In situ-Generation of Magnesium- and Calcium-Based Grignard Reagents for Amide Synthesis

The alkaline-earth metals Mg and Ca are too inert for the direct metalation of primary and secondary amines. Consequently, activation prior to use is required. Alternatively, the Grignard reagents RMgX (R = alkyl, aryl, X = halide) can be applied in metalation of amines. However, such a straightforward procedure for the synthesis of alkylcalcium reagents is disadvantageous due to diverse side reactions, including Wurtz-type C-C coupling and ether degradation reactions. Therefore, suspensions of magnesium or calcium with amine can be treated in a smooth reaction with ethyl bromide in an ethereal solvent at room temperature. Intermediately formed RAeX (Ae = Mg, Ca) either metalates amines yielding the corresponding amides in an in situ-Grignard-Metalation-Method (iGMM) or adds across C=N bonds of imines in an in situ Grignard Addition Method (iGAM). The amides R'2N-AeX (Ae = Mg: Hauser bases) undergo Schlenk-type ligand exchange reactions yielding homoleptic Ae(NR'2)2 and potentially sparingly soluble AeX2.

[Closure of persisting rectourethral fistula after suprasymphyseal adenoma enucleation of the prostate by combining the Bressel-Naujox and gracilis flap procedure]

When taking into consideration the basic principles of fistula surgery, numerous options are available for the surgical repair of rectourethral fistulas. However, there is no standard regarding which surgical method should be used under which circumstances-due to the heterogeneity of this disease. This case report describes the individual adaptation of a surgical technique that is used for the treatment of vesicovaginal fistulas to treat a rectourethral fistula in a patient who had already undergone an unsuccessful fistula closure attempt. Successful closure of the fistula was achieved on the basis of an established method using tissue interposition.

Synthesis of Sterically Encumbered Alkaline-Earth Metal Amides Applying the In Situ Grignard Reagent Formation

Magnesium and calcium are too inert to deprotonate amines directly. For the synthesis of bulky amides alternative strategies are required and in the past, N-bound trialkylsilyl groups have been used to ease metalation reactions. The in situ Grignard reagent formation in stirred suspensions of magnesium or calcium with hydryl halide and imine in THF allows the synthesis of a plethora of amides with bulky silyl-free substituents. Ball milling protocols partially favor competitive side reactions such as aza-pinacol coupling reactions. Calcium is the advantageous choice for the in situ Grignard reagent formation and subsequent addition onto the imines yielding bulky calcium bis(amides) whereas the stronger reducing heavier alkaline-earth metals strontium and barium are less selective and hence, the aza-pinacol coupling reaction becomes competitive. Exemplary, the solid-state molecular structures of [(Et₂ O)Mg(N(Ph)(CHPh₂ )₂ ] and [(Et₂ O)₂ Ca(N(Ph)(CHPh₂ )₂ ] have been determined.

In situ Grignard Metalation Method, Part II: Scope of the One-Pot Synthesis of Organocalcium Compounds

The in situ Grignard Metalation Method (iGMM) is a straightforward one-pot strategy to synthesize alkaline-earth metal amides in multi-gram scale with high yields via addition of bromoethane to an ethereal suspension of a primary or secondary amine and magnesium (Part I) or calcium (Part II). This method is highly advantageous because no activation of calcium is required prior to the reaction. Contrary to the magnesium-based iGMM, there are some limitations, the most conspicuous one is the large influence of steric factors. The preparation of Ca(hmds)₂ succeeds smoothly within a few hours with excellent yields opening the opportunity to prepare large amounts of this reagent. Side reactions and transfer of the iGMM to substituted anilines and N-heterocycles as well as other H-acidic substrates such as cyclopentadienes are studied. Bulky amidines cannot be converted directly to calcium amidinates via the iGMM but stoichiometric calciation with Ca(hmds)₂ enables their preparation.

In Situ Grignard Metalation Method for the Synthesis of Hauser Bases

The in situ Grignard Metalation Method (iGMM) is a straightforward one‐pot procedure to quickly produce multigram amounts of Hauser bases R₂N‐MgBr which are valuable and vastly used metalation reagents and novel electrolytes for magnesium batteries. During addition of bromoethane to a suspension of Mg metal and secondary amine at room temperature in an ethereal solvent, a smooth reaction yields R₂N‐MgBr under evolution of ethane within a few hours. A Schlenk equilibrium is operative, interconverting the Hauser bases into their solvated homoleptic congeners Mg(NR₂)₂ and MgBr₂ depending on the solvent. Scope and preconditions are studied, and side reactions limiting the yield have been investigated. DOSY NMR experiments and X‐ray crystal structures of characteristic examples clarify aggregation in solution and the solid state.

Sterically shielded primary anilides of the alkaline-earth metals of the type (thf)nAe(NH-Ar*)2 (Ae = Mg, Ca, Sr, and Ba; Ar* = bulky aryl)

Metalation of 2,4,6-triphenylphenylamine (H₂N-C₆H₂-2,4,6-Ph₃, 1a) and 4-methyl-2,6-bis(diphenylmethyl)aniline (2,6-bis(diphenylmethyl)-p-toluidine, H₂N-C₆H₂-4-Me-2,6-(CHPh₂)₂, 2a) with dibutylmagnesium and Ae[N(SiMe₃)₂]₂ with a stoichiometric 1 : 2 ratio in THF at room temperature yields the corresponding primary anilides [(thf)_nAe{N(H)-C₆H₂-2,4,6-Ph₃}₂] (Ae/n = Mg/2 (1b), Ca/2 (1c), Sr/3 (1d), and Ba/3 (1e)) and [(thf)_nAe{N(H)-C₆H₂-4-Me-2,6-(CHPh₂)₂}₂] (Ae/n = Mg/2 (2b), Ca/3 (2c) and Sr/2 (2d)), respectively. The 1 : 1 reaction of Mg(n/sBu)₂ and MgPh₂ with 2a leads to the formation of heteroleptic [(thf)₂Mg(R){N(H)-C₆H₂-4-Me-2,6-(CHPh₂)₂}] (R = n/sBu (2bBu), Ph (2bPh)). At 50 °C, the strontium complex 2d liberates one equivalent of 2avia intramolecular deprotonation of the triarylmethyl functionality yielding dinuclear [(thf)₂Sr{N(H)-C₆H₂-4-Me-2-(CPh₂)-6-(CHPh₂)₂}]₂ (2d'). The barium compound is significantly more reactive and regardless of applied stoichiometry the isotypic barium congener [(thf)₂Ba{N(H)-C₆H₂-4-Me-2-(CPh₂)-6-(CHPh₂)₂}]₂ (2e') forms. The molecular structures of 1c, 2d, 2d', and 2e' are stabilized by metal-phenyl π-interactions.

One-Step Synthesis and Schlenk-Type Equilibrium of Cyclopentadienylmagnesium Bromides

In the in situ Grignard metalation method (iGMM), the addition of bromoethane to a suspension of magnesium turnings and cyclopentadienes [C5 H6 (HCp), C5 H5 -Si(iPr)3 (HCpTIPS )] in diethyl ether smoothly yields heteroleptic [(Et2 O)Mg(CpR )(μ-Br)]2 (CpR =Cp (1), CpTIPS (2)). The Schlenk equilibrium of 2 in toluene leads to ligand exchange and formation of homoleptic [Mg(CpR )2 ] (3) and [(Et2 O)MgBr(μ-Br)]2 (4). Interfering solvation and aggregation as well as ligand redistribution equilibria hamper a quantitative elucidation of thermodynamic data for the Schlenk equilibrium of 2 in toluene. In ethereal solvents, mononuclear species [(Et2 O)2 Mg(CpTIPS )Br] (2'), [(Et2 O)n Mg(CpTIPS )2 ] (3'), and [(Et2 O)2 MgBr2 ] (4') coexist. Larger coordination numbers can be realized with cyclic ethers like tetrahydropyran allowing crystallization of [(thp)4 MgBr2 ] (5). The interpretation of the temperature-dependency of the Schlenk equilibrium constant in diethyl ether gives a reaction enthalpy ΔH and reaction entropy ΔS of -11.5 kJ mol-1 and 60 J mol-1 , respectively.

Magnesium bis(amidinate) and bis(guanidinate) complexes: impact of the ligand backbone and bridging groups on the coordination behaviour

A library of ten dinucleating bis(amidine) and bis(guanidine) ligands, in which the bridging groups, terminal rests, and backbone substituents were systematically altered, has been synthesized and subsequently applied in metallation reactions using three different magnesium sources. Eight Mg complexes could be isolated and fully characterized, and in seven cases their solid-state structure could be determined by means of single crystal X-ray diffraction analysis. The results evidence a versatile coordination behaviour, which ranges from the first dinuclear heteroleptic magnesium iodide complex to dinuclear homoleptic complexes. These findings indicate the crucial impact of both the ligand and the magnesium source not only on the accessibility of well-defined dinuclear complexes but also on the aggregation in solution and in the solid state.

Stripping and Plating a Magnesium Metal Anode in Bromide-Based Non-Nucleophilic Electrolytes

A non-nucleophilic Hauser base hexamethyldisilazide (HMDS) magnesium electrolyte possesses inherent properties required for a magnesium-sulfur battery. However, the development of full cell batteries using HMDSCl-based electrolytes is still hampered by a low coulombic efficiency. A new electrolyte formulation of non-nucleophilic HMDS magnesium containing bromide as a halide instead of chloride was obtained through a simple and straightforward synthesis route. The electrochemistry of magnesium was investigated through plating and stripping in three different HMDSBr-based electrolytes: Mg(HMDS)Br, Mg(HMDS)Br-BEt₃ , and Mg(HMDS)Br-AlEt₃ dissolved in tetrahydrofuran. The different magnesium species present in the electrolytes were determined using NMR. Weak electron-withdrawing Lewis acids, BEt₃ and AlEt₃ were used intentionally and their impact was investigated. Contrary to expectation, the substitution of chloride by bromide does not drastically narrow the electrochemical stability window. HMDSBr-based electrolytes demonstrated long-term (1000 cycles) stable reversibility and highly efficient (≈99 %) magnesium plating/tripping without a high ratio of bromide compared with the MgHMDSCl-based electrolytes. The aprotic electrolyte shows comparatively high anodic stability (≈2.4 V vs. Mg/Mg²⁺ ) and high ionic conductivity of 1.16 mS cm^-1 at room temperature. Plating of magnesium with low overpotential (<188 mV) revealed a morphology dependence on the electrolyte type with a shiny metallic homogenous layer, suggesting a rational balance between the nucleation and growth process in HMDSBr-based electrolytes.

Scope and Limitations of the s-Block Metal-Mediated Pudovik Reaction

The hydrophosphorylation of phenylacetylene with di(aryl)phosphane oxides Ar₂P(O)H (Pudovik reaction) yields E/Z‐isomer mixtures of phenylethenyl‐di(aryl)phosphane oxides (1). Alkali and alkaline‐earth metal di(aryl)phosphinites have been studied as catalysts for this reaction with increasing activity for the heavier s‐block metals. The Pudovik reaction can only be mediated for di(aryl)phosphane oxides whereas P‐bound alkyl and alcoholate substituents impede the P−H addition across alkynes. The demanding mesityl group favors the single‐hydrophosphorylated products 1‐Ar whereas smaller aryl substituents lead to the double‐hydrophosphorylated products 2‐Ar. Polar solvents are beneficial for an effective addition. Increasing concentration of the reactants and the catalyst accelerates the Pudovik reaction. Whereas Mes₂P(O)H does not form the bis‐phosphorylated product 2‐Mes, activation of an ortho‐methyl group and cyclization occurs yielding 2‐benzyl‐1‐mesityl‐5,7‐dimethyl‐2,3‐dihydrophosphindole 1‐oxide (3).

Synthesis of β-Lactams via Enantioselective Allylation of Anilines with Morita–Baylis–Hillman Carbonates

Enantioenriched β-lactams are accessed via enantioselective allylation of anilines with Morita–Baylis–Hillman carbonates followed by a base-promoted cyclization. The resulting 3-methyleneazetidin-2-ones are amenable to diastereoselective functionalization to produce analogues of biologically active β-lactams. The use of nearly equimolar quantities of the starting materials make this method efficient and straightforward.

Bis(trimethylsilyl)amide complexes of s-block metals with bidentate ether and amine ligands

The synthesis of the bis(trimethylsilyl)amide complexes of alkali and alkaline-earth metals with bidentate ether and amine bases 1,2-bis(dimethylamino)ethane (tmeda), dimethyl-methoxyethylamine (dmmea), and 1,2-dimethoxyethane (dme) succeedsviaaddition of these bases to coligand-free complexes orvialigand exchange of thf adducts.

Straightforward One-Pot Syntheses of Silylamides of Magnesium and Calcium via an In Situ Grignard Metalation Method

Calcium bis[bis(trimethylsilyl)amide] (Ca(HMDS)2) is a widely used reagent in diverse stoichiometric and catalytic applications. These processes necessitate a straightforward and large-scale access of this complex. Calcium does not react with primary and secondary amines, but the addition of excess bromoethane to a mixture of calcium turnings and amines in THF at room temperature yields the corresponding calcium bis(amides), calcium bromide and ethane. This in situ Grignard metalation method (iGMM) allows the preparation of calcium bis(amides) from secondary and primary trialkylsilyl-substituted amines and anilines on a multigram scale.

1 Background

2 The In Situ Grignard Metalation Method (iGMM)

3 Properties of [(thf)2M(HMDS)2]

4 Applications and Perspective

Straightforward synthesis of rubidium bis(trimethylsilyl)amide and complexes of the alkali metal bis(trimethylsilyl)amides with weakly coordinating 2,2,5,5-tetramethyltetrahydrofuran

Rubidium bis(trimethylsilyl)amide (rubidium hexamethyldisilazanide, Rb(hmds)) is accessible on a large scale with excellent yields via a magnetite-catalyzed metalation of hexamethyldisilazane (H(hmds)) in liquid ammonia. Recrystallization of solvent-free alkali metal hexamethyldisilazanides [A(hmds)]n of sodium to cesium from solutions containing 2,2,5,5-tetramethyltetrahydrofuran (Me4THF, thf*) yields the dinuclear complexes [(thf*)A(hmds)]2, which show a rather asymmetric coordination behavior of the bulky ether ligand with strongly bent A-A-O moieties for the heavier K, Rb, and Cs congeners, whereas in the Na complex, the ether ligand is clamped between the trimethylsilyl groups. In hydrocarbon solutions, dissociation of these compounds is observed leading to the liberation of this bulky and weakly binding cyclic ether.

Biomimetic cellular metals-using hierarchical structuring for energy absorption

Fruit walls as well as nut and seed shells typically perform a multitude of functions. One of the biologically most important functions consists in the direct or indirect protection of the seeds from mechanical damage or other negative environmental influences. This qualifies such biological structures as role models for the development of new materials and components that protect commodities and/or persons from damage caused for example by impacts due to rough handling or crashes. We were able to show how the mechanical properties of metal foam based components can be improved by altering their structure on various hierarchical levels inspired by features and principles important for the impact and/or puncture resistance of the biological role models, rather than by tuning the properties of the bulk material. For this various investigation methods have been established which combine mechanical testing with different imaging methods, as well as with in situ and ex situ mechanical testing methods. Different structural hierarchies especially important for the mechanical deformation and failure behaviour of the biological role models, pomelo fruit (Citrus maxima) and Macadamia integrifolia, were identified. They were abstracted and transferred into corresponding structural principles and thus hierarchically structured bio-inspired metal foams have been designed. A production route for metal based bio-inspired structures by investment casting was successfully established. This allows the production of complex and reliable structures, by implementing and combining different hierarchical structural elements found in the biological concept generators, such as strut design and integration of fibres, as well as by minimising casting defects. To evaluate the structural effects, similar investigation methods and mechanical tests were applied to both the biological role models and the metallic foams. As a result an even deeper quantitative understanding of the form-structure-function relationship of the biological concept generators as well as the bio-inspired metal foams was achieved, on deeper hierarchical levels and overarching different levels.

The Case for Using Actigraphy Generated Sleep and Activity Endpoints in Alzheimer's Disease Clinical Trials

More and more people in the industrialised world use wearables and smartphones to monitor their health and fitness. These devices are often used in combination with special apps to monitor and document daily activities and sleep. It would appear to be a logical step to assess the relevance of these devices in drug development trials. In contrast to the consumer devices, the technology used in clinical trials needs to be validated and compliant with the relevant regulations. Even under these complex requirements, wearables offer a number of new opportunities to objectively capture clinically relevant outcome measures -potentially with lower burden for patients and site staff. As an example, we describe the use in Alzheimer's disease drug development studies. This is an indication where there have been a number of failures, in part due to the difficulties this patient population has in reliably completing existing tools. In addition rater scales add complexity due to inter- and intra-rater variability.

Effectiveness of triclosan-coated PDS Plus versus uncoated PDS II sutures for prevention of surgical site infection after abdominal wall closure: the randomised controlled PROUD trial

BACKGROUND

Postoperative surgical site infections are one of the most frequent complications after open abdominal surgery, and triclosan-coated sutures were developed to reduce their occurrence. The aim of the PROUD trial was to obtain reliable data for the effectiveness of triclosan-coated PDS Plus sutures for abdominal wall closure, compared with non-coated PDS II sutures, in the prevention of surgical site infections.

METHODS

This multicentre, randomised controlled group-sequential superiority trial was done in 24 German hospitals. Adult patients (aged ≥18 years) who underwent elective midline abdominal laparotomy for any reason were eligible for inclusion. Exclusion criteria were impaired mental state, language problems, and participation in another intervention trial that interfered with the intervention or outcome of this trial. A central web-based randomisation tool was used to randomly assign eligible participants by permuted block randomisation with a 1:1 allocation ratio and block size 4 before mass closure to either triclosan-coated sutures (PDS Plus) or uncoated sutures (PDS II) for abdominal fascia closure. The primary endpoint was the occurrence of superficial or deep surgical site infection according to the Centers for Disease Control and Prevention criteria within 30 days after the operation. Patients, surgeons, and the outcome assessors were masked to group assignment. Interim and final analyses were by modified intention to treat. This trial is registered with the German Clinical Trials Register, number DRKS00000390.

FINDINGS

Between April 7, 2010, and Oct 19, 2012, 1224 patients were randomly assigned to intervention groups (607 to PDS Plus, and 617 to PDS II), of whom 1185 (587 PDS Plus and 598 PDS II) were analysed by intention to treat. The study groups were well balanced in terms of patient and procedure characteristics. The occurrence of surgical site infections did not differ between the PDS Plus group (87 [14·8%] of 587) and the PDS II group (96 [16·1%] of 598; OR 0·91, 95% CI 0·66-1·25; p=0·64). Serious adverse events also did not differ between the groups-146 of 583 (25·0%) patients treated with PDS Plus had at least one serious adverse event, compared with 138 of 602 (22·9%) patients treated with PDS II; p=0·39).

INTERPRETATION

Triclosan-coated PDS Plus did not reduce the occurrence of surgical site infection after elective midline laparotomy. Innovative, multifactorial strategies need to be developed and assessed in future trials to reduce surgical site infections.

FUNDING

Johnson & Johnson Medical Limited.

Emergency repair of giant inguinoscrotal hernia in a septic patient

INTRODUCTION

Giant inguinoscrotal hernias are rare but still exist even in developed countries. Although accompanied by a higher perioperative mortality, an elective surgical approach should be undertaken. In critically ill patients, however, the surgical intervention requires specific demands.

METHODS

We report a case of a 45-year-old man who was referred to the hospital after perforation of the hernia with concomitant peritonitis and sepsis.

RESULTS

After initial stabilization of the patient, a subtotal colectomy and a partial small bowl resection was performed. In a second step after stabilization of organ functions, the hernia sac was resected, and the abdominal cavity was reconstructed. The patient was discharged and is doing well until today but still refuses any plastic surgery.

CONCLUSION

Resection of giant inguinoscrotal hernia is feasible even in patients being administered in an emergency setting. Especially in case of an intra-abdominal infection, intestinal resection is the therapy of choice to allow the reconstruction of the abdominal cavity. A two-step approach should be considered to allow a successful recovery.

Enrichment of CD133-expressing cells in rectal cancers treated with preoperative radiochemotherapy is an independent marker for metastasis and survival

BACKGROUND

The transmembrane glycoprotein CD133 (cluster of differentiation 133; also known as Prominin or PROM1) has been described as a potential stem cell marker in colorectal cancer and is associated with higher tumorigenic potential and resistance to radiochemotherapy (RCT). In this study, CD133 expression was evaluated in pre-RCT tumor biopsies and the corresponding post-RCT surgical specimens from patients with locally advanced rectal adenocarcinoma, and expression levels were correlated with histopathologic features and clinical follow-up.

METHODS

One hundred twenty-six patients with International Union Against Cancer (UICC) stage II/III rectal cancer who received preoperative 5-fluorouracil (5-FU)-based RCT within the German Rectal Cancer Trials were investigated. Pre-RCT and post-RCT CD133 expression levels were determined using immunohistochemistry and were correlated with histopathologic parameters, tumor regression grade, cancer recurrence, and patient survival.

RESULTS

Compared with pre-RCT biopsies, significantly higher CD133 expression was observed in tumor specimens (P = .01). However, no correlations were observed for either biopsies or tumor specimens between CD133 expression levels, histopathologic characteristics, or survival. In matched analyses of corresponding biopsy/tumor pairs, patients who had an increased fraction of CD133-expressing (CD133+) cells after preoperative RCT had significantly higher residual tumor stages (P = .02) and lower histopathologic tumor regression (P < .01). Moreover, these patients had significantly reduced disease-free survival and cancer-specific overall survival in univariate analysis (P < .001 and P = .004, respectively) and multivariate analysis (P = .003 and P = .024, respectively).

CONCLUSIONS

The enrichment of CD133+ cancer cells during preoperative RCT was correlated with minor local tumor response, increased distant cancer recurrence, and decreased survival. The current results indicate that the up-regulation of intratumoral CD133 expression, in contrast to absolute pre-RCT and post-RCT CD133 levels, plays an important role in tumor progression and metastasis in patients with rectal cancer who are receiving neoadjuvant RCT.

Gastrointestinal stromal tumors

INTRODUCTION

The gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the intestinal tract, known to be refractory to conventional chemotherapy or radiation. Its pathogenesis is defined by mutations within the KIT and PDGFRA gene, which constitutively activate KIT and PDGFRA oncoproteins, and serve as crucial diagnostic and therapeutic targets.

DISCUSSION

Besides surgery, therapy with imatinib mesylate, which inhibits KIT kinase activity, represents the other cornerstone for the treatment of GIST. Still, the only curative option for GIST is given after complete surgical removal even in a metastatic setting, but recurrence is common, and the risk can be defined by surgical factors like incomplete resection, intraperitoneal rupture, or bleeding and tumor associated factors like tumor size, mitotic index, or localization.

CONCLUSION

Consequently, adjuvant therapy with imatinib mesylate or other tyrosine kinase inhibitors is recommended for high-risk patients after complete resection. For unresectable and advanced GIST, a partial response or stable disease can be achieved in about 80% of patients with imatinib mesylate.

Common genomic aberrations in basaloid squamous cell carcinoma and carcinosarcoma of the esophagus detected by CGH and array CGH

Basaloid squamous cell carcinoma (BSCC) and carcinosarcoma of the esophagus are rare entities, making up fewer than 2% of esophageal malignancies. Comparative genomic hybridization (CGH) in 1 case of BSCC and 2 cases of carcinosarcoma and subsequent array CGH in 1 case each of BSCC and carcinosarcoma revealed common chromosomal gains at 2p25.3-2p12, 7q21.3-7q22.3, and 11q13.2-11q13.4. Chromosomal losses at 13q31qter were observed in both carcinosarcomas. In addition, progression of genomic instability from in situ to invasive carcinosarcoma could be demonstrated by using array CGH. Our observations suggest a common genetic origin of BSCC and carcinosarcoma.

High chromosomal instability in adenocarcinoma of the ileum arising from multifocal gastric heterotopia with gastritis cystica profunda

Adenocarcinoma of the small intestine arising from heterotopic gastric mucosa is extremely rare. In this report, we present the case of a 68-year-old woman who complained of abdominal pain, weight loss and subileus. Gross examination of resected small bowel revealed multiple flat polypous lesions with cysts in the ileal submucosa, one of which containing an ulcerated, stenosing tumour. On microscopic examination, an adenocarcinoma of the ileum arising from multifocal gastric heterotopia with secondary gastritis cystica profunda was diagnosed. Comparative genomic hybridization of the adenocarcinoma revealed chromosomal gains at 1q, 3q, 5p, 8q, 11p, 12p, 13q and losses at Xp, 4q, 8p, 10p, 14q, 17p, 20p, compatible with a high degree of genomic instability.

Efficacy and safety of high-dose cabergoline in Parkinson's disease

OBJECTIVES

To assess the efficacy and safety of high-dose (up to 20 mg/day) cabergoline in Parkinson's disease (PD) patients with motor fluctuations and/or dyskinesias.

MATERIALS AND METHODS

Thirty-four PD patients had cabergoline up-titrated and their levodopa (L-dopa) reduced over a maximum of 20 weeks, followed by at least 6 weeks steady cabergoline dosing. Primary endpoint was change in mean hyperkinesia intensity at the final visit (week 26).

RESULTS

Mean (+/- SD) cabergoline was increased from 6.43 +/- 2.66 to 12.78 +/- 5.67 mg/day and mean L-dopa reduced from 606.6 +/- 263.9 to 370.6 +/- 192.5 mg/day. A significant reduction (P < 0.001) in mean hyperkinesia intensity occurred from baseline (day 0) to week 26. Improvements in 'on with dyskinesias', mean dystonia intensity (P < 0.05), time spent in 'severe off' condition, severity of 'off' periods as well as clinical/patient global impression, and health-related quality of life were observed. Twenty-four drug-related adverse events were recorded of which four were regarded as serious.

CONCLUSION

High-dose cabergoline was well tolerated and provided significant improvements in the Parkinson symptomatology and a reduced requirement for L-dopa.

Microcirculation and excretory function of the liver under conditions of carbon dioxide pneumoperitoneum

BACKGROUND

To date, the effects of increased abdominal pressure, as given during carbon dioxide (CO(2)) pneumoperitoneum, on hepatic microcirculation and biliary excretion are unknown.

METHODS

Using a custom-made peritoneal cavity chamber, we performed intravital microscopy of the left liver lobe under conditions of CO(2) pneumoperitoneum in a rat model. In addition, biliary excretion was assessed.

RESULTS

The establishment of a CO(2) pneumoperitoneum of 4 or 8 mmHg resulted in sinusoidal perfusion failure that was more pronounced in the periportal regions than in the midzonal and pericentral regions of the liver acinus. Biliary excretion was considerably reduced at an intraabdominal pressure of 8 mmHg. Leukocyte-endothelial cell interactions increased significantly in both hepatic sinusoids and postsinusoidal venules.

CONCLUSION

Alterations in hepatic microcirculation and liver function must be taken into consideration in any kind of laparoscopic surgery and may be of particular clinical relevance in patients with liver pathology.

Ampicillin + sulbactam vs. clindamycin ± cephalosporin for the treatment of aspiration pneumonia and primary lung abscess

Aspiration pneumonia, necrotising pneumonia and primary lung abscess are complications arising from the aspiration of infectious material from the oral cavity or stomach. There is limited information on optimal antibacterial therapeutic regimens. Patients with pulmonary infection following aspiration (n = 95) were included in a prospective, open, randomised, comparative multicentre trial to compare the safety, clinical and bacteriological efficacy of ampicillin + sulbactam vs. clindamycin +/- cephalosporin. Treated patients (n = 70) received sequential antibiotic therapy with either ampicillin + sulbactam (n = 37) or clindamycin (n = 33), with or without a second- or third-generation cephalosporin, administered until the complete resolution of clinical and radiological abnormalities. Definite or presumptive pathogens were isolated from 58 patients. Mean duration of therapy was 22.7 days for ampicillin + sulbactam and 24.1 days for clindamycin. In patients treated with ampicillin + sulbactam, the clinical response was 73.0% at the end of therapy and 67.5% 7-14 days after therapy. For clindamycin, the rates were 66.7% and 63.5%, respectively. Bacteriological response was similar in both treatment arms. Nine patients died (12.9%), with a Simplified Acute Physiology Score of > 30 points being the only significant predictive factor for therapeutic failure. Ampicillin + sulbactam and clindamycin +/- cephalosporin were both well-tolerated and proved equally effective in the treatment of aspiration pneumonia and lung abscess.

Effect of laparotomy and CO(2) pneumoperitoneum on tumor growth of human colon carcinoma and expression pattern of tumor-associated proteins in the SCID mouse

BACKGROUND AND AIMS

The impact of laparoscopy on tumor progression is still unclear. This study investigated the effect of CO(2) pneumoperitoneum on the intra-abdominal growth of human colon carcinoma independently of the effect of the immune system.

METHODS

SCID mice underwent either median laparotomy or laparoscopy. Human colon carcinoma cells were implanted into the upper abdomen. The control group was not operated on following cell injection. Tumor growth and the protein expression pattern of proliferation marker Ki67, cell-cell adhesion molecules E-cadherin, alpha- and beta-catenin, and cell-extracellular matrix adhesion molecules CD44 v5 and v6 in tumor tissue were analyzed on postoperative day 14.

RESULTS

Total tumor volume in the laparoscopy group significantly exceeded that in the laparotomy group. Immunohistochemistry revealed reduced expression of alpha-catenin and elevated expression on beta-catenin and CD44 v5 in the tumor tissue of the laparoscopy group.

CONCLUSION

The expression pattern of proteins associated with tumor progression and the increase in tumor growth suggest an increased risk of laparoscopy at least for the growth of advanced human colon carcinoma.

A peritoneal cavity chamber for intravital microscopy of the liver under conditions of pneumoperitoneum

BACKGROUND

Intravital microscopy allows direct visualization of the hepatic microvasculature. We report on a novel application of this technique using a chamber model that simulates the conditions of pneumoperitoneum.

METHODS

For this purpose, we designed a peritoneal cavity chamber for rats. In the present study, we evaluated the technical procedure without any induction of increased intraabdominal pressure to assess undisturbed hepatic microcirculation. Intravital microscopy of the liver was performed in 12 rats. Animals that underwent the same operative procedure without the chamber served as controls (n = 12).

RESULTS

Hepatic sinusoidal perfusion rate, leukocyte-endothelial cell interaction, and bile flow showed no significant differences between the groups. Operating time was longer in the chamber group.

CONCLUSION

The peritoneal cavity chamber is an attractive approach for the study of hepatic microvascular, cellular, and molecular mechanisms that are important to our understanding of the potential harmful effects of laparoscopy on hepatic circulation and liver function.

Prognostic factors influencing surgical management and outcome of gastrointestinal stromal tumours

BACKGROUND

The purpose of this study was to review surgical experience with gastrointestinal stromal tumours (GISTs) at a single tertiary university hospital, and to identify morphological and genetic prognostic markers of tumour progression.

METHODS

Forty-eight GISTs from 39 patients were reviewed retrospectively. The prognostic significance of DNA copy number changes, measured by comparative genomic hybridization (CGH), and morphological markers in low-risk and high-risk tumours were investigated.

RESULTS

Significantly more patients died from disease after incomplete tumour resection than after complete primary resection (P = 0.020). Tumour size of 5 cm or greater, mitotic count of 2 or more, and proliferative activity greater than 10 per cent were significantly associated with a shorter recurrence-free survival (P = 0.020, P = 0.001 and P = 0.002 respectively). Patients with low-risk tumours had a significantly better outcome than those with high-risk GISTs, both in terms of overall and recurrence-free survival (P < or = 0.001). CGH performed on 16 tumours revealed fewer DNA sequence copy number changes in low-risk than in high-risk GISTs. Non-progressive GISTs contained significantly fewer genetic alterations than recurrent or metastatic tumours (P < 0.001). Only tumours with more than five changes showed disease progression.

CONCLUSION

Complete surgical resection is the most important means of cure for GISTs. DNA copy number changes are related to the behaviour of these tumours and may serve as additional prognostic markers.

[Analgesic effect of the selective noradrenaline reuptake inhibitor reboxetine]

BACKGROUND

Reboxetine is a selective noradrenaline reuptake inhibitor (NARI). As noradrenaline plays a relevant role in antinociceptive mechanisms, the hypothesis was investigated in this study whether reboxetine has analgetic efficacy.

METHODS

Twenty-four healthy volunteers were investigated in a crossover design. Reboxetine (2 x 2 mg) or placebo were given for 5 days with the "crossover" following a one-day washout in between. The primary end-points were the N1 and P2 amplitudes of laser evoked somatosensory potentials (laser SEP) of vertex EEG. In addition, visual analogue scales (VAS, 100 mm) were used.

RESULTS

Reboxetine showed a higher analgesic potency than placebo, with a statistically significant superiority in capsaicinirritated skin--in the objective tests (laser SEP, P < 0.0001 for N1 and P = 0.0002 for P2) as well as in the subjective pain measurements (VAS, P < 0.0003). Besides pain, the subjective feelings of burning and itching were lower with reboxetine than with the placebo.

CONCLUSIONS

The hypothesis that a selective noradrenergic substance could be of analgesic efficacy was proven the first time experimentally. Reboxetine reduced the N1 and the P2 components of the laser SEP, which speaks for central and peripheral mechanisms of action.

Treatment of idiopathic restless legs syndrome (RLS) with the D2-agonist cabergoline--an open clinical trial

STUDY OBJECTIVES

To define the effective dose of cabergoline and to evaluate the tolerability and efficacy of cabergoline in patients with restless legs syndrome (RLS).

DESIGN

Treatment of idiopathic RLS patients with cabergoline in a 12-week open label trial. Patients on levodopa therapy were allowed to either stop levodopa prior to study entry or to continue, taper or discontinue levodopa during the study. Efficacy parameters were assessed by polysomnography and subjective ratings at baseline and at week 12. Primary efficacy parameters were the number of PLM and total sleep time.

SETTING

Dept. of Neurology, Sleep Disorders Center

PATIENTS

Nine patients with moderate to severe RLS (age 38.1 to 64.3 years, mean 54.1 years) who had experienced insufficient benefit under levodopa therapy and/or in part developed daytime augmentation participated. At study entry five patients were still under levodopa therapy (400-800 mg).

INTERVENTIONS

Up-titration of cabergoline (single evening dose) until RLS symptoms clearly improved. Initial comedication with domperidone 20 mg t.i.d.

MEASUREMENTS AND RESULTS

At the endpoint all patients were on cabergoline monotherapy (mean dosage 2.1 mg, range 1 to 4 mg). Domperidone was stopped in all patients due to good tolerability. Polysomnographic data showed a significant reduction of the number of periodic leg movements (PLM) (195.8+/-109.1 (baseline) vs. 26.4+/-40.2 (12 weeks cabergoline monotherapy; p=0.002), PLM arousals (51.7+/-42.3 vs. 6.4+/-11.2; p=0.017) and PLM awakenings (10.4+/-7.8 vs. 1.0+/-1.7; p=0.001). Total sleep time was prolonged (302.7+/-50.7 vs. 379.4+/-59.8 min; p=0.018), sleep latency shortened (42.4+/-49.1 vs. 16.3+/-22.8 min; p=0.214) and sleep efficiency increased (63.1+/-10.5 vs. 79.1+/-12.5%; p=0.017). All patients reported a impressive relief or became free of RLS symptoms.

CONCLUSION

Cabergoline is effective and well tolerated in restless legs syndrome especially in patients with severe RLS and those who developed augmentation under levodopa therapy.

[Ictal syncopes. Cardiac sympathetic innervation disorder as the etiology?]

We report 3 cases of an ictal sinus arrest. All patients suffered from temporal lobe epilepsy (TLE). Seizures were monitored with simultaneous video-eeg during preoperative epilepsy diagnosis. One patient with cortical dysplasia, who frequently suffered from long lasting syncopes, had a nearly completely missing cardiac sympathetic innervation in MIBG-SPECT (=Meta-Iodide-Benzyle-Guanidine-single-photon-emission tomography). Cardiac investigation including long-term ECG and echocardiography had shown normal findings. After epilepsy surgery the syncopal events in all patients disappeared. A dominant parasympathetic ictal stimulus following excitation of the reticular formation might cause the ictal bradycardia and sinus arrest. A missing sympathetic innervation, possibly occurring as fehlbildung together with cortical dysplasia, which makes autoregulation impossible, might then be the explanation for sudden cardiac ictal death.

Penetration of sparfloxacin and ciprofloxacin into alveolar macrophages, epithelial lining fluid, and polymorphonuclear leucocytes

Sparfloxacin (SPX), a novel fluoroquinolone with a broad spectrum of antibacterial activity, has been shown, in vitro, to be more effective against common pulmonary pathogens, particularly Streptococcus pneumoniae, Mycoplasma pneumoniae and some intracellular organisms, than ciprofloxacin (CPX). The objective of this open, comparative, randomized study in two parallel groups was to assess the serum concentrations and penetration of SPX and CPX into alveolar macrophages (AMs), epithelial lining fluid (ELF), and peripheral polymorphonuclear leucocytes (PMNs). Patients received either a single oral dose of SPX, 400 mg (16 patients), or CPX, 500 mg (15 patients), at various times before a routine diagnostic bronchoscopy was performed. Antibiotic concentrations were determined by using a microbiological assay. The median serum elimination half-lives were 17.3 h for SPX and 5.3 h for CPX. Peak levels (median+/-68% confidence range) of CPX were attained in AMs (7.6+/-1.7 mg x L(-1)) at 5 h after admission, and in both ELF (2.13+/-0.91 mg x L(-1)) and PMNs (9.1+/-6.2 mg x L(-1)) at 2.5 h after administration. SPX achieved comparable peak levels in PMNs (median+/-68% range, 9.4+/-1.1 mg x L(-1) at 5 h), but peak concentrations attained in AMs and ELF (35.1+/-15.4 and 32.2+/-28.2 mg x L(-1), respectively, at 24 h) were several times higher than those of CPX. SPX demonstrated substantially greater accumulation in all three sites than did CPX (peak site to serum ratios of 11.0+/-4.3, 65.5+/-28.4 and 63.0+/-66 versus 4.94+/-0.64, 10.6+/-3.7 and 10.6+/-3.7 for PMNs, AMs and ELF, respectively). The results indicate, that sparfloxacin has a long elimination half-life and that it achieves higher concentrations in alveolar macrophages and epithelial lining fluid than ciprofloxacin. Site concentrations of sparfloxacin greatly exceeded the minimal inhibitory concentrations of common respiratory pathogens.

Probable Creutzfeldt-Jakob disease after a cadaveric dural graft

A 26-year old female who had received a cervical cadaveric dural graft 7 years earlier developed psychotic behavior and generalized myoclonic jerks. Following rapid deterioration and appearance of high-charge sharp periodic waves on electroencephalography she died within two months. We believe that this patient is the first German who acquired Creutzfeldt-Jakob disease by dural implant.