331 The Role of Prophylactic and Therapeutic Fasciotomy in Acute Limb Presentations

Introduction

Acute compartment syndrome is a surgical emergency that can be of traumatic or non-traumatic nature. Missed or delayed diagnosis can cause significant morbidity. The aim of this systematic review was to assess outcomes following prophylactic and therapeutic fasciotomies performed for acute limb presentations.

Method

This systematic review was undertaken following a predefined protocol registered with PROSPERO, in accordance with PRISMA guidelines. Searches of MEDLINE and Embase databases retrieved 623 articles; 19 articles were included in the study. A qualitative synthesis was performed due to heterogeneity between the studies.

Results

Overall mortality rates of 0–19 % were reported for traumatic causes and 24.5–27% for non-traumatic causes. In general, comparative studies reported lower amputation rates (0–21.7% vs 6.6–50%) and neurological deficit rates in the prophylactic versus therapeutic fasciotomy arms (8.8–18% vs 12.5–42%). Complication rates of up to 42% and 35% were reported in traumatic and non-traumatic cases respectively, which included wound infection, nerve injury and ischaemic contractures.

Conclusions

Prophylactic fasciotomies appear to have superior outcomes than therapeutic ones. There is insufficient evidence for a specific time cut-off for the performance of therapeutic fasciotomies; retrospective analysis of outcomes via a fasciotomy registry may help to guide future practice.

Size-dependent influence of NOx on the growth rates of organic aerosol particles

Atmospheric new-particle formation (NPF) affects climate by contributing to a large fraction of the cloud condensation nuclei (CCN). Highly oxygenated organic molecules (HOMs) drive the early particle growth and therefore substantially influence the survival of newly formed particles to CCN. Nitrogen oxide (NOx) is known to suppress the NPF driven by HOMs, but the underlying mechanism remains largely unclear. Here, we examine the response of particle growth to the changes of HOM formation caused by NOx. We show that NOx suppresses particle growth in general, but the suppression is rather nonuniform and size dependent, which can be quantitatively explained by the shifted HOM volatility after adding NOx. By illustrating how NOx affects the early growth of new particles, a critical step of CCN formation, our results help provide a refined assessment of the potential climatic effects caused by the diverse changes of NOx level in forest regions around the globe.

[Implications of EET in renal ischemia/reperfusion by regulating NLRP3 expression and pyroptosis]

Objective: To investigate the mechanism of epoxyeicosatrienoic acids (EET) on renal ischemia/reperfusion (I/R). Methods: Thirty 10-week male C57BL6 mice were randomly divided into five groups: sham goup, I/R group, I/R with EET group, I/R with toll-like receptor 4 (TLR4) inhibitor (TAK242) group, I/R with EET and TAK242 group. Blood urea nitrogen (BUN) and serum creatinine (Scr) as well as renal pathological changes were observed 24 h after reperfusion. The protein expression of NOD-like receptor pyrin domain containing 3 (NLRP3), cysteinyl aspartate specific proteinase 1 (caspase-1), interleukin-1β (IL-1β), TLR4 and myeloid differentiation factor 88 (MyD88) were evaluated using Western blot. Results: Severe renal tubular epithelial cell injury and decreased renal function [BUN:(10.37±0.53) vs (6.70±0.82)mmol/L, t=9.17, P<0.001; Scr: (83.67±3.88) vs (32.50±3.51)μmol/L, t=23.96, P<0.001] occurred in I/R group. Compared to the sham group, the relative expression of NLRP3 (1.54±0.10 vs 0.71±0.05, t=13.14, P<0.001), caspase-1 (2.35±0.05 vs 0.62±0.02, t=73.77, P<0.001), IL-1β (3.11±0.11 vs 1.26±0.05, t=35.97, P<0.001), TLR4 (1.58±0.03 vs 0.39±0.01, t=86.00, P<0.001), MyD88 (0.94±0.02 vs 0.26±0.01, t=72.61, P<0.001) were significantly increased. Mice pretreated with EET analog featured lower kidney damage and diminished levels of above proteins than I/R group (all P<0.001). Besides, the co-administration of TAK242 and EET analog could even markedly reduced the expression levels of each proteins than those in I/R group and I/R with EET group (all P<0.001). Conclusion: EET exerts a protective effect on attenuating renal I/R injury possibly through inhibiting TLR4 pathway to regulate the activation of NLRP3-induced pyroptosis.

Identification and characterization of hirudin-HN, a new thrombin inhibitor, from the salivary glands of Hirudo nipponia

Transcriptome sequencing data (6.5 Gb) of the salivary glands of the haematophagous leech Hirudo nipponia was obtained by using the BGIseq-500 platform. After identification and analysis, one transcript (Unigene5370) was annotated to hirudin HV3 from Hirudo medicinalis with an e-value of 1e-29 and was named hirudin-HN. This transcript was a new thrombin inhibitor gene belonging to the proteinase inhibitor I14 (hirudin) family. Hirudin-HN, with a 270-bp cDNA, encodes an 89-aa protein containing a 20-aa signal peptide. The mature hirudin-HN protein contains the typical structural characteristics of hirudin, e.g., three conserved disulfide bonds and the PKP and DFxxIP motifs. Proteins (Hir and M-Hir) were obtained via prokaryotic expression, and the mature hirudin-HN protein was shown to have anticoagulant activity and thrombin affinity by using the chromogenic substrate S2238 and surface plasmon resonance (SPR) interaction analysis, respectively. The N-terminal structure of the mature hirudin-HN protein was shown to be important for anticoagulant activity by comparing the activity and thrombin affinity of Hir and M-Hir. The abundances of Hirudin-HN mRNA and protein were higher in the salivary glands of starving animals than in those of feeding or fed leeches. These results provided a foundation for further study on the structure-function relationship of hirudin-HN with thrombin.

Gene cloning and expression of a partial sequence of Hirudomacin, an antimicrobial protein that is increased in leech (Hirudo nipponica Whitman) after a blood meal

The novel antimicrobial gene Hirudomacin (Hmc), with a 249-bp cDNA, encodes a mature protein of 61 amino acids and a 22-amino acid signal peptide. Hmc exhibits the highest similarity, at 90.1%, with macin family members found in the salivary gland of the leech Hirudo nipponica Whitman. A mature Hmc protein concentration of 219 μg/mL was detected using the Bradford method. The mature Hmc protein is 6862.82 Da and contains 8 cysteine residues. Antimicrobial assays showed a minimum bactericidal concentration and 50% lethal dose of 1.56 μg/mL and 0.78 μg/mL, respectively, for Staphylococcus aureus and 0.39 μg/mL and 0.195 μg/mL, respectively, for Bacillus subtilis. Transmission electron microscopy revealed membrane integrity disruption in S. aureus and B. subtilis, which resulted in bacterial lysis. The level of Hmc mRNA in the salivary gland during three blood meal stages indicated a remarkable trend of increase (P < .05), and western blotting demonstrated that among the three blood meal stages, expression of the mature Hmc protein was highest in both the salivary gland and intestine at the fed stage (P < .05). Immunofluorescence further showed the mature Hmc protein to be localized outside the cell nucleus, with the signal intensity in the salivary gland peaking at the fed stage (P < .05). In conclusion, the mature Hmc protein exhibits broad-spectrum antimicrobial effects against gram-positive and gram-negative bacteria, and a blood meal upregulates Hmc gene and protein expression in H. nipponica.

Computed tomography-guided iodine-125 interstitial implantation as an alternative treatment option for lung cancer

PURPOSE

The aim was to evaluate the safety, feasibility and efficacy of computed tomography (CT)-guided percutaneous interstitial brachytherapy using radioactive iodine-125 ( 125 I) seeds for the treatment of lung cancer.

MATERIALS AND METHODS

Included in this study were 45 male and 35 female patients aged 52-85 years (mean 72-year) who were diagnosed with lung cancer. Of the 80 cases of lung cancer, 38 were pathologically confirmed as squamous cell carcinoma, 29 as adenocarcinoma, 2 as small cell lung cancer, and 11 as metastatic lung cancer. Percutaneous interstitial implantation of radioactive 125 I seeds was performed under CT guidance. The treatment planning system was used to reconstruct three-dimensional images of the tumor to determine the quantity and distribution of 125 I seeds to be implanted. Under CT guidance, 125 I seeds were embedded into the tumor, with the matched peripheral dose set at 100-130 Gy. Follow-up CT scan was done in 2-month to explore the treatment efficacy.

RESULTS

The procedure was successful in all patients. No major procedure-associated death occurred. The duration of follow-up was 6-month. Complete response (CR) was seen in 38 cases (47.5%), partial response (PR) in 27 cases (33.75%), stable disease (SD) in 10 cases (12.5%), and progressive disease in 5 cases (6.25%), with a local control rate (CR + PR + SD) of 93.75%. The 2-, 4- and 6-month overall response rate (CR + PR) was 78%, 83% and 81%, respectively.

CONCLUSION

Implantation of CT-guided 125 I seeds is a safe and effective alternative option for the treatment of lung cancer.

Optimizing the high-resolution manometry (HRM) study protocol

BACKGROUND

Intolerance of the esophageal manometry catheter may prolong high-resolution manometry (HRM) studies and increase patient distress. We assessed the impact of obtaining the landmark phase at the end of the study when the patient has acclimatized to the HRM catheter.

METHODS

366 patients (mean age 55.4 ± 0.8 years, 62.0% female) undergoing esophageal HRM over a 1-year period were studied. The standard protocol consisted of the landmark phase, 10 5 mL water swallows 20-30 s apart, and multiple rapid swallows where 4-6 2 mL swallows were administered in rapid succession. The modified protocol consisted of the landmark phase at the end of the study after test swallows. Study duration, technical characteristics, indications, and motor findings were compared between standard and modified protocols.

KEY RESULTS

Of the 366 patients, 89.6% underwent the standard protocol (study duration 12.9 ± 0.3 min). In 10.4% with poor catheter tolerance undergoing the modified protocol, study duration was significantly longer (15.6 ± 1.0 min, p = 0.004) despite similar duration of study maneuvers. Only elevated upper esophageal sphincter basal pressures at the beginning of the study segregated modified protocol patients. The 95th percentile time to landmark phase in the standard protocol patients was 6.1 min; as many as 31.4% of modified protocol patients could not obtain their first study maneuver within this period (p = 0.0003). Interpretation was not impacted by shifting the landmark phase to the end of the study.

CONCLUSIONS & INFERENCES

Modification of the HRM study protocol with the landmark phase obtained at the end of the study optimizes study duration without compromising quality.

Streuung von Ionen. III. Regenbogeneffekt bei der Streuung von H+ an N2 , CO, CO2 , SF6, H2 und CH4 sowie von H2 + an Ar und Kr

Differential scattering cross sections of H+ on various molecules and of H2 + on Ar and Kr were measured at various energies between 5 eV and 40 eV. Several rainbows could be resolved for the systems H+-N2, H+-CO, H+-CO2 and H+-SF6 . In the case of H+-H2 , secondary rainbows could be traced at higher energies (30 eV). Only the primary rainbow was observed for H+-CH4 . The H2 +-Ar and H2 +-Kr systems also yielded rainbow structures. Broad additional maxima appeared at large angles for H2 +-Kr which were atttributed to the crossing of potential curves. The rapid oscillations could not be observed. The measured differential cross sections for the systems H+-N2 , CO, CO2, SF6 and H2 were fitted by a procedure described in part I using a simple Morse potential. The equilibrium distances rm were estimated from the relation rm = 0.7-rg (rg: gaskinetic radius of the molecule) which was found to hold approximately for the H+-noble gas systems.

The following potential depths e were obtained: 4.15 eV for N2-H+; 4.70 eV for CO-H+; 5.10 eV for CO2-H+; 3.66 eV for SF6-H+; 4.04 eV for H2-H+. These values are averages because of the anisotropy of the potentials. The potential depth for the H+-H2 system is little smaller than the theoretical value of 4.56 eV. This is attributed to nontriangular configurations in the scattering process. The scattering experiments with the system H4-CH4 were evaluated classically, ε (H+-CH4) was found to be 3.8 eV only. The large difference to the theoretical value ε = 5.45 eV is explained by the inadiabacity of the scattering process with respect to the movement of the H atoms in methane.

ε (Ar-H2 +) and ε (KrH2 +) were found to be (1.3 ± 0.2 ) eV and (1.1 ± 0.2 ) eV, respectively. Energy level diagram are dicussed for the ion-molecule reactions Ar+ (Kr+) + H2 → ArH+ (KrH+) + H including the ArH2 + and KrH2 + intermediate states. They show that most of the reaction energy becomes free in the approach of the reactants Ar++H2. This effect is less pronounced for the Kr+ (2P1/2)+H2-reaction and even a small threshold energy exists for the Kr+ (2P3/2)+H2-reaction. reaction

Streuung von Ionen. II. Regenbogeneffekt bei der elastischen Streuung von Protonen an Helium, Neon, Krypton, Xenon und von He+ an Helium

Differential scattering cross sections of H+ on various noble gases and of He+ on He were measured at various energies between 3 eV-80 eV. The rainbow structure and the superimposed rapid oscillations were resolved. Differential cross sections were calculated in WKB approximation and compared with experimentally obtained cross sections. Agreement was obtained by using the modified Morse potential:

U = exp{2 G1 G2(1 -ρ)} -2 exp{G1 G2(1-ρ)} , G2 = 1 for ρ>1,

whit ρ=r/rm, and U=V/ε. G2 ≠ 1 for ρ ≧1,

The fitting procedure discussed in part I was applied in order to obtain the parameters ε,rm, G1 and G2. Calculations with the modified Lennard-Jones potential described in part I gave the same values for ε and rm .

With exception of the system H+ -Xe, a single set of parameters could describe the rainbow structure and the fine structure at all ion energies. The values for ε and rm agree fairly well with ab-initio calculations. The reduced potentials have about the same shape, G1 being between 2.7 and 2.2, G2 being between 0.8 and 0.9.

In the case of H+ -Xe, ε increases significantly with decreasing proton energy, while G1 and G2 have only slightly to be changed. The potential well is narrower than for the other systems mentioned above. These effects are attributed to the crossing of the potential curves of the systems H+ -Xe and H-Xe+ .

Chemische Reaktionskinematik

The velocity spectra and cross sections of reactions of the type X*+D2 → XD++D (X+=Ar+, N2 +, CO+) have been found to be independent of the temperature of the target gas ( — 190° to 20°C). The additional forward scattering (as compared to spectator stripping) of the product ion at high energies cannot be explained by the thermal motion of the D2 molecules. A recoil stripping mechanism is proposed. At low energies, an intermediate XD2* is postulated that lives shorter than half a period of rotation and is forward scattered but quickly equilibrates the excess energy among the vibrational degrees of freedom. The reactions of Ar+ and N2 + with CD4 can well be understood by the stripping model over a wide range of energy. At low energies, no preferential forward scattering of the product ion is found as in the corresponding reactions with D2. The strongly unsymmetric broadening of the product ion band together with a small shift to lower velocities indicate a strong interaction of the incident ion with the CD3 group at low energies. The formation of an intermediate complex XCD4 + which isotropically decays is expected at energies of a few tenth of one eV. Direct measurements at such low primary ion energies have not yet been possible.

Development of an in situ magnetoelastic magneto-optical Kerr effect magnetometer

Reported here is the development and implementation of an integrated in situ magnetoelastic measurement setup with a MOKE magnetometer, repositionable electromagnet, and sample transfer/straining device. The former were used within a molecular beam epitaxial vacuum growth chamber. Consequently the magnetostriction constants for both Cr capped and uncapped Fe/GaAs(100) films were acquired without film oxidization occurring. Samples were bent in a four point bending geometry to produce a quantifiable tensile mechanical strain on the films during magnetoelastic measurements. In addition, a laser measurement system was developed to confirm the induced strain in the samples.

Antibody binding to neuronal surface in Sydenham chorea, but not in PANDAS or Tourette syndrome

OBJECTIVE

To test the hypothesis that Sydenham chorea (SC) immunoglobulin G (IgG) autoantibodies bind to specific neuronal surface proteins, whereas IgG from patients with pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) or Tourette syndrome (TS) do not bind to neuronal surface proteins.

METHODS

We used live differentiated SH-SY5Y cells, which have neuronal and dopaminergic characteristics. Using flow cytometry, we measured serum IgG cell surface binding in patients with SC (n = 11), PANDAS (n = 12), and TS (n = 11), and compared the findings to healthy controls (n = 11) and other neurologic controls (n = 11). In order to determine the specificity of binding to neuronal antigens, we also used a non-neuronal cell line, HEK 293.

RESULTS

The mean IgG cell surface binding was significantly higher in the SC group compared to all other groups (p < 0.001). By contrast, there was no difference between the PANDAS or TS groups and the controls. Using the non-neuronal HEK-293 cells, there was no significant difference in IgG cell surface binding between any groups.

CONCLUSIONS

Serum autoantibodies that bind to neuronal cell surface antigens are present in SC, but not in PANDAS or TS. These findings strengthen the hypothesis that SC is due to a pathogenic autoantibody, but weaken the autoantibody hypothesis in PANDAS and TS.

Hepatic encephalopathy as an unusual late complication of transjugular intrahepatic portosystemic shunt insertion for non-cirrhotic portal hypertension caused by nodular regenerative hyperplasia in an HIV-positive patient on highly active antiretroviral therapy

Transjugular intrahepatic portosystemic shunt (TIPS) is an artificially created conduit between the portal and systemic vascular system in the liver performed percutaneously via radiological guidance. It is used mainly in conditions causing portal hypertension and its resulting complications. It reduces portal pressure by diverting portal blood flow into the systemic circulation. Hepatic encephalopathy is the most common complication following TIPS insertion and tends to present fairly early. We describe a case of hepatic encephalopathy as an unusual late complication of TIPS insertion (first presenting six years after) for non-cirrhotic portal hypertension caused by nodular regenerative hyperplasia in an HIV-positive patient on highly active antiretroviral therapy.

Lysyl oxidase (lox) gene deficiency affects osteoblastic phenotype

Lysyl oxidase (LOX) catalyzes cross-linking of elastin and collagen, which is essential for the structural integrity and function of bone tissue. The present study examined the role of Lox gene deficiency for the osteoblast phenotype in primary calvarial osteoblasts from E18.5 Lox knockout (Lox ( -/- )) and wild type (wt) (C57BL/6) mice. Next to Lox gene depletion, mRNA expression of Lox isoforms, LOXL1-4, was significantly downregulated in Lox ( -/- ) bone tissue. A significant decrease of DNA synthesis of Lox ( -/- ) osteoblasts compared to wt was found. Early stages of osteoblastic apoptosis studied by annexin-V binding as well as later stages of DNA fragmentation were not affected. However, mineral nodule formation and osteoblastic differentiation were markedly decreased, as revealed by significant downregulation of osteoblastic markers, type I collagen, bone sialoprotein, and Runx2/Cbfa1.