Regioselective Formation of Enol Esters from the Ruthenium-Catalyzed Markovnikov Addition of Carboxylic Acids to Alkynes.

The ruthenium complexes [Ru(CO)2(P(p-C6H4-X)3)2(O2CPh)2] (1a, X = CF3; 1b, X = Cl; 1c, X = H; 1d, X = Me; 1e, X = OMe) were successfully applied in the regioselective Markovnikov addition of carboxylic acids to terminal alkynes, yielding valuable enol esters. Catalyst screening revealed a significant influence of phosphine's electronic nature on activity and selectivity. The highest activity was achieved with catalyst 1a, featuring the most electron-withdrawing phosphine ligand. Selectivity and activity could be further improved by the addition of catalytic amounts of AgOTf. Moreover, excellent selectivities with up to 99% of the Markovnikov product were achieved. The electronic influence of the substrates on the reaction rate was quantified by Hammett plots. By the use of electron-rich alkynes or highly acidic carboxylic acids, the reaction rate could be increased. Hence, the addition of highly acidic pentafluorobenzoic acid to electron-rich 4-methoxyphenylacetylene can even be carried out quantitatively at 25 °C within 4 h. Furthermore, a broad range of simple as well as electronically or sterically challenging substrates could be isolated in good to excellent yields with high regioselectivity and under mild reaction conditions (25-70 °C). The best reported activities and selectivities were obtained for the conversion of aromatic alkynes.

Three-dimensional fracture visualisation of multidetector CT of the skull base in trauma patients: comparison of three reconstruction algorithms.

The purpose of this study was to retrospectively assess the detection rate of skull-base fractures for three different three-dimensional (3D) reconstruction methods of cranial CT examinations in trauma patients. A total of 130 cranial CT examinations of patients with previous head trauma were subjected to 3D reconstruction of the skull base, using solid (SVR) and transparent (TVR) volume-rendering technique and maximum intensity projection (MIP). Three radiologists independently evaluated all reconstructions as well as standard high-resolution multiplanar reformations (HR-MPRs). Mean fracture detection rates for all readers reading rotating reconstructions were 39, 36, 61 and 64% for SVR, TVR, MIP and HR-MPR respectively. Although not significantly different from HR-MPR with respect to sensitivity (P = 0.9), MIP visualised 18% of fractures that were not reported in HR-MPR. Because of the relatively low detection rate using HR-MPRs alone, we recommend reading MIP reconstructions in addition to the obligatory HR-MPRs to improve fracture detection.

Mason type-I radial head fractures and interosseous membrane lesions--a prospective study.

BACKGROUND: The role of the forearm interosseous membrane (IOM) in trauma remains not fully understood. Information from experimental models simulating sudden axial loading of the IOM is limited. The results from several cadaver studies are controversially discussed in literature. Pronation and supination of the forearm as well as varus and valgus position of the elbow joint have been suspected to have influence on the injury pattern. The purpose of the current study, therefore, was to further investigate the role of the IOM in trauma mechanism. METHODS: We prospectively screened the forearms of 14 patients with Mason type-I radial head fractures for additional occult IOM lesions. The fractures were classified according to the Mason classification using plain radiographs. All patients were subjected to forearm magnetic resonance imaging visualizing the entire IOM within a week. Treatment consisted of nearly total immobilization of the elbow joint using a special elastic and gauze bandage for 7 days followed by an early motion recovery program. RESULTS: Partial disruptions of the distal part of the IOM were found in nine cases. The biomechanically essential interosseous ligament was not attained by these ruptures in any of the cases. None of the patient had the classical findings of the Essex Lopresti lesion. All patients had regular roentgenograms of both wrists. Patients were asymptomatic at the time of a 4-week follow-up. CONCLUSION: Our results suggest that injuries of the IOM are more frequent than generally expected. The findings support the conclusions of some of the previous cadaver studies. If IOM lesions are suspected, magnetic resonance imaging tomography should be performed.

Biomechanical comparison of modified Kessler and running suture repair in 3 different animal tendons and in human flexor tendons.

PURPOSE: To establish the animal flexor tendon that best mimics the biomechanical performance of human flexor tendons. We investigated the biomechanical behavior of core and running sutures in 3 different animal flexor tendons and in human flexor tendons. Additionally, we attempted to help standardize future flexor tendon studies. To that purpose, nearly all variables occurring in the test setup have been highlighted. METHODS: The species selected were pig, calf, sheep, and human. Two groups were formed. In the first group we tested 3-0 core sutures (Ticron; Tyco Healthcare, Vienna, Austria), and in the second group we tested 5-0 running sutures (Ethilon; Ethicon, Vienna, Austria). In each group, 10 tendons of each specimen were tested, which yielded a total of 80 tendons. In each group, the repaired tendons were subjected to 3,000 linear load cycles at a load of 15 N. At the end of this procedure, final gap values were recorded. In the next step, ultimate load-to-failure data were obtained from each specimen. RESULTS: Core sutures behaved similarly in the human, sheep, and pig tendons with respect to ultimate loads. With respect to gap formation, core sutures behaved similarly in the human, sheep, and calf tendons. Deep running sutures behaved similarly in the human, sheep, and pig tendons in terms of ultimate load to failure. CONCLUSIONS: In this study, sheep tendons were found to best mimic the biomechanical behavior of human tendons. Calf tendons seem to be unsuitable. There is a strong need for consistency in biomechanical test setups.

Publisher Correction: Exercise-induced bronchoconstriction, temperature regulation and the role of heat shock proteins in non-asthmatic recreational marathon and half-marathon runners.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Exercise-induced bronchoconstriction, temperature regulation and the role of heat shock proteins in non-asthmatic recreational marathon and half-marathon runners.

Exercise is the most common trigger of bronchospasm. Heat shock protein (HSP) expression was linked to asthmatic patients. The prevalence and pathophysiology of exercise-induced bronchoconstriction (EIB) in non-professional non-asthmatic runners is unknown. We sought to investigate the frequency of EIB and cytokine changes in non-professional non-asthmatic marathon and half marathoners with and without EIB. Testing was performed before the marathon (baseline), immediately post-marathon at the finish area (peak), and 2-7 days after the marathon (recovery): immunosorbent assays for measurement of HSP70, blood count analysis, spirometry and temperature measurements. We experienced a decline in FEV1 of ≥10% in 35.29% of marathon and 22.22% of half marathon runners. Runners with EIB had significantly higher HSP70 serum concentrations at baseline than those without EIB (987.4 ± 1486.7 vs. 655.6 ± 1073.9; p = 0.014). Marathoners with EIB had significantly increased WBC before participating in the competition (7.4 ± 1.7 vs. 6.0 ± 1.5; p = 0.021). After recovery we found increased HSP70 serum concentrations in marathoners with EIB compared to those without (2539.2 ± 1692.5 vs. 1237.2 ± 835.2; p = 0.032), WBC (7.6 ± 1.8 vs. 6.4 ± 1.6; p = 0.048) and PLT (273.0 ± 43.0 vs 237.2 ± 48.3; p = 0.040). At all measured skin sites skin temperatures in runners were significantly lower immediately after participating in the competition when compared to temperature before the race (skin temperature baseline vs. peak: abdominal: 33.1 ± 0.2 vs. 30.0 ± 0.4; p < 0.001; upper arm: 31.6 ± 0.2 vs. 29.4 ± 0.3; p < 0.001; upper leg: 30.7 ± 0.3 vs. 29.4 ± 0.2; p = 0.014; lower leg: 30.6 ± 1.0 vs. 30.2 ± 1.5; p = 0.007). We found a higher than expected number of non-professional athletes with EIB. HSP70 serum concentrations and elevated WBC could indicate a predisposition to EIB.

Non-professional marathon running: RAGE axis and ST2 family changes in relation to open-window effect, inflammation and renal function.

Conflicting data exist on the relevance of marathon (M) and half marathon (HM) running for health. The number of non-professional athletes finishing M and HM events is steadily growing. In order to investigate molecular changes occurring in amateur athletes, we enrolled 70 non-professional runners finishing a single M (34) or HM (36) event at baseline, the finish line and during recovery, and 30 controls. The measurement of the Receptor for Advanced Glycation Endproducts, Interleukin 1 receptor antagonist, ST2 and cytokeratin 18 was combined with molecules measured during clinical routine. Results were analyzed in the light of blood cell analysis, lactate measurements, correction for changes in plasma volume and body composition assessments. There were intrinsic differences in body mass index, abdominal body fat percentage and training time between M and HM runners. C-reactive protein changes in M and HM runners. While soluble RAGE, AGEs and ST2 increased immediately after the race in HM runners, HMGB1 increased in HM and M after the race and declined to baseline after a recovery period. We give insights into the regulation of various molecules involved in physical stress reactions and their possible implications for the cardiovascular system or renal function.

[Spinal cord injuries in infants and juveniles]. / Die verletzte Halswirbelsäule bei Kindern und Jugendlichen.

Trauma of the infant or juvenile spine is a very rare occurrence (less than 2%). Nevertheless, it is almost always dramatic. In 21 years 1630 patients with spinal cord injuries were treated. Of these, 21.7% (357 patients) had injuries in the area of the cervical spine. 23 patients (1.4%) were younger than 17.5 years, 8 of them were younger than 10 years. In 10 cases the cause was a traffic accident, in 7 cases it was a jump in too shallow water. In 4 times other leisure activities were the cause. A fall from a window sill and a falling tree were further reasons. Neck segment C0 to C3 was involved eight times, segment C3 to C7/Th1 was involved 15 times. The average age of the group with injuries in C0 to C3 was 5.6 years, in the group with injuries of segments C3 to C7/Th1 it was 15.8 years. In 11 cases the trauma caused complete tetraplegia, in six cases the paralysis was partial. In six further cases no neurological deficit occurred. 14 cases were treated surgically, six were treated conservatively. Four children younger than 10 years with complete tetraplegia died. In seven cases tetraplegia persisted; out of six patients with incomplete neurological deficit three improved and three patients recovered completely.

Occult scaphoid fractures: comparison of multidetector CT and MR imaging--initial experience.

PURPOSE: To compare the diagnostic performance of multidetector computed tomography (CT) and magnetic resonance (MR) imaging in patients clinically suspected of having a scaphoid fracture and who had normal initial radiographs, with radiographs obtained 6 weeks after trauma as the reference standard. MATERIALS AND METHODS: The ethics committee approved the study, and all patients gave written informed consent. Twenty-nine patients (17 male, 12 female; age range, 17-62 years; mean age, 34 years +/- 13) underwent multidetector CT and MR imaging within 6 days after trauma. CT data were obtained with 0.5-mm collimation. For image review, 0.7-mm-thick multiplanar reformations were performed in transverse, coronal, and sagittal planes relative to the wrist. The 1.0-T MR examination consisted of coronal and transverse short inversion time inversion-recovery, coronal and transverse T1-weighted spin-echo, and coronal volume-rendered T2-weighted gradient-echo sequences. Two radiologists analyzed the CT and MR images. A binomial test was used to evaluate the significance of the differences between MR imaging and CT in detection of scaphoid fractures and cortical involvement (P < .05). RESULTS: The 6-week follow-up radiographs depicted a scaphoid fracture in 11 (38%) patients. Eight patients had a cortical fracture, while three patients had only a bandlike lucency within the trabecular portion of the scaphoid. MR imaging depicted all 11 fractures but only three [corrected] cortical fractures. Multidetector CT depicted all eight cortical fractures but failed to depict trabecular fractures. No false-positive fractures were seen on MR or CT images. Differences between MR imaging and CT were not significant for the detection of scaphoid fractures (P = .25) but were significant for cortical involvement (P = .03). CONCLUSION: Multidetector CT is highly accurate in depicting occult cortical scaphoid fractures but appears inferior to MR imaging in depicting solely trabecular injury. MR imaging is inferior to multidetector CT in depicting cortical involvement.