Integrated data acquisition and processing to determine metabolite contents, relaxation times, and macromolecule baseline in single examinations of individual subjects

Absolute quantitation of clinical (1)H-MR spectra is virtually always incomplete for single subjects because the separate determination of spectrum, baseline, and transverse and longitudinal relaxation times in single subjects is prohibitively long. Integrated Processing and Acquisition of Data (IPAD) based on a combined 2-dimensional experimental and fitting strategy is suggested to substantially improve the information content from a given measurement time. A series of localized saturation-recovery spectra was recorded and combined with 2-dimensional prior-knowledge fitting to simultaneously determine metabolite T(1) (from analysis of the saturation-recovery time course), metabolite T(2) (from lineshape analysis based on metabolite and water peak shapes), macromolecular baseline (based on T(1) differences and analysis of the saturation-recovery time course), and metabolite concentrations (using prior knowledge fitting and conventional procedures of absolute standardization). The procedure was tested on metabolite solutions and applied in 25 subjects (15-78 years old). Metabolite content was comparable to previously found values. Interindividual variation was larger than intraindividual variation in repeated spectra for metabolite content as well as for some relaxation times. Relaxation times were different for various metabolite groups. Parts of the interindividual variation could be explained by significant age dependence of relaxation times.

Multi-channel search for squarks and gluinos in sqrts=7 TeV pp collisions with the ATLAS detector

A search for supersymmetric particles in final states with zero, one, and two leptons, with and without jets identified as originating from b-quarks, in 4.7 fb(-1) of root s = 7 TeV pp collisions produced by the Large Hadron Collider and recorded by the ATLAS detector is presented. The search uses a set of variables carrying information on the event kinematics transverse and parallel to the beam line that are sensitive to several topologies expected in supersymmetry. Mutually exclusive final states are defined, allowing a combination of all channels to increase the search sensitivity. No deviation from the Standard Model expectation is observed. Upper limits at 95 % confidence level on visible cross-sections for the production of new particles are extracted. Results are interpreted in the context of the constrained minimal supersymmetric extension to the Standard Model and in supersymmetry-inspired models with diverse, high-multiplicity final states.

Appendiceal mucocele in an elderly patient: how much surgery?

Appendiceal mucoceles are rare cystic lesions with an incidence of 0.3-0.7% of all appendectomies. They are divided into four subgroups according to their histology. Even though the symptoms may vary - depending on the level of complication - from right lower quadrant pain, signs of intussusception, gastrointestinal bleeding to an acute abdomen with sepsis, most mucoceles are asymptomatic and found incidentally. We present the case of a 70-year-old patient with an incidentally found appendiceal mucocele. He was seen at the hospital for backache. The CT scan showed a vertebral fracture and a 7-cm appendiceal mass. A preoperative colonoscopy displayed several synchronous adenomas in the transverse and left colon with high-grade dysplasia. In order to lower the cancer risk of this patient, we performed a subtotal colectomy. The appendiceal mass showed no histopathological evidence of malignancy and no sign of perforation. The follow-up was therefore limited to 2 months. In this case, appendectomy would have been sufficient to treat the mucocele alone. The synchronous high-grade dysplastic adenomas were detected in the preoperative colonoscopy and determined the therapeutic approach. Generally, in the presence of positive lymph nodes, a right colectomy is the treatment of choice. In the histological presence of mucinous peritoneal carcinomatosis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy is indicated. In conclusion, mucoceles of the appendix are detected with high sensitivity by CT scan. If there is no evidence of synchronous tumor preoperatively and no peritoneal spillage, invasion or positive sentinel lymph nodes during surgery, a mucocele is adequately treated by appendectomy.

A standardized protocol for the prevention of clinically relevant venous air embolism during neurosurgical interventions in the semisitting position

OBJECTIVE: We report the results and complications associated with standardized intraoperative management designed for the prevention of hemodynamically relevant venous air embolism during surgery performed in the semisitting position. METHODS: A protocol for preoperative evaluation and intraoperative monitoring was developed and applied in 187 consecutive patients who underwent surgery in the semisitting position between 1999 and 2004. The protocol included preoperative transesophageal echocardiography examination (TEE), intraoperative TEE monitoring, catheterization of the right atrium and a combination of fluid input, positive end expiratory pressure, and standardized positioning aiming at a positive pressure in the transverse and sigmoid sinuses. Data were collected retrospectively from the charts and intraoperative anesthesiological protocols of the patients for the incidence of clinically relevant air embolism (i.e., TEE-diagnosed air embolism plus a decrease in end tidal CO2 or hemodynamic changes) and other complications related to the semisitting position. RESULTS: Three cases (1.6%) of relevant venous air embolism occurred in 187 patients. Only 1 case (0.5%) was hemodynamically relevant, with temporary arterial blood pressure decrease and heart rate increase. Pneumatocephalus leading to lethargy was a frequent postoperative finding, which resolved spontaneously in all except 1 patient with epileptic seizure and oculomotor nerve palsy attributable to space-occupying subdurally trapped air, which had to be treated surgically. There was no permanent morbidity or mortality related to the semisitting position. CONCLUSION: Fear of massive venous air embolism is one reason for dramatic decline in the use of the semisitting position in neurosurgical practice. We found that strict adherence to a standardized protocol using TEE monitoring before and during surgery; exclusion of patients with patent foramen ovale; and a combination of positive end expiratory pressure, fluid input, and a standardized position aiming a positive pressure in the transverse and sigmoid sinuses helped to greatly minimize this complication to a rate of 0.5% for hemodynamically relevant events.

Posterior approaches to the acetabulum

Posterior approaches to the hip joint were developed by Langenbeck and Kocher in the nineteenth century. Letournel created the term Kocher-Langenbeck approach which became one of the most important approaches to the hip joint. The further extension of this approach by digastric trochanteric osteotomy and subsequently by surgical hip dislocation enables visualization of the entire hip joint which allows complete evaluation of articular joint damage, quality of reduction and confirmation of extra-articular hardware. With the increasing incidence of acetabular fractures in the elderly there is a concomitant increase of complicating factors, such as multifragmentary posterior wall fractures, dome impaction, marginal impaction and femoral head damage. These factors are negative predictors and compromise a favorable outcome after acetabular surgery. With direct joint visualization these factors can be reliably recognized and corrected as adequately as possible. Surgical hip dislocation thus offers advantages in complex posterior wall, transverse and T-shaped fractures with or without posterior wall involvement. For these fracture types surgical hip dislocation represents a standard approach in our hands.

Magnetic resonance imaging features of sinonasal disorders in horses.

Diseases of paranasal sinuses and nasal passages in horses can be a diagnostic challenge because of the complex anatomy of the head and limitations of many diagnostic modalities. Our hypothesis was that magnetic resonance (MR) imaging would provide excellent anatomical detail and soft tissue resolution, and would be accurate in the diagnosis of diseases of the paranasal sinuses and nasal passages in horses. Fourteen horses were imaged. Inclusion criteria were lesions located to the sinuses or nasal passages that underwent MR imaging and subsequent surgical intervention and/or histopathologic examination. A low field, 0.3 tesla open magnet was used. Sequences in the standard protocol were fast spin echo T2 sagittal and transverse, spin echo T1 transverse, short-tau inversion recovery (STIR) dorsal, gradient echo 3D T1 MPR dorsal (plain and contrast enhanced), spin echo T1 fatsat (contrast enhanced). Mean scan time to complete the examination was 53 min (range 39-99 min). Lesions identified were primary or secondary sinusitis (six horses), paranasal sinus cyst (four horses), progressive ethmoid hematoma (two horses), and neoplasia (two horses). The most useful sequences were fast spin echo T2 transverse and sagittal, STIR dorsal and FE3D MPR (survey and contrast enhanced). Fluid accumulation, mucosal thickening, presence of encapsulated contents, bone deformation, and thickening were common findings observed in MR imaging. In selected horses, magnetic resonance imaging is a useful tool in diagnosing lesions of the paranasal sinuses and nasal passages.

Alterations of the transverse ligament: an MRI study comparing patients with acute whiplash and matched control subjects

The objective of our study was to evaluate whether there is injury to the transverse ligament of the atlas in patients with acute whiplash.

Search for supersymmetry using final states with one lepton, jets, and missing transverse momentum with the ATLAS detector in √s=7 TeV pp collisions

This Letter presents the first search for supersymmetry in final states containing one isolated electron or muon, jets, and missing transverse momentum from √s=7  TeV proton-proton collisions at the LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of 35  pb(-1). No excess above the standard model background expectation is observed. Limits are set on the parameters of the minimal supergravity framework, extending previous limits. Within this framework, for A(0)=0 GeV, tanβ=3, and μ>0 and for equal squark and gluino masses, gluino masses below 700 GeV are excluded at 95% confidence level.