Epidemiology and clinical manifestations of unique Chlamydia trachomatis isolates that occupy nonfusogenic inclusions.

Unique Chlamydia trachomatis strains characterized by multiple nonfusing inclusions were recently described. These strains lack evidence of the protein IncA in the inclusion membrane and have mutations in the incA gene. This study evaluated the epidemiology and clinical manifestations of patients infected with nonfusing mutant strains (case patients) and compared them with patients infected with wild-type fusing strains (control subjects).

Endoscopic therapy of acute diverticular hemorrhage.

Objective: Diverticular hemorrhage is a common cause of lower GI bleeding and can be diagnosed acutely during colonoscopy. However, whether early diagnosis leads to effective intervention remains controversial. The aim of this study was to evaluate whether urgent colonoscopic therapy is effective as acute and long term treatment for diverticular bleeding with stigmata of hemorrhage.

Growth and development of tetracycline-resistant Chlamydia suis.

Tetracycline (TET) is a front-line antibiotic for the treatment of chlamydial infections in both humans and animals, and the emergence of TET-resistant (Tet(r)) Chlamydia is of significant clinical importance. Recently, several Tet(r) chlamydial strains have been isolated from swine (Sus scrofa) raised in production facilities in Nebraska. Here, the intracellular development of two Tet(r) strains, R19 and R27, is characterized through the use of tissue culture and immunofluorescence.

Comparison of patients' experiences during imaging tests of the colon.

Background: Physical discomfort, anxiety, embarrassment, and other aspects of patient experience impact on future compliance for colonic imaging tests. Therefore, a prospective study was performed comparing patient experiences during air contrast barium enema (ACBE), flexible sigmoidoscopy, and colonoscopy.

Methods: Immediately after each procedure, patients completed a questionnaire assessing pretest anxiety, difficulty with preparation, pain, cramping, bloating, overall discomfort, loss of dignity, willingness to repeat the test, and overall satisfaction.

Terlipressin for acute esophageal variceal hemorrhage.

Background: Terlipressin (triglycyl lysine vasopressin) is a synthetic analogue of vasopressin, which has been used in the treatment of acute variceal hemorrhage. In contrast to vasopressin, terlipressin can be administered as intermittent injections instead of continuous intravenous infusion and it has a safer adverse reactions profile. However, its effectiveness remains uncertain.

The cell and molecular biology of hepatic fibrogenesis. Clinical and therapeutic implications.

Much has been learned in the past 2 decades about the cellular and molecular mechanisms underlying hepatic fibrogenesis and about potential therapeutic approaches in patients with liver disease. The central event in fibrogenesis seems to be the activation of hepatic stellate cells. Stellate cell activation is characterized by several important features, including enhanced matrix synthesis and a prominent contractile phenotype, processes that probably contribute to the physical distortion and dysfunction of the liver in advanced disease.

A secondary structure motif predictive of protein localization to the chlamydial inclusion membrane.

Chlamydiae are obligate intracellular pathogens that spend their entire growth phase sequestered in a membrane-bound vacuole called an inclusion. A set of chlamydial proteins, labelled Inc proteins, has been identified in the inclusion membrane (IM). The predicted IncA, IncB and IncC amino acid sequences share very limited similarity, but a common hydrophobicity motif is present within each Inc protein.

Provocative angiography in obscure gastrointestinal bleeding.

Obscure gastrointestinal (GI) bleeding is relatively common but difficult to manage. By definition, diagnosis of a specific etiology is particularly challenging. We report the diagnostic use of provocative angiography in a patient with recurrent obscure GI bleeding.

Provocative angiography in patients with gastrointestinal hemorrhage of obscure origin.

Objective: A standard diagnostic evaluation including upper and/or lower endoscopy, tagged red blood cell scintigraphy, and visceral angiography identifies the source of GI bleeding in the majority of patients who present with acute GI hemorrhage. However, in a small group of patients the source of bleeding remains obscure; this form of GI hemorrhage is uncommon but represents a considerable diagnostic challenge. Some investigators have advocated provocation of bleeding with vasodilators, anticoagulants, and/or thrombolytics in association with tagged red blood cell scans or angiography.

Preliminary evaluation of 15-[18F]fluoro-3-oxa-pentadecanoate as a PET tracer of hepatic fatty acid oxidation.

Unlabelled: The liver is an important site of fat oxidation. Abnormalities of hepatic mitochondrial fatty acid oxidation (HMFAO) are associated with obesity, type II diabetes, alcoholic hepatitis, and nonalcoholic steatohepatitis. Noninvasive assessment of HMFAO by PET has been impeded by the lack of a specific radiotracer.

Ischemic hepatitis: clinical presentation and pathogenesis.

Background: The pathophysiology of ischemic hepatitis, otherwise known as "shock liver," is poorly understood, although it is believed to be the result of a reduction in systemic blood flow as typically occurs in shock. The aim of this study was to investigate the importance of this phenomenon as well as other clinical features in patients with ischemic hepatitis.

Methods: We identified a cohort of 31 patients (case group) who met the most commonly accepted definition of ischemic hepatitis (an acute reversible elevation in either the serum alanine or aspartate aminotransferase level of at least 20 times the upper limit of normal, excluding known causes of acute hepatitis or hepatocellular injury, in an appropriate clinical setting).

Expression of the integrin alpha8beta1 during pulmonary and hepatic fibrosis.

The fibrotic response after diverse forms of injury is characterized by the accumulation of extracellular matrix proteins, proliferation of myofibroblast-like cells, and organ contraction. Myofibroblasts are key effector cells in the development of the fibrotic response. They contribute to fibrosis through both increased cell number (proliferation) and enhanced matrix synthesis.

An immortalized rat liver stellate cell line (HSC-T6): a new cell model for the study of retinoid metabolism in vitro.

Hepatocytes and hepatic stellate cells play important roles in retinoid storage and metabolism. Hepatocytes process postprandial retinyl esters and are responsible for secretion of retinol bound to retinol-binding protein (RBP) to maintain plasma retinol levels. Stellate cells are the body's major cellular storage sites for retinoid.

A prospective multicenter evaluation of new fecal occult blood tests in patients undergoing colonoscopy.

Objective: Guaiac-based fecal occult blood (FOB) tests, in particular, Hemoccult II (HO), are commonly used to detect colorectal neoplasia. Because the sensitivity and specificity of these tests are critical to cost-effective screening programs, we aimed to investigate the improved performance characteristics of new FOB tests for known colonic lesions.

Methods: Nine centers worldwide performed FOB testing with guaiac-based tests (Hemoccult II [HO] and Hemoccult II SENSA [SENSA]) and immunochemical tests (HemeSelect [HS] and FlexSure OBT [FS]) on 554 patients referred for colonoscopy for predetermined indications.

Hepatic fibrogenesis and hepatitis C.

Hepatitis C virus (HCV) infection is currently the most common cause of fibrosing liver disease and represents a major clinical challenge. In patients with HCV infection, inflammation and injury lead to fibrosis and cirrhosis in a significant proportion of patients; cirrhosis in turn has multiple clinical sequelae. Therefore, understanding the pathological basis of fibrogenesis in hepatitis C infection is critical.

Gene transfer of the neuronal NO synthase isoform to cirrhotic rat liver ameliorates portal hypertension.

Reduced production of nitric oxide (NO) in the cirrhotic liver results from a defect in hepatic endothelial cell nitric oxide synthase (ecNOS) and appears to contribute to the high intrahepatic resistance and portal hypertension typical of cirrhosis. Therefore, we postulated that targeting a heterologous NOS isoform to sinusoidal endothelial cells or other perisinusoidal cells, such as hepatic stellate cells, would counter the defect in NO production and reduce resistance to blood flow. Recombinant adenovirus (Ad) carrying the neuronal NOS gene (nNOS) targeted liver sinusoidal endothelial cells, stellate cells, and hepatocytes more efficiently than the corresponding cells in cirrhotic livers, but transduction rates were substantial even in cirrhotic animals.

Identification of an antigen localized to an apparent septum within dividing chlamydiae.

The process of chlamydial cell division has not been thoroughly investigated. The lack of detectable peptidoglycan and the absence of an FtsZ homolog within chlamydiae suggest an unusual mechanism for the division process. Our laboratory has identified an antigen (SEP antigen) localized to a ring-like structure at the apparent septum within dividing chlamydial reticulate bodies (RB).

Hepatic tissue endothelin-1 levels in chronic liver disease correlate with disease severity and ascites.

Objectives: Plasma endothelin-1 (ET-1) levels are increased in patients with cirrhosis and ET-1 production is increased in the liver itself during experimental injury. These data suggest a possible role for this vasoactive peptide in intrahepatic microcirculatory changes that contribute to the pathogenesis of portal hypertension in cirrhosis. Therefore the aims of this study were to determine whether ET-1 levels were abnormal in the livers of patients with cirrhosis and to investigate possible clinical correlates of altered hepatic ET-1 in cirrhosis.