Daniel Stiel

Osteoporosis and skeletal fractures in chronic liver disease.

In order to determine the prevalence and severity of hepatic osteodystrophy by non-invasive means we compared 115 consecutive ambulant patients with histologically proven chronic liver disease to 113 age and sex matched control subjects. Methods used included the assessment of fracture prevalence rates, spinal radiography, and measurements of bone mineral density in the spine and the forearm. Spinal and peripheral fractures were more prevalent in the patients than in the control subjects (p less than 0.03 and p less than 0.01 respectively). The type of the underlying liver disease did not significantly affect the fracture prevalence rates, but alcoholic patients sustained more peripheral fractures than patients with other hepatic disorders (p less than 0.05). The bone mineral densities of the spines and the forearms were significantly reduced in male patients of all age groups and in female patients aged 60 years or more (p less than 0.001 for men and p less than 0.01 for women for both measurements). The prevalence rates of spinal and forearm osteoporosis were twice as high among patients with liver disease than in control subjects regardless of the definitions used. The presence of cirrhosis and hypogonadism were major risk factors for development of both spinal (Beta coef = 0.190 and 0.176; SE = 0.079 and 0.086 respectively) and forearm osteoporosis (Beta coef = 0.20 and 0.29; SE = 0.073 and 0.80 respectively). Spinal bone density was the predominant determinant of spinal fractures (Beta coef = -0.007; SE = 0.001), while hypogonadism (Beta coef = 0.363; SE = 0.075) and cirrhosis (Beta coef = 0.185; SE = 0.068) were the major predictors of peripheral fractures. The concentrations of serum calcium and serum vitamin D metabolites and the use of corticosteroids were apparently without effect on the prevalence of skeletal fractures or bone density.

Hepatic osteodystrophy: Static and dynamic bone histomorphometry and serum bone Gla-protein in 80 patients with chronic liver disease

To study the pathogenesis of osteoporosis in patients with chronic liver disease, we performed dynamic bone histomorphometry and measured serum bone Gla-protein in 80 patients with various types of chronic liver disease. These results were compared with results obtained in 40 healthy controls. Mean trabecular bone volume and mean trabecular thickness were significantly reduced in both men and women with chronic liver disease (p less than 0.001 for both measurements in men and p less than 0.01 for both measurements in women). Osteoporosis as defined by histologic parameters was present in 17 (21%) patients with no significant differences in prevalence rates among the various hepatic disorders. No patient had histologic evidence of osteomalacia, although mineralization lag times were prolonged (p less than 0.01 for men and women). Bone formation rates were significantly reduced in 46 (57%) patients, and unlike the static measurements, were related to the type and severity of the underlying liver disease. Patients with alcoholic liver disease, hemochromatosis, and cholestatic liver disease had lower bone turnover rates and osteoblastic surfaces (p less than 0.001 and p less than 0.05, respectively) than patients with chronic active hepatitis. Furthermore, the presence of hepatic cirrhosis was associated with diminished bone formation and lower osteoblast surfaces. Serum bone Gla-protein levels were significantly correlated with bone formation rates and osteoblast surfaces (r = 0.585 and r = 0.434, respectively). A reduction in osteoblast surfaces has not previously been demonstrated in liver disease. This reduction and the associated impairment of osteoblastic activity may contribute to the pathogenesis of osteoporosis and can be assessed by the measurement of serum bone Gla-protein.

Osteoporosis in Hemochromatosis: Iron Excess, Gonadal Deficiency, or Other Factors?

STUDY OBJECTIVE To define the prevalence, severity, type and pathogenesis of osteopenia in idiopathic hemochromatosis. DESIGN Prospective study conducted over 18 months. SETTING Tertiary care center. SUBJECTS Twenty-two men with idiopathic hemochromatosis and 20 age-matched controls. There were 5 hypogonadal patients, 9 eugonadal nonvenesected patients, and 8 eugonadal venesected patients. MEASUREMENTS AND MAIN RESULTS All patients and controls were evaluated by spinal radiography, spinal and forearm bone mineral density estimations, dynamic skeletal histomorphometry, and serum biochemistry. Ten patients (45%; 95% CI, 24% to 68%) had osteoporosis as defined by spinal and forearm bone density measurements. Trabecular bone volumes were significantly reduced in the patients (the difference in means between patients and age-matched controls was 3.9%; CI, 1.3% to 6.7%). No patient had osteomalacia. Hypogonadal men had lower bone mass measurements than eugonadal men (radial bone density: beta coefficient = -20.5; CI, -29.2 to -11.8; trabecular bone volume: beta coefficient = -7.1; CI, -10.8 to -3.3). Osteoid and osteoblastic surfaces and bone formation rates were significantly greater in the eugonadal venesected compared with the eugonadal nonvenesected persons (P less than 0.05 for all measurements). CONCLUSIONS A significant decrease in bone density is seen in idiopathic hemochromatosis, particularly when hypogonadism is present. Low serum free-testosterone concentrations rather than the calciotrophic hormones determine bone mass in this condition.

THE EFFECT OF ENTEROHEMORRHAGIC ESCHERICHIA-COLI O157-H7 ON INTESTINAL STRUCTURE AND SOLUTE TRANSPORT IN RABBITS

BACKGROUND The effect of enterohemorrhagic Escherichia coli O157:H7 infection on intestinal morphology and solute transport was examined. METHODS New Zealand white rabbits, aged 10 days, were infected with E. coli strain EDL933 (O157:H7 containing the 60-megadalton plasmid-encoding adhesion factors VT1 and VT2) and compared with controls. Small and large intestinal histology and solute transport were studied 5 days after inoculation. Ion transport in the distal colon was also examined in animals infected with different strains encoding a combination of pathogenic factors. RESULTS Infection with EDL933 induced diarrhea and mucosal disease in the colon, inhibited colonic Na+ absorption, and stimulated of Cl- secretion, but had no impact on the small intestine. Infection with strains A7785-C3A (O157:H7, plasmid-, VT1+, VT2+) and 85-170 (O157:H7, plasmid+, VT-) induced similar transport changes to EDL933. C600/1 (E. coli K-12, plasmid+, VT1+) decreased Na+ and Cl- absorption only. CONCLUSIONS Abnormalities of colonic structure and ion transport could account for diarrhea production, but pathogenic factors other than the 60-megadalton plasmid-encoding adhesion factor and verotoxins appear to be involved in enterohemorrhagic E. coli infection.

Modulation of host response to Escherichia coll 0157:H7 infection by anti-CD18 antibody in rabbits

BACKGROUND/AIMS Escherichia coli O157:H7 infection induces diarrhea, severe colitis, and colonic electrolyte transport abnormalities characterized by decreased Na absorption and Cl secretion. The aim of this study was to examine the role of the host inflammatory response in inducing distal colonic transport changes during infection with E. coli O157:H7. METHODS New Zealand white rabbits aged 10 days were infected with E. coli O157:H7 strain EDL933 (plasmid+, verotoxin 1+, verotoxin 2+). Studies were performed daily from day 1 to day 5 postinfection and compared with uninfected controls (10 days old). Distal colonic ion transport was studied in vitro under short-circuited conditions in Ussing chambers, and tissue inflammation was assessed by mucosal myeloperoxidase activities and mucosal neutrophil (polymorphonuclear neutrophil [PMN]) counts. In a second study, PMN infiltration was inhibited by an anti-CD18 (leukocyte adhesion molecule) monoclonal antibody, IB4, and histology and transport were studied on day 5 postinfection. RESULTS Infection with O157:H7 induced diarrhea and inhibition of Na absorption by day 3. CI secretion occurred on day 5, coincident with tissue infiltration with PMN. Pretreatment with IB4 prevented histological damage and tissue infiltration with PMN, and it inhibited the transport abnormalities induced by infection alone. CONCLUSIONS Infection with O157:H7 reduces Na absorption and stimulates Cl secretion in the distal colon. Disruption of the epithelium and changes in colonic electrolyte transport during enterohemorrhagic E. coli are mediated by the host inflammatory response.

Protective effect of enprostil against aspirin-induced gastroduodenal mucosal injury in man: Comparison with cimentidine and sucralfate

A single-blind endoscopic study was undertaken to test the relative efficacy of enprostil, a synthetic analogue of prostaglandin E2, cimetidine, and sucralfate in the prevention of aspirin-induced gastroduodenal mucosal injury. Fifty healthy, non-smoking male volunteers completed the study after having been randomly assigned to receive two weeks of therapy with one of the following regimens: enprostil 35 micrograms twice daily; enprostil 35 micrograms in the morning; cimetidine 200 mg three times daily and 400 mg at night; sucralfate 1 g four times daily; or placebo. In the second week, aspirin (900 mg three times daily) was also administered. Endoscopies were performed before and after the aspirin phase of the study, and lesions (mucosal erosions plus submucosal hemorrhages) were counted in the stomach and duodenal bulb. All treatments were superior to placebo (p less than 0.05). The mean number of lesions in the 70-micrograms enprostil group (8.5) was significantly less than in the 35-micrograms enprostil group, (11.1), the sucralfate group (12.4), or the placebo group (16.0); the benefit over cimetidine (10.1), however, was not statistically significant. The protective effect of enprostil was greatest in the antrum, the site of maximal mucosal injury. Gastrointestinal side effects were reported in all groups, though abdominal pain and dyspepsia were noted more frequently in those taking enprostil.

Does iron affect osteoblast function? Studies in vitro and in patients with chronic liver disease

SummaryIn order to study the role of trace elements as potential osteoblastic toxins, we measured bone aluminum, copper, and iron in 106 ambulant patients with histologically proven liver disease. We used analytical and histochemical methods and we correlated our results with serum biochemistry, forearm and spinal bone density, and dynamic bone histomorphometry. Patients with chronic liver disease had higher iron-stained perimeters than control subjects (P<0.001). However, the mean ironstained perimeter was no greater than 5% of the total mineralized bone perimeter and did not correlate significantly with either the osteoblast perimeters or bone formation rates. The mean concentration of bone iron were 2.5 times (P<0.01) greater in the patients than in the controls although 80% of the patients fell within the normal range. There was a weak negative correlation between bone iron and the osteoblast perimeters (R=−0.18,P=ns) and between bone iron and bone formation (R=−0.30,P<0.05). There were 57 patients (56% of the total) with diminished bone formation, but only 16 had elevated bone iron concentrations. In a regression analysis, age, hypogonadism, and serum albumin concentrations were the most important predictors of osteoblast perimeters and bone formation rates.In vitro experiments using rat osteoblast-like osteosarcoma cells showed that an iron concentration of 400 μmol/liter was required to diminish cellular proliferation and function. Iron concentrations are elevated in the bones of patients with chronic liver disease. However, there is at present insufficient evidence that this metal is responsible for the osteoblast dysfunction seen in these patients. Bone aluminum and bone copper concentrations were within the relevant reference ranges in all patients.

Fibrolamellar Carcinoma as a Cause of Bile Duct Obstruction

&NA; Obstructive jaundice due to growth within bile ducts of hepatocellular carcinoma is uncommon and usually a manifestation of advanced, lethal tumour. We report a case of fibrolamellar carcinoma of the liver presenting with obstructive jaundice, caused by tumorous permeation of the left hepatic duct with migration of tumour fragments into the common bile duct. Immunocytochemical and ultrastructural features are described. Two and a half years after complete surgical resection the patient is free of tumour. The importance of accurate diagnosis of such tumours is emphasized.