[Simultaneous surgical treatment of the long head of the biceps tendon during operative treatment of proximal humeral fractures]. / Simultane Versorgung der langen Bizepssehne im Rahmen der operativen Therapie proximaler Humerusfrakturen.

BACKGROUND: Pathologic conditions of the long biceps tendon can be found within treatment of proximal humeral fractures or as a source of pain after surgery. However, simultaneous surgical treatment at the index surgical intervention is so far not well established. The purpose of this study is to evaluate the results of a simultaneous biceps treatment during plate osteosynthesis of proximal humeral fractures. MATERIALS AND METHODS: Twenty-seven patients were included into this study. In 14 patients (high cosmetic and functional shoulder demand) a biceps tenodesis (LHB-TD) was carried out (7 women, 7 men; ø57 years). In 13 patients (12 women, 1 man; ø72 years) a biceps tenotomy (LHB-TT) was performed. In addition to the range of motion (ROM), the Constant score and the LHB score were evaluated. RESULTS: All 27 patients were investigated after a mean follow-up of 25 months (range: 18-32 months). The ROM did not reveal any significant differences in either group. The Constant score was significantly decreased compared to the non-affected side (CS) without differences between the groups (LBS-TT 77 ± 9 vs. LBS-TD 77 ± 14; LBS-TT (CS) 82 ± 4 vs. LBS-TD (CS) 87 ± 4). The LHB score showed excellent results for both groups without significant differences (LBS-TT 98 ± 3 vs. LBS-TD 93 ± 10). In one patient of each group, an examiner-dependent upper arm deformity was detected. No patient complained of a subjective cosmetic deformity. CONCLUSION: The simultaneous surgical treatment of the LHB during plate osteosynthesis of proximal humeral fractures shows good clinical and cosmetic results. In a preselected patient population (cosmetic and functional demand) the kind of treatment (LHB tenotomy or LHB tenodesis) is indifferent.

[Intra-articular bupivacaine following hip joint arthroscopy. Effect on postoperative pain]. / Intraartikuläre Bupivacaingabe bei Hüftgelenkarthroskopie. Effekt auf postoperative Schmerzen.

The effect of intra-articular bupivacaine on postoperative pain following arthroscopy has been intensively studied for the knee joint but no data are currently available for the hip joint. The aim of the present prospective, randomized and double-blind study was to evaluate a possible effect of intra-articular bupivacaine on postoperative pain intensity following hip arthroscopy. A total of 26 patients were included: 13 received 20 ml of 0.25% bupivacaine through the trocar at the end of surgery and 13 patients received 20 ml of 0.9% NaCl as placebo. Postoperative pain intensity was assessed using a visual analogue scale (VAS) at 0.5 h, 4 h, 8 h, 12 h, 16 h and 20 h, at rest and during movement of the joint and on the basis of additional piritramide requirements. Furthermore, a mean VAS was calculated as the arithmetic mean of all VAS scores assessed over the whole study period. In the bupivacaine group, a significantly lower mean VAS was recorded at rest (17.5 vs 27.5, p=0.05) and during movement of the hip joint (23 vs. 46, p=0.001). The additional piritramide consumption tended to be higher in the placebo group. In conclusion, intra-articular bupivacaine following arthroscopic hip surgery reduces pain in the postoperative period mainly during movement and thus may possibly allow earlier mobilization.

[Influence of gender on stimulated cytokine response in patients with severe sepsis]. / Einfluss des Geschlechts auf die stimulierbare Zytokinantwort bei Patienten mit schwerer Sepsis.

AIM: Studies suggest that female mice have lower mortality rates than males after sepsis or trauma-hemorrhage. This study investigated the impact of gender and disease severity on monocyte hyporesponsiveness in severe human sepsis. METHODS: We prospectively investigated 49 (male n=28, female n=21) consecutive patients with severe sepsis. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) were assayed by ELISA in unstimulated whole blood cultures or after stimulation with lipopolysaccharide (LPS; E. coli 0111:B4) or Staph. aureus Cowan strain I (SAC-I) lysate at days 1, 2, 3, 4, and 8 after enrollment. Testosterone and estradiol levels were quantified by electrochemoluminescence immunoassays. RESULTS: Mortality was similar for males (35.7%) and females (42.9%). While disease severity was also comparable, septic patients showed a substantial suppression in stimulated TNF-alpha response compared to healthy controls who recovered within 8 days in surviving patients. Stimulated cytokine response recovered in female non-surviving patients, while it remained suppressed in non-surviving male patients and was significantly different compared to female non-surviving patients. Testosterone levels were substantially suppressed in male but not female septic patients compared to normal values but did not differ between surviving and non-surviving patients. Estradiol levels were elevated in female and male septic patients. Addition of different concentrations of testosterone and estradiol to whole blood obtained from younger (<35 years old) and older (>60 years old) male as well as from younger (proestrous premenopausal) and older (postmenopausal) female non-septic volunteers revealed no effect on LPS-stimulated TNF-alpha and IL-10 release. CONCLUSION: Severe sepsis leads to a substantial suppression of stimulated cytokine response. Prolonged suppression may serve as a marker of unfavourable outcome in male but not in female individuals suffering from severe sepsis. Furthermore, our data suggest that gender differences in cellular immunity described for young, sexually mature animals obviously persist in typical postmenopausal intensive care unit patients, although a direct interaction between testosterone or estradiol and LPS-stimulated cytokine response could not be demonstrated.

[Influence of gender on the intubation conditions with rocuronium]. / Einfluss des Geschlechts auf die Intubationsbedingungen nach Rocuronium.

PURPOSE: There is increasing evidence for gender differences in the pharmacokinetics and pharmacodynamics of anaesthetic drugs and neuromuscular blocking agents, e.g. rocuronium (Roc). Females require 30% less Roc than males to achieve the same degree of neuromuscular block and onset times are shorter. However, whether this leads to an improvement of the intubation conditions in females is unclear. METHODS: After approval of the ethics committee 60 female and 60 male patients were each randomised into 2 groups to receive 0.6 mg/kg body weight Roc or 1.0 mg/kg succinylcholine (Sux; control group). Induction: thiopentone (5 mg/kg), fentanyl (3 microg/kg) then Roc (Roc groups) or Sux (Sux groups) and tracheal intubation after 60 s. Time to intubation, glottic exposure and intubating conditions were assessed. RESULTS: Men were significantly larger and heavier (p<0.001) than women, but the body mass index was comparable (ns). Number of attempts, time to intubation, and Cormack grades were comparable (ns). However, the rate of clinically acceptable intubation conditions was significantly higher in the female compared to the male Roc group: 80% vs 47%, p<0.05. The incidence of clinically acceptable intubation conditions in the female Roc and Sux groups were similar (80%). CONCLUSION: The intubation conditions after Roc were significantly better in women than in men. The differences were Roc-related and did not occur in the control groups.

Effect of cysteine to serine mutations on the properties of the [4Fe-4S] center in Escherichia coli fumarate reductase.

Site-directed mutants of Escherichia coli fumarate reductase in which FrdB Cys148, Cys151, Cys154, and Cys158 are replaced individually by Ser have been constructed and overexpressed in a strain of E. coli lacking a wild-type copy of fumarate reductase and succinate dehydrogenase. The consequences of these mutations on bacterial growth, enzymatic activity, and the EPR properties of the constituent iron-sulfur clusters have been investigated. The Cys154Ser and Cys158Ser FrdB mutations result in enzymes with negligible activity that have largely dissociated from the cytoplasmic membrane and consequently are incapable of supporting cell growth under conditions requiring a functional fumarate reductase. EPR studies indicate that these effects are associated with loss of both the [3Fe-4S] and [4Fe-4S] clusters. In contrast the Cys148Ser and Cys151Ser FrdB mutations result in functional membrane bound enzymes that are able to support growth under anaerobic and aerobic conditions. EPR studies of these mutants indicate that all three of the constituent Fe-S clusters are assembled, and the redox and spectroscopic properties of the [2Fe-2S] and [3Fe-4S] clusters are unchanged compared to the wild-type enzyme. In both mutants the [4Fe-4S] cluster is assembled with one non-cysteinyl ligand, and the available data suggest serinate coordination. The physicochemical consequences are perturbation of the intercluster spin interaction between the S = 1/2 [4Fe-4S]+ and S = 2 [3Fe-FS]0 clusters and a 60-mV decrease in redox potential for the [4Fe-FS]2+,+ cluster in the FrdB Cys148Ser mutant, and a S = 1/2 to S = 3/2 spin state conversion for the [4Fe-4S]+ cluster and a 72-mV decrease in redox potential for the [4Fe-4S]2+,+ cluster in the FrdB Cys151Ser mutant. Taken together with the previous FrdB Cys to Ser mutagenesis results [Werth, M. T., Cecchini, G., Manodori, A., Ackrell, B. A. C., Schröder, I., Gunsalus, R. P., & Johnson, M. K. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 8965-8969; Manodori, A., Cecchini, G., Schröder, I., Gunsalus, R. P., Werth, M. T., & Johnson, M. K. (1992) Biochemistry 31, 2703-2712], the results provide strong support for the proposal that all three clusters are located in the FrdB subunit with Cys57, Cys62, Cys65, and Cys77 ligating the [2Fe-2S] cluster, Cys148, Cys151, Cys154, and Cys214 ligating the [4Fe-4S] cluster, and Cys158, Cys204, and Cys210 ligating the [3Fe-4S] cluster. The role of the low potential [4Fe-4S] cluster in mediating electron transfer from menaquinol to the FAD active site is discussed in light of these mutagenesis results.

Evidence for non-cysteinyl coordination of the [2Fe-2S] cluster in Escherichia coli succinate dehydrogenase.

The consequences of replacing Cys65 in the FrdB subunit of Escherichia coli fumarate reductase by Asp or Ala have been investigated in terms of bacterial growth, enzymatic activity, and the ERP/redox properties of the [2Fe-2S] cluster. An aspartic acid residue occupies the equivalent position in E. coli succinate dehydrogenase, and the FrdBCys65Asp mutation has little effect on cell growth, enzyme activity or the physical properties of the Frd [2Fe-2S] cluster. In contrast, the [2Fe-2S] cluster was not observed in the FrdBCys65Ala mutant showing that a coordinating residue is required at this position for assembly of this cluster and significant levels of enzymatic activity. These results support the presence of one non-cysteinyl, oxygenic ligand for the [2Fe-2S] cluster in E. coli succinate dehydrogenase.

[3Fe-4S] to [4Fe-4S] cluster conversion in Escherichia coli fumarate reductase by site-directed mutagenesis.

Site-directed mutants of Escherichia coli fumarate reductase in which FrdB Cys204, Cys210, and Cys214 were individually replaced by Ser and in which Val207 was replaced by Cys were constructed and overexpressed in a strain of E. coli lacking a wild-type copy of fumarate reductase and succinate dehydrogenase. The consequences of these mutations on bacterial growth, enzymatic activity, and the EPR properties of the constituent iron-sulfur clusters were investigated. The FrdB Cys204Ser, Cys210Ser, and Cys214Ser mutations result in enzymes with negligible activity that have dissociated from the membrane and consequently are incapable of supporting cell growth under conditions requiring a functional fumarate reductase. EPR studies indicate that these effects are associated with loss of both the [3Fe-4S] and [4Fe-4S] clusters, centers 3 and 2, respectively. In contrast, the FrdB Val207Cys mutation results in a functional membrane-bound enzyme that is able to support growth under anaerobic and aerobic conditions. However, EPR studies indicate that the indigenous [3Fe-4S]+,0 cluster (Em = -70 mV), center 3, has been replaced by a much lower potential [4Fe-4S]2+,+ cluster (Em = -350 mV), indicating that the primary sequence of the polypeptide determines the type of clusters assembled. The results of these studies afford new insights into the role of centers 2 and 3 in mediating electron transfer from menaquinol, the residues that ligate these clusters, and the intercluster magnetic interactions in the wild-type enzyme.

Site-directed mutagenesis of conserved cysteine residues in Escherichia coli fumarate reductase: modification of the spectroscopic and electrochemical properties of the [2Fe-2S] cluster.

Site-directed mutants of Escherichia coli fumarate reductase in which each of the four N-terminal cysteine residues in the FrdB subunit, residues 57, 62, 65, and 77, was mutated individually to serine have been constructed, overexpressed, and investigated in terms of enzymatic activity as well as the EPR and redox properties of the iron-sulfur centers. In each case, the mutant contains a functional fumarate reductase in which all three of the constituent iron-sulfur clusters (i.e., center 1, [2Fe-2S]; center 2, [4Fe-4S]; center 3, [3Fe-4S]) have been assembled. The mutations affect the properties of center 1 only and demonstrate that the anomalously high redox potential of this [2Fe-2S] center is essential for optimal enzymatic activity. The results are consistent with cysteines 57, 62, 65, and 77 providing the ligands to center 1 but leave open the possibility of noncysteinyl coordination for the localized valence Fe(III) site of the reduced cluster. The implications of the results for the role of center 1 in the electron-transfer pathway and the valence localization of reduced center 1 are discussed.

Magnetic circular dichroism and electron paramagnetic resonance studies of iron(II)-metallothionein.

The electronic and magnetic properties of the Fe(II)-thiolate centers in Fe(II)-metallothionein have been investigated by low-temperature magnetic circular dichroism and electron paramagnetic resonance spectroscopies at various levels of Fe(II) incorporation. In agreement with previous results [Good, M., & Vasák, M. (1986) Biochemistry 25, 8353-8356], rabbit liver metallothionein was found to bind a maximum of seven Fe(II) ions, with cluster formation occurring when more than four Fe(II) ions are bound at pH 8.5. The results indicate that all the iron in fully loaded Fe(II)-metallothionein is accommodated in Fe(II)-thiolate clusters that have either S = 0 or S = 2 ground states as a result of antiferromagnetic coupling between high-spin Fe(II) ions. By analogy with the cluster composition and mechanism of assembly that have been established for other divalent metal ions, the clusters with S = 0 and S = 2 ground states are attributed to tetranuclear and trinuclear centers, respectively. EPR signals indicative of S = 2 species were observed for samples containing monomeric tetrathiolate-Fe(II) centers and trinuclear Fe(II)-thiolate clusters. However, the nature of the zero-field splitting of the S = 2 ground states that is indicated by the EPR signals is not consistent with that deduced from Mössbauer and magnetic circular dichroism studies, suggesting heterogeneity in both types of center.