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1.  Comparison of the clinical characteristics and imaging findings of acute cholangitis with and without biliary dilatation 
The British Journal of Radiology  2012;85(1020):e1219-e1225.
Objective
To evaluate the causes of acute cholangitis without biliary dilatation and to compare the clinical characteristics and the imaging findings between patients with acute cholangitis with and without biliary dilatation.
Methods
93 patients diagnosed with acute cholangitis underwent contrast-enhanced CT. Among them, 17 patients were classified as not having biliary dilatation (Group 1) and 76 patients were classified as having biliary dilatation (Group 2). The causes of acute cholangitis were evaluated in both groups. Clinical characteristics and imaging findings were compared between the two groups.
Results
The causes of acute cholangitis without biliary dilatation included common bile duct (CBD) stones (n=11), CBD sludge (n=3), a passed stone (n=1) and unknown causes (n=2). The total bilirubin levels of Group 1 were significantly lower than those of Group 2 (p=0.001). By contrast, Group 1 had higher median alanine aminotransferase (ALT) levels than Group 2 (p=0.04). The length of hospital stay was significantly longer in Group 2 than in Group 1 patients (p<0.001). In the imaging findings, the extent of transient hepatic attenuation differences (THADs) (p=0.003) were significantly smaller in Group 1 than in Group 2.
Conclusion
CBD stones and sludge were the most common causes of acute cholangitis in patients without biliary dilatation. These patients showed lower levels of bilirubin and higher levels of ALT than those with acute cholangitis with biliary dilatation, and had a shorter duration of hospital stay. The extent of THADs was the only discriminative CT finding between the two groups.
Advances in knowledge
Acute cholangitis can present without biliary dilatation on imaging, and the most common causes are CBD stones and sludge. The patients with acute cholangitis without biliary dilatation have different clinical characteristics and imaging findings compared with those with acute cholangitis presenting with biliary dilatation.
doi:10.1259/bjr/21182091
PMCID: PMC3611727  PMID: 23175488
2.  Perforated tumours in the gastrointestinal tract: CT findings and clinical implications 
The British Journal of Radiology  2012;85(1017):1307-1313.
Perforation usually requires emergency surgery and may affect the prognosis of patients with gastrointestinal tumours. Accurate pre-operative diagnosis of these conditions is important because proper management such as curative surgical treatment may be needed. The aims of this article are to illustrate CT appearances of perforated tumours of the gastrointestinal tract and to discuss their impact on clinical management.
doi:10.1259/bjr/21382039
PMCID: PMC3487063  PMID: 22496070
3.  Time-resolved MR angiography for detecting and grading ovarian venous reflux: comparison with conventional venography 
The British Journal of Radiology  2012;85(1014):e117-e122.
Objective
The purpose of this study was to compare the diagnostic accuracy of time-resolved MR angiography (TR-MRA) with that of conventional venography for the detection and grading of ovarian venous reflux, which aid in the diagnosis of pelvic venous congestion.
Methods
We performed a retrospective analysis of 19 consecutive patients who underwent TR-MRA and conventional venography. The images were analysed by two radiologists in a randomised “blinded” manner. With the use of conventional venography as a gold standard, the images were reviewed to determine if differences in the detection and grading of ovarian venous reflux were seen between TR-MRA and conventional venography; the sensitivity, specificity and accuracy of TR-MRA compared with that of conventional venography were evaluated. The McNemar test was performed to determine the significance of any differences. Interobserver agreement was analysed using generalised κ statistics.
Results
There was no significant difference between TR-MRA and conventional venography for grading ovarian venous reflux (p>0.05). The sensitivity, specificity and diagnostic accuracy of TR-MRA were found to be 66.7%, 100% and 78.9%, and 75%, 100% and 84.2%, respectively, for the two observers. The weighted κ-values indicated excellent agreement between the two observers for grading ovarian venous reflux on TR-MRA (κ=0.894).
Conclusion
TR-MRA is an accurate method for accessing pelvic venous congestion.
doi:10.1259/bjr/79155839
PMCID: PMC3474099  PMID: 21385913
4.  The detection and discrimination of malignant and benign focal hepatic lesions: T2 weighted vs diffusion-weighted MRI 
The British Journal of Radiology  2011;84(1000):319-326.
Objective
The purpose of this study was to evaluate the use of diffusion-weighted imaging (DWI) for the detection and characterisation of focal hepatic lesions compared with the use of T2 weighted imaging.
Method
45 patients with 97 hepatic lesions (51 malignant lesions and 46 benign lesions) were included in this retrospective study. Malignant hepatic lesions included 12 hepatocellular carcinomas, 26 metastases and 13 intrahepatic cholangiocarcinomas. Benign hepatic lesions included 19 haemangiomas and 27 cysts. The MRI protocol for the upper abdomen included T2 weighted images, in- and opposed-phase T1 weighted images and dynamic T1 weighted images. Breath-hold fat-suppressed single-shot echo planar DWI was performed with the following parameters: 1338/66; b factors, 0, 50 and 800 s mm–2. Two independent observers reviewed the T2 weighted images and the DWI to detect and to characterise the hepatic lesions.
Results
For detection of malignant hepatic lesions, the use of DWI showed a significantly higher detection rate than the use of T2 weighted images (p<0.05). However, there was no significant difference between the use of DWI and T2 weighted images for benign hepatic lesions. For the differentiation between malignant and benign hepatic lesions, there was no significant difference in sensitivity, specificity and accuracy between the use of T2 weighted images and the use of DWI.
Conclusion
The use of DWI was better for the detection of malignant hepatic lesions than the use of T2 weighted images. However, for detection of benign hepatic lesions and characterisation of hepatic lesions, the use of DWI was equivalent to the use of T2 weighted images.
doi:10.1259/bjr/50130643
PMCID: PMC3473479  PMID: 20959371
5.  Acute appendicitis: relationships between CT-determined severities and serum white blood cell counts and C-reactive protein levels 
The British Journal of Radiology  2011;84(1008):1115-1120.
Objectives
The aim of this study was to evaluate the relationships between the severity of appendicitis as depicted on CT and blood inflammatory markers of serum white blood cell (WBC) count and C-reactive protein (CRP).
Methods
CT images in 128 patients (109 surgically proven and 19 with clinically excluded appendicitis) were retrospectively reviewed. Two radiologists by consensus evaluated and scored (using a 0, 1 or 2 point scale) severities based on CT-determined appendiceal diameters, appendiceal wall changes, caecal changes, periappendiceal inflammatory stranding and phlegmon or abscess formation. We investigated whether CT findings were significantly related to elevated WBC counts or CRP levels and performed the correlations of WBC counts and CRP levels with CT severity scores. Patients were also subjectively classified using four grades from normal (Grade I) to perforated appendicitis (Grade IV) on the basis of CT findings to evaluate differences in WBC counts and CRP levels between grades.
Results
Only appendiceal wall changes and the phlegmon or abscess formation were related to elevated WBC counts and CRP levels, respectively (p<0.05). CT severity scores were found to be more strongly correlated with CRP levels (r = 0.669) than with WBC counts (r = 0.222). On the basis of CT grades, the WBC counts in Grade I were significantly lower than in other grades (p<0.001), whereas CRP levels in Grade IV were significantly higher than in other grades (p<0.001).
Conclusion
CRP levels were found to correlate with CT-determined acute appendicitis severity and could be a useful predictor for perforated appendicitis, whereas WBC counts might be useful to detect early acute appendicitis.
doi:10.1259/bjr/47699219
PMCID: PMC3473821  PMID: 21123307
6.  Reversal of Fv-1 host range by in vitro restriction endonuclease fragment exchange between molecular clones of N-tropic and B-tropic murine leukemia virus genomes. 
Journal of Virology  1983;48(1):110-119.
We molecularly cloned unintegrated viral DNA of the BALB/c endogenous N-tropic and B-tropic murine leukemia retroviruses and in vitro passaged N-tropic Gross (passage A) murine leukemia retroviruses. Recombinant genomes were constructed in vitro by exchanging homologous restriction enzyme fragments from N- or B-tropic parents and subsequent recloning. Infectious virus was recovered after transfection of these recombinant genomes into NIH-3T3 cells and cocultivation with the Fv-1 nonrestrictive SC-1 cells. XC plaque assays of recombinant virus progeny on Fv-ln and Fv-lb cells indicated that the Fv-l host range was determined by sequences located between the BamHI site in the p30 region of the gag gene (1.6 kilobase pairs from the left end of the map) and the HindIII site located in the pol gene (2.9 kilobase pairs from the left end of the map).
Images
PMCID: PMC255327  PMID: 6310140
7.  Molecular Cloning and Analysis of the Endogenous Retrovirus Chemically Induced from RFM/Un Mouse Cell Cultures 
Journal of Virology  1983;46(1):288-292.
We molecularly cloned and analyzed an N-tropic ecotropic retrovirus induced with iododeoxyuridine from RFM/Un mouse cell cultures. Based on the restriction map, the RFM/Un virus appears to be indistinguishable from other induced N-tropic retroviruses. A nucleotide sequence analysis of the long terminal repeat of an infectious clone revealed structural features characteristic of murine type C retrovirus long terminal repeats. The U3 region of the RFM/Un virus long terminal repeat, however, contained no short sequence duplication or insertion found in other murine leukemia virus isolates.
PMCID: PMC255120  PMID: 6827652
8.  Analysis of recombinant DNA clones of the endogenous BALB/c murine leukemia virus WN1802N: variation in long terminal repeat length. 
Journal of Virology  1983;45(1):484-488.
We analyzed 15 recombinant DNA clones of the unintegrated closed circular DNA intermediate of the BALB/c endogenous ecotropic murine leukemia virus WN1802N. Thirteen of these clones had an insert which corresponded to the complete murine leukemia virus genome. Of these, six contained a single long terminal repeat (LTR) and seven contained two LTRs. The viral genomes in nine clones had an LTR of 520 base pairs (bp), one had an LTR of 570 bp, three had an LTR of 600 bp, and one had an LTR of 670 bp. Restriction endonuclease analysis demonstrated that the size variability resides in the U3 region. Seven of eight clones which yielded infectious virus by DNA transfection had the 520-bp LTR, and the other had a 600-bp LTR. More detailed examination of plasmid subclones of three isolates with different-sized LTRs revealed that the approximate position which varies in the U3 region corresponds to the 72-bp repeat region of Moloney sarcoma virus. Possible consequences of these variations are discussed.
Images
PMCID: PMC256436  PMID: 6296458
9.  Negative regulatory element associated with potentially functional promoter and enhancer elements in the long terminal repeats of endogenous murine leukemia virus-related proviral sequences. 
Journal of Virology  1989;63(6):2746-2757.
Three series of recombinant DNA clones were constructed, with the bacterial chloramphenicol acetyltransferase (CAT) gene as a quantitative indicator, to examine the activities of promoter and enhancer sequence elements in the 5' long terminal repeat (LTR) of murine leukemia virus (MuLV)-related proviral sequences isolated from the mouse genome. Transient CAT expression was determined in mouse NIH 3T3, human HT1080, and mink CCL64 cultured cells transfected with the LTR-CAT constructs. The 700-base-pair (bp) LTRs of three polytropic MuLV-related proviral clones and the 750-bp LTRs of four modified polytropic proviral clones, in complete structures either with or without the adjacent downstream sequences, all showed very little or negligible activities for CAT expression, while ecotropic MuLV LTRs were highly active. The MuLV-related LTRs were divided into three portions and examined separately. The 3' portion of the MuLV-related LTRs that contains the CCAAC and TATAA boxes was found to be a functional promoter, being about one-half to one-third as active as the corresponding portion of ecotropic MuLV LTRs. A MboI-Bg/II fragment, representing the distinct 190- to 200-bp inserted segment in the middle, was found to be a potential enhancer, especially when examined in combination with the simian virus 40 promoter in CCL64 cells. A PstI-MboI fragment of the 5' portion, which contains the protein-binding motifs of the enhancer segment as well as the upstream LTR sequences, showed moderate enhancer activities in CCL6 cells but was virtually inactive in NIH 3T3 cells and HT1080 cells; addition of this fragment to the ecotropic LTR-CAT constructs depressed CAT expression. Further analyses using chimeric LTR constructs located the presence of a strong negative regulatory element within the region containing the 5' portion of the enhancer and the immediate upstream sequences in the MuLV-related LTRs.
Images
PMCID: PMC250771  PMID: 2542587
10.  Covalently closed circular DNAs of murine type C retrovirus: depressed formation in cells treated with cycloheximide early after infection. 
Journal of Virology  1980;36(1):181-188.
Formation of viral closed circular supercoiled DNA duplexes and production of progeny virus were both inhibited in cultured mouse cells treated with cycloheximide in the first 4 h of type C retrovirus infection. With different doses of cycloheximide to cause different degrees of inhibition, the number of viral supercoiled DNA duplexes detected in the cells at 11 h showed an apparent correlation with the amount of progeny virus produced in the 12- to 22-h period of infection. A slight accumulation of the full-genome linear duplex and an open circular duplex of viral DNA intermediate was observed in the cycloheximide-treated cells. Cycloheximide given to the cells during the time of conversion of viral DNA from linear to supercoiled duplex forms (6 to 11 h after virus inoculation) did not inhibit the conversion. These kinetic data suggest that a cycloheximide-sensitive metabolic process, probably early viral protein synthesis, is required for retrovirus replication and supercoiled viral DNA formation in the cell.
Images
PMCID: PMC353629  PMID: 6255205

Results 1-10 (10)