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Biomedical subjects

J Baillie

Publications and source records attributed to J Baillie.

At least 19 recordsLinked to original sources
PubMed1992

Repression of human cytomegalovirus major immediate early gene expression in a monocytic cell line.

We have previously shown that a major site of persistence of human cytomegalovirus (HCMV) in healthy carriers is in peripheral blood monocytes. However, monocytes are difficult to infect in vitro with HCMV, and HCMV gene expression cannot be reproducibly detected in peripheral blood cells of healthy carriers. Here we show that the monocytic cell line THP1 is non-permissive for HCMV infection due to a block in expression of the HCMV major immediate early (IE) promoter. This repression is correlated with the presence of a differentiation-specific cellular factor which binds to the imperfect dyad symmetry and the 21 bp enhancer repeats of the major IE promoter regulatory region and which has characteristics of MBF1, a factor which we have previously defined in HCMV non-permissive, undifferentiated teratocarcinoma cells. Both differentiation of THP1 cells into macrophages, which results in a decrease in this factor, or deletion of the factor's binding sites from the IE promoter/enhancer lifts this repression and permits expression from the major IE promoter.

Antigens, Viral↗
PubMed1992

Stent placement for benign pancreatic diseases: correlation between ERCP findings and clinical response.

OBJECTIVE: We performed a study to determine if the appearance of the pancreatic duct on ERCP before and after placement of pancreatic duct stents correlates with the therapeutic response in patients treated for impaired pancreatic drainage. MATERIALS AND METHODS: Findings in 29 consecutive patients with a variety of benign pancreatic diseases in whom pancreatic stents were placed and subsequently removed within a 3-year period were reviewed retrospectively. Early (1-5 days) and late (1-3 months) clinical outcomes after stent placement were assessed. These findings were correlated with a blinded interpretation of ERCP findings (Cambridge criteria were used) before and after stent placement. RESULTS: ERCP findings before stent placement were normal in 10 patients. At the end of stent therapy, ERCP showed changes associated with chronic pancreatitis in all 10; five had focal narrowing at the tip of the stent. Subsequent ERCP studies in five of these 10 patients showed that ductal changes induced by stents diminished after stent removal. Of the 19 patients with abnormal findings on ERCP at the time of stent placement, ERCP at the end of stent therapy showed some improvement in seven patients, no change in eight, and deterioration in four. Changes seen on ERCP had no statistically significant correlation with clinical outcome (p = .36). CONCLUSION: Our findings show that pancreatic duct stents can induce abnormalities on ERCP indicative of chronic pancreatitis. However, diminution of these abnormalities after stent removal in some patients suggests that these changes may be due to edema rather than to fibrosis. Ductal changes seen on ERCP are not a useful guide for determining the degree of response to pancreatic stents.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed1991

The 21bp repeat element of the human cytomegalovirus major immediate early enhancer is a negative regulator of gene expression in undifferentiated cells.

The major immediate early regulatory region of human cytomegalovirus (HCMV) has a complex set of DNA sites through which both cellular and viral factors coordinately regulate immediate early gene expression. In undifferentiated human teratocarcinoma (T2) cells we have previously shown that major immediate early gene expression is repressed by a differentiation specific nuclear factor MBF1, which binds to the imperfect dyad symmetry located upstream of the enhancer. However, upon differentiation MBF1 decreases resulting in immediate early gene expression. In this study we show, by mobility shift analysis that the same or similar factor(s) also binds to the 21bp repeat of the major immediate early enhancer. Deletion of this 21bp repeat from the immediate early enhancer expression vectors results in increased CAT expression in undifferentiated T2 cells, to levels similar to that in differentiated cells. Consequently, the 21bp repeat of the HCMV enhancer also acts to negatively regulate major immediate early enhancer function in non-permissive cells.

Base Sequence↗
PubMed1991

Use of computer graphics simulation for teaching of flexible sigmoidoscopy.

The concept of simulation training in endoscopy is now well-established. The systems currently under development employ either computer graphics simulation or interactive video technology; each has its strengths and weaknesses. A flexible sigmoidoscopy training device has been designed which uses graphic routines--such as object oriented programming and double buffering--in entirely new ways. These programming techniques compensate for the limitations of currently available desk-top microcomputers. By boosting existing computer 'horsepower' with next generation coprocessors and sophisticated graphics tools such as intensity interpolation (Gouraud shading), the realism of computer simulation of flexible sigmoidoscopy is being greatly enhanced. The computer program has teaching and scoring capabilities, making it a truly interactive system. Use has been made of this ability to record, grade and store each trainee encounter in computer memory as part of a multi-center, prospective trial of simulation training being conducted currently in the USA. A new input device, a dummy endoscope, has been designed that allows application of variable resistance to the insertion tube. This greatly enhances tactile feedback, such as resistance during looping. If carefully designed trials show that computer simulation is an attractive and effective training tool, it is expected that this technology will evolve rapidly and be made widely available to trainee endoscopists.

Computer Graphics↗
PubMed1991

Anatomic variants and artifacts in ERCP interpretation.

ERCP is a complex diagnostic procedure requiring manual dexterity, careful attention to endoscopic and radiographic technique, and correct interpretation of the resulting images. Not surprisingly, the procedure is associated with many potential pitfalls. Many of these are related to normal anatomic pancreatic and biliary variants and to artifacts associated with the examination itself. Knowledge of these variants and artifacts is necessary to perform procedures and interpret the results effectively. Our discussion and illustrations are based on a retrospective review of approximately 1300 ERCP studies performed at a single center during a 2-year period.

Biliary Tract↗
PubMed1991

Bile duct diverticula and webs: nonspecific cholangiographic features of primary sclerosing cholangitis.

Biliary tree diverticula and webs are considered by several authors to be specific cholangiographic features of primary sclerosing cholangitis (PSC). Our experience suggested that these findings can be seen in patients without PSC. The purpose of this study was twofold: to establish whether diverticula and webs are indeed specific for PSC and to assess whether PSC can be accurately diagnosed without reference to diverticula or webs. We retrospectively reviewed 861 consecutive ERCP studies and found 32 cases of webs and/or diverticula. Using accepted cholangiographic, clinical, and histologic criteria, we diagnosed PSC in nine patients and excluded it in 21, with two instances of uncertain diagnoses. Webs and diverticula seen in PSC were cholangiographically indistinguishable from those in the group without PSC. All 21 patients without PSC had other biliary abnormalities, and were grouped by the predominant abnormality or finding believed to be associated with diverticulum or web formation: common duct stones or cholangitis (n = 11 patients), postoperative stricture (n = 4), bile duct stent and balloon dilatation (n = 3), malignant stricture (n = 2), and choledochoduodenostomy (n = 1). To assess cholangiographic diagnosis of PSC in these patients, a blinded reviewer studied the radiographs of the 30 patients with diverticula and/or webs who had confirmed diagnoses. By using established radiologic criteria alone (ignoring diverticula and webs), the correct diagnosis was made in 27, yielding a sensitivity of 89% and specificity of 91%. We conclude that the presence of diverticula and/or webs on a cholangiogram is a nonspecific finding and may be due to inflammation or trauma to the bile duct wall. Further, PSC can be distinguished from other abnormalities on the basis of findings other than diverticula and webs.

Bile Ducts↗
PubMed1990

Endoscopic management of choledocholithiasis during pregnancy.

Extrahepatic biliary obstruction by gallstones during pregnancy is a difficult management problem. We present five patients--four with acute cholangitis and one with gallstone pancreatitis--in whom a surgical procedure was avoided by endoscopic sphincterotomy. All five women delivered healthy babies at term. Endoscopic retrograde cholangiopancreatography and sphincterotomy can be performed safely in pregnancy with minimal exposure to radiation. Endoscopic management should be considered in women presenting with acute cholangitis or gallstone pancreatitis during pregnancy.

Adult↗
PubMed1989

Endoscopic sphincterotomy in 1000 consecutive patients.

Between 1983 and 1988, endoscopic sphincterotomy was attempted on 1000 consecutive patients with a clinical diagnosis of bileduct stones in a centre with a policy to establish immediate bileduct drainage for retained stones. Endoscopic cholangiography was successful in 985 patients, of whom 782 had visible stones and 203 had a dilated bileduct but no visible stones. Endoscopic sphincterotomy was successful in 975 of these patients, with eventual bileduct clearance in 674 of 772 patients (87.3%) with visible stones; immediate bileduct drainage was achieved in 160 of the 161 patients (99%) in whom bileduct clearance failed at the first attempt. Overall, 771 of 797 patients (96.7%) with visible bileduct stones had successful bileduct clearance or drainage. Complications occurred in 6.9%, with a 30-day mortality rate of 1.2%, but procedure-related mortality was only 0.6%.

Adult↗