bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid emergence of a virulent PB2 E627K variant during adaptation of highly pathogenic avian influenza H7N7 virus to mice
Authors: de Jong Rineke MC , Stockhofe-Zurwieden Norbert , Verheij Eline S , de Boer-Luijtze Els A , Ruiter Saskia JM , de Leeuw Olav S , Cornelissen Lisette AHM 
Published: September 2013

Abstract

Background
Highly pathogenic avian influenza (HPAI) viruses pose a potential human health threat as they can be transmitted directly from infected poultry to humans. During a large outbreak of HPAI H7N7 virus among poultry in The Netherlands in 2003, bird to human transmission was confirmed in 89 cases, of which one had a fatal outcome.

Methods
To identify genetic determinants of virulence in a mammalian host, we passaged an avian H7N7/03 outbreak isolate in mouse lungs and evaluated the phenotype of the mouse-adapted variant in animal models and in vitro.

Results
Three passages in mouse lungs were sufficient to select a variant that was highly virulent in mice. The virus had a MLD50 that was >4.3 logs lower than that of its non-lethal parental virus. Sequence analysis revealed a single mutation at position 627 in PB2, where the glutamic acid was changed to a lysine (E627K). The mouse-adapted virus has this mutation in common with the fatal human case isolate. The virus remained highly pathogenic for chickens after its passage in mice. In ferrets, the mouse-adapted virus induced more severe disease, replicated to higher titers in the lower respiratory tract and spread more efficiently to systemic organs compared with the parental virus. In vitro, the PB2 E627K mutation had a promoting effect on virus propagation in mammalian, but not in avian cells.

Conclusions
Our results show that the E627K mutation in PB2 alone can be sufficient to convert an HPAI H7N7 virus of low virulence to a variant causing severe disease in mice and ferrets. The rapid emergence of the PB2 E627K mutant during mouse adaptation and its pathogenicity in ferrets emphasize the potential risk of HPAI H7N7 viruses for human health.
Intensity modulated radiotherapy of upper abdominal malignancies: dosimetric comparison with 3D conformal radiotherapy and acute toxicity
Authors: Nour Alaa Ahmad , Alaradi Aziz , Mohamed Adel , Altuwaijri Saleh , Rudat Volker 
Published: September 2013

Abstract

Background
The goal of this study was to assess a possible dosimetric advantage of intensity modulated radiotherapy (IMRT) of upper abdominal malignancies compared to three-dimensional conformal radiotherapy (3DCRT), and to assess the impact of IMRT on acute toxicity.

Methods
Thirty-one unselected consecutive patients with upper abdominal malignancies were treated with definitive (n =16) or postoperative (n =15) IMRT. Twenty-one patients (67.7%) received concomitant chemotherapy. 3DCRT plans were generated for comparison, and analysis of variance (ANOVA) for repeated measurements was used to test for significant difference of dosimetric parameters. Acute toxicity was assessed weekly using the Common Terminology Criteria for Adverse Events (CTCAE) grading scale.

Results
IMRT plans showed a small but statistically significant improvement of the conformity index compared to 3DCRT plans (difference (95% confidence interval), -0.06 (−0.109 to-0.005); p = 0.03). The homogeneity index was not significantly improved (p = 0.10). A significantly reduced high dose volume on cost of a significantly increased low dose volume was observed for the kidneys. The acute toxicity appeared to be less than commonly reported for corresponding patients treated with 3DCRT. No patient developed grade 3 or 4 non-hematological acute toxicity, and the most common grade 2 toxicity was vomiting (9.7%).

Conclusions
IMRT offers the potential of a clinically relevant dosimetric advantage compared to 3DCRT in terms of a reduced acute toxicity. Further optimization of the radiotherapy technique and more clinical trials are required before IMRT is routinely used for upper abdominal malignancies.
The role of preoperative pulmonary function tests in the surgical treatment of extremely severe scoliosis
Authors: Lao Lifeng , Weng Xisheng , Qiu Guixing , Shen Jianxiong 
Published: September 2013

Abstract

Background
The patients with extremely severe spinal deformity are commonly considered high-risk candidates for surgical treatment because of their underlying lung disease. Currently, little has been reported about the postoperative pulmonary complication events in this population. This retrospective study sought to evaluate preoperative pulmonary function tests in the surgical treatment of extremely severe scoliosis.

Methods
Preoperative forced vital capacity (FVC), FVC ratio, forced expiratory volume at the end of the first second (FEV1), FEV1 ratio, peak expiratory flow (PEF), and PEF ratio were performed and evaluated on 60 patients with extremely severe scoliosis (coronary main Cobb angle ≥100°).

Results
Among the 60 patients, 11 (18.3%), 13 (21.7%), and 22 (36.7%) had severe, moderate, and mild pulmonary dysfunction, respectively. Compared with the moderate and mild scoliosis groups, significant differences were observed in Cobb, FVC, FVC ratio, FEV1, FEV1 ratio, and PEF ratio in the extremely severe scoliosis group. Various postoperative pulmonary complications occurred in nine cases (15%). Patients with severe or moderate dysfunction as measured by the FVC ratio had a higher incidence of postoperative pulmonary complications. A transthoracic procedure was not related to postoperative pulmonary complications, but thoracoplasty significantly increased the incidence of postoperative pulmonary complications (P < 0.001, OR = 20, 95% CI = 3.45–115.97).

Discussion
Pulmonary function was impaired in extremely severe scoliosis. Patients with severe restrictive pulmonary dysfunction had a higher incidence of postoperative pulmonary complications. Thoracoplasty was an important risk factor in the prediction of postoperative pulmonary complications.
Risk factors and mortality after elective and emergent laparatomies for oncological procedures in 899 patients in the intensive care unit: a retrospective observational cohort study
Authors: Mallol Montserrat , Sabaté Antoni , Dalmau Antonia , Koo Maylin 
Published: September 2013

Abstract

Background
Abdominal surgeries for cancer are associated with postoperative complications and mortality. A view of the success of anaesthetic, surgical and critical care can be gained by analyzing factors associated with mortality in patients admitted to intensive care units (ICUs). The objective of this study was to identify the postoperative mortality rate and the causes of perioperative death in high-risk patients after abdominal surgery for cancer. A secondary objective was to explore possible risk factors for death in scheduled and emergency surgeries, with a view to finding guidance on preventable risk factors.

Methods
An observational study, in a 12-bed surgical ICU of a tertiary hospital. Patients admitted after abdominal surgery for cancer to the ICU for more than 24 hours’ care were included from January 1, 2008–December 31, 2009. Data were extracted from the minimum basic dataset. The main outcome considered was 90-day mortality.

Results
Of 899 patients included, 80 (8.9%) died. Seven died within 48 hours of surgery, 18 died between 2 and 7 days, and 55 died after 7 days. Non-survivors were older and had more respiratory comorbidity, chronic liver disease, metastasis, and underwent more palliative procedures. 112 patients underwent emergency surgery; mortality in these patients for resection surgery was 32.5%; in the 787 patients who underwent scheduled surgery, mortality was 4.7% for resection procedures. The estimated odds ratios (95% confidence interval) of preoperative patient factors in emergency surgery confirmed a negative association between survival and older age 0.96 (0.91–1), the presence of respiratory comorbidity 0.14 (0.02–0.77) and metastasis 0.18 (0.05–0.6). After scheduled surgery, survival was negatively associated with age 0.93 (0.90–0.96) and chronic liver disease 0.40 (0.17–0.91). Analysis of complications after emergency surgery also indicated a negative association with sepsis 0.03 (0.003–0.32), respiratory events 0.043 (0.011–0.17) and cardiac events 0.11 (0.027–0.45); after scheduled surgery, respiratory 0.03 (0.01–0.08) and cardiac 0.11 (0.02–0.45) events, renal failure 0.02 (0.006–0.14) and neurological events 0.06 (0.007–0.5).

Conclusions
As most deaths occurred after discharge from the ICU, postoperative sepsis, respiratory and cardiac events should be watched carefully on the ward.
Th17 memory cells: live long and proliferate
Authors: McGeachy Mandy J 
Published: September 2013

ABSTRACTThe development of immune memory is a double-edged sword, helping to maintain health by preventing repeated infections but also driving chronic inflammation when dysregulated. Th17 cells are now well-known as major drivers of autoimmune disease but also play roles in protective immune responses against pathogens. This mini-review will focus on the recent evidence for long-lived, robust Th17 memory cell populations in mouse models and humans, and their functional roles in mediating host protection and chronic disease states.
The chemokine CX3CL1 promotes trafficking of dendritic cells through inflamed lymphatics
Authors: Johnson Louise A. , Jackson David G. 
Published: September 2013

Tissue inflammation is characterized by increased trafficking of antigen-loaded dendritic cells (DC) from the periphery via afferent lymphatics to draining lymph nodes, with resulting stimulation of ongoing immune responses. Transmigration across lymphatic endothelium constitutes the first step in this process and is known to involve the chemokine CCL21 and its receptor CCR7. However, the precise details of DC transit remain obscure and it is likely that additional chemokine-receptor pairs have roles in lymphatic vessel entry.Here, we report that the transmembrane chemokine CX3CL1 (fractalkine) is induced in inflamed lymphatic endothelium, both in vitro in TNF-α-treated human dermal lymphatic endothelial cells (HDLEC) and in vivo in a mouse model of skin hypersensitivity. However, unlike blood endothelial cells, which express predominantly transmembrane CX3CL1 as a leukocyte adhesion molecule, HDLEC shed virtually all CX3CL1 at their basolateral surface via matrix metalloproteinases. We show for the first time that both recombinant soluble CX3CL1 and endogenous secreted CX3CL1 promote basolateral-to-luminal migration of DC across HDLEC monolayers in vitro. Furthermore, we show in vivo that neutralizing antibodies against CX3CL1 dramatically reduce allergen-induced trafficking of cutaneous DC to draining lymph nodes as assessed by FITC skin painting in mice. Finally, we show that deletion of CX3CL1 receptor in CX3CR1−/− DC results in markedly delayed lymphatic trafficking in vivo and impaired translymphatic migration in vitro, thus establishing a previously unrecognized role for this atypical chemokine in regulating DC trafficking through the lymphatics.
MRA in patients with cerebrovascular disease: Considerations of clinical effectiveness
Authors: Krug B. , Terstegge K. , Neveling M. , Zähringer M. , Kugel H. , Lackner K. 
Published: September 2013

Objective: To establish in which clinical contexts cerebral MR angiography (MRA) is routinely carried out in a neurological university department and to describe its clinical impact. Material and Methods: Medical records, reports of findings and documentation of imaging examinations carried out in all 69 patients referred to the Department of Radiology from the Department of Neurology between 1995 and 1998 for cerebral MRA were evaluated. The clinical impact of all imaging findings was assessed on the basis of the medical records. Results: Circulatory disturbances in the vertebrobasilor arteries (n=4) were the most frequent indication for investigation. MRA followed CT or duplex sonography in 66 of the 69 patients with a mean delay of 8 days. MRA was considered diagnostically inferior to conventional MR in 11 cases, comparable in 30 and superior in 25. Comparing MRA and duplex sonography, the corresponding figures were 12, 29 and 23. In retrospect, 56 MRAs were judged unnecessary. Conclusion: Controlled clinical studies on optimal use of MRA are needed to avoid wasting resources and to exploit the method's full diagnostic potential in appropriate cases.
CT of the brain in tuberculous meningitis: A review of 289 patients
Authors: Özateş M. , Kemaloǧlu S. , Gürkan F. , Özkan U. , Hoşoǧlu S. , Şimşek M.M 
Published: September 2013

Purpose: In this retrospective study, CT findings of 289 patients with tuberculous meningitis (TBM) are presented and diagnostic criteria are discussed. Material and methods: The medical records of patients who were diagnosed as having central nervous system tuberculosis were investigated. Cranial CT investigations of 289 patients with TBM were reviewed. Of these 289 patients, 214 were children and 75 adults; 157 patients were male and 132 were female. CT images were obtained with and without i.v. contrast administration. Results: CT findings were normal in 35 patients and abnormal in 254. The abnormalities were hydrocephalus (172 children, 32 adults), parenchymal enhancement (56 children, 6 adults), contrast enhancement of basal cisterns (32 children, 17 adults), cerebral infarct and focal or diffuse brain edema (29 children, 10 adults), and tuberculoma (9 children, 5 adults). Conclusion: CT is pathologic in the great majority of patients with TBM and is helpful in assessing the complications associated with the disease.
Dynamic MR imaging of mandibular osteoradionecrosis
Authors: Støre G. , Smith H.-J. , Larheim T.A. 
Published: September 2013

Purpose: Osteoradionecrotic bone has been characterised as hypovascular and metabolically inactive tissue with impaired perfusion. The present study was conducted to determine if dynamic contrast-enhanced MR imaging could provide additional information about the vascularity of radionecrotic mandibular bone. Material and Methods: Dynamic contrast-enhanced MR imaging was performed on 10 patients with mandibular osteoradionecrosis (ORN), and on 6 patients, irradiated for oropharyngeal tumours, without symptoms or signs of ORN. Nine patients in the ORN group received a series of 20 hyperbaric oxygen (HBO) treatments, after which the dynamic MR investigation was repeated. Results and Conclusion: Radiation per se did not lead to increased contrast enhancement, whereas all patients with ORN showed marked contrast enhancement of the osteoradionecrotic bone marrow. After HBO treatment, pathological contrast enhancement of the abnormal bone marrow could still be seen, but the rate of enhancement was less than before in 7 of 9 patients. Two patients had an increase in the enhancement rate. The findings suggest the existence of an increased and patent microvasculature.
Early glottic squamous cell carcinoma: Predictive value of MR imaging for the rate of 5-year local control with radiation therapy
Authors: Murakami R. , Baba Y. , Furusawa M. , Nishimura R. , Nakaura T. , Baba T. , Katsura F. , Eura M. , Masuyama K. , Takahashi M. 
Published: September 2013

Purpose: To evaluate MR findings in early (T1 and T2 stages) glottic carcinomas and the predictive value of MR imaging for the rate of 5-year local control with radiation therapy. Material and Methods: Eighty-three patients with early glottic carcinomas were prospectively examined with MR at 1.5 T. MR investigation included unenhanced T1-weighted, T2-weighted, dynamic and contrast-enhanced T1-weighted images. Three patients with presumed advanced diseases on MR were initially treated with total laryngectomy and were excluded from the study. The remaining 80 patients were treated with radiation therapy with curative intent. Tumor detectability, size and relationship to the thyroid cartilage were determined on MR images. The MR findings were then correlated with the rate of local control. Results: Forty-eight of 80 lesions (60%) were detected on MR imaging. All detected lesions but 1 demonstrated increased signal on T2-weighted images. The lesions were best delineated on dynamic images (statistically significant). The 5-year local control rate with radiation therapy was 72%. Univariate analysis revealed clinical T stage, MR detectability, tumor size and relationship to the thyroid cartilage as significant predictors. Multivariate analysis revealed that the relationship to the thyroid cartilage was an independent factor. Conclusion: MR provides prognostic information about the results of definitive radiation therapy. To evaluate the tumor extension in lesions detected on precontrast MR images, contrast-enhanced dynamic images should be obtained.
Effect on sensitivity and specificity of mammography screening with or without comparison of old mammograms
Authors: Thurfjell M. Gelig , Vitak B. , Azavedo E. , Svane G. , Thurfjell E. 
Published: September 2013

Purpose: To evaluate the effect of old mammograms on the specificity and sensitivity of radiologists in mammography screening. Material and Methods: One hundred and fifty sets of screening mammograms were examined by 3 experienced screeners twice: once without and once in comparison with older mammograms. The films came from a population-based screening done during the first half of 1994 and comprised all 35 cancers detected during screening in 1994, 12/24 interval cancers, 14/34 cancers detected in the following screening and 89 normal mammograms. Results: Without old mammograms, the screeners detected an average of 40.3 cancers (range 37–42), with a specificity of 87% (85–88%). With old mammograms, the screeners detected 37.7 cancers (range 34–42) with a specificity of 96% (94–99%). The change in detection rate was not significant. However, the increase in specificity was significant for each screener ( p = 0.0002–0.03). Conclusion: Mammography screening with old mammograms available for comparison decreased the false-positive recall rate. The effect on sensitivity, however, was unclear.
High-resolution MR imaging of the carpal tunnel and the wrist: Application of a 5-cm surface coil
Authors: Mäurer J. , Bleschkowski A. , Tempka A. , Felix R. 
Published: September 2013

Purpose: To make a comparative analysis of transversal tomograms obtained by high-resolution MR imaging with frozen cross-sections of an anatomical forearm specimen. Twenty-two healthy volunteers were also examined using the same coil system to test for a range of possible clinical applications and for the depiction of morphological and morphometrical values of normal anatomy in vivo. Material and Methods: MR images of the carpal tunnel of 22 healthy volunteers were obtained with a 1.5-T whole-body system with a 5-cm surface coil. Measurements were recorded with a field-of-view between 50 × 50 mm2 and 60 × 60 mm2 in a 256 × 256 pixel matrix for the T1 sequence. A slice thickness of 2 mm was used. The images were acquired using a T1-weighted SE sequence (TR/TE 500/38 ms) and a T2-weighted SE sequence (TR/TE 2000/70 ms). Additionally, a formalin-fixed anatomical forearm specimen was imaged for anatomic correlation. The imaged transversal cross-section levels in the specimen were subsequently freeze-sectioned. The anatomical structures of the MR findings were identified and compared with the macroscopical sections of the specimen. Results: Based on the good depiction of details at this coil system with a pixel size in T1 of 0.195 × 0.195 mm, high-resolution MR imaging enabled identification of the interior structures of the carpal tunnel, as well as delineation of connective tissue. The clinical value of high-resolution MR includes the diagnosis of carpal tunnel syndrome and inflammatory disorders of the wrist. Conclusion: Our results support the feasibility of high-resolution MR imaging of the carpal tunnel and the wrist using small surface coils.
Evaluation of dural sinus invasion and extension of extra-axial intracranial tumors: The advantages of a high-resolution postcontrast 3-D gradient-echo technique
Authors: Ikushima I. , Korogi Y. , Hirai T. , Sugahara T. , Shigematsu Y. , Okuda T. , Takahashi M. , Ushio Y. 
Published: September 2013

Objective: To assess the usefulness of a postcontrast 3-D Fourier transform (3DFT) gradient-echo (GRE) technique in dural sinus invasion and extension of extraaxial intracranial tumors in comparison with a conventional spin-echo (SE) technique. Material and Methods: Fourteen consecutive patients with 15 extra-axial tumors in contiguity with the dural sinus, including 14 meningiomas and 1 adenoid cystic carcinoma, underwent postcontrast T1-weighted SE and GRE MR studies. Detectability of dural sinus invasion and extension was evaluated using two sequences by two neuroradiologists in a blinded manner and compared with surgical results. Quantitative analysis was also performed to calculate the contrast-to-noise ratio (CNR) between lesion and dural sinus on SE and GRE images. The data were analyzed statistically using a matched paired t-test. Results: In the qualitative evaluation, the detectability of dural sinus invasion in 3DFT-GRE images was superior to that using SE images. The mean CNR for all lesions was 3.86 on SE images and 5.63 on 3DFT-GRE images ( p = 0.03). Conclusion: For evaluation of dural sinus invasion and the extension of extra-axial tumors, postcontrast 3DFT-GRE MR images were superior to conventional SE images.
Glycogen content in rat liver: Importance for CT and MR imaging
Authors: Leander P. , Månsson S. , Pettersson G. 
Published: September 2013

Purpose: CT and MR imaging are appropriate modalities for imaging of the liver. Contrast media are used to obtain a greater difference in attenuation and signal intensity, respectively, between normal liver tissue and focal lesions. However, no studies have attempted to determine whether physiological nutritional status of the liver during fasting is of importance for the native signal of normal liver tissue. Material and Methods: Using normal and fasting rats, we performed hepatic CT and MR imaging and glycogen analyses from excised tissue. Results: A significantly higher liver attenuation in normal rats compared to fasting rats was found in CT. In MR images, there was a small but significantly lower liver signal-to-noise ratio in normal rats compared to fasting rats in T1-weighted and proton density-weighted images. Glycogen analyses showed depleted glycogen deposits in fasting rats and a mean glycogen content of 50.1 mg glucose equivalent/g liver tissue in normal rats. Conclusion: In CT, a normal nutritional status increases the native attenuation in normal liver tissue. The changes in attenuation in normal liver tissue correlate well with the additional attenuation of glycogen storage in the hepatocyte. The results indicate that the nutritional status is of less importance in MR imaging.
Echo-planar MR imaging of dissolved hyperpolarized 129Xe: Potential for MR angiography
Authors: Måsson S. , Johansson E. , Svensson J. , Olsson L. E. , Ståhlberg F. , Petersson J. S. , Golman K. 
Published: September 2013

Purpose: The feasibility of hyperpolarized 129Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol, a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2≈20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. Conclusion: Based on the SNR of the obtained Xe EPI images, it was estimated that rapid in vivo MRA with 129Xe may be feasible, provided that an efficient, biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129Xe.