Hemicallotasis for correction of varus deformity of the proximal tibia using a unilateral external fixator.

BACKGROUND: Gradual correction of varus deformity of the proximal tibia is generally accepted and produces good results. However, most studies have used circular external fixators, which are complex and cause patient discomfort. This study was undertaken to determine the efficacy of hemicallotasis with a unilateral external fixator for correction of varus deformity of the proximal tibia. METHODS: Thirteen patients (21 legs, 8 bilateral) were included in this study: 6 with constitutional bowing, 3 with a malunion, 2 with Blount's disease, and 2 with Turner syndrome. There were 7 males and 6 females of mean age 21 years (range 13-40). With an oblique osteotomy on the proximal tibia, a unilateral external fixator was placed on the medial side. Using a distraction of 1 mm/day, the external fixator was removed after consolidation of the callus. RESULTS: Surgery corrected medial proximal tibia angle from a preoperative average of 75.1° (64°-81°) to 88.6° (86°-90°) at final follow-up. Average tibiofemoral angle improved from -7° to 6.8°. The duration of external fixation averaged 101.3 days and the external fixation index was 70 days/cm. No patient had a limited ambulation, and all recovered preoperative range of knee motion (mean 130.1°) at final follow-up. Seven minor complications (pin tract infection, clamp loosening) and 1 major complication (uncorrected genu procurvatum) were observed. CONCLUSIONS: Hemicallotasis using a unilateral external fixator was found to be a safe and simple corrective procedure for varus deformity of the proximal tibia, with few complications.

Ultrasonographic evaluation of the shoulder in elite wheelchair tennis players.

CONTEXT: Wheelchair tennis has been identified as a high-risk sport for shoulder injury, so understanding shoulder pathology in these athletes is important. OBJECTIVE: This study investigated the incidence and pattern of shoulder injuries in wheelchair tennis players using high-resolution ultrasonography. DESIGN: Descriptive study. SETTING: International Wheelchair Tennis Open. PARTICIPANTS: 33 elite-level wheelchair tennis players. OUTCOME MEASURES: Wheelchair tennis players completed a self-administered questionnaire, and shoulders of each athlete were investigated using high-resolution ultrasonography (linear probe 7.5 MHz). RESULTS: The most common pathology in the dominant shoulder was acromioclavicular pathology, in 21 players (63.6%). Full-thickness rotator-cuff tears involving the supraspinatus were found in 8 dominant shoulders and 6 nondominant shoulders. There were no correlations between identified shoulder pathology and the different variables studied, such as age, training time per day, length of wheelchair use, and length of career as a wheelchair tennis player. CONCLUSION: High prevalence of rotator-cuff and acromioclavicular pathology was found by ultrasonographic examination in the elite wheelchair tennis players in both dominant and nondominant shoulders. A high index of suspicion of these pathologies in wheelchair athletes is required.

Proton magnetic resonance spectroscopy of musculoskeletal lesions at 3 T with metabolite quantification.

PURPOSE: To evaluate whether proton MR spectroscopy (MRS) at 3 T with metabolite quantification is helpful for characterizing musculoskeletal lesions and to reveal whether the concentration of choline is correlated with the pathologic degree of malignancy. MATERIAL AND METHODS: Three-tesla MR images and proton MRS data from 27 consecutive patients with surgically proven musculoskeletal lesions were retrospectively analyzed. We analyzed the presence of choline peaks of malignant tumors according to the degree of malignancies, and we compared them with those of benign lesions. The concentrations of choline calculated by means of the linear combination of model spectra were also compared with respect to the degree of malignancy in each group. RESULTS: The proton MRS had an overall sensitivity of 68.4%, specificity of 87.5%, positive predictive value of 92.3%, and negative predictive value of 53.8% for the detection of choline compounds. The positive detection rate for choline compounds in the primary malignancy group (53.8%) was lower than that of the metastasis group (100%). All false-negative results were shown in the Grade 1 primary malignancy group. There was no difference in the concentration of choline compounds with respect to the pathologic degree of differentiation. CONCLUSION: MR spectroscopy at 3 T with metabolite quantification is a helpful method that shows high specificity (87.5%) in characterizing musculoskeletal lesions, even though its sensitivity (68.4%) is relatively low. Grade 1 primary malignancies of bone and soft tissue tumor have a high potential for producing false-negative results.

Requirement of Split ends for epigenetic regulation of Notch signal-dependent genes during infection-induced hemocyte differentiation.

Drosophila producing a mutant form of the putative transcription coregulator, Split ends (Spen), originally identified in the analysis of neuronal development, display diverse immune defects. In order to understand the role of Spen in the innate immune response, we analyzed the transcriptional defects associated with spen mutant hemocytes and their relationship to the Notch signaling pathways. Spen is regulated by the Notch pathway in the lymph glands and is required for Notch-dependent activation of a large number of genes involved in energy metabolism and differentiation. Analysis of the epigenetic marks associated with Spen-dependent genes indicates that Spen performs its function as a coactivator by regulating chromatin modification. Intriguingly, expression of the Spen-dependent genes was transiently downregulated in a Notch-dependent manner by the Dif activated upon recognition of pathogen-associated molecules, demonstrating the existence of cross talk between hematopoietic regulation and the innate immune response. Our observations reveal a novel connection between the Notch and Toll/IMD signaling pathways and demonstrate a coactivating role for Spen in activating Notch-dependent genes in differentiating cells.

Microarray analysis of the gene expression profiles of SL2 cells stimulated by LPS/PGN and curdlan.

Essential aspects of the innate immune response to microbial infection appear to be conserved between insects and mammals. In order to identify new Drosophila melanogaster genes involved in the immune response, we performed gene expression profiling of Drosophila SL2 cells stimulated with bacterial (LPS/PGN) or fungal (curdlan) components using a cDNA microarray that contained 5,405 Drosophila cDNAs. We found that some genes were similarly regulated by LPS/PGN and curdlan. However, a large number, belonging to the functional classes of cell organization, development, signal transduction, morphogenesis, cell cycle, and DNA replication, displayed significant differences in their transcription profiles between the two treatments, demonstrating that bacterial and fungal components induce different immune response even in an in vitro cell system.

Screening and formulation of chemoattractant coatings for artificial reef structures.

This study was carried out to augment the colonization of marine benthic communities on artificial reef structure. Increasing marine pollution along with various natural hazards cause severe damages to marine algae and associated fauna. In recent years, artificial reefs have been deployed in coastal regions of several parts of the world in order to increase the marine productivity. They are mainly built with concrete materials, however their leachates have considerable impacts on algae. Therefore to increase the algal colonization five chemoattractants such as ferrous sulfate, zinc oxide, ammonium nitrate, sodium phosphate and ferrous lactate were screened against spores of a fouling alga, Ulva pertusa. FeSO4 / ZnO (8:2) and ferrous lactate coatings showed the highest spore attachment with 52 +/- 5.2 cm2 and 79.5 +/- 10.2 cm2 spores respectively (p<0.01). Furthermore using these chemoattractants, coating formulations were made and their performances were investigated at East coast (Ayajin harbor) and South coast (Meejo harbor) of Korea. A maximum fouling coverage (with green algae 25%, red algae 11.3% and brown algae 63.7%) was estimated from ferrous lactate coatings (p<0.01). Different composition of coating formulations and their chemoattractive properties were evaluated.

Down-regulation of NF-kappaB target genes by the AP-1 and STAT complex during the innate immune response in Drosophila.

The activation of several transcription factors is required for the elimination of infectious pathogens via the innate immune response. The transcription factors NF-kappaB, AP-1, and STAT play major roles in the synthesis of immune effector molecules during innate immune responses. However, the fact that these immune responses can have cytotoxic effects requires their tight regulation to achieve restricted and transient activation, and mis-regulation of the damping process has pathological consequences. Here we show that AP-1 and STAT are themselves the major inhibitors responsible for damping NF-kappaB-mediated transcriptional activation during the innate immune response in Drosophila. As the levels of dAP-1 and Stat92E increase due to continuous immune signaling, they play a repressive role by forming a repressosome complex with the Drosophila HMG protein, Dsp1. The dAP-1-, Stat92E-, and Dsp1-containing complexes replace Relish at the promoters of diverse immune effector genes by binding to evolutionarily conserved cis-elements, and they recruit histone deacetylase to inhibit transcription. Reduction by mutation of dAP-1, Stat92E, or Dsp1 results in hyperactivation of Relish target genes and reduces the viability of bacterially infected flies despite more efficient pathogen clearance. These defects are rescued by reducing the Relish copy number, thus confirming that mis-regulation of Relish, not inadequate activation of dAP-1, Stat92E, or Dsp1 target genes, is responsible for the reduced survival of the mutants. We conclude that an inhibitory effect of AP-1 and STAT on NF-kappaB is required for properly balanced immune responses and appears to be evolutionarily conserved.

Epigenomics: novel aspect of genomic regulation.

An International Symposium on Epigenomics took place at Yonsei University, Korea in December, 2006. The meeting brought to light new aspects of genome regulation by DNA and protein modification.