and enables objectivity to have access to subjectivity in the unconscious. As such, subjective experiences can be recalled to consciousness as subjective conscious experiences or qualia through co-operative interactions between exciplex states of DNA molecules and biophotons leading to metabolic activity and energy transfer across proteins as a result of protein-ligand binding during protein-protein communication. The biophoton field as a conscious field is attributable to the resultant effect of specifying qualia from the metabolic energy field that is transported in macromolecular proteins throughout specific networks of neurons that are constantly transforming into more stable associable representations as molecular solitons. The metastability of subjective experiences based on resonant dynamics occurs when bottom-up patterns of neocortical excitatory activity are matched with top-down expectations as adaptive dynamic pressures. These dynamics of on-going activity patterns influenced by the environment and selected as the preferred subjective experience in terms of a functional field through functional interactions and biological laws are realized as subjectivity and actualized through functional integration as qualia. It is concluded that interactionism and not information processing is the key in understanding how consciousness bridges the explanatory gap between subjective experiences and their neural correlates in the transcendental brain.
    Matched MeSH terms: Brain/physiology*; Cognition/physiology; Consciousness/physiology*; Neurons/physiology*
  17. Shariat A, Kargarfard M, Danaee M, Bahri Mohd Tamrin S
    J Strength Cond Res, 2015 Jan;29(1):151-8.
    PMID: 25051005 DOI: 10.1519/JSC.0000000000000632
    Strength and morphological adaptations to resistance exercise are mediated in part by anabolic hormones such as testosterone, yet the time course of variability in circadian hormone concentrations is not well characterized. This study, investigated how the circadian rhythm of salivary testosterone is altered by resistance exercise in young men. Twenty healthy young male recreational lifters (age, 18.0 ± 1.3 years) with 2 years of experience in weightlifting were recruited. A randomized controlled trial was conducted, and subjects were randomly assigned to either the resistance exercise group (n = 10), who completed a series of resistance exercise (3 times a week, in the afternoon, 6-7 repetitions, at 85% of 1 repetition maximum for 3 weeks), or a control group (n = 10), who did not exercise during the 3 weeks. Before and after the study, an unstimulated saliva sample (2 ml) was taken every 2 hours for a maximum of 16 hours during each day. A significant decrease was observed in the resistance exercise (44.2%, p = 0.001) and control group (46.1%, p = 0.001) for salivary testosterone at each time point compared with baseline (p = 0.001). There was also no significant difference between the exercise and resting conditions in both groups for salivary testosterone (p > 0.05), except a significantly higher increase by 38.4% vs. -0.02% (p = 0.001), at 1730 hours during exercise sessions in the resistance exercise group compared with the control group. Resistance exercise has no noteworthy effect on circadian secretion of salivary testosterone throughout the 16 waking hours. These results indicate that athletes can undertake resistance exercise in either the morning or afternoon with the knowledge that a similar testosterone response can be expected regardless of the time of day.
    Matched MeSH terms: Adaptation, Physiological/physiology; Circadian Rhythm/physiology*; Rest/physiology; Weight Lifting/physiology*
  18. Sekeli R, Abdullah JO, Namasivayam P, Muda P, Abu Bakar UK, Yeong WC, et al.
    Molecules, 2014 Jun 19;19(6):8350-62.
    PMID: 24950439 DOI: 10.3390/molecules19068350
    The purpose of this study was to evaluate the effectiveness of using RNA interference in down regulating the expression of 1-aminocyclopropane-1-carboxylic acid oxidase gene in Eksotika papaya. One-month old embryogenic calli were separately transformed with Agrobacterium strain LBA 4404 harbouring the three different RNAi pOpOff2 constructs bearing the 1-aminocyclopropane-1-carboxylic acid oxidase gene. A total of 176 putative transformed lines were produced from 15,000 calli transformed, selected, then regenerated on medium supplemented with kanamycin. Integration and expression of the targeted gene in putatively transformed lines were verified by PCR and real-time RT-PCR. Confined field evaluation of a total of 31 putative transgenic lines planted showed a knockdown expression of the targeted ACO1 and ACO2 genes in 13 lines, which required more than 8 days to achieve the full yellow colour (Index 6). Fruits harvested from lines pRNAiACO2 L2-9 and pRNAiACO1 L2 exhibited about 20 and 14 days extended post-harvest shelf life to reach Index 6, respectively. The total soluble solids contents of the fruits ranged from 11 to 14° Brix, a range similar to fruits from non-transformed, wild type seed-derived plants.
    Matched MeSH terms: Fruit/physiology; Carica/physiology; Plants, Genetically Modified/physiology; RNA Interference/physiology
  19. Ali MA, Sundaraj K, Ahmad RB, Ahamed NU, Islam MA, Sundaraj S
    Technol Health Care, 2014;22(4):617-25.
    PMID: 24990168 DOI: 10.3233/THC-140833
    Normally, surface electromyography electrodes are used to evaluate the activity of superficial muscles during various kinds of voluntary contractions of muscle fiber. The objective of the present study was to investigate the effect of repetitive isometric contractions on the three heads of the triceps brachii muscle during handgrip force exercise.
    Matched MeSH terms: Isometric Contraction/physiology*; Muscle Contraction/physiology*; Muscle, Skeletal/physiology; Hand Strength/physiology*
  20. Zuha RM, Omar B
    Parasitol Res, 2014 Jun;113(6):2285-94.
    PMID: 24728523 DOI: 10.1007/s00436-014-3883-z
    Cosmopolitan scuttle fly, Megaselia scalaris (Loew) (Diptera: Phoridae) is one of the commonest forensic species recorded colonizing human corpse indoors and in concealed environment. The occurrence of this species in such environments provides a higher evidential value to assist estimation of postmortem interval (PMI) compared to other forensically important dipterans. However, developmental and size data of M. scalaris are still lacking and they are derived from a limited range of thermal values. The objective of this study is to develop the growth model of M. scalaris by emphasizing the size range of larvae and puparia at different constant temperatures. This species was reared in six replicates at eight varying constant temperatures ranging from 23 to 36 °C and cow's liver was provided as food source. Larvae and puparia were sampled at set time intervals and measured by their length and weight. Because interpretation of forensic entomological evidence is subject to application of different techniques, development of M. scalaris is expressed herein by using developmental table, length/morphological stage diagrams and linear/nonlinear estimation methods. From the findings, it is very important to highlight that sexual dimorphism of M. scalaris during post feeding larva and pupa stage could be observed based on size and developmental periods. Mean length and weight ratios of male to female puparia are approximately 0.8 and 0.3-0.5, respectively, indicating sexual dimorphism of this species. Developmental period in female are 4.0-11.4 h (post feeding larval stage), 3.7-24.0 h (pupal stage), and 3.0-20.1 h (total developmental period) longer in male. Due to this dimorphism, PMI estimation using M. scalaris post feeding larva or puparium specimens must be carried out carefully by to avoid inaccuracy and misinterpretation.
    Matched MeSH terms: Diptera/physiology; Larva/physiology; Ovum/physiology; Pupa/physiology
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