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Initial Insights (initial + insight)
Selected AbstractsA Life Table for Psittacosaurus lujiatunensis: Initial Insights Into Ornithischian Dinosaur Population BiologyTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2009Gregory M. Erickson Abstract Very little is known about nonavian dinosaur population biology. Multi-individual sampling and longevity estimation using growth line counts can be used to construct life tables,the foundation for population analyses in ecology. Here we have determined the size and age distribution for a sample consisting of 80 individuals of the small ornithischian, Psittacosaurus lujiatunensis from the early Cretaceous Yixian Formation of China. Their ages ranged from less than a year to eleven years and the distribution was strongly right-skewed. This is consistent with taphonomic interpretations that these animals derive from a catastrophic death assemblage. The static life table analysis revealed the same general pattern of survivorship as tyrannosaurs including increased attrition before the attainment of full adult size. This may reflect increased physiological demands and/or predation exposure associated with reproduction. Collectively these findings suggest that most nonavian dinosaurs may have had a similar life history strategy. Anat Rec, 292:1514,1521, 2009. © 2009 Wiley-Liss, Inc. [source] Naturally occurring fatal herpes simplex virus 1 infection in a family of white-faced saki monkeys (Pithecia pithecia pithecia)JOURNAL OF MEDICAL PRIMATOLOGY, Issue 1 2003M.D. Schrenzel Abstract: A family of three white-faced saki monkeys (Pithecia pithecia pithecia) died 48,96 hours after the onset of anorexia, nasal discharge, pyrexia and oral ulceration. One animal also had clonic seizures. Lesions found post-mortem consisted of oral and esophageal ulcers, hepatic and intestinal necrosis, meningoencephalitis and sporadic neuronal necrosis. Intranuclear inclusion bodies and syncytial cells were present in oral lesions and affected areas of liver. Herpes simplex virus 1 (HSV-1) was identified as the etiology of disease by virus isolation, polymerase chain reaction, or in situ hybridization in all three animals. Immunohistochemistry for detection of apoptotic DNA and activated caspase-3 showed significant levels of apoptosis in oral and liver lesions and occasional apoptotic neurons in the brain. These findings demonstrate the vulnerability of white-faced saki monkeys to HSV-1 and provide initial insight into the pathogenesis of fatal HSV-1-induced disease, indicating that apoptosis plays a significant role in cell death. [source] Haspin-like proteins: A new family of evolutionarily conserved putative eukaryotic protein kinasesPROTEIN SCIENCE, Issue 8 2001Jonathan M.G. Higgins Abstract Haspin (haploid germ cell,specific nuclear protein kinase) is reported to be a serine/threonine kinase that may play a role in cell-cycle cessation and differentiation of haploid germ cells. In addition, Haspin mRNA can be detected in diploid cell lines and tissues. Here, Haspin-like proteins are identified in several major eukaryotic phyla,including yeasts, plants, flies, fish, and mammals,and an extended group in Caenorhabditis elegans. The Haspin-like proteins have a complete but divergent eukaryotic protein kinase domain sequence. Although clearly related to one another and to other eukaryotic protein kinases, the Haspin-related proteins lack conservation of a subset of residues that are almost invariant in known kinases and possess distinctive inserted regions. In fact, phylogenetic analysis indicates that the Haspin-like proteins form a novel eukaryotic protein kinase family distinct from those previously defined. The identification of related proteins in model organisms provides some initial insight into their functional properties and will provide new experimental avenues by which to determine the function of the Haspin proteins in mammalian cells. [source] Cholesterol and Kir channelsIUBMB LIFE, Issue 8 2009Irena Levitan Abstract To date, most of the major types of Kir channels, Kir2s, Kir3s, Kir4s, and Kir6s, have been found to partition into cholesterol-rich membrane domains and/or to be regulated by changes in the level of membrane cholesterol. Surprisingly, however, in spite of the structural similarities between different Kirs, effects of cholesterol on different types of Kir channels vary from cholesterol-induced decrease in the current density (Kir2 channels) to the loss of channel activity by cholesterol depletion (Kir4 channels) and loss of channel coupling by different mediators (Kir3 and Kir6 channels). Recently, we have gained initial insights into the mechanisms responsible for cholesterol-induced suppression Kir2 channels, but mechanisms underlying cholesterol sensitivity of other Kir channels are mostly unknown. The goal of this review is to present a summary of the current knowledge of the distinct effects of cholesterol on different types of Kir channels in vitro and in vivo. © 2009 IUBMB IUBMB Life 61(8): 781,790, 2009 [source] The leptin receptor system of human plateletsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2005G. GIANDOMENICO Summary., Obesity is associated with elevated levels of leptin in the blood. Elevated leptin is a risk factor for thrombosis in humans, and leptin administration promotes platelet activation and thrombosis in the mouse. The current study examines the effect of leptin on human platelets, and provides initial insights into the nature of the leptin receptor on these platelets. Leptin potentiated the aggregation of human platelets induced by low concentrations of ADP, collagen and epinephrine. However, the response varied significantly between donors, with platelets from some donors (approximately 40%) consistently responding to leptin (responders) and those from other donors (approximately 60%) never responding (non-responders). Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) experiments showed that platelets from both groups only express the signaling form of the leptin receptor, and that responder platelets express higher levels of this receptor than non-responders. Ligand-binding assays demonstrate specific, saturable binding of leptin to platelets from both groups with apparent Kd values of 76 ± 20 nm for responders and 158 ± 46 nm for non-responders. Thus, the decreased sensitivity of non-responder platelets to leptin does not result from the absence of the signaling form of this receptor, but may reflect differences in its level of expression and/or affinity for leptin. These preliminary studies demonstrate that platelets are a major source of leptin receptor in the circulation, and suggest that leptin-responsive individuals may have a higher risk for obesity-associated thrombosis than non-responsive individuals. [source] Gene Expression during Formation of Earlywood and Latewood in Loblolly Pine: Expression Profiles of 350 GenesPLANT BIOLOGY, Issue 6 2004U. Egertsdotter Abstract: The natural variability of wood formation in trees affords opportunities to correlate transcript profiles with the resulting wood properties. We have used cDNA microarrays to study transcript abundance in developing secondary xylem of loblolly pine (Pinus taeda) over a growing season. The cDNAs were selected from a collection of 75 000 ESTs that have been sequenced and annotated (http:web.ahc.umn.edubiodatansfpine). Cell wall thickness and climatic data were related to earlywood and latewood formation at different time points during the growing season. Seventy-one ESTs showed preferential expression in earlywood or latewood, including 23 genes with no significant similarity to genes in GenBank. Seven genes involved in lignin synthesis were preferentially expressed in latewood. The studies have provided initial insights into the variation of expression patterns of some of the genes related to the wood formation process. [source] Riding The Ciliate Cell Cycle,A Thirty-Five-Year Prospective,THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 5 2001JAMES D. BERGER ABSTRACT. Studies of the ciliate cell cycle have moved from early examination of its biochemistry with heat-synchronized Tetra-hymena through descriptive studies of Paramecium using small synchronous cell samples. These studies described what happens during the cell cycle and provided some initial insights into control, especially the idea that there was a point at which cells became committed to division. This early work was followed by an analytical phase in which the same small sample techniques, combined with gene mutations, were used to tease apart some major features of the regulation of cell growth kinetics, including regulation of macronuclear DNA content and regulation of cell size, the control of timing of initiation of macronuclear DNA synthesis, and the control of commitment to division in Paramecium. The availability of new molecular genetic approaches and new means of manipulating cells en masse made it possible to map out some of the basic features of the molecular biology of cell cycle regulation in ciliates. The challenge before us is to move beyond the ,me-too-ism' of validating the presence of basic molecular regulative machinery underlying the cell cycle in ciliates to a deeper analysis of the role of specific molecules in processes unique to ciliates or to analysis of the role of regulatory molecules in the control of cell process that can be uniquely well studied in ciliates. [source] | |||||||||||||