Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data.

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level.

Dark matter results from 225 live days of XENON100 data.

We report on a search for particle dark matter with the XENON100 experiment, operated at the Laboratori Nazionali del Gran Sasso for 13 months during 2011 and 2012. XENON100 features an ultralow electromagnetic background of (5.3 ± 0.6) × 10(-3) events/(keV(ee) × kg × day) in the energy region of interest. A blind analysis of 224.6 live days × 34 kg exposure has yielded no evidence for dark matter interactions. The two candidate events observed in the predefined nuclear recoil energy range of 6.6-30.5 keV(nr) are consistent with the background expectation of (1.0 ± 0.2) events. A profile likelihood analysis using a 6.6-43.3 keV(nr) energy range sets the most stringent limit on the spin-independent elastic weakly interacting massive particle-nucleon scattering cross section for weakly interacting massive particle masses above 8 GeV/c(2), with a minimum of 2 × 10(-45) cm(2) at 55 GeV/c(2) and 90% confidence level.

Dark matter results from 100 live days of XENON100 data.

We present results from the direct search for dark matter with the XENON100 detector, installed underground at the Laboratori Nazionali del Gran Sasso of INFN, Italy. XENON100 is a two-phase time-projection chamber with a 62 kg liquid xenon target. Interaction vertex reconstruction in three dimensions with millimeter precision allows the selection of only the innermost 48 kg as the ultralow background fiducial target. In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found. Three candidate events were observed in the signal region with an expected background of (1.8 ± 0.6) events. This leads to the most stringent limit on dark matter interactions today, excluding spin-independent elastic weakly interacting massive particle (WIMP) nucleon scattering cross sections above 7.0 × 10(-45) cm(2) for a WIMP mass of 50 GeV/c(2) at 90% confidence level.

First dark matter results from the XENON100 experiment.

The XENON100 experiment, in operation at the Laboratori Nazionali del Gran Sasso in Italy, is designed to search for dark matter weakly interacting massive particles (WIMPs) scattering off 62 kg of liquid xenon in an ultralow background dual-phase time projection chamber. In this Letter, we present first dark matter results from the analysis of 11.17 live days of nonblind data, acquired in October and November 2009. In the selected fiducial target of 40 kg, and within the predefined signal region, we observe no events and hence exclude spin-independent WIMP-nucleon elastic scattering cross sections above 3.4 × 10⁻44 cm² for 55 GeV/c² WIMPs at 90% confidence level. Below 20 GeV/c², this result constrains the interpretation of the CoGeNT and DAMA signals as being due to spin-independent, elastic, light mass WIMP interactions.

Serogroups and antibiotic susceptibility patterns of Neisseria meningitidis isolated from army recruits in a training camp.

Invasive Neisseria meningitidis infection is rare but carries a high mortality rate. The carriage rate in the normal population is around 10% and can be higher in confined populations. A study on the prevalence of carriage of N. meningitidis was conducted among 3195 army recruits after 2 months of intensive training in an army camp. N. meningitidis was isolated from 37.0% of these recruits. Two hundred and ten of N. meningitidis isolates were subjected to serogrouping and 100 to antibiotic sensitivity testing by the disc diffusion method and E-test for penicillin. Ten (4.8%) of 210 Neisseria meningitidis serogrouped belonged to serogroup W135, 3.33% serogroup A and 81.4% belonged to either serogroup X, Y or Z. With the agar disc diffusion method, all the N. meningitidis showed susceptiblity to chloramphenicol, rifampicin, cefotaxime and levofloxacin; 85% of the strains were resistant to cotrimoxazole and 12.5% resistant to penicillin. However, based on minimum inhibitory concentration, none of the Neisseria meningitidis tested was resistant to penicillin.

Clcn7F318L/+ as a new mouse model of Albers-Schönberg disease.

Dominant negative mutations in CLCN7, which encodes a homodimeric chloride channel needed for matrix acidification by osteoclasts, cause Albers-Schönberg disease (also known as autosomal dominant osteopetrosis type 2). More than 25 different CLCN7 mutations have been identified in patients affected with Albers-Schönberg disease, but only one mutation (Clcn7G213R) has been introduced in mice to create an animal model of this disease. Here we describe a mouse with a different osteopetrosis-causing mutation (Clcn7F318L). Compared to Clcn7+/+ mice, 12-week-old Clcn7F318L/+ mice have significantly increased trabecular bone volume, consistent with Clcn7F318L acting as a dominant negative mutation. Clcn7F318L/F318L and Clcn7F318L/G213R mice die by 1month of age and resemble Clcn7 knockout mice, which indicate that p.F318L mutant protein is non-functional and p.F318L and p.G213R mutant proteins do not complement one another. Since it has been reported that treatment with interferon gamma (IFN-G) improves bone properties in Clcn7G213R/+ mice, we treated Clcn7F318L/+ mice with IFN-G and observed a decrease in osteoclast number and mineral apposition rate, but no overall improvement in bone properties. Our results suggest that the benefits of IFN-G therapy in patients with Albers-Schönberg disease may be mutation-specific.

Proton MR spectroscopy in patients with complex partial seizures: single-voxel spectroscopy versus chemical-shift imaging.

BACKGROUND AND PURPOSE: Proton MR spectroscopy has recently been applied to the evaluation of seizures, but few comparisons have been made between different clinical spectroscopic techniques. Our goal was to determine whether there is a significant difference between hippocampal NAA/(Cho+Cr) ratios obtained by single-voxel spectroscopy (SVS) and by chemical-shift imaging (CSI). METHODS: Twelve healthy adults and eight patients with complex partial seizures were studied on a 1.5-T MR scanner using a proton SVS method. Another 12 healthy adults and 10 patients with complex partial seizures were recruited for a proton CSI study, which was performed on a different 1.5-T MR system. The NAA/(Cho+Cr) ratio was calculated from the integral peak areas by curve fitting. The two-tailed t-test was used for statistical analysis. RESULTS: The mean value +/- standard deviation of the hippocampal NAA/(Cho+Cr) ratio in healthy control subjects was 0.63 +/- 0.07 by SVS, with 0.62 +/- 0.15 for the anterior hippocampus and 0.65 +/- 0.11 for the posterior hippocampus by CSI. There was no significant difference between the control group data obtained by SVS and those by CSI, nor was there a regional difference in the CSI NAA/(Cho+Cr) ratio in the hippocampus. Relative to the control group, the patients with seizures had a significant decrease in the NAA/(Cho+Cr) ratio in the abnormal hippocampus: -28% by SVS, and -24% in the anterior hippocampus and -18% in the posterior hippocampus by CSI. Proton SVS and CSI detected hippocampal abnormalities, unilateral or bilateral, in all patients of each group. CONCLUSION: Under similar measurement conditions, proton SVS and CSI provide similar NAA/(Cho+Cr) ratios among healthy control subjects, and they possess comparable ability for detecting hippocampal abnormalities in patients with complex partial seizures.

Concomitant fracture of the coracoid and acromion after direct shoulder trauma.

Fractures of the acromial process or coracoid process of the scapula are rare. We present a combined fracture of the coracoid and acromion after direct trauma to the shoulder. An anteroposterior radiography with the central x-ray beam angled 25 degrees cephalad or an axillary lateral radiograph may be needed to detect these fractures.

Diagnosis of the congenital urethral anomalies of male child by voiding cystourethrography.

Congenital urethral anomalies in boys are rare. This report concerns seven children with congenital urethral anomalies other than hypospadias from March 1995 to February 1998. Seven cases of congenital urethral anomalies were diagnosed by voiding cystourethrography (VCUG) from 1246 examinations of boys over a period of three years. There were four posterior urethral values, one anterior urethral valve, one anterior urethral diverticulum, and one megalourethra. Five of them had vesicoureteral reflux (VUR). Two cases of posterior urethral valve had renal failure in spite of surgery. Three cases exhibited renal cystic dysplasia. The clinical presentation and imaging findings are presented. Conventional fluoroscopically monitored VCUG is the principal examination used for bladder and urethra study in children. Therefore, in boys presenting the signs and symptoms related to voiding disturbance, VCUG is used to detect not only VUR but also anomalies in the bladder and urethra. In conclusion, VCUG is safe and essential for diagnosis of congenital urethral anomalies.

Plate osteosynthesis of the humerus shaft fracture an its association with radial nerve injury--a retrospective study in Melaka General Hospital.

Over a seven-year period, 170 cases of humerus fractures were plated in Hospital Melaka. Of these, 131 cases were successfully traced for this study. Besides looking at fracture epidemiology, its relationship with radial nerve injury was examined. The incidence of post-traumatic wrist drop in closed and compound fractures were 14.9% and 35.3% respectively. In relation to the site of fracture, lower third fracture had the highest incidence of wrist drop (29%). The recovery from post-traumatic wrist drop was 83%. The average duration taken for recovery was 11.8 weeks. The incidence of post-operative wrist drop was high at 17.6% but all recovered during follow-up.

Mycotic aneurysm of the superior mesenteric artery in a young woman.

Aneurysm of the superior mesenteric artery (SMA) is rare. We, in this study, present the case of a 21-year-old woman with a history of heroin abuse who was admitted to our hospital for infective endocarditis complicated by floating vegetation at the posterior mitral valve. After receiving 2-week antibiotic treatment, the patient had acute abdominal pain. Computed tomography demonstrated an aneurysm at the SMA. The mycotic aneurysm was resected and the mitral valve was repaired successfully. This report reviews the pathophysiology of mycotic aneurysms of the SMA and role of computed tomography in the differential diagnosis of this condition from acute mesenteric ischaemia.

Vallecular cysts: report of two cases.

A vallecular cyst is an unusual cause of inspiratory stridor in the infant. We report our findings in two infants with this lesion. Thorough diagnostic evaluation is mandatory in the pediatric patient with concomitant inspiratory stridor and respiratory distress or feeding difficulties.

Computed tomography-guided percutaneous transpedicular biopsy of the thoracic spine.

BACKGROUND: Despite the recent, widespread use around the world of computed tomography (CT)-guided spinal biopsy for presurgical evaluation, its use has remained uncommon in Taiwan. Using 9 patients, we attempted to evaluate the safety of its use for the thoracic spine biopsy. METHODS: In the past 3 years (May 1996 to May 1999), 9 patients with known thoracic or multiple spinal lesions underwent CT-guided biopsy. The patients comprised 4 men and 5 women; with ages ranging between 28 and 85 years. For the transpedicular approach, patients were laid prone on the CT table. A trephine bone biopsy needle set was used after local anaesthesia. The specimens obtained had tissue pathology and/or bacterial/tuberculosis (TB) culture. RESULTS: Excellent results were achieved in 8 of the 9 patients, with no significant procedure-related complications. Among them, 2 were diagnosed as metastatic carcinomas; 3 as osteoporotic compression fractures; 2 were proved to be bacterial or tuberculosis spondylitis and the last one was a healing fracture. CONCLUSION: CT-guided transpedicular trephine biopsy of the thoracic spine is a safe and effective method for preoperative evaluation of various thoracic spinal disorders. Based on the biopsy results, more effective treatment regimens were prescribed and, in turn, better outcomes were expected.

Cerebral arteriovenous malformations in children: neuroimaging findings.

Cerebral arteriovenous malformations (CAVMs) are uncommon in children. CAVMs represent the most frequent intracranial vascular pathology at pediatric ages. This report concerns 13 children below the age of 16; all were identified between September 1995 and December 1996 with 14 CAVMs among them. All were proved by conventional cerebral angiography (CCA). Thirteen computed tomography (CT), 7 magnetic resonance images (MRI), 2 magnetic resonance angiography (MRA) and 13 conventional cerebral angiography (CCA) were analyzed. Most CAVMs nidus were located in cerebral hemispheres. Four in the temporal lobe, two in the parietal lobe, three in the frontal lobe, two in the occipital lobe, and three in the corpus callosum. One of them was of a mixed type with two nidi. The major clinical features of CAVMs were intracranial hemorrhage and seizures. Experience here was that MRI is superior to CT in showing the exact anatomic relationships of the nidus and in demonstrating the extent of CAVMs nidus obliteration after treatment. MRA provided a noninvasive means of studying blood vessels and vascular pathology in relationship to the CAVMs nidus. Standard angiography is still necessary to characterize in-flow and out-flow of vessels in CAVMs when definitive treatment is considered.

Combined computed tomographic pulmonary angiography and venography for evaluation of pulmonary embolism and lower extremity deep venous thrombosis: report of two cases.

Pulmonary embolism (PE) and deep venous thrombosis (DVT) are major causes of morbidity and mortality, which can be reduced with accurate diagnosis and proper treatment. More than 90% of PEs originate in lower-extremity DVT. Currently, evaluation of PEs and lower-extremity DVT requires 2 separate tests (ventilation-perfusion scan, computed tomographic pulmonary angiography (CTPA), or pulmonary angiography for PE and sonography, computed tomographic venography (CTV), conventional venography, or magnetic resonance venography for DVT). Combined computed tomographic pulmonary angiography and venography (CTPAV) is a new diagnostic technique that combines CTPA and CTV into a single study for the screening of PE and subdiaphragmatic DVT. CTPAV is a modified CTPA study that evaluates the subdiaphragmatic deep vein system at the time of CTPA, without additional venipuncture or contrast medium. It is easy to perform, fairly easy to interpret, readily available, and requires no invasive procedure. We present 2 cases of multiple PE and lower-extremity DVT in which CTPAV was used.

CT features of genitourinary tuberculosis.

The genitourinary system is the most common site of extrapulmonary tuberculous infection. The diagnosis is difficult and often delayed. In this essay, we illustrate the CT features of the kidneys, ureters, bladder, prostate gland, and seminal vesicles caused by tuberculosis.

Bridging bronchus in an infant demonstrated by direct coronal computed tomography and three-dimensional rendering display.

Bridging bronchus is a rare anomaly in which the right lower lobe bronchus arises from the left main bronchus and bridges the lower mediastinum. The first reported case was diagnosed at autopsy in 1976. The second reported case was diagnosed by bronchography confirmed at autopsy in 1980. We describe a 9-month-old infant with such an anomaly. Our patient presented with cough, shortness of breath, and rhinorrhea with no fever or sputum production. The physical examination revealed only coarse breath sound and chest retraction with no other abnormalities. Chest radiography showed decreased lung volume and shifting of the mediastinum to the left. Diagnosis of this anomaly was not possible with computed tomography (CT) axial imaging. Direct coronal CT and 3D rendering with the surface-shaded display technique showed a small right upper lobe bronchus and proximal stenotic left main bronchus, with the intermediate bronchus originating from the left main bronchus and crossing the midline to enter the contralateral lung.

Reproducibility of hippocampal single-Voxel proton MR spectroscopy and chemical shift imaging.

OBJECTIVE: We investigated between- and within-acquisition reproducibility of hippocampal metabolite ratios obtained using automated proton MR spectroscopy. SUBJECTS AND METHODS: We examined 30 healthy adults with a 1.5-T scanner four times on 3 days using single-voxel spectroscopy over the left hippocampus, chemical shift imaging over the left hippocampus, and chemical shift imaging over the bilateral hippocampi. Metabolite ratios were derived from the integral values of three major peaks: N:-acetylaspartate (NAA), choline-containing compounds (Cho), and creatine plus phosphocreatine (Cr). The random-effects model of one-way analysis of variance was used to evaluate the reproducibility in terms of coefficient of variation; the mixed-effects model was used to compare the results of different hippocampal regions and spectroscopic techniques. RESULTS: Most coefficients of variation for the NAA/(Cho+Cr) ratio were less than 20%. All the coefficients of variation for the posterior hippocampus (15-25%) were less than those for the anterior hippocampus (20-44%). The posterior hippocampal NAA/(Cho+Cr) ratio of unilateral chemical shift imaging had the lowest coefficient of variation (<16%). Single-voxel spectroscopy and unilateral chemical shift imaging had similar coefficients of variation for the anterior hippocampal NAA/(Cho+Cr) ratios (17-20%). There was a significant difference in metabolite ratios measured in different hippocampal regions (p<0.01) and in those acquired with different spectroscopic techniques (p<0.001). CONCLUSION: The NAA/(Cho+Cr) ratio is the most reproducible parameter for hippocampal MR spectroscopy on a 1.5-T scanner. Regional variation and technical differences in metabolite ratios must be considered when interpreting proton spectra of the hippocampus.

Pulmonary lymphangitic sarcomatosis from cutaneous angiosarcoma: an unusual presentation of diffuse interstitial lung disease.

Pulmonary lymphangitic sarcomatosis (PLS) is not much recognized clinically although it shows similar pathological patterns and diagnostic features to pulmonary lymphangitic carcinomatosis (PLC). We report a case with hand angiosarcoma whose chest X-ray findings revealed a diffuse interstitial pattern consistent with lymphangitic spreading. The final diagnosis was made by open lung biopsy. The clinical, diagnostic and pathological features of this disease process are reviewed.

CT grading of blunt pancreatic injuries: prediction of ductal disruption and surgical correlation.

PURPOSE: The purpose of our study was to devise a CT grading scheme for blunt pancreatic injuries (BPIs) and to apply it to predict the presence or absence of ductal disruption. METHOD: We retrospectively reviewed CT scans of 22 patients with proven BPIs. We graded these injuries on CT (A, BI, BII, CI, and CII) based on the (a) presence or absence of pancreatic lacerations, (b) site of lacerations, and (c) depth of lacerations. CT grading was correlated with surgical findings for glandular and ductal injuries. RESULTS: Main pancreatic ducts were intact in 2 patients with normal CT scans and in all grade A injuries (n = 10). Distal pancreatic ducts were disrupted in all grade B injuries (BI, n = 1; BII, n = 4). Of five grade C injuries, three CII injuries had disruption of proximal pancreatic duct, one CII injury had disruption of minor duct, and one CI injury had an intact ductal system. CONCLUSION: CT grading of BPIs was useful in predicting ductal integrity or disruption. Ductal disruption was likely present if the pancreas appeared to have a transection or deep laceration on CT scans. It was accurate in grade A and B injuries. Overestimation could occur in grade CI and CII injuries.