2014-2015 Open Access Publishing Fund
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Item Open Access Prognostic factor from MR spectroscopy in rat with astrocytic tumour during radiation therapy(2014-11-27) Yu, T G; Feng, Y; Feng, XY; Dai, J Z; Huang, ZhibinObjective: To investigate the relationship between the tumour volume and metabolic rates of astrocytic tumours using MR spectroscopy (MRS) during radiation therapy (RT). Methods: 12 healthy male Sprague-Dawley® rats (Sprague–Dawley Animal Company, Madison, WI) were used, and a tumour model was created through injecting C6 tumour cells into the right caudate nuclei of the rats. Tumours grew for 18 days after the injection and before the imaging study and radiation treatment. MRS was performed with two-dimensional multivoxel point-resolved spectroscopy sequence using a GE Signa VH/i 3.0-T MR scanner (GE Healthcare, Milwaukee, WI) equipped with rat-special coil. RT was given on the 19th day with a dose of 4 Gy in one single fraction. The image examinations were performed before RT, and on the 4th, 10th, 14th and 20th days after treatment, respectively. GE FuncTool software package (GE Healthcare) was used for post-processing of spectrum. Results: Metabolic ratios of serial MRS decrease progressively with time after RT. Choline-containing components (Cho)/creatine and creatine phosphate (Cr) ratios immediately prior to RT differed significantly from those on the 10th, 14th and 20th days after RT; both Cho/N-acetyl aspartate (NAA) ratios and NAA/Cr ratios immediately prior to RT differed significantly from those on the 14th and 20th days after RT. A positive correlation between changes of tumour volume and changes of Cho/Cr, lipid and lactate/Cr and glutamate plus glutamine/Cr ratio was observed on the 4th day after RT. Conclusion: MRS provides potential in monitoring tumour response during RT, and the imaging biomarkers predict the response of astrocytic tumours to treatment. Advances in knowledge: MRS is combined with both tumour size and Ki-67 labelling index to access tumour response to radiation.Item Open Access Osteomyelitis Infection of Mycobacterium marinum: A Case Report and Literature Review(2014-12) Nguyen, Hao H.; Fadul, Nada; Ashraf, Muhammad S.; Siraj, Dawd S.Mycobacterium marinum (M. marinum) is a ubiquitous waterborne organism that grows optimally at temperatures around 30°C. It is a nontuberculous Mycobacterium found in nonchlorinated water with worldwide prevalence. It is the most common atypical Mycobacterium that causes opportunistic infection in humans. M. marinum can cause superficial infections and localized invasive infections in humans, with the hands being the sites most frequently affected. It can cause skin lesions, which are either single, papulonodular lesions, confined to an extremity, or may resemble cutaneous sporotrichosis. This infection can also cause deeper infections including tenosynovitis, bursitis, arthritis, and osteomyelitis. Disseminated infections and visceral involvements have been reported in immunocompromised patients. We here report a case of severe deep soft tissue infection with necrotizing fasciitis and osteomyelitis of the left upper extremity (LUE) caused by M. marinum in an immunocompromised patient.Item Open Access The dicer-like1 Homolog fuzzy tassel Is Required for the Regulation of Meristem Determinacy in the Inflorescence and Vegetative Growth in Maize(2014-12) Thompson, Beth E.; Basham, Christine Elizabeth; Hammond, Reza; Ding, Queying; Kakranan, Atul; Lee, Tzuz-Fen; Simon, Stacey A.; Meeley, Robert; Meyers, Blake C.; Hake, SarahPlant architecture is determined by meristems that initiate leaves during vegetative development and flowers during reproductive development. Maize (Zea mays) inflorescences are patterned by a series of branching events, culminating in floral meristems that produce sexual organs. The maize fuzzy tassel (fzt) mutant has striking inflorescence defects with indeterminate meristems, fasciation, and alterations in sex determination. fzt plants have dramatically reduced plant height and shorter, narrower leaves with leaf polarity and phase change defects. We positionally cloned fzt and discovered that it contains a mutation in a dicer-like1 homolog, a key enzyme required for microRNA (miRNA) biogenesis. miRNAs are small noncoding RNAs that reduce target mRNA levels and are key regulators of plant development and physiology. Small RNA sequencing analysis showed that most miRNAs are moderately reduced in fzt plants and a few miRNAs are dramatically reduced. Some aspects of the fzt phenotype can be explained by reduced levels of known miRNAs, including miRNAs that influence meristem determinacy, phase change, and leaf polarity. miRNAs responsible for other aspects of the fzt phenotype are unknown and likely to be those miRNAs most severely reduced in fzt mutants. The fzt mutation provides a tool to link specific miRNAs and targets to discrete phenotypes and developmental roles.Item Open Access The evolution of photosynthesis in chromist algae through serial endosymbioses(2014-12-10) Stiller, John W.; Schreiber, John; Yue, Jipei; Hui, Guo; Ding, Qin; Huang, JinlingChromist algae include diverse photosynthetic organisms of great ecological and social importance. Despite vigorous research efforts, a clear understanding of how various chromists acquired photosynthetic organelles has been complicated by conflicting phylogenetic results, along with an undetermined number and pattern of endosymbioses, and the horizontal movement of genes that accompany them. We apply novel statistical approaches to assess impacts of endosymbiotic gene transfer on three principal chromist groups at the heart of long-standing controversies. Our results provide robust support for acquisitions of photosynthesis through serial endosymbioses, beginning with the adoption of a red alga by cryptophytes, then a cryptophyte by the ancestor of ochrophytes, and finally an ochrophyte by the ancestor of haptophytes. Resolution of how chromist algae are related through endosymbioses provides a framework for unravelling the further reticulate history of red algal-derived plastids, and for clarifying evolutionary processes that gave rise to eukaryotic photosynthetic diversity.Item Open Access Nicotine exposure and transgenerational impact: a prospective study on small regulatory microRNAs(2014-12-17) Taki, Faten A.; Pan, Xiaoping; Lee, Myon-Hee; Zhang, BaohongEarly developmental stages are highly sensitive to stress and it has been reported that pre-conditioning with tobacco smoking during adolescence predisposes those youngsters to become smokers as adults. However, the molecular mechanisms of nicotine-induced transgenerational consequences are unknown. In this study, we genome-widely investigated the impact of nicotine exposure on small regulatory microRNAs (miRNAs) and its implication on health disorders at a transgenerational aspect. Our results demonstrate that nicotine exposure, even at the low dose, affected the global expression profiles of miRNAs not only in the treated worms (F0 parent generation) but also in two subsequent generations (F1 and F2, children and grandchildren). Some miRNAs were commonly affected by nicotine across two or more generations while others were specific to one. The general miRNA patterns followed a “two-hit” model as a function of nicotine exposure and abstinence. Target prediction and pathway enrichment analyses showed daf-4, daf-1, fos-1, cmk-1, and unc-30 to be potential effectors of nicotine addiction. These genes are involved in physiological states and phenotypes that paralleled previously published nicotine induced behavior. Our study offered new insights and further awareness on the transgenerational effects of nicotine exposed during the vulnerable post-embryonic stages, and identified new biomarkers for nicotine addiction.Item Open Access The evolution of photosynthesis in chromist algae through serial endosymbioses(2014-12-10) Stiller, John W.; Schreiber, John; Yue, Jipei; Hui, Guo; Ding, Qin; Huang, JinlingChromist algae include diverse photosynthetic organisms of great ecological and social importance. Despite vigorous research efforts, a clear understanding of how various chromists acquired photosynthetic organelles has been complicated by conflicting phylogenetic results, along with an undetermined number and pattern of endosymbioses, and the horizontal movement of genes that accompany them. We apply novel statistical approaches to assess impacts of endosymbiotic gene transfer on three principal chromist groups at the heart of long-standing controversies. Our results provide robust support for acquisitions of photosynthesis through serial endosymbioses, beginning with the adoption of a red alga by cryptophytes, then a cryptophyte by the ancestor of ochrophytes, and finally an ochrophyte by the ancestor of haptophytes. Resolution of how chromist algae are related through endosymbioses provides a framework for unravelling the further reticulate history of red algal-derived plastids, and for clarifying evolutionary processes that gave rise to eukaryotic photosynthetic diversity.Item Open Access Lexical diversity in Parkinson’s disease(2015-03-02) Ellis, Charles; Holt, Yolanda F; West, ThomasBackground: Parkinson’s disease (PD) is a neurodegenerative syndrome of the basal ganglia (BG) believed to disrupt cortical-subcortical pathways critical to motor, cognitive and expressive language function. Recent studies have shown subtle deficits in expressive language performance among individuals with PD even in the earliest stage of the disease. The objective of this study was to use measures of lexical diversity to examine expressive language performance during discourse production in a sample of individuals with PD. Methods: Twelve individuals with idiopathic Parkinson’s disease (PD) were compared to twelve matched, neurologically intact controls on measures of lexical diversity. Three minute discourse samples describing a typical day were collected and analyzed for lexical diversity with the CHILDES program using measures of type token ratio (TTR) and voc-D (D). Results: Comparisons of three minute discourse samples indicated non-significant differences between individuals with PD and controls in word productivity (387 vs 356; p = .48). Similarly, there were also non-significant differences on measures of lexical diversity between the two groups (TTR = .45 vs.44; p = .50 and D 74 vs 68; p = .23). Conclusions: These results suggest that lexical diversity during discourse production among individuals with PD is similar to non-neurological controls. These findings indicate that lexical diversity is an aspect of expressive language performance that is not impacted by the disease process in the earliest stages.Item Open Access Drosophila Oocytes as a Model for Understanding Meiosis: An Educational Primer to Accompany “Corolla Is a Novel Protein That Contributes to the Architecture of the Synaptonemal Complex of Drosophila”(2015-01) Ables, Elizabeth TweedieAchieving a thorough understanding of the events and ramifications of meiosis is a common learning objective for undergraduate introductory biology, genetics, and cell biology courses. Meiosis is also one of the most challenging cellular processes for students to conceptualize. Connecting textbook descriptions of meiosis to current research in the field of genetics in a problem-based learning format may aid students’ understanding of this important biological concept. This primer seeks to assist students and instructors by providing an introductory framework upon which to integrate discussions of current meiosis research into traditional genetics or cell biology curriculum.Item Open Access Circadian influences on myocardial infarction(2014-10-30) Virag, Jitka A. I.; Lust, Robert M.Components of circadian rhythm maintenance, or “clock genes,” are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations.Item Restricted Conspicuous female ornamentation and male mate preference of Threespine Sticklebacks (Gasterosteus aculeatus)(East Carolina University, 2012) Wright, Daniel ShaneSexual selection drives the evolution of exaggerated male ornaments (traits showing little function outside social interactions) in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on females has been little studied. Moreover, in those species in which female ornaments have been examined, research has often been limited to a single trait. Ornamented female threespine sticklebacks provide an excellent opportunity to examine male preference on multiple traits and the correlations between those traits. Using a combination of sequential and simultaneous mate choice trials, male-mating preferences for female throat color (as well as other traits) is examined using wild-captured male and female threespine sticklebacks from the Little Campbell River, British Columbia. In sequential and simultaneous choice tests, males do not exhibit a preference for female throat and pelvic spine color. Surprisingly, males also lack a preference for female standard length. Using mixed modeling, males were tested for differences in the slopes of their preferences for female traits and their mean responsiveness. Results showed that males did not differ in their preference slopes but differed significantly in their mean responsiveness to females. Additionally, when presented with a conspecific male in sequential choice tests, males responded differently than to females and male response decreased as conspecific male body size and throat coloration increased, showing that males can discriminate conspecific traits in the experimental setting. Mean response rates of experimental males toward females had significant, positive correlations with individual throat and pelvic spine coloration, as well as overall male condition. Male condition, however, lacks any correlation with throat or spine coloration. The results presented here are the first to explicitly address male preference for female throat color as well as documenting the relationship between male pelvic spine color and responsiveness.