CC BY
36
UDK 611.738.3
K.J. van Zwieten a, F.H.M. Narain a, S. De Munter a, L. Kosten a, K.S. Lamur b, K.P. Schmidta, P.L. Lippens a, I.A. Zubovac, O.E. Piskunc, S.A. Varzin c
ANALYZING PACE FREQUENCIES IN BIPEDAL PRIMATES AND PRIMATE "PREDECESSORS" REVEALS MECHANISMS THAT REGULATE FOOT INVERSION AND THUS ENSURE FOOT STABILITY AT TOUCHDOWN
a University of Hasselt, Diepenbeek, Belgium, b Anton-de-Kom University of Suriname, Paramaribo, Suriname, c Peter-the-Great St. Petersburg Polytechnic University, St. Petersburg, Russia koosjaap.vanzwieten@uhasselt.be
Introduction and hypothesis: The characteristic high-pitched sounds of unintentional lateral foot-shuffling along the ground during the swing phase of gait have been recognized as almost pathognomonic signs of fatigue in lower leg and foot evertor muscles in the early stages of Multiple Sclerosis (MS) [1]. MS patients diagnosed in the early stages of the disease encounter several ominous events like tripping and falling. Recovery from foot inversion at toe-off and during the swing phase by lower leg internal rotation as well as stabilization of foot inversion after touchdown by subsequent foot eversion are affected. Inversion is defined as turning the sole of the foot inward, foot eversion is turning the sole outward. In order to explore the key features of this phenomenon extensive investigation is worthwhile. Studying normal functional morphology of the lower leg, particularly in primates (humans included) plus predecessors, may enlighten the evolutionary path leading to this phenomenon. Recent literature shows that in walking bipedally, various arboreal New World primate species use a "forefoot first" strategy, after which heel contact occurs [2]. A similar walking scenario is seen in arboreal New World marsupials like the opossum, a quadrupedal primate "predecessor". In opossum walking, halfway its swing (recovery)-phase, a rapid eversion of the highly inverted foot occurs thus moving the foot forward to proceed to the next touchdown in the inverted position [3]. We therefore hypothesized that those quadrupedal marsupials which are mainly or exclusively terrestrial like e.g., wombats, will also display rapid foot eversion during recovery. However, while lower leg rotational mechanisms in wombats are well-described [4], currently "no detailed analyses of wombat locomotion have been carried out. (...) Wombats are plantigrade, walking on the soles of their feet with three distinct gaits, walk, trot and bound" [5].
Material and methods: Various semi-domesticated fully terrestrial Vombatus ursinus (common wombats) were videotaped (November 2013) before dusk, walking in their natural environments at Cradle Mountain Road (C132), Cradle Mountain, Tasmania. Following current guidelines, we took utmost care to leave all animals undisturbed [6]. Posterior and lateral views were analyzed frame by frame. Observational results: Average wombat walking speed is about 2,5 km/h, with hind-limb pace frequencies of about 1 Hz. In man, this is : 0,25 Hz (walking) - 2,5 Hz (running) [3]. Wombat toe-off (Fig. 1) shows inversion of the foot, coupled to shank external rotation (Fig. 2). Halfway recovery, rapid eversion of the foot occurs, coupled to shank internal rotation. Surprisingly, at touchdown a "forefoot first" position was neither observed nor captured. Instead the wombat recovery phase apparently ends with a heel-strike (Fig. 3, red arrowhead) of about 0,05 Hz, immediately followed by a rapid inverted forefoot placement. Nevertheless, the shape of the foot and long foot nails [5] may obstruct proper forefoot landing. Heel-strikes are currently only seen in terrestrial primates, including humans [7]. To our knowledge, until now, heel-strike as a characteristic in Vombatus ursinus walking gait has never been reported.
Conclusion: Marsupials such as wombats, though being exclusively quadrupedal and non-arboreal, show basically the same strategies of foot eversion to ensure safe touchdown as bipedally walking arboreal New World primate species [2], with morphologically guided adjustments. Meanwhile, terrestriality per se in these primate "predecessors" may have influenced adopting a prehuman-like heel-strike. Analyzing this hopefully helps to understand gait training problems in patients too. Acknowledgements: The authors gratefully acknowledge Jikke van Osnabrugge, PT for making the videos.
References.
1. van Zwieten KJ, Narain FHM, Kosten L, Wens I, Eijnde BO, Vandersteen M, Schmidt KP (2013) Reappraisal of gait patterns in minimally impaired Multiple Sclerosis patients reveals characteristic foot shuffling sounds. International Sound and Vibration Digest, 14, 1, 5-6.
2. Schmitt D, Larson SG (1995) Heel contact as a function of substrate type and speed in primates. American Journal of Physical Anthropology, 96, 1, 39-50.
3. Narain FHM (2013) Foot inversion and eversion in stance and swing of the gait cycle of the hind limb of the opossum (Didelphis marsupialis) - some comparative-anatomical and functional-morphological aspects. PhD Thesis, University of Hasselt, Belgium.
4. Home E (1808) An account of some peculiarities in the anatomical structure of the wombat. Philosophical Transactions of the Royal Society, 98, 2, 304-312.
5. Wells RT (1989) Vombatidae. In Fauna of Australia. Vol. 1B, Mammalia, 32, AGPS, Canberra.
6. Dennis L, Rolls K, Fowler A, Dineen A-M (2010) A Guide to the Care of Bare-Nosed Wombats (Vombatus ursinus) Version 3. Fourth Crossing Wildlife, www.fourthcrossingwildlife.com
7. Hanna JB, Schmitt D (2011) Comparative triceps surae morphology in primates: a review. Hindawi Publishing Corporation, Anatomy Research International, Article ID 191509, 1-22.
Zheng Yuanyuan
THE EFFECT OF NOD8 ON PRODUCTION OF NO, TNF-a AND IL-1P IN LPS-TREATED MACROPHAGES12
Цзинанъский университет, город Гуанъчжоу
[ABSTRACT] AIM: To investigate the effect of NOD8 on lipopolysaccharide (LPS) -induced releases of nitricoxide (NO), tumor necrosis factor a (TNF-a) and interleukin-1p (IL-1p) in RAW264. 7 cells. METHODS: The plas-mids of pEGFP-C2 and pEGFP-NOD8 were transfected into RAW264. 7 cells respectively. The transfected and non-trans-fected cells were stimulated by LPS for 0, 6, 12 and 24 h. NO production was evaluated by Griess reagent assay, and the levels of IL-1 p and TNF-a were measured by ELISA. The protein expression of NOD8 and the nuclear translocation of nu-clear factor kB (NF-kB) p65 subunit were detected by Western blotting. The level of activated caspase-1 was determined by fluorimetric method. RESULTS: Compared with pEGFP-C2 group, the protein expression of NOD8 was
12 NOD8 ^LPS |!®IlfflW&NO, TNF-afPIL-1p
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