We report here for the first time that 5 red-tide dinoflagellates (Gymnodinium catenatum, G. impudicum, Lingulodinium polyedrum, Prorocentrum donghaiense, and P. triestinum) which had been previously thought to be exclusively autotrophic dinoflagellates are mixotrophic species. We investigated the feeding behaviors, the kinds of prey species that 11 mixotrophic red-tide dinoflagellates (Akashiwo sanguinea, Alexandrium tamarense, G. catenatum, G. impudicum, Heterocapsa triquetra, L. polyedrum, P. donghaiense, P. micans, P. minimum, P. triestinum, and Scrippsiella trochoidea) fed on, and the effects of the prey concentration on the growth and ingestion rates of P. donghaiense, H. triquetra, P. micans, and L. polyedrum when feeding on algal prey. We have also calculated grazing coefficients by combining field data on abundances of P. donghaiense, H. triquetra, P. micans, and L. polyedrum and co-occurring prey species. All algal predators tested in the present study ingested small phytoplankton species that had equivalent spherical diameters (ESDs) < 12 μm. A. sanguinea and L. polyedrum were able to ingest large phytoplankton species such as H. triquetra, S. trochoidea, and A. tamarense. Prorocentrum spp. fed on prey by engulfing the prey cell through body sutures, while S. trochoidea engulfed prey through the apical horn as well as through the sulcus. Specific growth rates of P. donghaiense, H. triquetra, and P. micans on a cryptophyte and L. polyedrum on P. minimum and S. trochoidea increased with increasing mean prey concentration, with saturation occurring at mean prey concentrations of 110 to 480 ng C ml , respectively. Maximum ingestion rates of P. donghaiense, H. triquetra, and P. micans on the cryptophyte were much lower than those of L. polyedrum on S. trochoidea and P. minimum. The calculated grazing coefficients of P. donghaiense, H. triquetra, and P. micans on the cryptophyte were up to 2.67, 0.091, and 0.041 h
Under careful case selection, BTX-A may be an effective treatment alternative for patients with excessive gingival display caused by hyperactive lip elevator muscles.
BRIEF SUMMARYCurrent Knowledge/Study Rationale: Botulinum toxin type A (BoNT-A) has been used for managing involuntary orofacial movements and secondary bruxism in patients with movement disorders, but its usefulness and objective effects on sleep bruxism (SB) have not been evaluated using objective measures. The aim of this study was to investigate the effects of intramuscular BoNT-A injection on orofacial motor events during sleep in patients with clinical diagnosis of SB. Study Impact: A single injection of BoNT-A into jaw-closing muscles is an effective strategy for controlling SB for at least a month. It reduces the intensity rather than the generation of the contraction in the jaw-closing muscles. Establishing management of SB with BoNT-A awaits further studies on larger samples over a longer follow-up period. Medicine, Vol. 10, No. 3, 2014 YJ Shim, MK Lee, T Kato et al equally effective in pain reduction when compared with oral splint. 17,18 The result of these studies and case reports were based on the subjective evaluation of SB, not on the objective assessment using electromyography (EMG) or polysomnography (PSG). A study using portable electromyographic (EMG) device showed that the counts of sleep related masticatory EMG bursts, detected by the pre-defined threshold, were significantly reduced after a single injection of BoNT-A in the masseter muscle. 19 However, it remains unclear how BoNT-A injection works specifically for sleep-related masticatory EMG activity, as a variety of jaw motor activities occur in association with transient arousal changes during sleep. 20 Video-polysomnography (vPSG) can be a useful tool allowing discrimination of the types of sleep-related masticatory EMG events. 2 In previous case reports and studies, some cases injected BoNT-A into the masseter muscle only, [13][14][15]17,18 and others into both the masseter and temporalis muscles. 10,11,15 The masseter and temporalis muscles are synergetic muscles and activated during teeth grinding and clenching; however, there have been no studies assessing the difference between the choices or the combination of the injected muscles for motor activity control of the jaw during sleep. 292 Journal of Clinical SleepTherefore, the aims of this study were to investigate the effects of intramuscular BoNT-A injection on jaw motor episodes using vPSG. In addition to the use of vPSG, we compared the effects of BoNT-A on jaw motor episodes between the injection sites (i.e., the masseter muscle injection only versus injection of both masseter and temporalis muscles). METHODS SubjectsThe protocol of this study was undertaken with the approval of Korea Food & Drug Administration and Institutional Review Board of the Yonsei University Dental Hospital. All subjects were informed of the nature of the study, and written consent was obtained from each participant.Twenty-four subjects (M: 10; F: 14, age: 20.2-38.7 years) were selected from among outpatients at the Department of Orofacial Pain and Oral Medicine, Yonsei University Dental Hospital. A...
We investigated growth rates, grazing rates, and prey selection of Polykrikos kofoidii when feeding on several species of red-tide and/or toxic dinoflagellates. Polykrikos kofoidii ingested all prey species used in this study, exhibiting positive growth on Lingulodinium polyedrum, Scrippsiella trochoidea, Ceratium furca, Gymnodinium catenatum, Gyrodinium impudicum, Prorocentrum micans, and the toxic dinoflagellate Amphidinium carterae, but not on P. minimum. Specific growth rates of P. kofoidii increased rapidly with increasing density of L. polyedrum, S. trochoidea, C. furca, and G. catenatum before saturating between 500-2,000 ng C ml(-1). Specific growth rates increased continuously when P. kofoidii was fed the other prey species. Maximum specific growth rates of P. kofoidii on G. catenatum (1.12 d(-1)), S. trochoidea (0.97 d(-1)), and L. polyedrum (0.83 d(-1)) were higher than those on C. furca (0.35 d(-1)), A. carterae (0.10 d(-1)), P. micans (0.06 d(-1)), G. impudicum (0.06 d(-1)), and P. minimum (-0.03 d(-1)). Threshold prey concentrations (where net growth = 0) were 54-288 ng C ml(-1). Maximum ingestion and clearance rates of P. kofoidii on these dinoflagellates were 5-24 ng C pseudocolony(-1) d(-1) and 1.0-5.9 microl pseudocolony(-1) h(-1), respectively. Polykrikos kofoidii strongly selected L. polyedrum over S. trochoidea in prey mixtures. Polykrikos kofoidii exhibited higher maximum growth, ingestion, and clearance rates than previously reported for the mixotrophic dinoflagellate Fragilidium cf. mexicanum or the heterotrophic dinoflagellates Protoperidinium cf. divergens and P. crassipes, when grown on the same prey species. Grazing coefficients calculated by combining field data on abundances of Polykrikos spp. and co-occurring red-tide dinoflagellate prey with laboratory data on ingestion rates obtained in the present study suggest that Polykrikos spp. sometimes have a considerable grazing impact on prey populations.
As part of the development of a method to control the outbreak and persistence of red tides using mass-cultured heterotrophic protist grazers, we measured the growth and ingestion rates of cultured Oxyrrhis marina (a heterotrophic dinoflagellate) on cultured Heterosigma akashiwo (a raphidophyte) in bottles in the laboratory and in mesocosms (ca. 60 liter) in nature, and those of the cultured grazer on natural populations of the red-tide organism in mesocosms set up in nature. In the bottle incubation, specific growth rates of O. marina increased rapidly with increasing concentration of cultured prey up to ca. 950 ng C ml(-1) (equivalent to 9,500 cells ml(-1)), but were saturated at higher concentrations. Maximum specific growth rate (mumax), KGR (prey concentration sustaining 0.5 mumax) and threshold prey concentration of O. marina on H. akashiwo were 1.43 d(-1), 104 ng C ml(-1), and 8.0 ng C ml(-1), respectively. Maximum ingestion and clearance rates of O. marina were 1.27 ng C grazer(-1) d(-1) and 0.3 microl grazer(-1) h(-1), respectively. Cultured O. marina grew well effectively reducing cultured and natural populations of H. akashiwo down to a very low concentration within 3 d in the mesocosms. The growth and ingestion rates of cultured O. marina on natural populations of H. akashiwo in the mesocosms were 39% and 40%, respectively, of those calculated based on the results from the bottle incubation in the laboratory, while growth and ingestion rates of cultured O. marina on cultured H. akashiwo in the mesocosms were 55% and 36%, respectively. Calculated grazing impact by O. marina on natural populations of H. akashiwo suggests that O. marina cultured on a large scale could be used for controlling red tides by H. akashiwo near aquaculture farms that are located in small ponds, lagoons, semi-enclosed bays, and large land-aqua tanks to which fresh seawater should be frequently supplied.
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