Evolutionary Patterns in the Dentition of Duplicidentata (Mammalia) and a Novel Trend in the Molarization of Premolars

The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone, metacone, amphicone, or an entirely new cusp.Here we present newly described fossil duplicidentates (Lagomorpha and Mimotonidae) in the context of a well-constrained phylogeny to establish a nomenclatural system for cusps based on the tribosphenic pattern. We show that the central cusp of lagomorphs is homologous with the metaconule of other mammals. We also show that the buccal acquisition of a second cusp on the premolars (molarization) within duplicidentates is atypical with respect to other mammalian lineages; within the earliest lagomorphs, a second buccal cusp is added mesially to an isolated buccal cusp.The distal shift of the ‘ancestral’ paracone within early duplicidentates amounts to the changing of a paracone into a metacone in these lineages. For this reason, we support a strictly topological approach to cusp names, and suggest a discontinuity in nomenclature to capture the complexity of the interplay between evolutionary history and the developmental process that have produced cusp patterns in duplicidentates

New symmetrodont

20 p. : ill. ; 26 cm.Includes bibliographical references (p. 18-20).Symmetrodonts are Mesozoic mammals having lower molars with nearly symmetrical trigonids but lacking talonids. They appear to be stem members of the mammalian clade that led to extant tribosphenic mammals, but the fossil record of symmetrodonts is poor. Here we report a new genus and species of an acute-angled spalacotheriid symmetrodont, Heishanlestes changi, n.gen. and n.sp., represented by well-preserved lower jaws with teeth from the early Cretaceous of northeastern China. The new mammal has four tightly spaced premolars and three morphological groups of lower molars, in which the first molar has an obtuse trigonid angle and the last two molars have a large neomorphic cusp in the center of the trigonid, a feature not seen in other mammals. Heishanlestes appears to be a specialized member of the spalacotheriid subfamily, Spalacolestinae, which is otherwise only known from North America. The animal probably used the premolars to crush its prey before shearing it with the molars

Relationship among the Expression of Lymphatic Vessel Density, Microvessel Density, Carcinoembryonic Antigenic mRNA, KAI1, and Kiss-1, and Prognosis in Patients with Non-small Cell Lung Cancer

Background and objective In recent years, many studies have revealed the prognosis in patients with non-small cell lung cancer (NSCLC). In general, some clinic-pathological parameters have been related with prognosis. The aim of this study is to detect the relationship among lymphatic vessel density (LVD), microvessel density (MVD), expression of carcinoembryonic antigen (CEA) mRNA, metastasis suppressor genes (KAI1 and Kiss-1), and the prognosis of NSCLC patients. Methods Blood samples were collected from 57 cases of NSCLC. The transcription of CEA mRNA was detected via nested reverse transcriptase-polymerase chain reaction and micro-fluid chip. Immunohistochemistry was performed to detect the expression of LVD, MVD, KAI1 and Kiss-1 in the patients. All follow-up data were collected and analyzed. Results The overall five-year survival rate was 18%, and the median survival was 34 months. TNM stage, lymph node metastasis, and expression of MVD, LVD, CEA mRNA and Kiss-1 were factors to survival, as determined via single survival analysis. Multivariate analysis demonstrated that TNM stage, lymph node metastasis, and expression of CEA mRNA were independent prognostic factors for NSCLC patients. Conclusion The expression of MVD, LVD, Kiss-1 and CEA mRNA is related to the prognosis of NSCLC

Comparison of Fine Needle Aspiration and Fine Needle Nonaspiration Cytology of Thyroid Nodules: A Meta-Analysis

Background. Fine needle aspiration cytology (FNAC) and fine needle nonaspiration cytology (FNNAC) are useful cost-effective techniques for preoperatively assessing thyroid lesions. Both techniques have advantages and disadvantages, and there is controversy over which method is superior. This meta-analysis was performed to evaluate the differences between FNAC and FNNAC for diagnosis of thyroid nodules. Methods. Primary publications were independently collected by two reviewers from PubMed, Web of Science, Google Scholar, EBSCO, OALib, and the Cochrane Library databases. The following search terms were used: fine needle, aspiration, capillary, nonaspiration, sampling without aspiration, thyroid, and cytology. The last search was performed on February 1, 2015. Results. Sixteen studies comprising 1,842 patients and 2,221 samples were included in this study. No statistically significant difference was observed between FNAC and FNNAC groups with respect to diagnostically inadequate smears, diagnostically superior smears, diagnostic performance (accuracy, sensitivity, specificity, negative predictive value, and positive predictive value), area under the summary receiver operating characteristic curve, average score of each parameter (background blood or clot, amount of cellular material, degree of cellular degeneration, degree of cellular trauma, and retention of appropriate architecture), and total score of five parameters. Conclusion. FNAC and FNNAC are equally useful in assessing thyroid nodules

SEMs of fossil duplicidentates that show the presence (sometimes, incipiently) and absence of the paracone in premolars.

<p>All teeth shown buccal up, mesial to the left. A, P³ (IVPP V7499.2) and P³–M² (IVPP 7462) of <i>Dawsonolagus antiquus</i> showing the increased development of the second buccal cusp in the distal dentition. B, P³ and P⁴ of <i>Desmatolagus gobiensis</i> (AMNH 83703) showing the absence of a paracone on P³, but presence on P⁴. C, and Isolated P³ of <i>D. gobiensis</i> (AMNH 83689) showing a minor, atypical, mesiobuccal cusp in the position of the paracone.</p