The Effect of Targeted Hyperoxemia on Brain Immunohistochemistry after Long-Term, Resuscitated Porcine Acute Subdural Hematoma and Hemorrhagic Shock.

Epidemiological data suggest that moderate hyperoxemia may be associated with an improved outcome after traumatic brain injury. In a prospective, randomized investigation of long-term, resuscitated acute subdural hematoma plus hemorrhagic shock (ASDH + HS) in 14 adult, human-sized pigs, targeted hyperoxemia (200 < PaO2 < 250 mmHg vs. normoxemia 80 < PaO2 < 120 mmHg) coincided with improved neurological function. Since brain perfusion, oxygenation and metabolism did not differ, this post hoc study analyzed the available material for the effects of targeted hyperoxemia on cerebral tissue markers of oxidative/nitrosative stress (nitrotyrosine expression), blood-brain barrier integrity (extravascular albumin accumulation) and fluid homeostasis (oxytocin, its receptor and the H2S-producing enzymes cystathionine-ß-synthase and cystathionine-γ-lyase). After 2 h of ASDH + HS (0.1 mL/kgBW autologous blood injected into the subdural space and passive removal of 30% of the blood volume), animals were resuscitated for up to 53 h by re-transfusion of shed blood, noradrenaline infusion to maintain cerebral perfusion pressure at baseline levels and hyper-/normoxemia during the first 24 h. Immediate postmortem, bi-hemispheric (i.e., blood-injected and contra-lateral) prefrontal cortex specimens from the base of the sulci underwent immunohistochemistry (% positive tissue staining) analysis of oxidative/nitrosative stress, blood-brain barrier integrity and fluid homeostasis. None of these tissue markers explained any differences in hyperoxemia-related neurological function. Likewise, hyperoxemia exerted no deleterious effects.

An exploratory study investigating the effect of targeted hyperoxemia in a randomized controlled trial in a long-term resuscitated model of combined acute subdural hematoma and hemorrhagic shock in cardiovascular healthy pigs.

Severe physical injuries and associated traumatic brain injury and/or hemorrhagic shock (HS) remain leading causes of death worldwide, aggravated by accompanying extensive inflammation. Retrospective clinical data indicated an association between mild hyperoxemia and improved survival and outcome. However, corresponding prospective clinical data, including long-term resuscutation, are scarce. Therefore, the present study explored the effect of mild hyperoxemia for 24 hours in a prospective randomized controlled trial in a long-term resuscitated model of combined acute subdural hematoma (ASDH) and HS. ASDH was induced by injecting 0.1 ml × kg-1 autologous blood into the subdural space and HS was triggered by passive removal of blood. After 2 hours, the animals received full resuscitation, including retransfusion of the shed blood and vasopressor support. During the first 24 hours, the animals underwent targeted hyperoxemia (PaO2 = 200 - 250 mmHg) or normoxemia (PaO2 = 80 - 120 mmHg) with a total observation period of 55 hours after the initiation of ASDH and HS. Survival, cardiocirculatory stability, and demand for vasopressor support were comparable between both groups. Likewise, humoral markers of brain injury and systemic inflammation were similar. Multimodal brain monitoring, including microdialysis and partial pressure of O2 in brain tissue, did not show significant differences either, despite a significantly better outcome regarding the modified Glasgow Coma Scale 24 hours after shock that favors hyperoxemia. In summary, the present study reports no deleterious and few beneficial effects of mild targeted hyperoxemia in a clinically relevant model of ASDH and HS with long-term resuscitation in otherwise healthy pigs. Further beneficial effects on neurological function were probably missed due to the high mortality in both experimental groups. The present study remains exploratory due to the unavailability of an a priori power calculation resulting from the lack of necessary data.

Spindle cell oncocytoma of the neurohypophysis with metastasis to the sphenoparietal sinus and immunohistochemical negativity for S100 and epithelial membrane antigen (EMA).

We report the case of a 61-year-old male with spindle cell oncocytoma of the hypophysis. On presentation to the Department of Neurosurgery at the German Armed Forces Hospital of Ulm, the patient reported a history of several years of left sixth nerve palsy, right ptosis, increased sensitivity to light, and a bilateral retrobulbar pressure sensation. Pituitary function was normal. A chromophobe non-functioning pituitary adenoma was initially suspected. The diagnosis was established on the basis of examination at a histopathology reference laboratory using immunohistochemistry to identify cell surface markers. During two years of follow-up, there were two clinical recurrences requiring surgery. To our knowledge, this is the 35th documented case of spindle cell oncocytoma of the pituitary gland and the first that was immunohistochemically negative for epithelial membrane antigen (EMA) and S100; and the first that displayed haematogenous metastasis to the right sphenoparietal sinus. The three surgical procedures were associated with massive intraoperative bleeding and thus resulted in subtotal tumor resection. Following surgery for the recurrences, the patient underwent radiotherapy.

Multifocal and hormone-dependent epithelioid hemangioendothelioma with osteolysis of the second cervical vertebral body: report of an unprecedented surgical approach by using autologous bone graft.

We report the case of a 28-year-old female patient who complained of extreme neck pain when giving birth to a child. Magnetic resonance imaging (MRI) of the cervical spine demonstrated an osteolytic lesion at the second cervical vertebral body (C2). In this presentation, we highlight a transoral surgical approach in order to prevent instability of this osteolytic lesion. To the best of our knowledge, this is the first time that such a route of access has been described for this tumor entity. A histopathologic examination led to the diagnosis of epithelioid hemangioendothelioma. During a follow-up period of 33 months, the patient had no complaints.

13C-Metabolic flux analysis detected a hyperoxemia-induced reduction of tricarboxylic acid cycle metabolism in granulocytes during two models of porcine acute subdural hematoma and hemorrhagic shock.

Introduction: Supplementation with increased inspired oxygen fractions has been suggested to alleviate the harmful effects of tissue hypoxia during hemorrhagic shock (HS) and traumatic brain injury. However, the utility of therapeutic hyperoxia in critical care is disputed to this day as controversial evidence is available regarding its efficacy. Furthermore, in contrast to its hypoxic counterpart, the effect of hyperoxia on the metabolism of circulating immune cells remains ambiguous. Both stimulating and detrimental effects are possible; the former by providing necessary oxygen supply, the latter by generation of excessive amounts of reactive oxygen species (ROS). To uncover the potential impact of increased oxygen fractions on circulating immune cells during intensive care, we have performed a 13C-metabolic flux analysis (MFA) on PBMCs and granulocytes isolated from two long-term, resuscitated models of combined acute subdural hematoma (ASDH) and HS in pigs with and without cardiovascular comorbidity. Methods: Swine underwent resuscitation after 2 h of ASDH and HS up to a maximum of 48 h after HS. Animals received normoxemia (PaO2 = 80 - 120 mmHg) or targeted hyperoxemia (PaO2 = 200 - 250 mmHg for 24 h after treatment initiation, thereafter PaO2 as in the control group). Blood was drawn at time points T1 = after instrumentation, T2 = 24 h post ASDH and HS, and T3 = 48 h post ASDH and HS. PBMCs and granulocytes were isolated from whole blood to perform electron spin resonance spectroscopy, high resolution respirometry and 13C-MFA. For the latter, we utilized a parallel tracer approach with 1,2-13C2 glucose, U-13C glucose, and U-13C glutamine, which covered essential pathways of glucose and glutamine metabolism and supplied redundant data for robust Bayesian estimation. Gas chromatography-mass spectrometry further provided multiple fragments of metabolites which yielded additional labeling information. We obtained precise estimations of the fluxes, their joint credibility intervals, and their relations, and characterized common metabolic patterns with principal component analysis (PCA). Results: 13C-MFA indicated a hyperoxia-mediated reduction in tricarboxylic acid (TCA) cycle activity in circulating granulocytes which encompassed fluxes of glutamine uptake, TCA cycle, and oxaloacetate/aspartate supply for biosynthetic processes. We further detected elevated superoxide levels in the swine strain characterized by a hypercholesterolemic phenotype. PCA revealed cell type-specific behavioral patterns of metabolic adaptation in response to ASDH and HS that acted irrespective of swine strains or treatment group. Conclusion: In a model of resuscitated porcine ASDH and HS, we saw that ventilation with increased inspiratory O2 concentrations (PaO2 = 200 - 250 mmHg for 24 h after treatment initiation) did not impact mitochondrial respiration of PBMCs or granulocytes. However, Bayesian 13C-MFA results indicated a reduction in TCA cycle activity in granulocytes compared to cells exposed to normoxemia in the same time period. This change in metabolism did not seem to affect granulocytes' ability to perform phagocytosis or produce superoxide radicals.

The effect of targeted hyperoxemia in a randomized controlled trial employing a long-term resuscitated, model of combined acute subdural hematoma and hemorrhagic shock in swine with coronary artery disease: An exploratory, hypothesis-generating study.

Controversial evidence is available regarding suitable targets for the arterial O2 tension (PaO2) after traumatic brain injury and/or hemorrhagic shock (HS). We previously demonstrated that hyperoxia during resuscitation from hemorrhagic shock attenuated cardiac injury and renal dysfunction in swine with coronary artery disease. Therefore, this study investigated the impact of targeted hyperoxemia in a long-term, resuscitated model of combined acute subdural hematoma (ASDH)-induced brain injury and HS. The prospective randomized, controlled, resuscitated animal investigation consisted of 15 adult pigs. Combined ASDH plus HS was induced by injection of 0.1 ml/kg autologous blood into the subdural space followed by controlled passive removal of blood. Two hours later, resuscitation was initiated comprising re-transfusion of shed blood, fluids, continuous i.v. noradrenaline, and either hyperoxemia (target PaO2 200 - 250 mmHg) or normoxemia (target PaO2 80 - 120 mmHg) during the first 24 h of the total of 54 h of intensive care. Systemic hemodynamics, intracranial and cerebral perfusion pressures, parameters of brain microdialysis and blood biomarkers of brain injury did not significantly differ between the two groups. According to the experimental protocol, PaO2 was significantly higher in the hyperoxemia group at the end of the intervention period, i.e., at 24 h of resuscitation, which coincided with a higher brain tissue PO2. The latter persisted until the end of observation period. While neurological function as assessed using the veterinary Modified Glasgow Coma Score progressively deteriorated in the control group, it remained unaffected in the hyperoxemia animals, however, without significant intergroup difference. Survival times did not significantly differ in the hyperoxemia and control groups either. Despite being associated with higher brain tissue PO2 levels, which were sustained beyond the intervention period, targeted hyperoxemia exerted neither significantly beneficial nor deleterious effects after combined ASDH and HS in swine with pre-existing coronary artery disease. The unavailability of a power calculation and, thus, the limited number of animals included, are the limitations of the study.

First Report of Tumor Treating Fields (TTFields) Therapy for Glioblastoma in Comorbidity with Multiple Sclerosis.

Tumor Treating Fields (TTFields) therapy is FDA approved and has the CE mark for treatment of newly diagnosed and recurrent glioblastoma. To our knowledge, to date TTFields therapy remains unstudied in glioblastoma patients with multiple sclerosis (MS) as a comorbidity. Here, we present a patient who was diagnosed with MS at the age of 34. Treatment included several corticoid pulse treatments and therapies with interferon beta-1a and sphingosine-1-phosphate receptor modulator fingolimod. At the age of 52 the patient was diagnosed with glioblastoma, after experiencing worsening headaches which could not be attributed to the MS condition. After subtotal resection and concomitant radiochemotherapy, the patient received temozolomide in combination with TTFields therapy. For two years, the tumor condition remained stable while the patient showed high adherence to TTFields therapy with low-grade skin reactions being the only therapy-related adverse events. After two years, the tumor recurred. The patient underwent re-resection and radiotherapy and restarted TTFields therapy together with chemotherapy and is currently still on this therapy regime. Although having not been studied systematically, the case presented here demonstrates that TTFields therapy may be considered for newly diagnosed and recurrent glioblastoma patients with previously diagnosed multiple sclerosis.

In-depth characterization of a long-term, resuscitated model of acute subdural hematoma-induced brain injury.

OBJECTIVE: Acute subdural hematoma (ASDH) is a leading entity in brain injury. Rodent models mostly lack standard intensive care, while large animal models frequently are only short term. Therefore, the authors developed a long-term, resuscitated porcine model of ASDH-induced brain injury and report their findings. METHODS: Anesthetized, mechanically ventilated, and instrumented pigs with human-like coagulation underwent subdural injection of 20 mL of autologous blood and subsequent observation for 54 hours. Continuous bilateral multimodal brain monitoring (intracranial pressure [ICP], cerebral perfusion pressure [CPP], partial pressure of oxygen in brain tissue [PbtO2], and brain temperature) was combined with intermittent neurological assessment (veterinary modified Glasgow Coma Scale [MGCS]), microdialysis, and measurement of plasma protein S100ß, GFAP, neuron-specific enolase [NSE], nitrite+nitrate, and isoprostanes. Fluid resuscitation and continuous intravenous norepinephrine were targeted to maintain CPP at pre-ASDH levels. Immediately postmortem, the brains were taken for macroscopic and histological evaluation, immunohistochemical analysis for nitrotyrosine formation, albumin extravasation, NADPH oxidase 2 (NOX2) and GFAP expression, and quantification of tissue mitochondrial respiration. RESULTS: Nine of 11 pigs survived the complete observation period. While ICP significantly increased after ASDH induction, CPP, PbtO2, and the MGCS score remained unaffected. Blood S100ß levels significantly fell over time, whereas GFAP, NSE, nitrite+nitrate, and isoprostane concentrations were unaltered. Immunohistochemistry showed nitrotyrosine formation, albumin extravasation, NOX2 expression, fibrillary astrogliosis, and microglial activation. CONCLUSIONS: The authors describe a clinically relevant, long-term, resuscitated porcine model of ASDH-induced brain injury. Despite the morphological injury, maintaining CPP and PbtO2 prevented serious neurological dysfunction. This model is suitable for studying therapeutic interventions during hemorrhage-induced acute brain injury with standard brain-targeted intensive care.

Spine surgery in the International Security Assistance Force Role 3 combat support hospital in Mazar-e-Sharif, northern Afghanistan, 2007-2014.

OBJECTIVESince 2007, a continuous neurosurgery emergency service has been available in the International Security Assistance Force (ISAF) field hospital in Mazar-e-Sharif (MeS), Afghanistan. The object of this study was to assess the number and range of surgical procedures performed on the spine in the period from 2007 to 2014.METHODSThis is a retrospective analysis of the annual neurosurgical caseload statistics from July 2007 to October 2014 (92 months). The distribution of surgical urgency (emergency, delayed urgency, or elective), patient origin (ISAF, Afghan National Army, or civilian population), and underlying causes of diseases and injuries (penetrating injury, blunt injury/fracture, or degenerative disease) was analyzed. The range and pattern of diagnoses in the neurosurgical outpatient department from 2012 and 2013 were also evaluated.RESULTSA total of 341 patients underwent neurosurgical operations in the period from July 2007 to October 2014. One hundred eighty-eight (55.1%) of the 341 procedures were performed on the spine, and the majority of these surgeries were performed for degenerative diseases (127/188; 67.6%). The proportion of spinal fractures and penetrating injuries (61/188; 32.4%) increased over the study period. These spinal trauma diagnoses accounted for 80% of the cases in which patients had to undergo operations within 12 hours of presentation (n = 70 cases). Spinal surgeries were performed as an emergency in 19.8% of cases, whereas 17.3% of surgeries had delayed urgency and 62.9% were elective procedures. Of the 1026 outpatient consultations documented, 82% were related to spinal issues.CONCLUSIONSCompared to the published numbers of cases from neurosurgery units in the rest of the ISAF area, the field hospital in MeS had a considerably lower number of operations. In addition, MeS had the highest rates of both elective neurosurgical operations and Afghan civilian patients. In comparison with the field hospital in MeS, none of the other ISAF field hospitals showed such a strong concentration of degenerative spinal conditions in their surgical spectrum. Nevertheless, the changing pattern of spine-related diagnoses and surgical therapies in the current conflict represents a challenge for future training and material planning in comparable missions.

Primary Amelanotic CNS Melanoma: Case Report and Literature Review.

Primary malignant melanomas of the central nervous system (CNS) are rarely seen entities in the clinical routine. Primary amelanotic melanomas are even rarer. In our literature review, we found only six case reports of primary amelanotic CNS melanomas. Our case report describes the course of a 71-year-old man with a primary amelanotic CNS melanoma with secondary spread to the spine.

[Clinical and Radiological Results after Anterior Cervical Corpectomy with Cage Fusion - a Retrospective Comparison of PEEK vs. Titanium Cages]. / Implantatassoziierte Komplikationen sowie klinischer und radiologischer Verlauf nach anteriorer zervikaler Korpektomie und Cage-Fusion ­ retrospektiver Vergleich von PEEK- gegen Titan-Cages.

Background Anterior cervical corpectomy and fusion (ACCF) has become a standard procedure for patients with spondylotic myelopathy due to multisegmental stenosis of the cervical canal. Beside the fusion technique using autogenous bone grafts, synthetic cages have been increasingly used in recent years. Published information on the clinical and radiological results of different cage materials for ACCF is still limited. The study presented here is the largest series to date reporting clinical and radiological outcomes and complication rates after one- to three-level ACCF using structural polyetheretherketone (PEEK) or titanium cages augmented by anterior plate-screw osteosynthesis. Materials and Methods Retrospective comparative study on 126 patients after cage ACCF using modular PEEK (n = 101) or distractable titanium (n = 25) cages with a minimum follow-up of 6 months. The numbers of hardware failures and implant-related surgical revisions were determined. The rate of subsidence and fusion and the course of lordotic alignment (segmental and regional Cobb's angles) were analysed. Neck Disability Index (NDI) and European Myelopathy Score (EMS) were assessed. Results Significantly greater number of screw and cage complications were detected in the titanium cage group (36 vs. 7.9 % and 64 vs. 36.6 %, respectively). Non-significant trend to a higher rate of implant related revision rate in the titanium cage group (16 vs. 2.97 %). Significantly greater rate of grade I or II fusion in the PEEK cage group after 6 months (82 vs. 52 %). NDI, EMS and lordotic alignment improved significantly in both groups. There were neither significant differences between the two groups nor significant correlations between these clinico-radiological parameters and the cage material. Partial correlations performed with control of parameters showing inhomogenous distribution (patient age, fusion distance, rate of multilevel corpectomy and the rate of intraoperative segmental overdistraction) showed no significant correlations for any of the clinical or radiological outcome parameters and the complications or revisions to the cage material. Conclusion Cages are a safe and effective alternative to autogenous bone graft for ACCF. A significant improvement in clinical and radiological parameters can be achieved with both titanium and PEEK implants. Significant differences between the two cage material groups or significant correlations of clinico-radiological outcome and cage material were not proven. Moreover there is no evidence in the literature for clinical advantages of one special cage material, to date. Therefore further prospective randomised evaluation of different fusion techniques in ACCF is still necessary.

Pediatric Neurosurgical Care in a German Field Hospital in Afghanistan.

Background and Study Objectives Children are commonly found among the injured in war settings. Prognosis often depends on the presence of brain injury. Not all neurosurgery departments of German Armed Forces hospitals, however, have experience in the care of children with neurosurgical conditions. Against this background, we assessed the group of pediatric neurosurgical patients in a German (Role 3) field hospital in Mazar-e-Sharif, Afghanistan. Patients/Materials and Methods We analyzed the operative logbooks from January 1, 2008, to December 31, 2013, to assess the number of neurosurgical procedures that were performed on children (< 18 years of age) at the field hospital of Mazar-e-Sharif. Results During the study period, 327 neurosurgical procedures were performed at the German field hospital. Of these, 29 (9%) were performed on children. The mean age of the pediatric patients (7 girls and 22 boys) was 11.7 years (median age: 12 years; range: 5-17 years). Only three procedures were performed for conditions other than trauma. Pediatric patients accounted for almost 10% of all patients who underwent neurosurgery during a recent military deployment in Mazar-e-Sharif. This percentage is similar to those reported by other nations. These findings show that a considerable number of children underwent neurosurgical treatment. Conclusions Military planners should be aware that Role 3 medical treatment facilities must provide care for pediatric emergencies and must therefore be staffed and equipped accordingly. For military hospitals at home, this means that the management of pediatric patients is an opportunity for medical personnel to receive important pediatric training that enables them to provide care to children in deployed medical facilities.

Treatment of unresectable skull base meningiomas with somatostatin analogs.

OBJECT: The standard surgical treatment for meningiomas is total resection, but the complete removal of skull base meningiomas can be difficult for several reasons. Thus, the management of certain meningiomas of the skull base--for example, those involving basal vessels and cranial nerves--remains a challenge. In recent reports it has been suggested that somatostatin (SST) administration can cause growth inhibition of unresectable and recurrent meningiomas. The application of SST and its analogs is not routinely integrated into standard treatment strategies for meningiomas, and clinical studies proving growth-inhibiting effects do not exist. The authors report on their experience using octreotide in patients with recurrent or unresectable meningiomas of the skull base. METHODS: Between January 1996 and December 2010, 13 patients harboring a progressive residual meningioma (as indicated by MR imaging criteria) following operative therapy were treated with a monthly injection of the SST analog octreotide (Sandostatin LAR [long-acting repeatable] 30 mg, Novartis). Eight of 13 patients had a meningioma of the skull base and were analyzed in the present study. Postoperative tumor enlargement was documented in all patients on MR images obtained before the initiation of SST therapy. All tumors were benign. No patient received radiation or chemotherapy before treatment with SST. The growth of residual tumor was monitored by MR imaging every 12 months. RESULTS: Three of the 8 patients had undergone surgical treatment once; 3, 2 times; and 2, 3 times. The mean time after the last meningioma operation (before starting SST treatment) and tumor enlargement as indicated by MR imaging criteria was 24 months. A total of 643 monthly cycles of Sandostatin LAR were administered. Five of the 8 patients were on SST continuously and stabilized disease was documented on MR images obtained in these patients during treatment (median 115 months, range 48-180 months). Three of the 8 patients interrupted treatment: after 60 months in 1 case because of tumor progression, after 36 months in 1 case because of side effects, and after 36 months in 1 case because the health insurance company denied cost absorption. CONCLUSIONS: Although no case of tumor regression was detected on MR imaging, the study results indicated that SST analogs can arrest the progression of unresectable or recurrent benign meningiomas of the skull base in some patients. It remains to be determined whether a controlled prospective clinical trial would be useful.

Subtle reactivity patterns of non-heteroatom-substituted manganese alkynyl carbene complexes in the presence of phosphorus probes.

The non-heteroatom-substituted manganese alkynyl carbene complexes (eta5-MeC5H4)(CO)2Mn=C(R)C[triple bond]CR'(3; 3a: R = R'= Ph, 3b: R = Ph, R'= Tol, 3c: R = Tol, R'= Ph) have been synthesised in high yields upon treatment of the corresponding carbyne complexes [eta5-MeC5H4)(CO)2Mn[triple bond]CR][BPh4]([2][BPh4]) with the appropriate alkynyllithium reagents LiC[triple bond]CR' (R'= Ph, Tol). The use of tetraphenylborate as counter anion associated with the cationic carbyne complexes has been decisive. The X-ray structures of (eta5-MeC5H4)(CO)2Mn=C(Tol)C[triple bond]CPh (3c), and its precursor [(eta5-MeC5H4)(CO)2Mn=CTol][BPh4]([2b](BPh4]) are reported. The reactivity of complexes toward phosphines has been investigated. In the presence of PPh3, complexes act as a Michael acceptor to afford the zwitterionic sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)=C=C(PPh3)R' (5) resulting from nucleophilic attack by the phosphine on the remote alkynyl carbon atom. Complexes 5 exhibit a dynamic process in solution, which has been rationalized in terms of a fast [NMR time-scale] rotation of the allene substituents around the allene axis; metrical features within the X-ray structure of (eta5-MeC5H4)(CO)2MnC(Ph)=C=C(PPh3)Tol (5b) support the proposal. In the presence of PMe3, complexes undergo a nucleophilic attack on the carbene carbon atom to give zwitterionic sigma-propargylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)(PMe3)C[triple bond]CR' (6). Complexes 6 readily isomerise in solution to give the sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R')=C=C(PMe3)R (7) through a 1,3 shift of the [(eta5-MeC5H4)(CO)2Mn] fragment. The nucleophilic attack of PPh2Me on 3 is not selective and leads to a mixture of the sigma-propargylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)(PPh(2)Me)C[triple bond]CR' (9) and the sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R)=C=C(PPh(2)Me)R' (10). Like complexes 6, complexes 9 readily isomerize to give the sigma-allenylphosphonium complexes (eta5-MeC5H4)(CO)2MnC(R')=C=C(PPh2Me)R'). Upon gentle heating, complexes 7, and mixtures of 10 and 10' cyclise to give the sigma-dihydrophospholium complexes (eta5-MeC5H4)(CO)2MnC=C(R')PMe2CH2CH(R)(8), and mixtures of complexes (eta5-MeC5H4)(CO)2MnC=C(Ph)PPh2CH2CH(Tol)(11) and (eta5-MeC5H4)(CO)2MnC=C(Tol)PMe2CH2CH(Ph)(11'), respectively. The reactions of complexes 3 with secondary phosphines HPR(1)(2)(R1= Ph, Cy) give a mixture of the eta2-allene complexes (eta5-MeC5H4)(CO)2Mn[eta2-{R(1)(2)PC(R)=C=C(R')H}](12), and the regioisomeric eta4-vinylketene complexes [eta5-MeC5H4)(CO)Mn[eta4-{R(1)(2)PC(R)=CHC(R')=C=O}](13) and (eta5-MeC5H4)(CO)Mn[eta4-{R(1)(2)PC(R')=CHC(R)=C=O}](13'). The solid-state structure of (eta5-MeC5H4)(CO)2Mn[eta2-{Ph2PC(Ph)=C=C(Tol)H}](12b) and (eta5-MeC5H4)(CO)Mn[eta4-{Cy2PC(Ph)=CHC(Ph)=C=O}](13d) are reported. Finally, a mechanism that may account for the formation of the species 12, 13, and 13' is proposed.

Electrocatalytic dimerisation of non-heteroatom-substituted manganese alkynylcarbene complexes.

Upon controlled potential electrolysis (-1.30 V vs. SCE), the alkynylcarbene complexes MeCp(CO)2Mn=C(R)C [triple bond]CR' are seen to undergo an electrocatalytic dimerisation by coupling of the remote alkynyl carbon atoms to afford the ene-diyne dimanganese complexes [MeCp(CO)2Mn]2[eta 4-(E)-RC [triple bond] C(R')C=C(R')C [triple bond] CR].

First fluorescent ferrocenyl compound as multiresponsive calcium-sensing device. NMR, electrochemical, and photophysical preliminary investigations in CH(3)CN.

A new ferrocene receptor binds a calcium guest via complex processes involving the whole unsaturated core of the ligand. Complexation induces significant changes in the ligand properties, as evidenced by the unprecedented cation sensing observed both by electrochemistry and fluorescence spectroscopy.