Identification of KU-55933 as an anti-atherosclerosis compound by using a hemodynamic-based high-throughput drug screening platform

Several compounds have been used for atherosclerosis treatment, including clinical trials; however, no anti-atherosclerotic drugs based on hemodynamic force-mediated atherogenesis have been discovered. Our previous studies demonstrated that "small mothers against decapentaplegic homolog 1/5" (Smad1/5) is a convergent signaling molecule for chemical [e.g., bone morphogenetic proteins (BMPs)] and mechanical (e.g., disturbed flow) stimulations and hence may serve as a promising hemodynamic-based target for anti-atherosclerosis drug development. The goal of this study was to develop a high-throughput screening (HTS) platform to identify potential compounds that can inhibit disturbed flow- and BMP-induced Smad1/5 activation and atherosclerosis. Through HTS using a Smad1/5 downstream target inhibitor of DNA binding 1 (Id-1) as a luciferase reporter, we demonstrated that KU-55933 and Apicidin suppressed Id-1 expression in AD-293 cells. KU-55933 (10 μM), Apicidin (10 μM), and the combination of half doses of each [1/2(K + A)] inhibited disturbed flow- and BMP4-induced Smad1/5 activation in human vascular endothelial cells (ECs). KU-55933, Apicidin, and 1/2(K + A) treatments caused 50.6%, 47.4%, and 73.3% inhibitions of EC proliferation induced by disturbed flow, respectively, whereas EC inflammation was only suppressed by KU-55933 and 1/2(K + A), but not Apicidin alone. Administrations of KU-55933 and 1/2(K + A) to apolipoprotein E-deficient mice inhibited Smad1/5 activation in ECs in athero-susceptible regions, thereby suppressing endothelial proliferation and inflammation, with the attenuation of atherosclerotic lesions in these mice. A unique drug screening platform has been developed to demonstrate that KU-55933 and its combination with Apicidin are promising therapeutic compounds for atherosclerosis based on hemodynamic considerations.

Designing a Trifoliate Flap for Isolated Congenital Alar Rim Defect in Pediatric Patients

Isolated congenital alar rim defects are extremely rare, and there has been no standard technique for the reconstruction of remarkable aesthetic deformity. Herein, we introduce a trifoliate flap for the correction of isolated congenital alar rim defects in pediatric patients. Fifteen cases undergoing nasal alar sulcus rotation flap surgery were analyzed retrospectively. This rotation flap including 3 triangles was a modified flap based on prior studies. Clinical medical notes and photographs were reviewed. Patients' (or their parents) reported satisfactions with aesthetic outcome were also evaluated during the post-operative follow-up period. In all patients, the isolated congenital alar rim defects were successfully reconstructed. The rotation flap survived and the wound healed primarily. The follow-up period ranged from 6 to 22 months (average 11 months). There were no incidents of flap loss, step-off deformities, nasal obstruction, or alar retraction. At follow-up of post-operative 3 months, pale red scars were observed in the operative area in few patients (2/15). However, these scars gradually became invisible at post-operative 6 months. All patients (or their parents) were satisfied with the aesthetic outcome of this operation. This newly designed trifoliate flap can be an alternative method for the reconstruction of isolated congenital alar rim defects in pediatric patients. The scars of this procedure can be unobvious with fine surgical suture.

Vinculin phosphorylation impairs vascular endothelial junctions promoting atherosclerosis

BACKGROUND AND AIMS

Atherosclerosis preferentially develops in arterial branches and curvatures where vascular endothelium is exposed to disturbed flow. In this study, the effects of disturbed flow on the regulation of vascular endothelial phosphoproteins and their contribution to therapeutic application in atherogenesis were elucidated.

METHODS

Porcine models, large-scale phosphoproteomics, transgenic mice, and clinical specimens were used to discover novel site-specific phosphorylation alterations induced by disturbed flow in endothelial cells (ECs).

RESULTS

A large-scale phosphoproteomics analysis of native endothelium from disturbed (athero-susceptible) vs. pulsatile flow (athero-resistant) regions of porcine aortas led to the identification of a novel atherosclerosis-related phosphoprotein vinculin (VCL) with disturbed flow-induced phosphorylation at serine 721 (VCLS721p). The induction of VCLS721p was mediated by G-protein-coupled receptor kinase 2 (GRK2)S29p and resulted in an inactive form of VCL with a closed conformation, leading to the VE-cadherin/catenin complex disruption to enhance endothelial permeability and atherogenesis. The generation of novel apolipoprotein E-deficient (ApoE-/-) mice overexpressing S721-non-phosphorylatable VCL mutant in ECs confirmed the critical role of VCLS721p in promoting atherosclerosis. The administration of a GRK2 inhibitor to ApoE-/- mice suppressed plaque formation by inhibiting endothelial VCLS721p. Studies on clinical specimens from patients with coronary artery disease (CAD) revealed that endothelial VCLS721p is a critical clinicopathological biomarker for atherosclerosis progression and that serum VCLS721p level is a promising biomarker for CAD diagnosis.

CONCLUSIONS

The findings of this study indicate that endothelial VCLS721p is a valuable hemodynamic-based target for clinical assessment and treatment of vascular disorders resulting from atherosclerosis.

Pursuing the Precision Study for Color Glass Condensate in Forward Hadron Productions

With the tremendous accomplishments of RHIC and the LHC experiments and the advent of the future electron-ion collider on the horizon, the quest for compelling evidence of the color glass condensate (CGC) has become one of the most aspiring goals in the high energy quantum chromodynamics research. Pursuing this question requires developing the precision test of the CGC formalism. By systematically implementing the threshold resummation, we significantly improve the stability of the next-to-leading-order calculation in CGC for forward rapidity hadron productions in pp and pA collisions, especially in the high p_{T} region, and obtain reliable descriptions of all existing data measured at RHIC and the LHC across all p_{T} regions. Consequently, this technique can pave the way for the precision studies of the CGC next-to-leading-order predictions by confronting them with a large amount of precise data.

FibROAD: a manually curated resource for multi-omics level evidence integration of fibrosis research

Organ fibrosis represents a vital health threat that substantially contributes to yearly mortality rates. While a considerable amount of research has been conducted on fibrosis, these reports have only focused on specific organs as affected within distinct disorders. Accordingly, results from such studies have been unable to provide a comprehensive understanding of the pathological processes involved. Here, we describe the development of FibROAD, an open-access database that integrates evidence from fibrosis-associated disorders as obtained from both the literature and multi-omics data. This resource will greatly assist both researchers and clinicians in the comprehension and treatment of this condition. FibROAD currently involves an assembly of 232 strong evidence-based fibrosis-related genes (FRGs) as garnered from 909 PubMed publications and contains lists of multi-omics data from > 4000 samples including RNA-seq, single-cell RNA-seq, miRNA-seq, ChIP-seq, ATAC-seq MeDIP-seq and MBD-seq as obtained from 17 different organs in 5 species. Results from integrative analyses as obtained using FibROAD have demonstrated that FRGs can be indicators for a wide range of organ fibrosis and reveal potential pro-fibrotic candidate genes for fibrosis research. In conclusion, FibROAD serves as a convenient platform where researchers can acquire integrated evidence and a more comprehensive understanding of fibrosis-related disorders.

Database URL  https://www.fibroad.org

Endothelial Yin Yang 1 Phosphorylation at S118 Induces Atherosclerosis Under Flow

Rationale: Disturbed flow occurring in arterial branches and curvatures induces vascular endothelial cell (EC) dysfunction and atherosclerosis. We postulated that disturbed flow plays important roles in modulating phosphoprotein expression profiles to regulate endothelial functions and atherogenesis. Objective: The goal of this study is to discover novel site-specific phosphorylation alterations induced by disturbed flow in ECs to contribute to atherosclerosis. Methods and Results: Quantitative phosphoproteomics analysis of ECs exposed to disturbed flow with low and oscillatory shear stress (OS, 0.5plusminus4 dynes/cm²) vs. pulsatile flow with high shear stress (PS, 124plusminus dynes/cm²) revealed that OS induces serine (S)118 phosphorylation of Yin Yang 1 (phospho-YY1^S118) in ECs. Elevated phospho-YY1^S118 level in ECs was further confirmed to be present in the disturbed flow regions in experimental animals and human atherosclerotic arteries. This disturbed flow-induced EC phospho-YY1^S118 is mediated by casein kinase 2α (CK2α) through its direct interaction with YY1. Yeast two-hybrid library screening and in situ proximity ligation assays demonstrate that phospho-YY1^S118 directly binds zinc finger with KRAB and SCAN domains 4 (ZKSCAN4) to induce promoter activity and gene expression of human double minute 2 (HDM2), which consequently induces EC proliferation through down-regulations of p53 and p21^CIP1. Administration of apolipoprotein E-deficient (ApoE^-/-) mice with CK2-specific inhibitor tetrabromocinnamic acid or atorvastatin inhibits atherosclerosis formation through down-regulations of EC phospho-YY1^S118 and HDM2. Generation of novel transgenic mice bearing EC-specific overexpression of S118-non-phosphorylatable mutant of YY1 in ApoE^-/- mice confirms the critical role of phospho-YY1^S118 in promoting atherosclerosis through EC HDM2. Conclusions: Our findings provide new insights into the mechanisms by which disturbed flow induces endothelial phospho-YY1^S118 to promote atherosclerosis, thus indicating phospho-YY1^S118 as a potential molecular target for atherosclerosis treatment.

Mechanoresponsive Smad5 Enhances MiR-487a Processing to Promote Vascular Endothelial Proliferation in Response to Disturbed Flow

MicroRNAs (miRs) and bone morphogenetic protein receptor-specific Smads are mechano-responsive molecules that play vital roles in modulating endothelial cell (EC) functions in response to blood flow. However, the roles of interplay between these molecules in modulating EC functions under flows remain unclear. We elucidated the regulatory roles of the interplay between miR-487a and Smad5 in EC proliferation in response to different flow patterns. Microarray and quantitative RT-PCR showed that disturbed flow with low and oscillatory shear stress (OS, 0.5 ± 4 dynes/cm²) upregulates EC miR-487a in comparison to static controls and pulsatile shear stress (12 ± 4 dynes/cm²). MiR-487a expression was higher in ECs in the inner curvature (OS region) than the outer curvature of the rat aortic arch and thoracic aorta and also elevated in diseased human coronary arteries. MiR-487a expression was promoted by nuclear phospho-Smad5, which bound to primary-miR-487a to facilitate miR-487a processing. Algorithm prediction and luciferase reporter and argonaute 2-immunoprecipitation assays demonstrated that miR-487a binds to 3'UTR of CREB binding protein (CBP) and p53. Knockdown and overexpression of miR-487a decreased and increased, respectively, phospho-Rb and cyclin A expressions through CBP and p53. A BrdU incorporation assay showed that miR-487a enhanced EC proliferation under OS in vitro and in disturbed flow regions of experimentally stenosed rat abdominal aorta in vivo. These results demonstrate that disturbed flow with OS induces EC expression of miR-487a through its enhanced processing by activated-Smad5. MiR-487 inhibits its direct targets CBP and p53 to induce EC cycle progression and proliferation. Our findings suggest that EC miR-487 may serve as an important molecular target for intervention against disturbed flow-associated vascular disorders resulting from atherosclerosis.

Elliptic Flow of Heavy Quarkonia in pA Collisions

Using the dilute-dense factorization in the color glass condensate framework, we investigate the azimuthal angular correlation between a heavy quarkonium and a charged light hadron in proton-nucleus collisions. We extract the second harmonic v_{2}, commonly known as the elliptic flow, with the light hadron as the reference. This particular azimuthal angular correlation between a heavy meson and a light hadron was first measured at the LHC recently. The experimental results indicate that the elliptic flows for heavy flavor mesons (J/ψ and D^{0}) are almost as large as those for light hadrons. Our calculation demonstrates that this result can be naturally interpreted as an initial state effect due to the interaction between the incoming partons from the proton and the dense gluons inside the target nucleus. Since the heavy quarkonium v_{2} exhibits a weak mass dependence according to our calculation, we predict that the heavy quarkonium ϒ should have a similar elliptic flow as compared to that of the J/ψ, which can be tested in future measurements.

[The role and mechanism of regulatory T cells in indirect acute lung injury]

Objective: To study the role and mechanism of CD(4)(+) CD(25)(+) FoxP3(+) regulatory T cells (Tregs) in the pathophysiological process of indirect acute lung injury (iALI) in mice. Methods: The iALI model was successfully induced by shock/cecal ligation and puncture method. Sham (n=8), cecal ligation and puncture (CLP, n=10), and hemorrhage (Hem, n=12) groups were established as controls. Two experimental groups were established: CLP+Hem (n=15) without Tregs adoptive transfer (AT), and CLP+Hem with Tregs adoptive transfer (CLP+Hem+AT, n=14). The number of Tregs, subsets of lymphocytes, neutrophil activity, apoptosis, cytokine levels and histopathological changes were measured in the lung tissue of each group. The protein exudation and the expression of IL-10 in bronchoalveolar lavage fluid (BALF) were also detected. After in vitro cell co-culture, the proliferation of activated T cells and the expression of IL-10, INF-γ and iNOS protein were detected. Results: The percentage and the absolute cell number of CD(4)(+) CD(25)(+) FoxP3(+) Tregs in lung tissue of iALI mice were (2.530±0.086)%, and (1.441±0.090)×10(4)/ml, respectively, which were significantly higher than the control groups (P<0.05). Adoptive transfer of Tregs could significantly decrease CD3-positive T lymphocytes, myeloperoxidase (MPO) activity, caspase-3 activity in lung tissue as well as protein leakage in BALF (P<0.05). Meanwhile interleukin-10 (IL-10) levels in lung tissue and BALF were up-regulated from (121.4±43.76) pg/ml to (201.0±61.96) pg/ml (t=2.776, P<0.05) and (206.2±90.88) pg/ml to (339.4±109.5) pg/ml (t=2.477, P<0.05), respectively. Histopathology was also significantly improved. The proliferation of activated T lymphocytes in the adoptive transfer Treg (AT-Treg) group (n=5) was significantly lower than that in the natural regulatory T cell (N-Treg) group (n=5, t=7.485, P<0.01) and the negative control group (n=5, t=16.66, P<0.01). However, iNOS enzyme inhibitor L-NMMA could significantly reduce the T cell proliferation (P<0.05). Conclusion: CD(4)(+)CD(25)(+)FoxP3(+) Tregs could reduce inflammatory reaction in mice with iALI, and the iNOS signaling pathway may be involved in this process.

Induction of microRNA-10a using retinoic acid receptor-α and retinoid x receptor-α agonists inhibits atherosclerotic lesion formation

BACKGROUND AND AIMS

MicroRNA (miR)-10a is a shear-regulated miR with the lowest expression in vascular endothelial cells (ECs) in athero-susceptible regions with oscillatory shear stress (OS). The aim of this study is to elucidate the relationship between EC miR-10a and atherosclerosis and develop a hemodynamics-based strategy for atherosclerosis treatment.

METHODS

A combination of in vitro flow system and in vivo experimental animals was used to examine the functional roles of EC miR-10a and its clinical applications in atherosclerosis.

RESULTS

En face staining showed that EC miR-10a is down-regulated in the inner curvature (OS region) of aortic arch in rats. Co-administration with retinoic acid receptor-α (RARα)- and retinoid X receptor-α (RXRα)-specific agonists rescued EC miR-10a expression in this OS region. These effects of OS and RARα/RXRα-specific agonists on EC miR-10a expression were confirmed by the in vitro flow system, and were modulated by the RARα-histone deacetylases complex, with the consequent modulation in the downstream GATA6/vascular cell adhesion molecule (VCAM)-1 signaling cascade. Animal studies showed that miR-10a levels are decreased in both aortic endothelium of atherosclerotic lesions and blood plasma from apolipoprotein E-deficient (ApoE^-/-) mice. In vivo induction of EC miR-10a by administration of RARα/RXRα-specific agonists protects ApoE^-/- mice from atherosclerosis through inhibition of GATA6/VCAM-1 signaling and inflammatory cell infiltration.

CONCLUSIONS

Our findings indicate that down-regulation of miR-10a in aortic endothelium and blood serum is associated with atherosclerosis, and miR-10a has potential to be developed as diagnostic molecule for atherosclerosis. Moreover, EC miR-10a induction by RARα/RXRα-specific agonists is a potential hemodynamics-based strategy for atherosclerosis treatment.

Autologous Buccal Micro-Mucosa Free Graft combined with Posterior Scrotal Flap Transfer for Vaginoplasty in Male-To-Female Transsexuals: A Pilot Study

BACKGROUND

The inverted peno-scrotal flap method is considered the standard method of vaginoplasty in male-to-female genital reassignment surgery. Though with numerous advantages, the method has its limitations regarding skin texture, lack of inherent lubrication, and that the tissues for creating the labia depend on the amount of tissues remaining after vaginoplasty. Our purpose was to describe the procedure and outcome of vaginoplasty applying a new technique: autologous buccal micro-mucosa free graft combined with posterior scrotal flap transfer, which could solve some of the problems the previous methods had.

METHODS

Nine male-to-female transsexual patients received our new method of vaginoplasty from July 2010-October 2015. We described the details of the surgical procedure and evaluated the long-term anatomical and functional outcomes.

RESULTS

In a mean clinical follow-up period of 25.3 months and phone interview follow-up of 50.3 months, we observed that the neovaginas in the nine cases were all of sufficient volume, lined with mucosa, with natural mucosal discharge. The oral donor sites resulted in no visible scars or malfunction. Eight patients experienced uneventful postoperative periods, while one patient suffered from scrotal flap prolapse. All the patients were sexually active and reported sexual satisfaction, with no need of lubrication.

CONCLUSION

The reported technique achieves the outcomes of creating a neovagina of sufficient volume, without serious stenosis in long-term follow-up. The neovagina is lined with mucosa and has appropriate lubrication as well as good sexual sensation. The reported method is easy and economical to perform and retains enough tissues for vulvoplasty to achieve a superior cosmetic appearance, with rare risk of complications and donor area malfunction. Additionally, this technique is feasible and advantageous to the patients who have insufficient peno-scrotal skin for neovaginal lining as well as those with unfavorable previous vaginoplasty. All of these indicate that this technique is a promising option for vaginoplasty in male-to-female transsexual surgery.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Differential regulations of fibronectin and laminin in Smad2 activation in vascular endothelial cells in response to disturbed flow

BACKGROUND

Atherosclerosis occurs in arterial curvatures and branches, where the flow is disturbed with low and oscillatory shear stress (OSS). The remodeling and alterations of extracellular matrices (ECMs) and their composition is the critical step in atherogenesis. In this study, we investigated the effects of different ECM proteins on the regulation of mechanotransduction in vascular endothelial cells (ECs) in response to OSS.

METHODS

Through the experiments ranging from in vitro cell culture studies on effects of OSS on molecular signaling to in vivo examinations on clinical specimens from patients with coronary artery disease (CAD), we elucidated the roles of integrins and different ECMs, i.e., fibronectin (FN) and laminin (LM), in transforming growth factor (TGF)-β receptor (TβR)-mediated Smad2 activation and nuclear factor-κB (NF-κB) signaling in ECs in response to OSS and hence atherogenesis.

RESULTS

OSS at 0.5±12 dynes/cm² induces sustained increases in the association of types I and II TβRs with β1 and β3 integrins in ECs grown on FN, but it only transient increases in ECs grown on LM. OSS induces a sustained activation of Smad2 in ECs on FN, but only a transient activation of Smad2 in ECs on LM. OSS-activation of Smad2 in ECs on FN regulates downstream NF-κB signaling and pro-inflammatory gene expression through the activation of β1 integrin and its association with TβRs. In contrast, OSS induces transient activations of β1 and β3 integrins in ECs on LM, which associate with type I TβR to regulate Smad2 phosphorylation, resulting in transient induction of NF-κB and pro-inflammatory gene expression. In vivo investigations on diseased human coronary arteries from CAD patients revealed that Smad2 is highly activated in ECs of atherosclerotic lesions, which is accompanied by the concomitant increase of FN rather than LM in the EC layer and neointimal region of atherosclerotic lesions.

CONCLUSIONS

Our findings provide new insights into the mechanisms of how OSS regulates Smad2 signaling and pro-inflammatory genes through the complex signaling networks of integrins, TβRs, and ECMs, thus illustrating the molecular basis of regional pro-inflammatory activation within disturbed flow regions in the arterial tree.

Unequal Arterial Stiffness With Overall and Cardiovascular Mortality in Patients Receiving Hemodialysis

BACKGROUND

Pulse wave velocity is a marker of arterial stiffness. Unequal arterial stiffness has been associated with increased risk of cardiovascular events. This study calculated bilateral brachial-ankle pulse wave velocity (baPWV) differences and investigated the associations of unequal bilateral baPWV with overall and cardiovascular mortality in patients receiving hemodialysis (HD).

MATERIALS AND METHODS

A total of 205 patients receiving HD were enrolled in this study. The mean follow-up period was 4.4 ± 1.5 years. The baPWV was measured using an ankle-brachial index-form device, and bilateral baPWV difference was calculated and defined as ΔbaPWV.

RESULTS

The median value of ΔbaPWV was 88cm/second. ankle-brachial index < 0.95 and high baPWV were independently associated with a ΔbaPWV ≥ 88cm/s. Furthermore, patients with a ΔbaPWV ≥ 88cm/s demonstrated poorer overall (log-rank P = 0.035) and cardiovascular (log-rank P = 0.036) survival than did those with a ΔbaPWV < 88cm/s. After multivariate analysis, this difference was independently associated with overall (hazard ratio = 1.006; 95% CI: 1.001-1.011; P = 0.024) and cardiovascular (hazard ratio = 1.006; 95% CI: 1.000-1.013; P = 0.049) mortality.

CONCLUSIONS

ΔbaPWV was associated with an increased risk of cardiovascular and overall mortality in patients receiving HD. Earlier evaluation of ΔbaPWV may facilitate the identification of patients receiving HD who have an increased risk of cardiovascular and overall mortality.

Comparison of Long-Term Outcomes of Postmastectomy Radiotherapy between Breast Cancer Patients with and without Immediate Flap Reconstruction

PURPOSE

To compare the long-term clinical outcomes of postmastectomy radiotherapy (PMRT) between breast cancer patients with and without immediate transverse rectus abdominis myocutaneous (TRAM) flap reconstruction.

METHODS

The study included 492 patients with stage II or III breast cancer who underwent modified radical mastectomy (MRM) and chemotherapy followed by PMRT between 1997 and 2011. Cox regression model and Kaplan-Meier curves were calculated, and the log-rank test was used to evaluate the differences between overall and disease-free survival rates in the 2 groups.

RESULTS

Among 492 patients, 213 patients had immediate TRAM flap reconstruction. The mean follow-up was 7.2 years (range, 11-191 months). The 5-year and 10-year disease free survival rates were 81% and 76% for the TRAM flap group and 78% and 73% for the non-flap group. The 5-year and 10-year overall survival rates were 89% and 73% for the TRAM flap group and 83% and 74% for the non-flap group.

CONCLUSIONS

There exists no statistically significant difference in the rates of local recurrence, distant metastasis, disease-free and overall survival when comparing immediate TRAM flap reconstruction with no reconstruction. Our results suggest that immediate TRAM flap reconstruction does not compromise long term clinical outcomes in breast cancer patients requiring PMRT.

Protein kinase C-δ and -β coordinate flow-induced directionality and deformation of migratory human blood T-lymphocytes

T-lymphocyte migration under flow is critical for immune responses, but the mechanisms by which flow modulates the migratory behaviors of T-lymphocytes remain unclear. Human peripheral blood T-lymphocytes (PBTLs), when stimulated with phorbol 12-myristate 13-acetate (PMA), stretched their cell bodies dramatically and moved along the flow direction. In contrast, stromal cell-derived factor-1α-stimulated PBTLs deformed and migrated in a random manner. Here we elucidated the molecular mechanisms underlying flow-induced directionality and deformation of PMA-stimulated PBTLs. PMA primed PBTLs for polarization under flow, with protein kinase C (PKC)-δ enriched in the leading edge, PKC-βI in the microtubule organizing center, and PKC-βII in the uropod and peripheral region. PKC-δ regulated cell protrusions in the leading edge through Tiam1/Rac1/calmodulin, whereas PKC-β regulated RhoA/Rho-associated kinase activity and microtubule stability to modulate uropod contractility and detachment. Our findings indicate that PKC-δ and -β coordinate in the cell leading edge and uropod, respectively, to modulate the directionality and deformability of migratory T-lymphocytes under flow.

P wave dispersion and maximum P wave duration are associated with renal outcomes in chronic kidney disease

P wave parameters measured by 12-lead electrocardiogram (ECG) are commonly used as a noninvasive tool to evaluate left atrial enlargement. This study was designed to assess whether P wave parameters were associated with renal outcomes in chronic kidney disease (CKD) patients. This longitudinal study enrolled 439 patients with CKD stages 3–5. Renal end points were defined as the commencement of dialysis or death. Change in renal function was measured using the estimated glomerular filtration rate (eGFR) slope. We measured two ECG P wave parameters corrected for heart rate, i.e., corrected P wave dispersion and corrected maximum P wave duration. The values of P wave dispersion and maximum P wave duration were 88.8±21.7 ms and 153.3±21.7 ms, respectively. During the follow-up period (mean, 25.2 months), 95 patients (21.6%) started hemodialysis and 30 deaths (6.8%) were recorded. Multivariate Cox regression analysis identified that increased P wave dispersion [hazard ratio (HR), 1.020; 95% confidence interval (CI), 1.009–1.032; P<0.001] and maximum P wave duration (HR, 1.013; 95% CI, 1.003–1.024; P = 0.012) were associated with progression to renal end points. Furthermore, increased P wave dispersion (unstandardized coefficient β = –0.016; P = 0.037) and maximum P wave duration (unstandardized coefficient β = –0.014; P = 0.040) were negatively associated with the eGFR slope. We demonstrated that increased P wave dispersion and maximum P wave duration were associated with progression to the renal end points of dialysis or death and faster renal function decline in CKD patients. Screening CKD patients on the basis of P wave dispersion and maximum P wave duration may help identify patients at high risk for worse renal outcomes.

Regulation of nuclear translocation of the Myb1 transcription factor by TvCyclophilin 1 in the protozoan parasite Trichomonas vaginalis

In Trichomonas vaginalis, a Myb1 protein was previously demonstrated to repress transcription of an iron-inducible ap65-1 gene. In this study, a human cyclophilin A homologue, TvCyclophilin 1 (TvCyP1), was identified as a Myb1-binding protein using a bacterial two-hybrid library screening system. The recombinant TvCyP1 exhibited typical peptidyl-prolyl isomerase activity with kcat/Km of ∼7.1 μm(-1) s(-1). In a pulldown assay, the His-tagged Myb1 interacted with a GST-TvCyP1 fusion protein, which had an enzymatic proficiency half that of recombinant TvCyP1. Both the enzymatic proficiency of GST-TvCyP1 and its binding to His-Myb1 were eliminated by mutation of Arg(63) in the catalytic motif or inhibited by cyclosporin A. TvCyP1 was primarily localized to the hydrogenosomes by immunofluorescence assay, but it was also co-purified with Myb1 in certain vesicle fractions from differential and gradient centrifugations. Transgenic cells overexpressing HA-TvCyP1 had a higher level of nuclear Myb1 but a much lower level of Myb1 associated with the vesicles than control and those overexpressing HA-TvCyP1(R63A). Myb1 was detected at a much higher level in the HA-TvCyP1 protein complex than in the HA-TvCyP1(R63A) protein complex immunoprecipitated from P15 and P100, but not S100, fractions of postnuclear lysates. A TvCyP1-binding motif, (105)YGPKWNK(111), was identified in Myb1 in which Gly(106) and Pro(107) were essential for its binding to TvCyP1. Mutation of Gly(106) and Pro(107), respectively, in HA-Myb1 resulted in cytoplasmic retention and elevated nuclear translocation of the overexpressed protein. These results suggest that TvCyP1 may induce the release of Myb1 that is restrained to certain cytoplasmic vesicles prior to its nuclear translocation.

Somatometric measurements, and clinical chemistry and hematology parameters in Tibetan macaque (Macaca thibetana)

BACKGROUND

Limited physiological data for Tibetan macaques are available at present. This study will provide more rationale for evaluating this species.

METHODS

Thirty-seven Tibetan macaques (15 males and 22 females) were used in this study. Somatometric measurements, clinical chemistry and hematology parameters, insulin, and C-peptide were analyzed.

RESULTS

Females had higher values of waist and waist hip ratio (WHR) than males in somatometric measurements. There were no significant differences between the two genders in hematology. Significant differences between males and females were only found for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in biochemistry testing. In addition, females had higher fasting insulin and C-peptide than males. There was a strongly positive correlation between age and some somatometric parameters.

CONCLUSIONS

These physiological data will provide veterinarians and researchers with baseline values to evaluate experimental results using Tibetan macaques.

Mechanical regulation of epigenetics in vascular biology and pathobiology

Vascular endothelial cells (ECs) and smooth muscle cells (VSMCs) are constantly exposed to haemodynamic forces, including blood flow-induced fluid shear stress and cyclic stretch from blood pressure. These forces modulate vascular cell gene expression and function and, therefore, influence vascular physiology and pathophysiology in health and disease. Epigenetics, including DNA methylation, histone modification/chromatin remodelling and RNA-based machinery, refers to the study of heritable changes in gene expression that occur without changes in the DNA sequence. The role of haemodynamic force-induced epigenetic modifications in the regulation of vascular gene expression and function has recently been elucidated. This review provides an introduction to the epigenetic concepts that relate to vascular physiology and pathophysiology. Through the studies of gene expression, cell proliferation, angiogenesis, migration and pathophysiological states, we present a conceptual framework for understanding how mechanical force-induced epigenetic modifications work to control vascular gene expression and function and, hence, the development of vascular disorders. This research contributes to our knowledge of how the mechanical environment impacts the chromatin state of ECs and VSMCs and the consequent cellular behaviours.

Structure of the Trichomonas vaginalis Myb3 DNA-binding domain bound to a promoter sequence reveals a unique C-terminal β-hairpin conformation

Trichomonas vaginalis Myb3 transcription factor (tvMyb3) recognizes the MRE-1 promoter sequence and regulates ap65-1 gene, which encodes a hydrogenosomal malic enzyme that may play a role in the cytoadherence of the parasite. Here, we identified tvMyb3_53–180 as the essential fragment for DNA recognition and report the crystal structure of tvMyb3_53–180 bound to MRE-1 DNA. The N-terminal fragment adopts the classical conformation of an Myb DNA-binding domain, with the third helices of R2 and R3 motifs intercalating in the major groove of DNA. The C-terminal extension forms a β-hairpin followed by a flexible tail, which is stabilized by several interactions with the R3 motif and is not observed in other Myb proteins. Interestingly, this unique C-terminal fragment does not stably connect with DNA in the complex structure but is involved in DNA binding, as demonstrated by NMR chemical shift perturbation, ¹H-¹⁵N heteronuclear-nuclear Overhauser effect and intermolecular paramagnetic relaxation enhancement. Site-directed mutagenesis also revealed that this C-terminal fragment is crucial for DNA binding, especially the residue Arg¹⁵³ and the fragment K¹⁷⁰KRK¹⁷³. We provide a structural basis for MRE-1 DNA recognition and suggest a possible post-translational regulation of tvMyb3 protein.

Differential adhesion and actomyosin cable collaborate to drive Echinoid-mediated cell sorting

Cell sorting involves the segregation of two cell populations into `immiscible' adjacent tissues with smooth borders. Echinoid (Ed), a nectin ortholog, is an adherens junction protein in Drosophila, and cells mutant for ed sort out from the surrounding wild-type cells. However, it remains unknown which factors trigger cell sorting. Here, we dissect the sequence of this process and find that cell sorting occurs when differential expression of Ed triggers the assembly of actomyosin cable. Conversely, Ed-mediated cell sorting can be rescued by recruitment of Ed, via homophilic or heterophilic interactions, to the wild-type cell side of the clonal interface, even when differential Ed expression persists. We found, unexpectedly, that when actomyosin cable was largely absent, differential adhesion was sufficient to cause limited cell segregation but with a jagged tissue border (imperfect sorting). We propose that Ed-mediated cell sorting is driven both by differential Ed adhesion that induces cell segregation with a jagged border and by actomyosin cable assembly at the interface that smoothens this border.

Thigh muscle volume predicted by anthropometric measurements and correlated with physical function in the older adults

OBJECTIVES

(1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects.

DESIGN

Cross-sectional, nonrandomized study.

SETTING

Outpatient clinic in Taiwan.

PARTICIPANTS

Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older.

MEASURMENTS

The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard.

RESULTS

The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3－42.5 × Age (year)－955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P < 0.001; standard error of the estimate = 581.6 cm3).

CONCLUSION

The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.

Human RegIV protein adopts a typical C-type lectin fold but binds mannan with two calcium-independent sites

Human RegIV protein, which contains a sequence motif homologous to calcium-dependent (C-type) lectin-like domain, is highly expressed in mucosa cells of the gastrointestinal tract during pathogen infection and carcinogenesis and may be applied in both diagnosis and treatment of gastric and colon cancers. Here, we provide evidence that, unlike other C-type lectins, human RegIV binds to polysaccharides, mannan, and heparin in the absence of calcium. To elucidate the structural basis for carbohydrate recognition by NMR, we generated the mutant with Pro91 replaced by Ser (hRegIV-P91S) and showed that the structural property and carbohydrate binding ability of hRegIV-P91S are almost identical with those of wild-type protein. The solution structure of hRegIV-P91S was determined, showing that it adopts a typical fold of C-type lectin. Based on the chemical shift perturbations of amide resonances, two calcium-independent mannan-binding sites were proposed. One site is similar to the calcium-independent sugar-binding site on human RegIII and Langerin. Interestingly, the other site is adjacent to the conserved calcium-dependent site at position Ca-2 of typical C-type lectins. Moreover, model-free analysis of (15)N relaxation parameters and simplified Carr-Purcell-Meiboom-Gill relaxation dispersion experiments showed that a slow microsecond-to-millisecond time-scale backbone motion is involved in mannan binding by this site, suggesting a potential role for specific carbohydrate recognition. Our findings shed light on the sugar-binding mode of Reg family proteins, and we postulate that Reg family proteins evolved to bind sugar without calcium to keep the carbohydrate recognition activity under low-pH environments in the gastrointestinal tract.

Echinoid regulates Flamingo endocytosis to control ommatidial rotation in the Drosophila eye

Planar cell polarity (PCP) refers to a second polarity axis orthogonal to the apicobasal axis in the plane of the epithelium. The molecular link between apicobasal polarity and PCP is largely unknown. During Drosophila eye development, differentiated photoreceptors form clusters that rotate independently of the surrounding interommatidial cells (ICs). Here, we demonstrate that both Echinoid (Ed), an adherens junction-associated cell adhesion molecule, and Flamingo (Fmi), a PCP determinant, are endocytosed via a clathrin-mediated pathway in ICs. Interestingly, we found that Ed binds the AP-2 adaptor and is required for the internalization of Fmi into ICs. Loss of ed led to increased amounts of Fmi on the cell membrane of non-rotating ICs and also to the misrotation of photoreceptor clusters. Importantly, overexpression of fmi in ICs alone was sufficient to cause misrotation of the adjacent photoreceptor clusters. Together, we propose that Ed, when internalized by AP-2, undergoes co-endocytosis with, and thereby decreases, Fmi levels on non-rotating ICs to permit correct rotation of ommatidial clusters. Thus, co-endocytosis of Ed and Fmi provides a link between apicobasal polarity and PCP.

NMR structural analysis of DNA recognition by a novel Myb1 DNA-binding domain in the protozoan parasite Trichomonas vaginalis

The transcription regulator, tvMyb1, is the first Myb family protein identified in Trichomonas vaginalis. Using an electrophoretic mobility shift assay, we defined the amino-acid sequence from Lys(35) to Ser(141) (tvMyb1(35-141)) as the minimal DNA-binding domain, encompassing two Myb-like DNA-binding motifs (designated as R2 and R3 motifs) and an extension of 10 residues at the C-terminus. NMR solution structures of tvMyb1(35-141) show that both the R2 and R3 motifs adopt helix-turn-helix conformations while helix 6 in the R3 motif is longer than its counterpart in vertebrate Myb proteins. The extension of helix 6 was then shown to play an important role in protein stability as well as in DNA-binding activity. The structural basis for the tvMyb1(35-141)/DNA interaction was investigated using chemical shift perturbations, residual dipolar couplings, DNA specificity data and data-driven macromolecular docking by HADDOCK. Our data indicate that the orientation between R2 and R3 motifs dramatically changes upon binding to DNA so as to recognize the DNA major groove through a number of key contacts involving residues in helices 3 and 6. The tvMyb1(35-141)/DNA complex model furthers our understanding of DNA recognition by Myb proteins and this approach could be applied in determining the complex structures involving proteins with multiple domains.

Solution structure of a novel D-naphthylalanine substituted peptide with potential antibacterial and antifungal activities

A new type of Trp-rich peptide, Ac-KWRRWVRWI-NH2, designated as Pac-525, was found to possess improved activity against both gram-positive and negative bacteria. We have synthesized two Pac-525 analogues, D-Pac-525 containing all D-amino acids and D-Nal-Pac-525, the D-Pac-525 analogue with tryptophan replaced by D-beta-naphthylalanine. We have determined the solution structure of D-Nal-Pac-525 bound to membrane-mimetic DPC micelles by two-dimensional NMR methods. The DPC micelle-bound structure of D-Nal-Pac-525 adopts a left-hand alpha-helical segment and the positively charged residues are clustered together to form a hydrophilic patch. The surface electrostatic potential map indicates the three D-beta-naphthylalanines are packed against the peptide backbone and form an amphipathic structure. A variety of biophysical and biochemical experiments, including circular dichroism, fluorescence spectroscopy, and microcalorimetry, were used to show that D-Nal-Pac-525 interacted strongly with negatively charged phospholipid vesicles and induced efficient dye release from these vesicles, suggesting that the strong antimicrobial activity of D-Nal-Pac-525 may be due to interactions with bacterial and fungus membranes.

Cell adhesion molecule Echinoid associates with unconventional myosin VI/Jaguar motor to regulate cell morphology during dorsal closure in Drosophila

Echinoid (Ed) is a homophilic immunoglobulin domain-containing cell adhesion molecule (CAM) that localizes to adherens junctions (AJs) and cooperates with Drosophila melanogaster epithelial (DE)-cadherin to mediate cell adhesion. Here we show that Ed takes part in many processes of dorsal closure, a morphogenetic movement driven by coordinated cell shape changes and migration of epidermal cells to cover the underlying amnioserosa. Ed is differentially expressed, appearing in epidermis but not in amnioserosa cells. Ed functions independently from the JNK signaling pathway and is required to regulate cell morphology, and for assembly of actomyosin cable, filopodial protrusion and coordinated cell migration in dorsal-most epidermal cells. The effect of Ed on cell morphology requires the presence of the intracellular domain (Ed(intra)). Interestingly, Ed forms homodimers in vivo and Ed(intra) monomer directly associates with unconventional myosin VI/Jaguar (Jar) motor protein. We further show that ed genetically interacts with jar to control cell morphology. It has previously been shown that myosin VI is monomeric in vitro and that its dimeric form can associate with and travel processively along actin filaments. Thus, we propose that Ed mediates the dimerization of myosin VI/Jar in vivo which in turn regulates the reorganization and/or contraction of actin filaments to control changes in cell shape. Consistent with this, we found that ectopic ed expression in the amnioserosa induces myosin VI/Jar-dependent apical constriction of this tissue.

Solution structure of a novel tryptophan-rich peptide with bidirectional antimicrobial activity

Trp-rich antimicrobial peptides play important roles in the host innate defense mechanisms of many plants, insects, and mammals. A new type of Trp-rich peptide, Ac-KWRRWVRWI-NH(2), designated Pac-525, was found to possess improved activity against both gram-positive and -negative bacteria. We have determined that the solution structures of Pac-525 bound to membrane-mimetic sodium dodecyl sulfate (SDS) micelles. The SDS micelle-bound structure of Pac-525 adopts an alpha-helical segment at residues Trp2, Arg3, and Arg4. The positively charged residues are clustered together to form a hydrophilic patch. The three hydrophobic residues Trp2, Val6, and Ile9 form a hydrophobic core. The surface electrostatic potential map indicates the three tryptophan indole rings are packed against the peptide backbone and form an amphipathic structure. Moreover, the reverse sequence of Pac-525, Ac-IWRVWRRWK-NH(2), designated Pac-525(rev), also demonstrates similar antimicrobial activity and structure in membrane-mimetic micelles and vesicles. A variety of biophysical and biochemical methods, including circular dichroism, fluorescence spectroscopy, and microcalorimetry, were used to show that Pac-525 interacted strongly with negatively charged phospholipid vesicles and induced efficient dye release from these vesicles, suggesting that the antimicrobial activity of Pac-525 may be due to interactions with bacterial membranes.

Echinoid Is a Component of Adherens Junctions That Cooperates with DE-Cadherin to Mediate Cell Adhesion

Echinoid is an immunoglobulin domain-containing transmembrane protein that modulates cell-cell signaling by Notch and the EGF receptors. We show that, in the Drosophila wing disc epithelium, Echinoid is a component of adherens junctions that cooperates with DE-Cadherin in cell adhesion. Echinoid and beta-catenin (a DE-Cadherin interacting protein) each possess a C-terminal PDZ domain binding motif that binds to Bazooka/PAR-3; these motifs redundantly position Bazooka to adherens junctions. Echinoid also links to actin filaments by binding to Canoe/AF-6/afadin. Moreover, interfaces between Echinoid- and Echinoid+ cells, like those between DE-Cadherin- and DE-Cadherin+ cells, are deficient in adherens junctions and form actin cables. These characteristics probably facilitate the strong sorting behavior of cells that lack either of these cell-adhesion molecules. Finally, cells lacking either Echinoid or DE-Cadherin accumulate a high density of the reciprocal protein, further suggesting that Echinoid and DE-Cadherin play similar and complementary roles in cell adhesion.

Echinoid synergizes with the Notch signaling pathway in Drosophila mesothorax bristle patterning

echinoid (ed) encodes an immunoglobulin domain-containing cell adhesion molecule that negatively regulates the Egfr signaling pathway during Drosophila photoreceptor development. We show a novel function of Ed, i.e. the restriction of the number of notum bristles that arise from a proneural cluster. Thus, loss-of-function conditions for ed give rise to the development of extra macrochaetae near the extant ones and increase the density of microchaetae. Analysis of ed mosaics indicates that extra sensory organ precursors (SOPs) arise from proneural clusters of achaete-scute expression in a cell-autonomous way. edembryos also exhibit a neurogenic phenotype. These phenotypes suggest a functional relation between ed and the Notch (N) pathway. Indeed,loss-of-function of ed reduces the expression of the N pathway effector E(spl)m8 in proneural clusters. Moreover, combinations of moderate loss-of-function conditions for ed and for different components of the N pathway show clear synergistic interactions manifested as strong neurogenic bristle phenotypes. We conclude that Ed is not essential for, but it facilitates, N signaling. It is known that the N and Egfr pathways act antagonistically in bristle development. Consistently, we find that Ed also antagonizes the bristle-promoting activity of the Egfr pathway, either by the enhancement of N signalling or, similar to the eye, by a more direct action on the Egfr pathway.

Neuroglian activates Echinoid to antagonize the Drosophila EGF receptor signaling pathway

echinoid (ed) encodes an cell-adhesion molecule (CAM) that contains immunoglobulin domains and regulates the EGFR signaling pathway during Drosophila eye development. Based on our previous genetic mosaic and epistatic analysis, we proposed that Ed, via homotypic interactions, activates a novel, as yet unknown pathway that antagonizes EGFR signaling. In this report, we demonstrate that Ed functions as a homophilic adhesion molecule and also engages in a heterophilic trans-interaction with Drosophila Neuroglian (Nrg), an L1-type CAM. Co-expression of ed and nrg in the eye exhibits a strong genetic synergy in inhibiting EGFR signaling. This synergistic effect requires the intracellular domain of Ed, but not that of Nrg. In addition, Ed and Nrg colocalize in the Drosophila eye and are efficiently co-immunoprecipitated. Together, our results suggest a model in which Nrg acts as a heterophilic ligand and activator of Ed, which in turn antagonizes EGFR signaling.

External beam radiation therapy for inoperable hepatocellular carcinoma with portal vein thrombosis

Portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC) has a poor impact on prognosis. Many of these tumors may cause intrahepatic and extrahepatic metastases. From January 1991 to December 1996, 41 unresectable HCC patients with PVT underwent transcatheter arterial chemoembolization (TACE) and external beam radiation therapy (EBRT) to the portion of PVT. The irradiated field, with a mean equivalent field size of 6.6 x 7.1 cm2, was localized and simulated by abdominal sonography, angiography and computed tomography. Radiation dose ranged from 36 to 66 Gy (mean dose: 51.4 Gy), in a daily fraction of 1.8 to 2 Gy. The response of EBRT was evaluated by abdominal sonography within 3 months of completion of EBRT. The response rates of the PVT after treatment were 39% for complete response (CR), 41% for partial response (PR), and 19% for no response (NR), respectively. The median overall survival time from start of radiotherapy was 10 months for all patients, 17 months for CR patients, 8 months for PR patients and 4 months for NR patients. By multivariate analysis, response of PVT resulted in a significant improvement in survival. (P = 0.001) There was no occurrence of severe complication of radiation-induced liver disease. The results obtained with combined treatment modality of EBRT and TACE in the treatment of HCC patients with PVT are encouraging.

Red blood cell osmotic fragility in chronically hemodialyzed patients

Chronic renal failure induces anemia and a short erythrocyte life span. Red blood cell (RBC) osmotic fragility is the resistance of RBC hemolysis to osmotic changes that is used to evaluate RBC friability. To find the cause of shortened red cell survival in uremic patients, we evaluated the RBC osmotic fragility in 57 chronic hemodialyzed patients. Each patient had received 12 h of dialysis per week continuously prior to being enrolled in the study. Nineteen healthy volunteers served as a control group. Biochemistry, hemoglobin, electrolyte, osmolarity, beta2-microglobulin, and intact parathyroid hormone were examined before and after the dialysis session. To evaluate the osmotic fragility of RBC, blood samples were collected in heparinized test tubes. Fifty microliters of the RBC of each individual was then incubated in solutions containing a series of various concentrations of NaCl ranging from 0 to 0.6%. The concentration of NaCl at which 50% of RBCs were lysed was considered the median osmotic fragility (MOF). The results showed that the MOF was significantly greater in hemodialyzed patients before dialysis than in the control group (0.41 +/- 0.03 vs. 0.39 +/- 0.02%). The osmotic resistance to hemolysis was also recorded after dialysis (MOF 0.38 +/- 0.03%). Correlation analysis showed that the MOF was significantly correlated with urea nitrogen, serum osmolarity, and intact parathyroid hormone level. In addition, the osmotic fragility was higher in patients who had a predialysis intact parathyroid hormone level > 100 pg/dl. In conclusion, hemodialysis can improve the osmotic fragility. The mechanism underlying this improvement may be the removal of low molecular weight uremic toxins, resulting in normalization of serum osmolarity. Our results indicate that parathyroid hormone is probably a major factor influencing RBC osmotic fragility in chronic renal failure.

Talo-navicular arthrodesis for residual midfoot deformities of a previously corrected clubfoot

Triangular navicular, dorsal-lateral subluxation of the talo-navicular (TN) joint with a secondary forefoot cavovarus deformity, and degenerative changes of the TN joint are frequent causes of residual clubfoot deformity and pain in the midfoot after surgical correction. This study investigates the usefulness of TN arthrodesis to correct these deformities and to resolve symptoms resulting from these deformities. During the period from 1991-1996, the senior author performed 19 TN fusions (16 patients) for the above residual clubfoot deformities involving a painful TN joint. Eight of the procedures (seven patients) also required a lateral column shortening with a calcaneal wedge osteotomy to allow for a complete correction of the TN joint. The procedure was only performed in cases involving a hindfoot that was adequately aligned during a previous clubfoot correction. The average age of the patients at the time of surgery was 11 years (range: 4-20). One patient (bilateral procedures) was lost to follow-up. Fifteen patients (17 procedures) were followed-up for an average of four years (range: 2-6). All patients reported symptomatic improvement after the TN arthrodesis. Fourteen of the patients (15 procedures) were completely satisfied. The remaining patient (bilateral procedures) was only partially satisfied due to the subsequent development of navicular-cuneiform osteoarthritis in both feet. Two cases (2 patients) developed complications requiring a second procedure for satisfactory results. In addition, the procedure resulted in an improvement of the talus-first metatarsal angle on both antero-posterior and lateral radiographs. TN arthrodesis produced a correction of the residual clubfoot deformities of the midfoot and resulted in satisfactory clinical improvement in all the patients.

Avascular necrosis in children with acute lymphoblastic leukemia

This study describes the prevalence and demographics of avascular necrosis (AVN) in children with acute lymphoblastic leukemia (ALL). With improving survival of ALL patients on modern chemotherapy regimens, an increasing number of children with AVN will be presenting to orthopaedists. From 1991 to 1996, 202 patients were treated for ALL at a major tertiary pediatric cancer referral center. Eight patients (4.0%) subsequently developed AVN at an average of 30.0 months after beginning chemotherapy. A total of 27 documented joints were involved, with an average of 3.4 joints affected per patient diagnosed with AVN. The subset of patients with high-risk ALL who underwent an aggressive chemotherapy protocol was particularly susceptible to developing AVN. Six of 58 high-risk ALL patients (10.3%) developed AVN at an average of 18.5 months. As ALL patients now frequently survive into adulthood, orthopaedists will be increasingly called on to manage AVN affecting multiple joints in children and young adults.

Solution structure and dynamics of G1TE, a nonphosphorylated cyclic peptide inhibitor for the Grb2 SH2 domain

The solution structure and dynamics of G1TE, a nonphosphorylated cyclic peptide inhibitor for the Grb2 SH2 domain, was determined using two-dimensional NMR and simulated annealing methods. G1TE consists of 10 amino acids and a C-terminal Cys cyclized through its side-chain sulfur atom by a thioether linkage to its N terminus. The results indicate that G1TE assumes a circle-like shape in solution in which all the side chains are protruding outside, and none of the residues are involved in intramolecular hydrogen bonding. The average root-mean-square deviations were found to be 0.41 +/- 0.11 A for the backbone heavy atoms C, Calpha, and N, and 1.03 +/- 0.14 A for all heavy atoms in a family of 10 structures. (15)N relaxation measurements indicate that G1TE has rather restricted dynamics in the fast time scale within its backbone. However, residues Tyr3, Val6, and Gly7 may be involved in a possible conformational exchange. The structural comparison between G1TE in solution and the BCR-Abl phosphopeptide bound to Grb2 SH2 domain revealed that G1TE may form a larger circle-like binding surface than the BCR-Abl phosphopeptide in the bound form. Also, the restricted backbone dynamics of G1TE may result in a reduced loss of entropy and can compensate for the absence of a phosphate group at the Tyr3 position. These structural and dynamic properties of G1TE may provide a molecular basis for understanding its interactions with the Grb2 SH2 domain.

Revision total hip arthroplasty in patients with avascular necrosis

This retrospective study compared the results of revision total hip arthroplasty (THA) in patients with avascular necrosis to patients with osteoarthritis. Twenty-two revision THAs (34 components) in 19 patients with avascular necrosis were compared with 35 revision THAs (55 components) in 31 patients with osteoarthritis. All of the procedures were performed by a single surgeon between 1981 and 1994, and all patients had a minimum of 2 years of follow-up. At the time of revision surgery, the average age was 54 years for the avascular necrosis patients and 67 years for the osteoarthritis patients (P=.002). Clinical and radiographic follow-up was performed for an average of 7 years (range: 2-12 years). Six (18%) components in the avascular necrosis group and nine (16%) components in the osteoarthritis group required re-revision for aseptic loosening an average of 7 years after the original revision (range: 2-11 years). Statistical analysis demonstrated no significant difference between the two groups in regard to the incidence of failure, time to failure, Harris Hip Score, and radiographic appearance. Contrary to expectations derived from the literature on primary THA, no difference was found between the outcome and survivorship of revision THA in patients with avascular necrosis and patients with osteoarthritis, despite a significant difference in age.

Nonoperatively treated displaced bimalleolar and trimalleolar fractures: a 20-year follow-up

This study evaluates the long-term results of displaced bi- and trimalleolar fractures treated closed. Few reports exist in the literature regarding the long-term outcomes of ankle fractures, and none of these specifically addresses displaced bi- and trimalleolar fractures treated nonoperatively. This study analyzed the results of bi- and trimalleolar fractures treated by a single surgeon from 1973 to 1981. As was the standard of care at that time, these fractures were treated nonoperatively if a stable reduction was achieved and maintained. Serial radiographs confirmed the maintenance of reduction in a non-weightbearing long leg cast for 6 weeks and then a short leg walking cast for 6 weeks. Of the 34 patients in this series, 19 were available for review, 10 were deceased, and five were lost to follow-up. The average age at the time of injury was 39 years (range, 17-79 years), and the average length of follow-up was 20 years (range, 16-24 years). At the time of review, only two patients with trimalleolar fractures were minimally symptomatic or had radiographic evidence of mild degenerative changes. The average American Orthopaedic Foot and Ankle Score was 98 of 100 points (range, 87-100 points). This long-term follow-up shows that bi- and trimalleolar fractures can be treated nonoperatively if an anatomic reduction is maintained and closely followed. With reports indicating as much as a 5% deep infection rate and a 10% incidence of loss of reduction after internal fixation, universally recommending an operation for these injuries should be reconsidered, especially in high surgical risk patients.

Diaphyseal forearm fractures treated with and without bone graft

BACKGROUND

The purpose of this study was to determine whether the acute bone grafting of diaphyseal forearm fractures decreases the incidence of nonunion and reduces the time to union. Although the traditional treatment of comminuted radius and/or ulnar shaft fractures involves bone graft, a recent report called into question this practice.

PATIENTS

A database search was used to identify all acute diaphyseal forearm fractures presenting to an urban Level I trauma center between 1988 and 1996. All radius and/or ulnar shaft fractures, as well as all Monteggia and Galeazzi fracture-dislocations, in patients with closed physes were included. The charts and operative reports were available for 64 diaphyseal forearm fractures in 49 patients. Fifty-six fractures were followed for at least 1 year beyond clinical and radiographic union. The injuries were treated with open reduction and plate fixation by experienced orthopedic traumatologists. All noncomminuted fractures were treated without bone graft. For the comminuted fractures, the decision to use bone graft was left to the discretion of the operating surgeon.

RESULTS

Overall, 55 of 56 fractures (98%) achieved union at a mean of 49 days (range, 19-123 days), with the only nonunion occurring in a patient with a closed, noncomminuted Galeazzi injury. Among the 20 noncomminuted fractures, all of which were treated without bone graft, 19 (95%) achieved union at a mean of 50 days (range, 19-102 days). Among the 36 comminuted fractures, all 25 treated without bone graft achieved fusion at an average of 50 days (range, 20-123 days) and all 11 treated with bone graft achieved union at an average of 45 days (range, 22-67 days). No statistically significant difference in the incidence of nonunion or time to union was noted between fractures that were treated with and without bone graft.

CONCLUSION

Acute bone grafting of diaphyseal forearm fractures did not affect the union rate or the time to union.

Aggressive treatment of 119 open fracture wounds

BACKGROUND

The purpose of this study was to determine whether immediate primary closure of open fracture wounds can be performed without increasing the incidence of infections and delayed unions/nonunions. Although the traditional management of these injuries has been open treatment, a trend toward immediate primary closure has evolved on our service.

METHODS

All open fractures presenting to an urban Level I trauma center during a 42-month period were reviewed. Of the 127 patients with open fractures, 90 patients (119 open fractures) were initially treated at the above institution within 24 hours of injury, had fractures proximal to the carpus or tarsals, and were followed-up until fracture union. All patients underwent emergent wound irrigation and debridement. The method of fracture immobilization and timing of wound closure was left to the discretion of the attending orthopedic surgeon. Immediate primary closure was used in 22 of 25 Grade I open fractures (88%), 37 of 43 Grade II fractures (86%), 24 of 32 Grade IIIa fractures (75%), 4 of 12 Grade IIIb fractures (33%), and 0 of 7 Grade IIIc fractures (0%).

RESULTS

Eight fractures (7%) were complicated by a deep wound infection/osteomyelitis, and 19 fractures (16%) developed a delayed union/nonunion. Statistical analysis revealed no significant difference in delayed/nonunion and infection rates between immediate and delayed closures.

CONCLUSION

Immediate primary closure of open fracture wounds after a thorough debridement by an experienced fracture surgeon appears to cause no significant increase in infections or delayed union/nonunions. In addition, early closure may decrease the requirement for subsequent debridements and soft-tissue procedures, thereby minimizing surgical morbidity, shortening hospital stays, and reducing costs. We feel that a randomized, prospective study of this aggressive approach to open fracture care is warranted.