Nearly 70% of the 535 species of salamanders in the world are members of a single family, the Plethodontidae, or lungless salamanders. The centre of diversity for this clade is North and Middle America, where the vast majority (99%) of species are found. We report the discovery of the first Asian plethodontid salamander, from montane woodlands in southwestern Korea. The new species superficially resembles members of North American genera, in particular the morphologically conservative genus Plethodon. However, phylogenetic analysis of the nuclear encoded gene Rag-1 shows the new taxon to be widely divergent from Plethodon. The new salamander differs osteologically from putative relatives, especially with respect to the tongue (attached protrusible) and the derived tarsus. We place the species in a new genus on the basis of the morphological and molecular data. The distribution of the new salamander adds to the enigma of Old World plethodontids, which are otherwise restricted to the western Mediterranean region, suggesting a more extensive past distribution of the family.
Stable poly(methyl methacrylate-co-divinylbenzene) (poly(MMA-co-DVB)) microspheres were prepared by precipitation polymerization using acetonitrile as the main medium under various polymerization conditions, including modifications of the agitation speed, monomer and initiator concentrations, DVB content in the monomer mixture, and the use of various cosolvents. Gentle agitation was required to obtain smooth spherical particles. The individually stable microspheres were obtained at monomer concentrations of up to 15 vol% in an acetonitrile medium. The number-average diameter increased linearly with respect to increases in the monomer and initiator concentrations. We found, however, that the uniformity of the microspheres was independent of the variation of the polymerization ingredients because nuclei formation was solely influenced by the crosslinking reaction of the monomers. We obtained higher yields for the polymerization at higher concentrations of monomer and initiator. The concentration of DVB in the monomer mixture composition played an important role in determining not only the size of the microspheres but also the yield of the polymerization. In addition, although we employed various cosolvents as the polymerization medium, we found that acetonitrile/2-methoxyethanol was the only system that provided spherical particles without coagulation. This finding indicates that the precipitation polymerization is strongly dependent on the solvent used as the medium.
ObjectiveThis study evaluates the effect of the specific human papillomavirus (HPV) genotype as a prognostic factor in stage I-IIA cervical cancer patients following primary surgical treatment.MethodsThe medical records of 116 cervical cancer patients treated with primary surgical treatment were reviewed. The HPV genotypes were categorized into following groups: negative and unclassified, HPV 16, HPV 18, and other high risk (HPV 31, 33, 35, 45, 51, 52, 56, and 58).ResultsAmong the HPV genotypes, HPV 16 predominated (40.52%), followed by intermediate risk and unclassified (25%), HPV 18, 45, and 56 (17.24%) and negative (17.24%). In univariate analysis, HPV genotypes (P=0.03), parametrial spread (P=0.02), depth of invasion (DOI) (P<0.01) and lymph-vascular space invasion (P=0.02) were significantly associated with progression free survival (PFS). In multivariate analysis, HPV 18 (hazard ratio [HR], 5.2; 95% confidence interval [CI], 1.29 to 20.90; P=0.02) and ≥one half of DOI (HR, 5.4; 95% CI, 1.08 to 27.31; P=0.04) were significantly associated with PFS. HPV genotypes are not significantly associated with overall survival.ConclusionHPV 18 was a poor prognostic factor for the PFS in stage I-IIA cervical cancer patients following primary surgical treatment. Careful long-term observation and regular exams are recommended for cervical cancer patients with HPV 18 compared to those with other HPV genotypes.
We prepared thermally robust fully crosslinked poly(methyl methacrylate-co-divinyl benzene) [poly(MMAco-DVB)] microspheres successfully by precipitation polymerization in the absence of a stabilizing agent. The DVB concentration plays a pivotal role not only in the formation of the individually stable microspheres but also in the polymerization characteristics, including the particle size, the uniformity of size, the polymerization yield, and the thermal properties. The number-average diameter of the microspheres increased linearly, from 0.72 to 2.15 μm, and the particle size distribution became narrower, by elevating the uniformity from 1.35 to 1.12, as the DVB concentration increased from 20 to 75 mol%. In addition, the yield of the polymerization increased, from 73.4 to 98.6%, as the DVB concentration increased. Since the prepared particles possess fully crosslinked microstructures, no glass transition temperatures were observed, but all the samples prepared with DVB concentrations ranging from 20 to 75 mol% possess enhanced thermal properties. Based on the DSC and TGA data, the thermal stability of the microspheres prepared by the precipitation polymerization is significantly improved as a result of crosslinking with DVB.
Comparison of nucleotide sequences of mitochondrial cytochrome b gene among populations of the brown frog, Rana dybowskii, showed that the population from south Korea is very similar genetically to the Tsushima population and they are considered to be conspecific. The latter population is thought to have invaded Tsushima recently via the Korean Peninsula. These frogs, however, have sequences substantially different from those of the population from near the type locality, the Maritime Territory of Russia. Thus, the current taxonomic treatment to unify all populations into the single species (R. dybowskii) is genetically not supported.
The STAT4 RA-susceptibility haplotype identified in other previously reported populations has not been replicated in the Han Chinese population with individually matched case-control study design. It is associated only with the presence of RF in the Han Chinese population with RA disease.
Analyses of complete 1143-base pair sequence of the mitochondrial cytochrome b gene demonstrated a sister relationship between Japanese R. nigromaculata and Korean R. plancyichosenica, but not with Korean R. nigromaculata, while the allozyme data strongly supported the monophyly of the Korean and Japanese populations of R. nigromaculata. We surmise this discordance to be the result of the inheritance of introduced mtDNA and the dilution of introduced nuclear DNA in mixed lineages after past hybridization and genome introgression between the two species, although the direction of introgression is unknown.
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