Transcriptome analysis of air-breathing land slug, Incilaria fruhstorferi reveals functional insights into growth, immunity, and reproduction.

BACKGROUND: Incilaria (= Meghimatium) fruhstorferi is an air-breathing land slug found in restricted habitats of Japan, Taiwan and selected provinces of South Korea (Jeju, Chuncheon, Busan, and Deokjeokdo). The species is on a decline due to depletion of forest cover, predation by natural enemies, and collection. To facilitate the conservation of the species, it is important to decide on a number of traits related to growth, immunity and reproduction addressing fitness advantage of the species. RESULTS: The visceral mass transcriptome of I. fruhstorferi was enabled using the Illumina HiSeq 4000 sequencing platform. According to BUSCO (Benchmarking Universal Single-Copy Orthologs) method, the transcriptome was considered complete with 91.8% of ortholog genes present (Single: 70.7%; Duplicated: 21.1%). A total of 96.79% of the raw read sequences were processed as clean reads. TransDecoder identified 197,271 contigs that contained candidate-coding regions. Of a total of 50,230 unigenes, 34,470 (68.62% of the total unigenes) annotated to homologous proteins in the Protostome database (PANM-DB). The GO term and KEGG pathway analysis indicated genes involved in metabolism, phosphatidylinositol signalling system, aminobenzoate degradation, and T-cell receptor signalling pathway. Many genes associated with molluscan innate immunity were categorized under pathogen recognition receptor, TLR signalling pathway, MyD88 dependent pathway, endogenous ligands, immune effectors, antimicrobial peptides, apoptosis, and adaptation-related. The reproduction-associated unigenes showed homology to protein fem-1, spermatogenesis-associated protein, sperm associated antigen, and testis expressed sequences, among others. In addition, we identified key growth-related genes categorized under somatotrophic axis, muscle growth, chitinases and collagens. A total of 4822 Simple Sequence Repeats (SSRs) were also identified from the unigene sequences of I. fruhstorferi. CONCLUSIONS: This is the first available genomic information for non-model land slug, I. fruhstorferi focusing on genes related to growth, immunity, and reproduction, with additional focus on microsatellites and repeating elements. The transcriptome provides access to greater number of traits of unknown relevance in the species that could be exploited for in-depth analyses of evolutionary plasticity and making informed choices during conservation planning. This would be appropriate for understanding the dynamics of the species on a priority basis considering the ecological, health, and social benefits.

The increase in posterior tibial slope provides a positive biomechanical effect in posterior-stabilized total knee arthroplasty.

PURPOSE: This study aims to clarify the influence of the posterior tibial slope (PTS) on knee joint biomechanics after posterior-stabilized (PS) total knee arthroplasty (TKA) using a computer simulation. METHODS: A validated TKA computational model was used to evaluate and quantify the effects of an increased PTS. In order to conduct a squat simulation, models with a - 3° to 15° PTS using increments of 3° were developed. Forces on the quadriceps and collateral ligament, a tibial posterior translation, contact point on a polyethylene (PE) insert, and contact stress on the patellofemoral (PF) joint and post in a PE insert were compared. RESULTS: The maximum force on the quadriceps and the PF contact stress decreased with increases in the PTS. The kinematics on the tibiofemoral (TF) joint translated in an increasingly posterior manner, and the medial and lateral contact points on a PE insert were located in posterior regions with increases in the PTS. Additionally, increases in the PTS decreased the force on the collateral ligament and increased the contact stress on the post in a PE insert. A higher force on the quadriceps is required when the PTS decreases with an equivalent flexion angle. CONCLUSIONS: A surgeon should be prudent in terms of determining the PTS because an excessive increase in the PTS may lead to the progressive loosening of the TF joint due to a reduction in collateral ligament tension and failure of the post in a PE insert. Thus, we support a more individualized approach of optimal PTS determination given the findings of the study.

Influence of Increased Posterior Tibial Slope in Total Knee Arthroplasty on Knee Joint Biomechanics: A Computational Simulation Study.

BACKGROUND: The reconstructed posterior tibial slope (PTS) plays a significant role in restoring knee kinematics in cruciate-retaining-total knee arthroplasty (TKA). A few studies have reported the effect of the PTS on biomechanics. METHODS: This study investigates the effect of the PTS on tibiofemoral (TF) kinematics, patellofemoral (PF) contact stress, and forces at the quadriceps, posterior cruciate ligament (PCL) and collateral ligament after cruciate-retaining-TKA using computer simulations. The simulation for the validated TKA finite element model was performed under deep knee bend condition. All analyses were repeated from -3° to 15° PTS in increments of 3°. RESULTS: The kinematics on the TF joint translated increasingly posteriorly when the PTS increased. Medial and lateral contact points translated in posterior direction in extension and flexion as PTS increased. The maximum contact stress on the PF joint and quadriceps, and collateral ligament force decreased when the PTS increased. An implantation of the tibial plate with increased PTS reduced the PCL load. Physiologic insert movement led to an increasingly posterior position of the femur and reduced quadriceps force especially for knee flexion angles above high flexion (120°) when compared to TKA with a decreased slope of the tibial base plate. CONCLUSION: An increase in the PTS increased medial and lateral movements without paradoxical motion. However, an excessive PTS indicated progressive loosening of the TF joint gap due to a reduction in collateral ligament tension during flexion.

Transcriptome sequencing and de novo characterization of Korean endemic land snail, Koreanohadra kurodana for functional transcripts and SSR markers.

The Korean endemic land snail Koreanohadra kurodana (Gastropoda: Bradybaenidae) found in humid areas of broadleaf forests and shrubs have been considered vulnerable as the number of individuals are declining in recent years. The species is poorly characterized at the genomic level that limits the understanding of functions at the molecular and genetics level. In the present study, we performed de novo transcriptome sequencing to produce a comprehensive transcript dataset of visceral mass tissue of K. kurodana by the Illumina paired-end sequencing technology. Over 234 million quality reads were assembled to a total of 315,924 contigs and 191,071 unigenes, with an average and N50 length of 585.6 and 715 bp and 678 and 927 bp, respectively. Overall, 36.32 % of the unigenes found matches to known protein/nucleotide sequences in the public databases. The direction of the unigenes to functional categories was determined using COG, GO, KEGG, and InterProScan protein domain search. The GO analysis search resulted in 22,967 unigenes (12.02 %) being categorized into 40 functional groups. The KEGG annotation revealed that metabolism pathway genes were enriched. The most prominent protein motifs include the zinc finger, ribonuclease H, reverse transcriptase, and ankyrin repeat domains. The simple sequence repeats (SSRs) identified from >1 kb length of unigenes show a dominancy of dinucleotide repeat motifs followed with tri- and tetranucleotide motifs. A number of unigenes were putatively assessed to belong to adaptation and defense mechanisms including heat shock proteins 70, Toll-like receptor 4, AMP-activated protein kinase, aquaporin-2, etc. Our data provide a rich source for the identification and functional characterization of new genes and candidate polymorphic SSR markers in K. kurodana. The availability of transcriptome information ( http://bioinfo.sch.ac.kr/submission/ ) would promote the utilization of the resources for phylogenetics study and genetic diversity assessment.

De novo Transcriptome Generation and Annotation for Two Korean Endemic Land Snails, Aegista chejuensis and Aegista quelpartensis, Using Illumina Paired-End Sequencing Technology.

Aegista chejuensis and Aegista quelpartensis (Family-Bradybaenidae) are endemic to Korea, and are considered vulnerable due to declines in their population. The limited genetic resources for these species restricts the ability to prioritize conservation efforts. We sequenced the transcriptomes of these species using Illumina paired-end technology. Approximately 257 and 240 million reads were obtained and assembled into 198,531 and 230,497 unigenes for A. chejuensis and A. quelpartensis, respectively. The average and N50 unigene lengths were 735.4 and 1073 bp, respectively, for A. chejuensis, and 705.6 and 1001 bp, respectively, for A. quelpartensis. In total, 68,484 (34.5%) and 77,745 (33.73%) unigenes for A. chejuensis and A. quelpartensis, respectively, were annotated to databases. Gene Ontology terms were assigned to 23,778 (11.98%) and 26,396 (11.45) unigenes, for A. chejuensis and A. quelpartensis, respectively, while 5050 and 5838 unigenes were mapped to 117 and 124 pathways in the Kyoto Encyclopedia of Genes and Genomes database. In addition, we identified and annotated 9542 and 10,395 putative simple sequence repeats (SSRs) in unigenes from A. chejuensis and A. quelpartensis, respectively. We designed a list of PCR primers flanking the putative SSR regions. These microsatellites may be utilized for future phylogenetics and conservation initiatives.

Transcriptome sequencing of the endangered land snail Karaftohelix adamsi from the Island Ulleung: De novo assembly, annotation, valuation of fitness genes and SSR markers.

BACKGROUND: The Bradybaenidae snail Karaftohelix adamsi is endemic to Korea, with the species tracked from Island Ulleung in North Gyeongsang Province of South Korea. K. adamsi has been classified under the Endangered Wildlife Class II species of Korea and poses a severe risk of extinction following habitat disturbances. With no available information at the DNA (genome) or mRNA (transcriptome) level for the species, conservation by utilizing informed molecular resources seems difficult. OBJECTIVE: In this study, we used the Illumina short-read sequencing and Trinity de novo assembly to draft the reference transcriptome of K. adamsi. RESULTS: After assembly, 13,753 unigenes were obtained of which 10,511 were annotated to public databases (a maximum of 10,165 unigenes found homologs in PANM DB). A total of 6,351, 3,535, 358, and 3,407 unigenes were ascribed to the functional categories under KOG, GO, KEGG, and IPS, respectively. The transcripts such as the HSP 70, aquaporin, TLR, and MAPK, among others, were screened as putative functional resources for adaptation. DNA transposons were found to be thickly populated in comparison to retrotransposons in the assembled unigenes. Further, 2,164 SSRs were screened with the promiscuous presence of dinucleotide repeats such as AC/GT and AG/CT. CONCLUSION: The transcriptome-guided discovery of molecular resources in K. adamsi will not only serve as a basis for functional genomics studies but also provide sustainable tools to be utilized for the protection of the species in the wild. Moreover, the development of polymorphic SSRs is valuable for the identification of species from newer habitats and cross-species genotyping.

Elevated levels of serum tumor markers CA 15-3 and CEA are prognostic factors for diagnosis of metastatic breast cancers.

To investigate the prognostic value of tumor markers, cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) levels at diagnosis of systemic recurrence. After primary treatments of locoregional breast cancers, serum CA 15-3 and/or CEA concentrations were regularly measured, and systemic recurrences were identified in 351 patients between January 1999 and December 2009. The association between tumor marker levels at systemic recurrence and survival were investigated by univariate and multivariate analyses. Elevated CA 15-3 and CEA levels were identified in 194 of 349 (55.6 %) and 111 of 308 (36.0 %) patients, respectively, at diagnosis of systemic recurrence. Elevated levels of CA 15-3 and CEA were correlated with visceral or multiple recurrences and elevated preoperative levels. Elevation of CA 15-3 was more prominent in younger patients and in primary node-positive tumors, while CEA was elevated in older patients at diagnosis and in estrogen receptor (ER)-positive tumors. Elevated tumor markers as well as ER negativity, short disease-free interval, and advanced stage at initial diagnosis showed independent prognostic significance on multivariate analysis. Among 306 patients for whom levels of both tumor markers at recurrence were available, 106 patients without elevation of either marker showed significantly better overall survival than those with elevated levels of either one or both markers, and the significance persisted in multivariate analysis. Elevated serum CA 15-3 and CEA levels at recurrence suggest increased tumor burden and may be prognostic for survival for metastatic breast cancer patients.

Soluble interleukin-6 receptor is a prognostic marker for relapse-free survival in estrogen receptor-positive breast cancer.

Considering the protumorigenic roles of interleukin-6 (IL-6) transsignaling, we assessed the serum levels of IL-6, soluble interleukin-6 receptor (sIL-6R), and soluble glycoprotein 130 (sgp130) in 143 patients with breast cancer. Serum levels of IL-6 were elevated with advanced T and N stage. Serum levels of sIL-6R were lower in patients with estrogen receptor-positive cancer. The median values of IL-6 and sgp130 did not differ between patients with recurrence and those without recurrence. However, higher serum levels of sIL-6R at diagnosis were associated with significantly shorter relapse-free survival in patients with estrogen receptor-positive breast cancer.

A review of the endangered mollusks transcriptome under the threatened species initiative of Korea.

Transcriptome studies for conservation of endangered mollusks is a proactive approach towards managing threats and uncertainties facing these species in natural environments. The population of these species is declining due to habitat destruction, illicit wildlife trade, and global climate change. These activities risk the free movement of species across the wild landscape, loss of breeding grounds, and restrictions in displaying the physiological attributes so crucial for faunal welfare. Gastropods face the most negative ecological effects and have been enlisted under Korea's protective species consortium based on their population dynamics in the last few years. Moreover, with the genetic resources restricted for such species, conservation by informed planning is not possible. This review provides insights into the activities under the threatened species initiative of Korea with special reference to the transcriptome assemblies of endangered mollusks. The gastropods such as Ellobium chinense, Aegista chejuensis, Aegista quelpartensis, Incilaria fruhstorferi, Koreanohadra kurodana, Satsuma myomphala, and Clithon retropictus have been represented. Moreover, the transcriptome summary of bivalve Cristaria plicata and Caenogastropoda Charonia lampas sauliae is also discussed. Sequencing, de novo assembly, and annotation identified transcripts or homologs for the species and, based on an understanding of the biochemical and molecular pathways, were ascribed to predictive gene function. Mining for simple sequence repeats from the transcriptome have successfully assisted genetic polymorphism studies. A comparison of the transcriptome scheme of Korean endangered mollusks with the genomic resources of other endangered mollusks have been discussed with homologies and analogies for dictating future research.

Cyclooxygenase-2 expression in proliferative Ki-67-positive breast cancers is associated with poor outcomes.

In order to investigate the implications of cyclooxygenase-2 (COX-2) expression in combination with Ki-67 on breast cancer outcomes, the COX-2 and Ki-67 expression levels and other clinicopathologic parameters were investigated in 861 breast cancers. Clinicopathological parameters and survival were investigated in association with the expression levels of both COX-2 and Ki-67 using univariate and multivariate analyses. COX-2 expression was positive in 493 (57.3%) of invasive tumors. COX-2 was associated with favorable markers, but was not related to survival outcome by itself. However, COX-2 in proliferative tumors [COX-2(+)/Ki-67(+)] were significantly associated with unfavorable factors and the worst survival, but COX-2 in non-proliferative tumors [COX-2(+)/Ki-67(-)] showed significantly favorable parameters and better outcomes. COX-2(-)/Ki-67(any) showed intermediate prognosis. The statistical significance was maintained in stage-matched and multivariate analyses. The results of present study suggest that COX-2 expression is a common event in breast cancers and may play in a different ways by the proliferation status of the tumor cells. Further studies should be carried out to verify the role of COX-2 by proliferative conditions of breast tumor cells.

Novel microsatellite markers of Meretrix petechialis and cross-species amplification in related Taxa (Bivalvia: Veneroida).

The Asian hard clam, Meretrix petechialis, is an economically important bivalve, but its catch and population sizes are decreasing rapidly, owing to many factors, including large-scale reclamation of its natural habitat on the western coast of the Korean peninsula. Attempts to restore the resources and production of this species require genetic structure and diversity information. In this study, we developed 15 microsatellite markers from a partial genomic library enriched in GT repeats. Nine of these markers were polymorphic, with an average allele number of six, and six were monomorphic in 95 tested individuals. No linkage disequilibrium was found between any pair of loci (p > 0.05), and deviations from the Hardy-Weinberg equilibrium (HWE) test showing excess of heterozygotes was observed in only one of nine loci. In addition, no null alleles or genetic differentiation between two tested populations were detected. A cross-species amplification in 12 species of four families resulted in two M. petechialis-specific loci and three possible universal markers. This information will be useful in the future development of high-quality artificial seedlings and sustainable resource management.

Factors influencing the outcome of breast cancer patients with 10 or more metastasized axillary lymph nodes.

BACKGROUND: The purpose of this study was to investigate prognostic factors in breast cancer patients with metastasis of ten or more lymph nodes (pathologic N3a). METHODS: We conducted a retrospective analysis of the cases of 304 breast cancer patients with pathologic N3a disease who had undergone definitive surgery between 1986 and 2006, and investigated the correlation between clinicopathologic characteristics and treatment outcomes. RESULTS: With a median follow-up period of 55 months, the 5-year disease-free survival rate was 42.9% and the overall survival rate was 57.8%. Univariate analysis showed that the factors associated with poor disease-free survival were: age < 35 years (P = 0.001), history of neoadjuvant chemotherapy (P < 0.001), T4 stage (P < 0.001), 20 or more positive lymph nodes (P < 0.001), presence of lymphovascular invasion (P = 0.003), and negative progesterone receptor expression (P = 0.003). Multivariate analysis showed the factors with independent prognostic significance to be: history of neoadjuvant chemotherapy (hazard ratio [HR] 3.163; 95% confidence interval [CI], 2.025-4.941; P < 0.001), 20 or more positive nodes (HR 1.598; 95% CI, 1.063-2.402; P = 0.024), and presence of lymphovascular invasion (HR 1.636; 95% CI, 1.009-2.654; P = 0.046). Factors associated with poor overall survival in univariate analysis were: age < 35 years (P = 0.033), history of neoadjuvant chemotherapy (P < 0.001), T4 stage (P = 0.001), 20 or more positive lymph nodes (P < 0.001), and negative progesterone receptor expression (P = 0.013). Multivariate analysis showed these factors to be: history of neoadjuvant chemotherapy (HR 2.900; 95% CI, 2.011-4.182; P < 0.001), and 20 or more positive nodes (HR 1.956; 95% CI, 1.419-2.696; P < 0.001). CONCLUSION: Cases of breast tumors with extensive nodal metastasis were found to be heterogeneous in terms of prognosis. History of previous neoadjuvant chemotherapy and higher numbers of metastatic lymph nodes were found to be the two most important prognostic markers for pathologic N3a disease. New strategies such as biologic therapy and novel combinations should be considered for application in patients with poor prognosis, rather than conventional treatment.

Primary repair of untreated cleft palate in an elderly patient: a case report.

Untreated adult or elderly cleft lip and palate patients are rarely seen, but studies on delayed primary palatal closure have been performed in the less developed Asian and African countries, where access to medical care is difficult. A 64-year-old woman visited our clinic with untreated cleft palate with a 40×20-mm-wide defect in the medial palate. Two-flap palatoplasty under general anesthesia was performed to close the cleft palate. After 1 month, the result was favorable without any complications including oronasal fistula. Cleft palate primary repair in an elderly patient is rare and has some surgical problems that are associated with a wide range of defects, but good results can be obtained if surgery is performed well with appropriate considerations.

Time-Sequencing of the Neutrophil-to-Lymphocyte Ratio to Predict Prognosis of Triple-Negative Breast Cancer.

Since triple-negative breast cancers (TNBCs) have varying prognoses, it is important to identify subgroups with particularly poor prognosis. The aim of this study was to assess whether changes in the neutrophil-to-lymphocyte ratio (NLR) during the treatment process were associated with poor prognosis in TNBC patients. This study included 600 TNBC patients who underwent surgery from January 2005 to December 2016. The associations of the NLR and clinicopathologic factors with breast cancer recurrence and survival in patients who underwent both definitive local treatment (total mastectomy or breast-conserving surgery with radiotherapy) and systemic chemotherapy were analyzed. The NLRs at four time points (before surgery, before chemotherapy, before radiotherapy, and 1 year after surgery) were assessed. The univariate analysis showed that changes in the NLR before the start of radiotherapy (odds ratio: 1.115, confidence interval: 1.011-1.229) and 1 year after surgery (odds ratio: 1.196, confidence interval: 1.057-1.354) significantly increased the risk of recurrence or death. In multivariate analysis, T stage, N stage, and changes in the NLR were significant factors. A time-sequenced NLR may reflect the prognosis of TNBC patients. A poor prognosis is expected in patients whose NLR increases during treatment compared to the preoperative NLR, and additional treatment is needed.

De novo transcriptome sequencing of triton shell Charonia lampas sauliae: Identification of genes related to neurotoxins and discovery of genetic markers.

Charonia lampas sauliae (triton snails, triton shells or tritons; Mollusca, Caenogastropoda, Littorinimorpha, Ranellidae) is a marine species with a wide distribution. In Korea, this species is listed as vulnerable and is regionally protected as an endangered species. Here, we report the first comprehensive transcriptome dataset of C. lampas sauliae obtained using the Illumina HiSeq 2500 platform. In total, 97.68% of raw read sequences were processed as clean reads. Of the 577,478 contigs obtained, 146,026 sequences were predicted to contain coding regions. About 89.34% of all annotated unigene sequences showed homologous matches to protein sequences in PANM DB (Protostome database). Further, about one-third of the unigene sequences were annotated using the UniGene, Swiss-Prot, Clusters of Orthologous Groups (COG) and Gene Ontology (GO) databases. In total, 190 enzymes were predicted under key metabolic pathways under stood through Kyoto Encyclopedia of Genes and Genomes (KEGG) database annotation. Repetitive elements such as long terminal repeats (LTRs), short interspersed nuclear elements (SINEs), long interspersed nuclear elements (LINEs), and DNA elements were enriched in the unigene sequences. Among the identified transcripts were the channel proteins, some of which were blocked by tetrodotoxin, which is thought to be synthesized by symbiotic bacteria inhabiting the shells. In addition, conotoxin superfamily peptides, such as B-conotoxin, conotoxin superfamily T and alpha-conotoxin, were identified, which may have relevance to biomedical and evolutionary research. A transcriptome-wide search for polymorphic loci identified 21,568 simple sequence repeats (SSRs) in the unigene sequences. Most SSRs were dinucleotides, among which AC/GT was the dominant SSR type. The molecular and genetic resources revealed in this study could be utilized for investigations on the fitness of the species in the marine environment and sustainability in a changing habitat.

Molecular phylogenetic, population genetic and demographic studies of Nodularia douglasiae and Nodularia breviconcha based on CO1 and 16S rRNA.

Freshwater mussels belonging to the genus Nodularia (Family Unionidae) are known to be widely distributed in East Asia. Although phylogenetic and population genetic studies have been performed for these species, there still remain unresolved questions in their taxonomic status and biogeographic distribution pathways. Here, the nucleotide sequences of CO1 and 16S rRNA were newly determined from 86 N. douglasiae and 83 N. breviconcha individuals collected on the Korean Peninsula. Based on these data, we revealed the following results: (1) N. douglasiae can be divided into the three genetic clades of A (only found in Korean Peninsula), B (widely distributed in East Asia), and C (only found in the west of China and Russia), (2) the clade A is not an independent species but a concrete member of N. douglasiae given the lack of genetic differences between the clades A and B, and (3) N. breviconcha is not a subspecies of N. douglasiae but an independent species apart from N. douglasiae. In addition, we suggested the plausible scenarios of biogeographic distribution events and demographic history of Nodularia species.

Biomechanical analysis of a changed posterior condylar offset under deep knee bend loading in cruciate-retaining total knee arthroplasty.

BACKGROUND: The conservation of the joint anatomy is an important factor in total knee arthroplasty (TKA). The restoration of the femoral posterior condylar offset (PCO) has been well known to influence the clinical outcome after TKA. OBJECTIVE: The purpose of this study was to determine the mechanism of PCO in finite element models with conservation of subject anatomy and different PCO of ±1, ±2, ±3 mm in posterior direction using posterior cruciate ligament-retaining TKA. METHODS: Using a computational simulation, we investigated the influence of the changes in PCO on the contact stress in the polyethylene (PE) insert and patellar button, on the forces on the collateral and posterior cruciate ligament, and on the quadriceps muscle and patellar tendon forces. The computational simulation loading condition was deep knee bend. RESULTS: The contact stresses on the PE insert increased, whereas those on the patellar button decreased as posterior condylar offset translated to the posterior direction. The forces exerted on the posterior cruciate ligament and collateral ligaments increased as PCO translated to the posterior direction. The translation of PCO in the anterior direction, in an equivalent flexion angle, required a greater quadriceps muscle force. CONCLUSIONS: Translations of the PCO in the posterior and anterior directions resulted in negative effects in the PE insert and ligament, and the quadriceps muscle force, respectively. Our findings suggest that orthopaedic surgeons should be careful with regard to the intraoperative conservation of PCO, because an excessive change in PCO may lead to quadriceps weakness and an increase in posterior cruciate ligament tension.

Comparison of the biomechanical effect of posterior condylar offset and kinematics between posterior cruciate-retaining and posterior-stabilized total knee arthroplasty.

BACKGROUND: The effect of the changes in the femoral posterior condylar offset (PCO) on anterior-posterior (AP) translation and internal-external (IE) rotation in cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) remains unknown. The purpose of this study was to compare the kinematics in CR and PS TKA with respect to the difference in prosthetic design and PCO change through a computational simulation. METHODS: We developed three-dimensional finite element models with the different PCOs of ±1, ±2 and ±3 mm in the posterior direction using CR and PS TKA. We performed the simulation with different PCOs under a deep knee bend condition and evaluated the kinematics for the AP and IE in CR and PS TKA. RESULTS: The more tibiofemoral (TF) translation in the posterior direction was found as PCO translated in posterior direction for both CR and PS TKA compared to the neutral position. However, the change of the AP translation with respect to the PCO change in CR TKA was greater than PS TKA. The more TF external rotation was found as PCO translated in the anterior direction for both CR and PS TKA compared to the neutral position. However, unlike the TF translation, the TF rotation was not influenced by the PCO change in both CR and PS TKA. CONCLUSION: The PCO magnitude was influenced by a postoperative change in the kinematics in CR TKA although a relatively smaller effect was observed in PS TKA. Hence, surgeons should be aware of the PCO change, especially for CR TKA.

Langerhans cell histiocytosis of the mandible: two case reports and literature review.

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the proliferation of dendritic cells resulting in local or systemic symptoms. The clinical symptoms of patients with Langerhans cell histiocytosis depend on the site and the degree of involvement. This article describes two case histories of unifocal bony Langerhans cell histiocytosis with mandibular involvement and further discusses the appropriate management of such via a review of the literature.

Control of accumulated volatile fatty acids by recycling nitrified effluent.

BACKGROUND: Volatile fatty acids (VFA) often accumulate in anaerobic digestion systems, decreasing pH levels and causing unstable operational performance and poor biogas production. The aim of this study is to improve anaerobic digestion efficiency by controlling/reducing the accumulation of VFAs in a continuous anaerobic digestion system. METHODS: NO3 --N was added to the digester and its effects on VFAs were investigated. When the system reached an unstable condition with the accumulation of VFAs, the digester was fed at an organic loading rate of 6 kg COD (chemical oxygen demand)/m3∙d and 0.5Q of aeration tank effluent (1500 mg/L of NO3 --N) was recirculated. RESULTS: With the addition of NO3 --N, VFAs were utilized during denitrification, after which methane production started. Furthermore, the accumulated VFAs could be used as a carbon substrate by denitrifying bacteria. After 56 d, a normal VFA concentration could be achieved. Methane production was 0.02-0.03 L CH4/g VS higher with NO3 --N recirculation and feeding than that without feeding. CONCLUSIONS: The results show that the addition of NO3 --N is a potentially feasible method to control VFAs. Combined with recirculation and feeding, the method can be used to effectively prevent the inhibition of methanogenic microbial activities caused by accumulated VFAs and enhance denitrification and methane production in anaerobic digesters.