Ladder Phenylenes Synthesized on Au(111) Surface via Selective [2+2] Cycloaddition.

Ladder phenylenes (LPs) composed of alternating fused benzene and cyclobutadiene rings have been synthesized in solution with a maximum length no longer than five units. Longer polymeric LPs have not been obtained so far because of their poor stability and insolubility. Here, we report the synthesis of linear LP chains on the Au(111) surface via dehalogenative [2+2] cycloaddition, in which the steric hindrance of the methyl groups in the 1,2,4,5-tetrabromo-3,6-dimethylbenzene precursor improves the chemoselectivity as well as the orientation orderliness. By combining scanning tunneling microscopy and noncontact atomic force microscopy, we determined the atomic structure and the electronic properties of the LP chains on the metallic substrate and NaCl/Au(111). The tunneling spectroscopy measurements revealed the charged state of chains on the NaCl layer, and this finding is supported by density functional theory calculations, which predict an indirect bandgap and antiferromagnetism in the polymeric LP chains.

Post-Functionalization of Supramolecular Polymers on Surface and the Chiral Assembly-Induced Enantioselective Reaction.

Although post-functionalization is extensively used to introduce diverse functional groups into supramolecular polymers (SPs) in solution, post-functionalization of SPs on surfaces still remains unexplored. Here we achieved the on-surface post-functionalization of two SPs derived from 5,10,15-tri-(4-pyridyl)-20-bromophenyl porphyrin (Br-TPyP) via cross-coupling reactions on Au(111). The ladder-shaped, Cu-coordinated SPs preformed from Br-TPyP were functionalized through Heck reaction with 4-vinyl-1,1'-biphenyl. In the absence of Cu, Br-TPyP formed chiral SPs as two enantiomers via self-assembly, which were functionalized via divergent cross-coupling reaction with 4-isocyano-1,1'-biphenyl (ICBP). Surprisingly, this reaction was discovered as an enantioselective on-surface reaction induced by the chirality of SPs. Mechanistic analysis and DFT calculations indicated that after debromination of Br-TPyP and the first addition of ICBP, only one attack direction of ICBP to the chiral SP intermediate is permissive in the second addition step due to the steric hindrance, which guaranteed the high enantioselectivity of the reaction.

NSTI Organisms and Regions: A Multicenter Study From the American Association for the Surgery of Trauma.

BACKGROUND: Conflicting data on the microbiology and epidemiology of necrotizing soft tissue infections (NSTIs) appear to stem from the heterogeneity in microbiology observed in regions across the United States. Our goal was to determine current differences in organism prevalence and outcomes for NSTI and non-necrotizing severe soft tissue infections across the United States. We hypothesized that there were geographical differences in organism prevalence that would lead to differences in outcomes. MATERIALS AND METHODS: This study was a retrospective multi-institutional trial from centers across the United States and Canada. Demographic, clinical, and outcomes data were collected. Bivariate and multivariable analyses were performed to determine the effects of region and microbiology on outcomes. RESULTS: A total of 622 patients were included in this study. Polymicrobial infections (45%) were the most prevalent infections in all regions. On bivariate analysis, Clostridium and polymicrobial infections had higher mean Laboratory Risk Indicator for Necrotizing Fasciitis scores and American Association for the Surgery of Trauma grades (P < 0.001 for both) than other organisms. Patients in the South were more likely to be uninsured and had worse unadjusted outcomes. In a risk-adjusted model, increasing American Association for the Surgery of Trauma grade was predictive of mortality (OR, 2.3; 95% CI, 1.6-3.1; P < 0.001), as was age ≥ 55 y (OR 2.7, 95% CI 1.3-5.3, P = 0.006), but region and organism type were not associated with mortality. CONCLUSIONS: We found important regional differences with respect to organism type and demographics. However, on risk-adjusted models, neither region nor organism type predicted mortality.

Role of oxidative stress in surgical cavernous nerve injury in a rat model.

This study investigates the role of oxidative stress in surgical cavernous nerve (CN) injury in a rat model. Eighty-four male Sprague-Dawley rats were randomly divided into three groups: group 1, sham-operated rats; group 2, bilateral CN-crushed rats; and group 3, bilateral CN-transection-and-sutured-immediately rats. Oxidative stress was evaluated by malondialdehyde levels, super oxide dismutase (SOD) activities, and glutathione peroxidase (GPX) activities in serum. Erectile function was assessed by CN electrostimulation at 3 months with mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure. Nerve injury was assessed by toluidine blue staining of CNs and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining of penile tissue. GPX protein expression and nitrotyrosine-3 (NT-3) levels in penile tissue were measured. Erectile function and the number of myelinated axons of CNs and NADPH-diaphorase-positive nerve fibers were statistically decreased between groups, from sham to crush to transection. For markers, both nerve-injury groups showed increased oxidative stress markers at early time points, with the transection group showing greater oxidative stress than the crushed group and values normalizing to sham levels by week 12. GPX expression and NT-3 levels in penile tissue were in concordance with the results of SOD and GPX. These results show that oxidative stress plays an important role in injured CNs, and different methods of CN injury can lead to different degrees of oxidative stress in a rat model.

Left ventricular global longitudinal strain using a novel fully automated method: A head-to-head comparison with a manual layer-specific strain and establishment of normal reference ranges.

BACKGROUND: A novel automated method for measuring left ventricular (LV) global longitudinal strain (GLS) along the endocardium has advantages in terms of its rapid application and excellent reproducibility. However, it remains unclear whether the available normal range for conventional GLS using the manual method is applicable to the automated GLS method. This study aimed to compare automated GLS head-to-head with manual layer-specific GLS, and to identify whether a specialized normal reference range for automated GLS is needed and explore the main determinants. METHODS: In total, 1683 healthy volunteers (men, 43%; age, 18-80 years) were prospectively enrolled from 55 collaborating laboratories. LV GLS was measured using both manual layer-specific and automated methods. RESULTS: Automated GLS was higher than endocardial, mid-myocardial, and epicardial GLS. Women had a higher automated GLS than men. GLS had no significant age dependency in men, but first increased and then decreased with age in women. Accordingly, sex- and age-specific normal ranges for automated GLS were proposed. Moreover, GLS appeared to have different burdens in relation to dominant determinants between the sexes. GLS in men showed no dominant determinants; however, GLS in women correlated with age, body mass index, and heart rate. CONCLUSIONS: Using the novel automated method, was LV GLS higher than when using the manual GLS method. The normal ranges of automated GLS stratified according to sex and age were provided, with dominant determinants showing sex disparities that require full consideration in clinical practice.

[Thermodynamics process of laser drilling on copper surface].

The laser drilling experiment was carried out on the copper surface by ns laser pulse, then the micro-morphology of the micro-hole was observed and the thermodynamic process was analyzed accordingly. The research results show that micro-hole is made of the pit in the center and surrounding uplift. The pit becomes deeper with the incident laser pulse energy. The thermodynamic analysis indicates that laser drilling on the metal requires two basic conditions: the first is the deposition of laser pulse energy, which makes the occurrence of melting, vaporization and ionization. Such phase transition can make the materials easy to remove and the laser plasma can accelerate the laser pulse energy deposition as the secondary heat source. The second condition is the production of the laser plasma shock wave, it can eject the materials of phase transition effectively and timely, thus the micro hole can be formed.

Empiric tranexamic acid use provides no benefit in urgent orthopedic surgery following injury.

Background: Orthopedic literature has demonstrated a significant decrease in postoperative transfusion requirements when tranexamic acid (TXA) was given during elective joint arthroplasty. The purpose of this study was to evaluate the empiric use of TXA in semi-urgent orthopedic procedures following injury. We hypothesized that TXA would be associated with increased rates of venous thromboembolic events (VTE) and have no effect on transfusion requirements. Methods: Patients who empirically received TXA during a semi-urgent orthopedic surgery following injury (TXA+) were matched using propensity scoring to historical controls (CONTROL) who did not receive TXA. Outcomes included VTE within 6 months of injury and packed red blood cell utilization. Multivariable logistic regression and generalized linear modeling were used to determine odds of VTE and transfusion. Results: 200 patients were included in each group. There was no difference in mortality between groups. TXA+ patients did not have an increase in VTE events (OR 0.680, 95% CI 0.206 to 2.248). TXA+ patients had a significantly higher odds of being transfused during their hospital stay (OR 2.175, 95% CI 1.246 to 3.797) and during the index surgery (increased 0.95 units (SD 0.16), p<0.0001). Overall transfusion was also significantly higher in the TXA+ group (p=0.0021). Conclusion: Empiric use of TXA in semi-urgent orthopedic surgeries did not increase the odds of VTE. Despite the elective literature, TXA administration did not associate with less transfusion requirements. A properly powered, prospective, randomized trial should be designed to elucidate the risks and benefits associated with TXA use in this setting. Level of evidence: Level IV.

Normal reference values for mitral annular plane systolic excursion by motion-mode and speckle tracking echocardiography: a prospective, multicentre, population-based study.

AIMS: Mitral annular plane systolic excursion (MAPSE) is a simple and reliable index for evaluating left ventricular (LV) systolic function, particularly in patients with poor image quality; however, the lack of reference values limits its widespread use. This study aimed to establish the normal ranges for MAPSE measured using motion-mode (M-mode) and two-dimensional speckle tracking echocardiography (2D-STE) and to explore its principal determinants. METHODS AND RESULTS: This multicentre, prospective, cross-sectional study included 1952 healthy participants [840 men (43%); age range, 18-80 years] from 55 centres. MAPSE was measured using M-mode echocardiography and 2D-STE. The results showed that women had a higher MAPSE than men and MAPSE decreased with age. The age- and sex-specific reference values for MAPSE were established for these two methods. Multiple linear regression analyses revealed that MAPSE on M-mode echocardiography correlated with age and MAPSE on 2D-STE with age, blood pressure (BP), heart rate, and LV volume. Moreover, MAPSE measured by 2D-STE correlated more strongly with global longitudinal strain compared with that measured using M-mode echocardiography. CONCLUSION: Normal MAPSE reference values were established based on age and sex. BP, heart rate, and LV volume are potential factors that influence MAPSE and should be considered in clinical practice. Normal values are useful for evaluating LV longitudinal systolic function, especially in patients with poor image quality, and may further facilitate the use of MAPSE in routine assessments.

[Research on cells ablation characters by laser plasma].

The study on the mechanism of laser ablated cells is of importance to laser surgery and killing harmful cells. Three radiation modes were researched on the ablation characteristics of onion epidermal cells under: laser direct irradiation, focused irradiation and the laser plasma radiation. Based on the thermodynamic properties of the laser irradiation, the cell temperature rise and phase change have been analyzed. The experiments show that the cells damage under direct irradiation is not obvious at all, but the focused irradiation can cause cells to split and moisture removal. The removal shape is circular with larger area and rough fracture edges. The theoretical analysis found out that the laser plasma effects play a key role in the laser ablation. The thermal effects, radiation ionization and shock waves can increase the deposition of laser pulses energy and impact peeling of the cells, which will greatly increase the scope and efficiency of cell killing and is suitable for the cell destruction.

[Estradiol stimulates proliferation of prostatic smooth muscle cells via estrogen receptor alpha and IGF1].

OBJECTIVE: To investigate the effects of estrogen receptor alpha (ERa) and insulin-like growth factor 1 (IGF1) on the proliferation of prostatic smooth muscle cells (PSMCs) in vitro. METHODS: The ERalpha shRNA expression frame was subcloned to the pGSadeno adenovirus vector by homologous recombination technology to construct the pGSaaeno-ERalpha vector. After the mouse PSMCs were transfected in vitro by pGSaaeno-ERalpha, the mRNA and protein expression levels of ERalpha were detected by RT-PCR and Western blot respectively. The expression of IGF1 in the ERa-reduced cells was determined by Western blot 6 hours after treatment with 17beta-estradiol (E2) at 10(-8) mol/L. The post-transfection activity of estrogen or exogenous IGF1 in the proliferation of PSMCs was evaluated by MTT chlormetric analysis. RESULTS: After treatment with E2, the proliferation of PSMCs and the expression of the IGF1 gene were significantly increased in the normal control group (P <0.05), but not obviously changed in the ERalpha-siRNA group (P> 0.05). And exogenous IGF1 failed to induce the proliferation of the ERalpha-reduced PSMCs. CONCLUSION: E2 induces the expression of IGF1 via ERalpha, and IGFl, with the interaction of ERalpha, promotes the proliferation of PSMCs.

Er3+-Ions-Doped Multiscale Nanoprobes for Fluorescence Imaging in Cellular and Living Mice.

With the development of biotechnology, luminescent nanoprobes for biological disease detection are widely used. However, the further application in clinic is limited by the reduced penetration depth in the tissues and light scattering. In this work, we have synthesized NaYF4:Yb,Er,Ce@SiO2-OAlg nanomaterials, which have both upconversion and near-infrared (NIR) luminescence. The optimized probes were determined to achieve cell imaging by its upconversion (UCL) luminescence and in vivo imaging through collection of NIR fluorescence signals simultaneously. The research is conducive to developing accurate diagnostic techniques based on UCL and NIR fluorescence imaging by a single nanoparticle.

Steering Metal-Organic Network Structures through Conformations and Configurations on Surfaces.

Molecular adsorption conformations and arrangement configurations on surfaces are important structural aspects of surface stereochemistry, but their roles in steering the structures of metal-organic networks (MONs) remain vague and unexplored. In this study, we constructed MONs by the coordination self-assembly of isocyanides on Cu(111) and Ag(111) surfaces and demonstrated that the MON structures can be steered by surface stereochemistry, including the adsorption conformations of the isocyanide molecules and the arrangement configurations of the coordination nodes and subunits. The coordination self-assembly of 1,4-phenylene diisocyanobenzene afforded a honeycomb MON consisting of 3-fold (isocyano)3-Cu motifs on a Cu(111) surface. In contrast, geometrically different chevron-shaped 1,3-phenylene diisocyanobenzene (m-DICB) failed to generate a MON, which is ascribable to its standing conformation on the Cu(111) surface. However, m-DICB was adsorbed in a flat conformation on a Ag(111) surface, which has a larger lattice constant than a Cu(111) surface, and smoothly underwent coordination self-assembly to form a MON consisting of (isocyano)3-Ag motifs. Interestingly, only C3-Ag nodes with heterotactic configurations could grow into larger subunits; those subunits with heterotactic configurations further grew into Sierpinski triangle fractals (up to fourth order), while subunits with homotactic configurations afforded a triangular MON.

[Induction of cell cycle arrest in bladder cancer RT4 cells by capsaicin].

OBJECTIVE: To study the effects of capsaicin on the growth of bladder cancer RT4 cell and its potential mechanism. METHODS: Cell counting kit-8 (CCK-8) assay and flow cytometry were employed to observe the effects of capsaicin (50, 100, 150, 200, 250 micromol/L) on cell growth, cell cycle and apoptosis. Capsaicin (0 micromol/L) was used as a control. The effects of mRNA and protein of transient receptor potential cation channel subfamily V 1 (TRPV1) on RT4 cells were tested by RT-PCR and immunofluorescence respectively. And the expressions of cell cycle protein P53, P21, CDK2 were detected by Western blot after the treatment of capsaicin. RESULTS: 100 micromol/L capsaicin significantly decreased the viability of RT4 cell [82.0% +/- 6.2% vs 100.0% +/- 12.4% (control), P = 0.036] while the cell viability was 7.8% +/- 2.9% at 250 micromol/L (P = 0.000). It was in a dose-dependent manner. On the other hand, capsaicin induced the cell cycle arrest of bladder cancer RT4 cells G(0)/G(1) phase in a dose-dependent way. The cell proportion of G(0)/G(1) phase in the control was 37.4% +/- 5.6%, however, it was 72.4% +/- 5.3% at 250 micromol/L (P = 0.000). It was showed that TRPV1 mRNA and protein were expressed in RT4 cells. After a 48-hour treatment with capsaicin, the expressions of P53 and P21 were up-regulated in contrary to the expression of CDK2. CONCLUSION: Capsaicin induces the cell cycle arrest of bladder cancer RT4 cells G(0)/G(1) phase and growth inhibition via TRPV1 receptor by modulating the expression of P53, P21 and CDK2.

The effect of platelet-rich plasma on cavernous nerve regeneration in a rat model.

The aim of this study was to investigate the effect of platelet-rich plasma (PRP) on cavernous nerve (CN) regeneration and functional status in a nerve-crush rat model. Twenty-four Sprague-Dawley male rats were randomly divided into three equal groups: eight had a sham operation, eight underwent bilateral nerve crushing with no further intervention and eight underwent bilateral nerve crushing with an immediate application of PRP on the site of injury. Erectile function was assessed by CN electrostimulation at 3 months and nerve regeneration was assessed by toluidine blue staining of CN and nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase staining of penile tissue. Three months after surgery, in the group that underwent bilateral nerve crushing with no further intervention, the functional evaluation showed a lower mean maximal intracavernous pressure (ICP) and maximal ICP per mean arterial pressure (MAP) with CN stimulation than those in the sham group. In the group with an immediate application of PRP, the mean maximal ICP and maximal ICP/MAP were significantly higher than those in the injured control group. Histologically, the group with the application of PRP had more myelinated axons of CNs and more NADPH-diaphorase-positive nerve fibres than the injured control group but fewer than the sham group. These results show that the application of PRP to the site of CN-crush injury facilitates nerve regeneration and recovery of erectile function. Our research indicates that clinical application of PRP has potential repairing effect on CN and peripheral nerves.

[Protective effects of L-carnitine upon testicular ischemia-reperfusion damage in rats].

OBJECTIVE: To investigate the protective effects of L-carnitine upon testicular ischemia-reperfusion injury in rats. METHODS: Sprague-Dawley rats were divided into 3 groups (n = 10). In those animals undergoing unilateral testicular torsion, right testes were rotated 720 degrees for 2 h. Sham operated group served as a control group. Torsion group underwent 2 h torsion and saline was injected intraperitoneally at 30 min pre-detorsion. Treatment group underwent similar torsion but L-carnitine (500 mg/kg) was infused intraoperatively. The right testes of 5 animals in each group were excised after 4 h reperfusion for measuring the levels of malondialdehyde (MDA) and heat shock protein 70 (HSP70), evaluation of activities of antioxidant enzyme including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Histopathological changes and germ cell apoptosis indices (AI) were determined at 24 h post-detorsion in right testes of the remaining 5 animals in each group. RESULTS: The mean number of apoptotic nuclei per tubule cross section and the malondialdehyde level were significantly lower in treatment group as compared with torsion group [AI( 6.87 +/- 2.47) vs (17.13 +/- 3.56), MDA (160 +/- 15) vs (199 +/- 15) nmol/g]. Activities of antioxidant enzyme and the level of HSP70 were significantly higher in treatment group than those in torsion group [SOD (1638 +/- 153) vs (1078 158) U/g, CAT (317 +/- 28) vs (188 +/- 33) U/g, GPx (667 +/- 94) vs (311 +/- 65) U/g, HSP70 (0.87 +/- 0.13) vs (0.25 +/- 0.04)]. The pathological damage of testes in the treatment group was lighter than that in the torsion group (all P < 0.05). CONCLUSIONS: The administration of L-carnitine exerts a beneficial effect upon testicular ischemia-reperfusion injury. This effect may be achieved through an induced expression of HSP70.

[The effect of diethylstilbestrol on inducing abdominal cryptorchidism and relevant genetic expression in rats].

OBJECTIVE: To study the effect of diethylstilbestrol (DES) at different doses on transabdominal testicular descent in rats and the expression of INSL3 in the testis and HOXA10 in the gubernaculum. METHOD: Fifty E13.5 (embryonic day 13.5) pregnant female SD rats were randomly divided into five groups that received a subcutaneous injection of DMSO, 2.5, 5.0, 10.0 and 20.0 mg/kg DES (group A, B, C, D and E), respectively. Male offspring were killed at E19.5, and then fetal mortality, the degree of transabdominal testicular ascent (DTA) was determined by a stereomicroscope. The mRNA expressions of INSL3 in the testis and HOXA10 in the gubernaculum were determined by RT-PCR. The expression of INSL3 protein was determined by Western blotting. RESULTS: Male fetal mortality in group A, B, C, D, and E were 3.57%, 6.90%, 12.00%, 19.23% and 36.36%, respectively, which showed a dose-effect relationship between DES and the male fatal mortality (r=0.999, P<0.01). DTA in group B, C, D and E were (23.7+/-1.7) U, (38.8+/-1.9) U, (49.3+/-1.8) U and (58.6+/-2.1) U that were significantly larger than that in group A [(8.5+/-1.3) U] (q=46.12, 88.53, 120.44 and 141.37, respectively, P<0.01). There was also a dose-effect relationship between DES and DTA. In group B, C, D, and E, the expression of INSL3 mRNA were 0.9570+/-0.1490, 0.6760+/-0.1380, 0.0170+/-0.0040 and 0.0013+/-0.0003, respectively; the expressions of INSL3 protein were 0.8360+/-0.1520, 0.5310+/-0.1070, 0.0140+/-0.0020 and 0.0011+/-0.0003, respectively, which were significantly larger than the expression of INSL3 mRNA (1.801+/-0.126) and INSL3 protein (1.612+/-0.134) in group A (qmRNA=40.4840, 52.4402, 83.1585 and 82.0582, respectively, and qprotein=38.6151, 52.2747, 77.2756 and 76.1983, respectively, P<0.01). The expression of HOXA10 mRNA in group A, B, C, D, and E were 0.945+/-0.125, 0.940+/-0.119, 0.656+/-0.115, 0.544+/-0.118 and 0.463+/-0.114, respectively. Compared with the expression of HOXA10 mRNA in group A, the expression of group B was not significantly different (q=0.2213, P>0.05), those in other groups were down-regulated significantly (q=12.4304, 17.2477 and 20.2789, respectively, P<0.01). CONCLUSION: DES inhibited transabdominal testicular descent dose-dependently via down-regulating the expression of INSL3. HOXA10 may play no role in low-dosage DES induced intra-abdominal cryptorchidism, but down-regulated HOXA10 mRNA was involved in high-dosage DES induced ones.

[Expression of estrogen receptor beta in benign prostatic hyperplasia complicated by chronic prostatitis].

OBJECTIVE: To observe the expression of estrogen receptor-beta (ERbeta) in benign prostatic hyperplasia (BPH) complicated by chronic prostatitis, and to evaluate the correlation of chronic prostatitis with ERbeta expression. METHODS: Histological sections of prostate tissues were obtained from 60 BPH patients complicated by chronic prostatitis and divided into Group 1 (Grade 1), 2 (Grade 2) and 3 (Grade 3) according to the scores on the inflammation of the prostate tissues using the four-point scale designed by Irani et al. The expression of ERbeta was determined by the immunohistochemical method. RESULTS: There were 24 cases (40%) in Group 1, 21 (35%) in Group 2 and 15 (25%) in Group 3, with no statistically significant differences in age and prostate volume among the three groups (P > 0.05). The expression of ERbeta was significantly decreased in Groups 2 and 3 as compared with Group 1 (P < 0.01). CONCLUSION: The expression of ERbeta is reduced with increased scores on the inflammation of the prostate tissues in BPH patients, and the decreased ERbeta expression may be associated with the inflammatory stimulation of prostatitis.

[Research Progress on Multiple Myeloma-Related Cardiovascular Events--Review].

Abstract　　The patients with multiple myeloma are often accompanied by cardiovascular injuries, that not only related with age, but also with the disease itself and treatment. Timely detection and proper supervision of cardiovascular injuries in patients will reduce the mortality of patients with multiple myeloma. In this review, the pathophysiology, diagnosis and treatment of cardiovascular damages in patients with multiple myeloma are summarized briefly, so as to provide some references for clinical treatment and research.

On-surface synthesis of planar dendrimers via divergent cross-coupling reaction.

Dendrimers are homostructural and highly branched macromolecules with unique dendritic effects and extensive use in multidisciplinary fields. Although thousands of dendrimers have been synthesized in solution, the on-surface synthetic protocol for planar dendrimers has never been explored, limiting the elucidation of the mechanism of dendritic effects at the single-molecule level. Herein, we describe an on-surface synthetic approach to planar dendrimers, in which exogenous palladium is used as a catalyst to address the divergent cross-coupling of aryl bromides with isocyanides. This reaction enables one aryl bromide to react with two isocyanides in sequential steps to generate the divergently grown product composed of a core and two branches with high selectivity and reactivity. Then, a dendron with four branches and dendrimers with eight or twelve branches in the outermost shell are synthesized on Au(111). This work opens the door for the on-surface synthesis of various planar dendrimers and relevant macromolecular systems.

The EGS grading scale for skin and soft-tissue infections is predictive of poor outcomes: a multicenter validation study.

INTRODUCTION: Over the last 5 years, the American Association for the Surgery of Trauma has developed grading scales for emergency general surgery (EGS) diseases. In a previous validation study using diverticulitis, the grading scales were predictive of complications and length of stay. As EGS encompasses diverse diseases, the purpose of this study was to validate the grading scale concept against a different disease process with a higher associated mortality. We hypothesized that the grading scale would be predictive of complications, length of stay, and mortality in skin and soft-tissue infections (STIs). METHODS: This multi-institutional trial encompassed 12 centers. Data collected included demographic variables, disease characteristics, and outcomes such as mortality, overall complications, and hospital and ICU length of stay. The EGS scale for STI was used to grade each infection and two surgeons graded each case to evaluate inter-rater reliability. RESULTS: 1170 patients were included in this study. Inter-rater reliability was moderate (kappa coefficient 0.472-0.642, with 64-76% agreement). Higher grades (IV and V) corresponded to significantly higher Laboratory Risk Indicator for Necrotizing Fasciitis scores when compared with lower EGS grades. Patients with grade IV and V STI had significantly increased odds of all complications, as well as ICU and overall length of stay. These associations remained significant in logistic regression controlling for age, gender, comorbidities, mental status, and hospital-level volume. Grade V disease was significantly associated with mortality as well. CONCLUSION: This validation effort demonstrates that grade IV and V STI are significantly predictive of complications, hospital length of stay, and mortality. Though predictive ability does not improve linearly with STI grade, this is consistent with the clinical disease process in which lower grades represent cellulitis and abscess and higher grades are invasive infections. This second validation study confirms the EGS grading scale as predictive, and easily used, in disparate disease processes. LEVEL OF EVIDENCE: Prognostic/Epidemiologic retrospective multicenter trial, level III.