CIRRHOSIS of the liver, usually as a complication of alcoholism, is the third most frequent cause of death among those 25 to 64 years of age in urban areas such as New York City.1 This alcohol-indu...

Biochemical and Molecular Basis of Alcohol-Induced Injury to Liver and Other Tissues

Specific antibodies to collagen type IV, laminin, and fibronectin were used to localise these proteins by indirect immunofluorescence in frozen sections of normal and fibrotic liver. In normal livers distinct staining was found in basement membranes of blood and lymph vessels, of bile ducts and ductules and around nerve axons. Positive reactions for type IV collagen and fibronectin were also observed in the perisinusoidal space, while hepatocytes and most of the interstitial matrix of portal fields remained unstained. Liver specimens obtained from patients with alcoholic liver disease (fatty liver, hepatitis or cirrhosis) and chronic active hepatitis showed a more intense reaction with the antibodies in the perisnusoidal space including now distinct staining for laminin. These patterns were particularly prominent at borders between fibrotic septa and remnants of parenchyma or pseudolobules. Strong reactions were also found for type IV collagen and fibronectin in the periportal interstitium and in large fibrotic areas. The findings support previous electron-microscopical and chemical evidence for increased basement membrane production in human liver fibrosis and demonstrate that this may involve different proteins and occur at different anatomical sites.

https://gut.bmj.com/content/gutjnl/21/1/63.full.pdf

Distribution of basement membrane proteins in normal and fibrotic human liver: collagen type IV, laminin, and fibronectin.

We measured iliac bone formation rates on all surfaces after double tetracycline labeling, serum levels of type 1 procollagen carboxy-terminal extension peptide (pColl-I-C), and serum levels of total alkaline phosphatase activity (TAP) in four normal subjects and in 44 patients with various forms of metabolic bone disease. In three patients with enzymatic evidence of liver disease both biochemical serum markers were disproportionately raised. In a patient with idiopathic axial osteosclerosis serum pColl-I-C was selectively increased by more than ten-fold. In the remaining 44 subjects pColl-I-C and TAP levels correlated significantly with each other (r = 0.70) and both showed the same directional changes and broadly similar correlations with iliac bone formation rate expressed in different ways. In general, pColl-I-C levels correlated better with cancellous bone formation rates and TAP levels cortical bone formation rates. There was a modest improvement in prediction of bone formation rate with multiple regression using both markers. In 15 patients with typical uncomplicated postmenopausal osteoporosis, neither biochemical marker, singly or jointly, correlated significantly with any expression of bone formation rate. Disadvantages to the use of pColl-I-C as a marker include a significant contribution to the serum level from type 1 collagen biosynthesis in tissues other than bone, and (probably) variable metabolic clearance. For both biochemical markers the most consistently high correlations (r = 0.77-0.79) were found with total bone formation rate for the entire biopsy core volume, which is the best estimate available from a biopsy of formation rate at the bone organ level of organization in vivo. The core volume as a referent also allows the amount of bone formed on cortical, endocortical, and cancellous surfaces to be compared. Measurement of serum pColl-I-C levels merits further study as a noninvasive index of bone metabolism. Differences between normal and abnormal subjects in the relationships between a variety of biochemical markers and a variety of histologic indices have the potential for providing insight into the pathogenesis of osteoporosis.

Procollagen type I carboxy-terminal extension peptide in serum as a marker of collagen biosynthesis in bone. Correlation with Iliac bone formation rates and comparison with total alkaline phosphatase.

It is the purpose of this review to show that the liver endothelial cells make up an important part of the hepatic reticuloendothelial system in that they are specialized in receptor-mediated endocytosis of a number of macromolecules which are taken up only to a minor extent, or not at all, by other types of liver cells.

Scavenger functions of the liver endothelial cell.

Schistosomiasis mansoni is a chronic helminthic disease that affects about 100 million people in the tropics. The worms have a life span of 5 to 10 years, and they live in the mesenteric veins of the host. Lightly infected individuals are asymptomatic or manifest mild intestinal symptoms. Heavily infected individuals often develop severe morbidity with hepatosplenomegaly, sometimes with a fatal outcome. Morbidity is attributed to the strong humoral and T-cell-mediated host immune responses developed to a variety of parasite antigens and expressed as tissue inflammations. The immunopathology includes dermatitis, immune complex-mediated kidney disease, and, chiefly, T-cell-mediated granuloma formation and fibrosis around disseminated parasite eggs. This review describes the mechanisms of induction and expression of immunopathology in infected persons and experimental animals. Immunoregulatory mechanisms that modulate the enhanced immune responses and may ameliorate excessive morbidity are discussed.

Immunopathology of Schistosoma mansoni infection.

. A sensitive and specific radioimmunoassay was developed for the precursor-specific peptide segment located at the amino end of bovine type III procollagen. Human material showed high cross-reactivity in this assay. Two forms of human procollagen peptides were detected in body fluids. The larger peptide (45K) was found in serum and ascites, and resembled the whole precursor-specific segment which is presumably released from human type III procollagen by a single enzymatic cleavage. The smaller peptide (10K) was found mainly in urine indicating that further degradation of circulating procollagen peptides is required prior to their passage through the kidney.



Compared to peptide concentrations in normal human serum, two to twenty-fold increases were observed in all patients with alcoholic liver disease, in fifteen of seventeen patients with acute hepatitis, and in ten of fourteen patients with chronic active hepatitis. Much higher levels were detected in ascites fluid. Patients with rheumatoid arthritis and other diseases showed far smaller elevations of the serum peptide. In alcoholic liver disease peptide levels correlated well with inflammation and necrosis observed in liver biopsies, but not with other laboratory parameters.

Ling Vargas

Papers

Radioimmunoassay for type III procollagen peptide and its application to human liver disease.