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Biomedical subjects

A Brian West

Publications and source records attributed to A Brian West.

At least 19 recordsLinked to original sources
PubMed2006

Focal myointimal hyperplasia of mesenteric veins is associated with previous trauma in surgical specimens.

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood disease that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. This disease is often confused with chronic idiopathic inflammatory bowel disease clinically, and pathologists may miss the diagnosis unless elastin stains are performed because diseased veins may readily be mistaken for arteries. The etiology of IMHMV is unclear, but a traumatic pathomechanism resulting in arterialization of the veins has been proposed. Review of bowel resection specimens (n=68) for non-neoplastic disease within a 1-year period in patients younger than 50 years of age revealed 10 cases with focal mesenteric vein myointimal hyperplasia. Significantly more cases with focal myointimal hyperplasia of mesenteric veins (MHMV) were associated with pre-resection trauma to the involved bowel segment (5/11 vs. 5/57; p=0.0016). A significant association of MHMV with pre-resection trauma supports the hypothesis that idiopathic myointimal hyperplasia of the mesenteric veins may be the result of trauma through torsion/stretching of the sigmoid colon and, subsequently, increased mesenteric venous pressure through arterialization.

Adult↗
PubMed2006

Carbonated soft drink consumption and risk of esophageal adenocarcinoma.

Carbonated soft drinks (CSDs) have been associated with gastroesophageal reflux, an established risk factor for esophageal adenocarcinoma. As both CSD consumption and esophageal adenocarcinoma incidence have sharply increased in recent decades, we examined CSD as a risk factor for esophageal and gastric cancers in a U.S. multicenter, population-based case-control study. Associations between CSD intake and risk were estimated by adjusted odds ratios (ORs), comparing the highest versus lowest quartiles of intake. All statistical tests were two-sided. Contrary to the proposed hypothesis, CSD consumption was inversely associated with esophageal adenocarcinoma risk (highest versus lowest quartiles, OR = 0.47, 95% confidence interval = 0.29 to 0.76; Ptrend = .005), due primarily to intake of diet CSD. High CSD consumption did not increase risk of any esophageal or gastric cancer subtype in men or women or when analyses were restricted to nonproxy interviews. These findings indicate that CSD consumption (especially diet CSD) is inversely associated with risk of esophageal adenocarcinoma, and thus it is not likely to have contributed to the rising incidence rates.

Adenocarcinoma↗
PubMed2006

The pathology of diverticulosis: classical concepts and mucosal changes in diverticula.

Left-sided diverticular disease affects upwards of 50% of the population over the age of 60 years in western countries and is becoming more common as the population ages. Studies from the 1960s to 1980s related its occurrence to the use of low fiber diets, and to the prolonged colonic transit time and increased intraluminal pressure associated with low-volume stools. Pulsion diverticula (pseudodiverticula) emerge through the muscularis propria of the left colon at points of penetration of the vasa recta that supply the submucosa and mucosa. Cardinal features of the sigmoid colon in diverticular disease are abnormalities of the muscularis propria, including thickening and elastosis of the teniae, shortening of the bowel, and thickening and folding of the circular muscle with the development of transverse semilunar ridges between the mesenteric and antimesenteric teniae. Complications of diverticular disease such as hemorrhage, diverticulitis, peridiverticular abscess, fistula, and perforation are well recognized.

Colon↗
PubMed2006

Hepatocellular carcinoma in the cirrhotic liver: gadolinium-enhanced 3D T1-weighted MR imaging as a stand-alone sequence for diagnosis.

PURPOSE: To retrospectively assess the usefulness of contrast material-enhanced T1-weighted magnetic resonance (MR) imaging alone and with T2-weighted MR imaging in the diagnosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: A waiver of informed consent and institutional review board approval for this retrospective study were granted. The study was HIPAA compliant. Twenty-eight men (mean age, 49 years; range, 23-70 years) and 10 women (mean age, 53 years; range, 42-72 years) with cirrhosis underwent T2-weighted and contrast-enhanced T1-weighted MR imaging at 1.5 T within 90 days of liver transplantation. Three readers reviewed the T1-weighted images alone and then the T2-weighted and T1-weighted images together. Lesion detection, characterization, and reader confidence levels were recorded. RESULTS: At liver explantation, 57 lesions were present in 18 patients: 19 HCCs, 33 dysplastic nodules, and five cysts. Contrast-enhanced T1-weighted imaging depicted 13 of 19 HCCs with an overall sensitivity of 68.4% (13 of 19) and specificity of 65.7% (23 of 35). The sensitivity and specificity for detection of dysplastic nodules (sensitivity, 9%; specificity, 68.4%) and HCCs (sensitivity, 68.4%; specificity, 65.7%) were nearly identical for T1-weighted images read alone or read with T2-weighted images. The only difference was the specificity for T1-weighted images read alone (65.7%) and read with T2-weighted images (62.9%). The addition of T2-weighted images altered the diagnosis in one of 90 (1.1%) cases and provided an increase in diagnostic confidence in four of 258 (1.6%) cases for independent readers and three of 90 (3.3%) cases at consensus reading. CONCLUSION: Contrast-enhanced T1-weighted imaging can be used as a stand-alone sequence for the diagnosis of HCC in patients with cirrhosis prior to liver transplantation.

Adult↗
PubMed2006

Interobserver agreement in hepatitis C grading and staging and in the Banff grading schema for acute cellular rejection: the "hepatitis C 3" multi-institutional trial experience.

CONTEXT: Establishing adequate interobserver agreement is crucial not only for standardization of patient care but also to ensure validity of findings in multi-institutional trials. OBJECTIVE: To evaluate interobserver agreement in assessing chronic hepatitis C (HCV) and acute cellular rejection (ACR) among 17 hepatopathologists involved in the "Hepatitis C 3" trial. DESIGN: The trial is a randomized multicenter (17 institutions) study involving 312 patients undergoing transplantation for HCV. Patients are randomized to 3 treatment arms. For final data analysis, all biopsy specimens are reviewed by a central pathologist (G.J.N.). Recurrence of HCV is evaluated according to the Batts and Ludwig schema. The 1997 Banff schema is used to evaluate ACR. To assess interobserver agreement, hematoxylin-eosin-stained sections from 11 liver biopsy specimens (6 HCV and 5 ACR) were sent by the central pathologist to 16 local pathologists from 13 institutions. Statistical analysis was performed on raw ACR/HCV data as well as data grouped according to clinically significant primary endpoint cutoffs. RESULTS: Statistically significant agreement was found among all participating pathologists (P < .001). On kappa analysis, the degree of agreement was rated "moderate" for HCV grade and stage and ACR global grading (kappa = 0.30, 0.33, and 0.37, respectively). Interobserver agreement was weaker for rejection activity index scoring of ACR (kappa = 0.15). A stronger degree of agreement was found when scores were grouped based on endpoint cutoffs (kappa = 0.76 "almost perfect" for HCV and 0.62 "substantial" for ACR). CONCLUSIONS: An overall statistically significant interobserver agreement was found among 17 pathologists using the 1997 Banff schema and the Batts and Ludwig schema.

Acute Disease↗
PubMed2005

Methotrexate (MTX) plus ursodeoxycholic acid (UDCA) in the treatment of primary biliary cirrhosis.

This placebo-controlled, randomized, multicenter trial compared the effects of MTX plus UDCA to UDCA alone on the course of primary biliary cirrhosis (PBC). Two hundred and sixty five AMA positive patients without ascites, variceal bleeding, or encephalopathy; a serum bilirubin less than 3 mg/dL; serum albumin 3 g/dL or greater, who had taken UDCA 15 mg/kg daily for at least 6 months, were stratified by Ludwig's histological staging and then randomized to MTX 15 mg/m2 body surface area (maximum dose 20 mg) once a week while continuing on UDCA. The median time from randomization to closure of the study was 7.6 years (range: 4.6-8.8 years). Treatment failure was defined as death without liver transplantation; transplantation; variceal bleeding; development of ascites, encephalopathy, or varices; a doubling of serum bilirubin to 2.5 mg/dL or greater; a fall in serum albumin to 2.5 g/dL or less; histological progression by at least two stages or to cirrhosis. Patients were continued on treatment despite failure of treatment, unless transplantation ensued, drug toxicity necessitated withdrawal, or the patient developed a cancer. There were no significant differences in these parameters nor to the time of development of treatment failures observed for patients taking UDCA plus MTX, or UDCA plus placebo. The trial was conducted with a stopping rule, and was stopped early by the National Institutes of Health at the advice of our Data Safety Monitoring Board for reasons of futility. In conclusion, methotrexate when added to UDCA for a median period of 7.6 years had no effect on the course of PBC treated with UDCA alone.

Adult↗
PubMed2005

Demographic and lifestyle predictors of survival in patients with esophageal or gastric cancers.

BACKGROUND AND AIMS: Risk factors for subtypes of esophageal and gastric cancer recently have been identified, but their effect on survival is unknown. METHODS: Incident cases (n = 1142) from a population-based case-control study were followed-up from diagnosis (1993-1995) until 2000. Cox regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for esophageal and gastric cancer in relation to prediagnostic factors. RESULTS: Relative to distant stage, esophageal adenocarcinoma (EA) patients with localized disease had a decreased risk for death (HR, .22; 95% CI, .15-.31), followed by those with regional spread (HR, .32; 95% CI, .23-.45). Similar patterns were seen for the other tumor types. Except for other (non-cardia) gastric adenocarcinomas (OGA), higher household income (> or =15,000 US dollars/y vs. <15,000 US dollars/y) was associated with a 33%-38% decrease in risk for death. Prediagnosis body mass index (BMI) between 25 and 29.9 kg/m 2 was associated with longer survival for EA and OGA patients (EA: HR, .67; 95% CI, .51-.88) vs. BMI <25 kg/m(2). Women with esophageal squamous cell carcinoma (ES) and OGA experienced longer survival compared with men. Age, education, cigarette smoking, alcohol intake, gastroesophageal reflux disease, and nonsteroidal anti-inflammatory drug use did not consistently predict survival. CONCLUSIONS: Predictors of lengthened esophageal and gastric cancer survival included higher income (except in OGA), overweight (among EA and OGA patients), and female sex (among ES and OGA patients).

Adenocarcinoma↗
PubMed2005

Idiopathic myointimal hyperplasia of mesenteric veins: a rare mimic of idiopathic inflammatory bowel disease.

Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood disease that occurs in the rectosigmoid colon of predominantly young, previously healthy male patients. IMHMV typically requires segmental resection due to complications after a relatively protracted clinical course. This disease presents a challenging diagnostic dilemma for the clinician because it is initially often confused with chronic idiopathic inflammatory bowel disease. We report a case of IMHMV, illustrate endoscopic and histopathologic features, and review key characteristics of this rare entity.

Adult↗
PubMed2005

Diverticulosis coli: update on a "Western" disease.

Diverticular disease affects upwards of 50% of the population over the age of 60 years in Western countries and is becoming more common as the population ages. Studies from the 1970s and 1980s related its occurrence to the use of low-fiber diets and to the prolonged colonic transit time and increased intraluminal pressure associated with low-volume stools. Pulsion diverticula (pseudodiverticula) emerge through the thickened circular layer of the muscularis propria of the left colon at points of penetration of the vasa recta that supply the submucosa and mucosa. Complications of diverticular disease such as hemorrhage, diverticulitis, peridiverticular abscess, fistula, and perforation are well recognized. More recently, attention has been drawn to the polypoid prolapsing mucosal folds that may develop as the affected segment of bowel (usually the sigmoid) becomes shorter and to changes in the mucosa surrounding the diverticula and in the bowel wall that may result in confusion with ulcerative colitis or Crohn disease (sigmoid colitis-associated diverticulosis [SCAD]). Distinguishing SCAD from these entities is extremely important, and pathologists should be aware of the possibility of overdiagnosing chronic inflammatory bowel disease in biopsies or resection specimens of sigmoid colon with diverticular disease.

Colitis, Ulcerative↗
PubMed2005

Importance of small (< or = 20-mm) enhancing lesions seen only during the hepatic arterial phase at MR imaging of the cirrhotic liver: evaluation and comparison with whole explanted liver.

PURPOSE: To retrospectively assess the importance and imaging appearance of small (< or = 20 mm in diameter) hepatic arterial phase-enhancing (HAPE) lesions that are occult during portal and/or equilibrium phases and at unenhanced T1- and T2-weighted magnetic resonance (MR) imaging and to determine the gross pathologic diagnosis with whole-liver explant comparison. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board and compliant with HIPPA. Forty-six patients with cirrhosis who underwent MR imaging and transplantation within 90 days were evaluated with breath-hold T2-weighted and volumetric three-dimensional gadolinium-enhanced gradient-echo MR imaging in the hepatic arterial, portal venous, and equilibrium phases at 1.5 T. Three readers, who were blinded to the pathologic results, retrospectively reviewed the MR images in consensus for small HAPE nodules that were occult at T2-weighted and portal and/or equilibrium phase MR imaging. Only patients with nodules that enhanced during the arterial phase were included in the final study group, which included 16 patients (12 men and four women) aged 18-66 years (median age, 51.5 years). Explanted livers were serially sliced into 5-8-mm-thick sections to evaluate dysplastic nodules and hepatocellular carcinomas (HCCs). The Fisher exact test was performed to determine whether there was a relationship between HCC and the presence of a neoplastic HAPE-only lesion. The Mann-Whitney test was used to determine if patients with at least one neoplastic HAPE-only lesion had a larger number of non-HAPE-only lesions. RESULTS: The 16 patients had 45 HAPE-only lesions; three (7%) of which were neoplastic, including one overt HCC, one HCC arising in a dysplastic nodule, and one dysplastic nodule. None of the remaining 42 HAPE-only lesions (93%) had correlative pathologic findings. All three neoplastic lesions seen only during the arterial phase were found in eight patients with concomitant HCC, who also had an additional 13 pathologically proved nonneoplastic HAPE-only lesions. In eight patients without HCC, none of the HAPE-only lesions were neoplastic. A concomitant non-HAPE-only neoplastic lesion was not a significant (P = .2) predictor for the presence of at least one neoplastic HAPE-only lesion. There was a preliminary but insignificant (P = .13) indication that the number of non-HAPE-only lesions tends to be higher in patients with neoplastic HAPE-only lesions. CONCLUSION: The majority (93%) of HAPE-only lesions that are occult at T2-weighted and portal and/or equilibrium phase MR imaging are nonneoplastic, even in patients with pathologically proved HCC.

Adolescent↗
PubMed2004

Nomenclature of the finer branches of the biliary tree: canals, ductules, and ductular reactions in human livers.

The work of liver stem cell biologists, largely carried out in rodent models, has now started to manifest in human investigations and applications. We can now recognize complex regenerative processes in tissue specimens that had only been suspected for decades, but we also struggle to describe what we see in human tissues in a way that takes into account the findings from the animal investigations, using a language derived from species not, in fact, so much like our own. This international group of liver pathologists and hepatologists, most of whom are actively engaged in both clinical work and scientific research, seeks to arrive at a consensus on nomenclature for normal human livers and human reactive lesions that can facilitate more rapid advancement of our field.

Biliary Tract↗
PubMed2004

Fractured colon: an endoscopically distinctive lesion associated with colonic perforation following colonoscopy in patients with collagenous colitis.

BACKGROUND: Collagenous colitis is characterized by collagen deposition in the superficial colonic mucosa, beneath the surface epithelium, resulting in chronic nonbloody diarrhea of variable severity. The mucosa generally appears endoscopically normal. METHODS: We report the occurrence of distinctive linear mucosal tears, unassociated with trauma, in 4 patients during diagnostic colonoscopy. The patients' tissue specimens were examined histologically, and clinical courses were recorded. OBSERVATIONS: Recognition of linear "fractures" was followed in 3 patients by colonic perforation. One patient required colectomy. Severe collagenous colitis was present in all. The resection specimen contained shallow linear ulcers overlying fibrotic submucosa, with pneumatosis and acute peritonitis. CONCLUSIONS: We theorize that the stiffness of the colon in areas of collagenous colitis with submucosal fibrosis makes it susceptible to linear "fractures" during colonoscopic air insufflation with subsequent transmural air dissection. We urge extreme caution if this lesion is recognized at colonoscopy and recommend aborting the examination and obtaining plain radiographs to detect free intraperitoneal air.

Aged↗
PubMed2004

Characterization of "Candidatus piscichlamydia salmonis" (order Chlamydiales), a chlamydia-like bacterium associated with epitheliocystis in farmed Atlantic salmon (Salmo salar).

To characterize intracellular gram-negative bacteria associated with epitheliocystis in farmed Atlantic salmon (Salmo salar), gills with proliferative lesions were collected for histopathology, conventional transmission and immunoelectron microscopy, in situ hybridization, and DNA extraction during epitheliocystis outbreaks in Ireland and Norway in 1999 and 2000, respectively, and compared by ultrastructure and immunoreactivity to nonproliferative gills from Ireland archived in 1995. Genomic DNA from proliferative gills was used to amplify 16S ribosomal DNA (rDNA) for molecular phylogenetic analyses. Epitheliocystis inclusions from proliferative gills possessed variably elongate reticulate bodies, examples of binary fission, and vacuolated and nonvacuolated intermediate bodies, whereas inclusions in nonproliferative gills had typical chlamydial developmental stages plus distinctive head-and-tail cells. Immunogold processing using anti-chlamydial lipopolysaccharide antibody labeled reticulate bodies from proliferative and nonproliferative gills. 16S rDNA amplified directly from Irish (1999) and Norwegian (2000) gill samples demonstrated 99% nucleotide identity, and riboprobes transcribed from cloned near-full-length 16S rDNA amplicons from Norwegian gills hybridized with inclusions in proliferative lesions from Irish (1999) and Norwegian (2000) sections. A 1,487-bp consensus 16S rRNA gene sequence representing the chlamydia-like bacterium (CLB) from proliferative gills had the highest percent nucleotide identity with endosymbionts of Acanthamoeba spp. (order Chlamydiales). Molecular phylogenetic relationships inferred from 16S rRNA gene sequences using distance and parsimony indicated that the CLB from proliferative gills branched with members of the order Chlamydiales. "Candidatus Piscichlamydia salmonis" is proposed for the CLB associated with epitheliocystis from proliferative gills of Atlantic salmon, which exhibits developmental stages different from those identified in nonproliferative gills.

Animals↗
PubMed2004

Nonsteroidal anti-inflammatory drug use associated with reduced incidence of adenocarcinomas of the esophagus and gastric cardia that overexpress cyclin D1: a population-based study.

This study was undertaken to determine whether selected risk factors for esophageal and gastric cancer are associated with tumors that overexpress cyclin D1. Archived tumor tissue was available for 630 esophageal and gastric cancer patients who participated in a population-based case-control study. Patients were categorized into case groups based on whether protein overexpression of the cyclin D1 gene, as assessed by immunohistochemistry, was present (cyclin D1+, n = 285) or not (cyclin D1-, n = 345) in the tumor. The distribution of risk factors in each of these case groups was then compared with the distribution among the 695 controls. Multivariate-adjusted odds ratios (OR) for esophageal adenocarcinoma were reduced in relation to use of aspirin and other nonsteroidal anti-inflammatory drug (NSAID) use but only among patients with cyclin D1+ tumors (0.45, 95% confidence interval [CI] = 0.26, 0.79) and not among those with cyclin D1- tumors (1.12, 95% CI = 0.67, 1.86). A similar pattern was observed for gastric cardia adenocarcinomas. In contrast, ORs for esophageal squamous cell carcinoma and noncardia gastric adenocarcinomas in relation to NSAID use were reduced, regardless of cyclin D1 status. ORs did not vary with cyclin D1 status in relation to alcohol, body size, or cigarette smoking, with the following exception; for noncardia gastric adenocarcinomas the cyclin D1- tumors showed a 2-fold elevation in the OR with ever smoking. These data suggest that the reduction in risk associated with NSAID use may be restricted to those esophageal and gastric cardia adenocarcinomas that overexpress cyclin D1.

Adenocarcinoma↗
PubMed2003

Population attributable risks of esophageal and gastric cancers.

BACKGROUND: Several risk factors have been identified for esophageal adenocarcinoma, gastric cardia adenocarcinoma, esophageal squamous cell carcinoma, and noncardia gastric adenocarcinoma, but no study has comprehensively examined their contributions to the cancer burden in the general population. Herein, we estimate the population attributable risks (PARs) for various risk factors observed in a multicenter population-based case-control study. METHODS: We calculated PARs by using 293 patients with esophageal adenocarcinoma, 261 with gastric cardia adenocarcinoma, 221 with esophageal squamous cell carcinoma, 368 with noncardia gastric adenocarcinoma, and 695 control subjects. We included smoking for all four tumor types and Helicobacter pylori infection for noncardia gastric adenocarcinoma as established causal risk factors as well as several other factors for which causality is under evaluation. RESULTS: Ever smoking, body mass index above the lowest quartile, history of gastroesophageal reflux, and low fruit and vegetable consumption accounted for 39.7% (95% confidence interval [CI] = 25.6% to 55.8%), 41.1% (95% CI = 23.8% to 60.9%), 29.7% (95% CI = 19.5% to 42.3%), and 15.3% (95% CI = 5.8% to 34.6%) of esophageal adenocarcinomas, respectively, with a combined PAR of 78.7% (95% CI = 66.5% to 87.3%). Ever smoking and body mass index above the lowest quartile were responsible for 45.2% (95% CI = 31.3% to 59.9%) and 19.2% (95% CI = 4.9% to 52.0%) of gastric cardia adenocarcinomas, respectively, with a combined PAR of 56.2% (95% CI = 38.1% to 72.8%). Ever smoking, alcohol consumption, and low fruit and vegetable consumption accounted for 56.9% (95% CI = 36.6% to 75.1%), 72.4% (95% CI = 53.3% to 85.8%), and 28.7% (95% CI = 11.1% to 56.5%) of esophageal squamous cell carcinomas, respectively, with a combined PAR of 89.4% (95% CI = 79.1% to 95.0%). Ever smoking, history of gastric ulcers, nitrite intake above the lowest quartile, and H. pylori infection were responsible for 18.3% (95% CI = 6.5% to 41.8%), 9.7% (95% CI = 5.4% to 16.8%), 40.7% (95% CI = 23.4% to 60.7%), and 10.4% (95% CI = 0.3% to 79.6%) of noncardia gastric adenocarcinomas, respectively, with a combined PAR of 59.0% (95% CI = 16.2% to 91.4%). CONCLUSION: In this population, a few known risk factors account for a majority of esophageal and gastric cancers. These results suggest that the incidence of these cancers may be decreased by reducing the prevalence of smoking, gastroesophageal reflux, and being overweight and by increasing the consumption of fruits and vegetables.

Adenocarcinoma↗