Invariom modeling of ceftazidime pentahydrate: molecular properties from a 200 second synchrotron microcrystal experiment

The structure of ceftazidime pentahydrate, a third generation cephalosporin antibiotic, is reported. Data collection was carried out in a remarkably short time with synchrotron radiation and the latest detector technology, illustrating that single-crystal X-ray diffraction can be used as a technique for screening hundreds of compounds in a short amount of time. Structure refinement made use of invarioms, namely non-spherical scattering factors, which allow more information to be derived from a diffraction experiment. Properties that can be screened are bond-topological parameters, empirical hydrogen-bond energies, molecular dipole moments and electrostatic potentials.

Re-operation for failed gastro-esophageal fundoplication. What results to expect?

The aim of this study is to evaluate short and medium term results of re-operation for failed fundoplication in a retrospective monocentric cohort of 47 patients.

PATIENTS AND METHODS

Between 1995 and 2011, 595 patients underwent a laparoscopic primary fundoplication (PFP) for gastroesophageal reflux disease (GERD). During the same period, 47 patients required a re-operative fundoplication (RFP). In 11 patients, the original wrap had herniated into the thorax. All these revisions consisted of a complete takedown of the original wrap before constructing a tension-free wrap using a standardized technique. Patients with a follow-up of at least 2 years were matched to patients who had been operated only once to assess satisfaction and quality of life.

RESULTS

Short term: All patients were operated by laparoscopy with no conversion. There was no mortality. Two postoperative complications necessitating re-operation were observed (morbidity 4.3%): one complete aphagia and one gastric perforation. Long term: 29 re-operated patients with a follow-up of at least 2 years (mean: 4,5 years) (Group RFP) were compared to a matched group of 29 patients operated only once (Group PFP). These groups were comparable in age, sex ratio, BMI and follow-up. In both groups, all patients were operated by laparoscopy without conversion. Morbidity was 3.5% in the RFP group, none in the PFP group. There was no mortality in either group. The length of stay and operative time were significantly higher in the RFP group (4.6 vs. 2.6 days, p<0.05). Two RFP patients (5%) required re-operation at three and seven months vs. none in the PFP group. The long-term satisfaction was comparable in the two groups (78% vs. 85%, p=NS). Quality of life assessed by the GIQLI was significantly better in the PFP group (104 vs. 84, p<0.05).

CONCLUSION

Re-do fundoplication is a safe procedure and is feasible by laparoscopy. In the long-term, patient satisfaction is comparable to primary intervention with, however, a slightly poorer quality of life.

Diffuse pulmonary uptake on FDG-PET with normal CT diagnosed as intravascular large B-cell lymphoma: a case report and a discussion of the causes of diffuse FDG uptake in the lungs

A 71-year-old woman was admitted to our hospital with asthenia, weight loss, fever, cognitive impairment and shortness of breath. Physical examination showed hemiparesis and cerebellar ataxia. There was no superficial lymphadenopathy. Blood tests showed raised levels of C-reactive protein and lactate dehydrogenase. Bone marrow aspiration and biopsy were negative. [¹⁸F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) showed intense uptake within a right apical nodule and intense and diffuse uptake of FDG in the lungs without corresponding structural CT abnormality. Lung biopsy showed intravascular large B-cell lymphoma (IVLBCL). FDG-PET findings in IVLBCL and causes of diffuse FDG lung uptake with and without CT abnormalities are discussed.

Guideline on the design and conduct of cystic fibrosis clinical trials: the European Cystic Fibrosis Society-Clinical Trials Network (ECFS-CTN)

We describe the rationale for disease specific research networks in general as well as the aims and function of the European Cystic Fibrosis Society-Clinical Trials Network (ECFS-CTN) specifically. The ECFS-CTN was founded in 2009 with the aim of improving the quality and quantity of clinical research in the area of cystic fibrosis (CF) in Europe. A network of 18 clinical trial sites in 8 European countries was established according to uniform state-of-the-art quality criteria. To support the ECFS-CTN in the acquisition, planning and conduct of clinical trials, the network is equipped with a coordinating centre, steering and executive committees, and committees for protocol review, standardization, training and networking as well as a data safety monitoring board. A strong partnership with European CF patient parent organizations aims to increase awareness of the need for efficient clinical research and the participation of patients in clinical trials.

Incidence of previously unknown cardiac malformations in asymptomatic children after prenatal obstetric ultrasound screening

BACKGROUND

Cardiac murmurs may be frequently found in otherwise asymptomatic children. Obstetric ultrasound screening for congenital heart disease is increasingly used to provide an antenatal diagnosis and an early treatment; thus, the incidence of cardiac anomalies in children has changed. We evaluated cardiac murmurs in otherwise healthy children referred to a level I pediatric cardiology institution.

METHODS

Echocardiography data from a cohort of 2045 patients from 2000 to 2009 were evaluated and the incidence and type of a newly diagnosed congenital heart disease have been determined.

RESULTS

The majority of the children with a cardiac murmur were found to have an innocent murmur, chordae tendinae, or a minor lesion. Children born after obstetric screening are nevertheless associated with a small risk of severe congenital heart disease. We found 14.9% with a previously unknown congenital cardiac malformation; 1.4% required medical treatment and 0.6% of the patients had either a catheter or a surgical intervention.

CONCLUSIONS

This study provides evidence that the use of obstetric screening for congenital heart disease reduces the occurrence of severe heart disease. Otherwise healthy children with murmurs still bear a small risk of having a cardiac defect, even if a prenatal study was negative. Therefore, the evaluation of children with a murmur by a pediatric cardiologist is recommended in an antenatally-screened population.

Radiographic analysis of type II odontoid fractures in a geriatric patient population: description and pathomechanism of the "Geier"-deformity

INTRODUCTION

Type II odontoid fractures are one among the most common cervical spine fractures in the elders. We reviewed a consecutive series of patients, aged 65 years and older, presenting to our institution with type II odontoid fractures. Our analysis focused on the radiographic outcome, union rate and the development of cervical spine postural deformity.

PATIENTS/METHODS

Indications for surgical treatment (OP) included displaced or unstable injuries. Stable, non-displaced injuries or patients with significant co-morbidities were treated nonoperatively (non-op).

RESULTS

Ninety patients (50 f, 40 m) with an average age of 83 years (65-101) were identified. 31 (34.4%) patients were received OP and 57 (63.3%) were received non-op treatments. The hospital length of stay was significantly longer after OP (mean 10 days vs. 6 days non-op) treatment (p = 0.007). At follow-up, higher union rates were noted in the OP (76.2%) than in the non-op group (58.3%).

CONCLUSION

We observed a characteristic cervical spine deformity in geriatric patients with type II odontoid fractures, and have termed this the "Geier-deformity". Clinical findings of the deformity include sagittal imbalance and kyphosis of the lower cervical spine.

Fluorodeoxyglucose positron emission tomography fails to detect distant metastases at initial staging of melanoma patients with metastatic involvement of sentinel lymph node

BACKGROUND

Positron emission tomography (PET) using fluorodeoxyglucose (FDG) has proven to be more sensitive and accurate than other imaging modalities for the detection of distant metastases in patients with melanoma. Sentinel lymph node (SLN) status is the most important prognostic factor in melanoma patients with no evidence of distant metastasis.

OBJECTIVES

To assess the rate of distant metastases in patients with a positive SLN biopsy (SLNB).

METHODS

Forty-six consecutive patients with a positive SLNB underwent PET or PET-computed tomography within 6 weeks of the SLNB procedure. The patients did not present any clinical sign of nodal involvement or of distant metastasis. PET findings were classified as positive, negative or nonconclusive.

RESULTS

No patient had a positive PET scan for distant metastasis. Six patients (13%) had a nonconclusive PET scan; none of them presented distant metastasis within 12 months. Forty patients (87%) had a negative PET scan; among them five (12%) presented with distant metastasis within 12 months.

CONCLUSIONS

Fluorodeoxyglucose positron emission tomography failed to detect distant metastases at initial staging in patients with a positive SLNB, even in patients who presented with distant metastases within 12 months after the FDG PET scan. These results could be explained by the low prevalence of macroscopic metastatic disease at this stage and by the important delay between the onset of the spread of microscopic metastatic disease and the identification by PET scan of macroscopic metastatic disease.

Influence of Film/Substrate Interface Structure on Plasticity in Metal Thin Films

In-situ transmission electron microscopy studies of metal thin films on substrates indicate that dislocation motion is influenced by the structure of the film/substrate interface. For Cu films grown on silicon substrates coated with an amorphous SiNx diffusion barrier, the transmission electron microscopy studies reveal that dislocations are pulled towards the interface, where their contrast finally disappears. However, in epitaxial Al films deposited on single-crystalline α- Al2O3 substrates, threading dislocations advance through the layer and deposit dislocation segments adjacent to the interface. In this latter case, the interface is between two crystalline lattices. Stresses in epitaxial Al films and polycrystalline Cu films were determined by substrate- curvature measurements. It was found that, unlike the polycrystalline Cu films, the flow stresses in the epitaxial Al films are in agreement with a dislocation-based model.

Improved column-based radiochemical processing of the generator produced 68Ga

An improved chemical strategy for processing of the generator produced (68)Ga was developed based on processing of the original (68)Ge/(68)Ga generator eluate on a micro-column. Direct pre-concentration and purification of the eluted (68)Ga is performed on a cation-exchange resin in hydrochloric acid/acetone media. A supplementary step based on a second micro-column filled with a second resin allows direct re-adsorption of (68)Ga eluted from the cation exchanger. (68)Ga is finally striped from the second resin with a small volume of pure water. For this purpose a strong anion exchanger and a novel extraction chromatographic resin based on tetraalkyldiglycolamides are characterized. The strategy allows online pre-concentration and purification of (68)Ga from the original generator eluate. The supplementary column allows transferring (68)Ga with high radionuclide and chemical quality in the aqueous solution with small volume and low acidity useful for direct radiolabeling reactions.

Epitaxial Growth and Structure of Cubic and Pseudocubic Perovskite Films on Perovskite Substrates

Cubic and pseudocubic perovskite films on perovskite substrates are used to study the influence of the lattice mismatch on the epitaxial growth of thin films on substrates of the same structure. For the growth of the films, a metalorganic decomposition route (MOD) using 2-ethylhexanoates and neodecanoates as precursors, was developed. The decomposition of the precursors was investigated with thermogravimetric analysis (TGA) and x-ray diffraction (XRD). The films were spin-coated on (001)-oriented SrTiO3- and LaAlO3-substrates, pyrolyzed and afterwards annealed between 600°C and 1200°C. XRD-nvestigations and conventional transmission electron microscopy (CTEM) show, that epitaxial films with the orientation relationship [100](001) film ║ [100](001) substrate can be grown. With XRD, it could be shown, that not only ternary oxide films (SrZrO3, BaZrO3and BaCeO3), but also perovskite solid solution films (SrTi0.5Zr0.5O3and BaCe0.5Zr0.5O3) can be prepared. Strong interdiffusion, detected by a shift of the film lattice parameter towards the substrate lattice parameter was found in SrZrO3- and BaZrO3-films on SrTiO3, annealed at temperatures above 1050°C. High resolution electron microscopy (HREM) studies of SrZrO3on SrTiO3show that a crystalline semicoherent interface with a periodical array of misfit dislocations is present.

Structural and Chemical Properties of MBE Grown Niobium Overlayers on (110) Rutile

Thin Nb films were grown by MBE in a UHV chamber at two different temperatures (50°C and 950°C) on the (110) surface of TiO2 (rutile).

At a growth temperature of 50°C, reflection high energy electron diffraction (RHEED) revealed epitaxial growth of Nb on rutile: (110)[001] TiO2 ¦¦ (100)[001] Nb. In addition, investigations with Auger electron spectroscopy (AES) revealed that a chemical reaction took place between the Nb overlayer and the TiO2 substrate at the initial growth stage. A 2 nm thick reaction layer at the Nb/TiO2 interface has been identified by means of conventional transmission electron microscopy (CTEM) and high-resolution transmission electron microscopy (HRTEM).

At a substrate temperature of 950°C, during growth, the Nb film was oxidized completely, and NbO2 grew epitaxially on TiO2. The structure and the chemical composition of the overlayers have been investigated by RHEED, AES, CTEM and HRTEM. Furthermore, it was determined that the reaction of Nb with TiO2 is governed by the defect structure of the TiO2 and the relative oxygen affinities of Nb and TiO2.

Hydrogen Induced Plastic Deformation of Thin Films

The mechanical behavior of a thin film that is clamped to an elastically hard substrate can be compared to a bulk metal by studying the absorption of hydrogen. Since hydrogen is dissolved in interstitial sites and exerts force on neighboring metal atoms, the in-plane stresses increase with increasing hydrogen concentration. In the case of Nb-films covered with a thin Pd layer, stresses of several GPa were measured. Nb and Pd films prepared by evaporation were loaded with hydrogen. Out-of-plane strain and in-plane stresses during electrolytic loading with hydrogen were determined by performing x-ray diffraction and substrate curvature measurements. At low H-concentrations the developing stresses correspond to a clamped film expanding elastically out-of-plane only. Above a critical H-concentration the films deform plastically. In some cases the critical hydrogen concentration corresponds to the terminal H-solubility, above which the hydride precipitates by emission of extrinsic dislocation loops. For the remaining cases a critical stress is reached before passing the phase boundary, which leads to the formation of misfit dislocations at the interface between film and substrate. The concomitant slip lines were observed on the surface of a Gd (0001) film using Scanning Tunneling Microscopy. An additional surface pattern that can be correlated with emitted dislocation loops was observed.

Epitaxial Growth and Structure of Highly Mismatched Oxide Films with Rock-salt Structure on MgO

CaO thin films were grown on (001) MgO single crystal substrates by a chemical solution deposition method to study the influence of a relatively high lattice mismatch (14%) on the epitaxial growth. In order to minimize an influence of a different crystal structure and chemistry between film and substrate, film and substrate were chosen to have the same structure (NaCl) and a similar chemistry. The films were heat treated until they broke up into single crystal islands on the MgO substrate. X-ray pole figure analysis and TEM observations of the CaO-films showed that most of the grains had a single out-of-plane orientation (111)CaO || (001)MgO, corresponding to two non-redundant, symmetry related in-plane variants [1 10](111)CaO || [110](001)MgO and [110](111)CaO || [110](001)MgO. A near coincidence site lattice (NCSL) model could be constructed for the interface, suggesting good lattice and charge matching for the observed orientation relations. The mechanisms and energetics leading to the experimentally observed orientation relations are discussed.