Ruy Pérez Tamayo

Colchicine in the Treatment of Cirrhosis of the Liver

There is preliminary evidence that colchicine, an inhibitor of collagen synthesis, may be beneficial in the treatment of cirrhosis of the liver. To evaluate the use of colchicine (1 mg per day, five days per week) in the treatment of hepatic cirrhosis, we performed a randomized, double-blind, placebo-controlled trial in which 100 patients were followed for up to 14 years. Forty-five patients had alcoholic cirrhosis, 41 had posthepatitic cirrhosis, and the remaining 14 had cirrhosis with various other causes. Histologic studies were available for 92 percent of patients. Seventy-three patients were in Child-Turcotte class A, 26 were in class B, and one was in class C. Fifty-four patients received colchicine, and 46 received placebo. The overall survival in the colchicine group was markedly better than in the placebo group (median survival, 11 and 3.5 years, respectively; P less than 0.001). The cumulative 5-year survival rates were 75 percent in the colchicine group and 34 percent in the placebo group; the corresponding 10-year survival rates were 56 percent and 20 percent. Among the 30 patients treated with colchicine who underwent repeated liver biopsies, histologic improvement was seen in 9; the liver appeared normal in 2, and 7 had minimal portal fibrosis. No histologic improvement was observed in the 14 members of the placebo group who had two or more biopsies. Few side effects were observed in either group.

Cellular Senescence in Livers from Children with End Stage Liver Disease

Background Senescent cells occur in adults with cirrhotic livers independent of the etiology. Aim: Investigate the presence rate of cellular senescence and expression of cell cycle check points in livers from children with end stage disease. Methodology/Principal Findings Livers of five children aged three years or less undergoing liver transplantation due to tyrosinemia (n = 1), biliary atresia (n = 2), or fulminant hepatitis (n = 2) were analyzed for senescence associated β-galactosidase (SA-βgal) activity and p16INK4a, p21cip1 and p53. All livers displayed positive cellular staining for SA-βgal in the canals of Hering and interlobular biliary ducts. In the presence of cirrhosis (3/5 cases) SA-βgal was found at the cholangioles and hepatocytes surrounding the regenerative nodules. Children with fulminant hepatic failure without cirrhosis had significant ductular transformation with intense SA-βgal activity. No SA-βgal activity was evident in the fibrous septa. Staining for p53 had a similar distribution to that observed for SA-βgal. Staining for p16INK4a and p21cip1 was positive in the explanted liver of the patient with tyrosinemia, in the hepatocytes, the canals of Hering, cholangioles and interlobular bile ducts. In the livers with fulminant hepatitis, p21cip1 staining occurred in the areas of ductular transformation and in the interlobular bile ducts. Conclusions/Significance Cellular senescence in livers of children with end stage disease is associated with damage rather than corresponding to an age dependent phenomenon. Further studies are needed to support the hypothesis that these senescence markers correlate with disease progression.

Systemic toxicity of polyinosinic acid: Polycytidylic acid in rodents and dogs

Abstract The double-stranded polymer of polyinosinic acid:polycytidylic acid (poly I:C), an interferon inducer, was well tolerated by mice, rats, and guinea pigs following the acute iv or ip administration of 20 mg/kg doses. The acute LD50 of Poly I:C was calculated to be 75 and 150 mg/kg in the mouse and 185 and 365 mg/kg in the rat following iv and ip administration, respectively. Poly I:C was lethal to mongrel dogs following acute iv doses as low as 2.5 mg/kg; toxicity was characterized by depression of spontaneous motor activity, incoordination, vomiting, and flaccid prostration. Subchronic (42 days) administration of poly I:C at daily doses of 2.0 mg/kg ip to rats or 0.2 mg/kg iv to beagle dogs was not accompanied by signs of toxicity. However, severe toxic manifestations were elicited in dogs upon the subchronic administration of poly I:C at a dose of 2.0 mg/kg daily iv, and 3 of 6 dogs died during the course of the experiment. Toxicity was characterized by decreased spontaneous activity, incoordination, vomiting, anorexia, weight loss, hematologic changes reflecting decreased hematopoiesis, increased alkaline phosphatase and transaminase activities, thymus degeneration, destruction of bone marrow, dilatation of hepatic sinusoidal capillaries in the centrolobular areas, necrosis of liver cells, collapse of hepatic structures, and a generalized arteritis. It was concluded that useful systemic therapeutic application of poly I:C will require that the effective doses be quite small, but that, since daily doses of 2.0 mg/kg in the rat and 0.2 mg/kg in the dog were well tolerated in subchronic experiments, cautious exploration of low systemic doses in man may be justified.

The presence of collagenase in collagen preparations

The frequently observed instability of neutral salt solutions of native collagen extracted from various sources and partially purified by standard procedures has been studied by disc electrophoresis in polyacrylamide gel and by electron microscopic examination of segment long spacing crystallites. The phenomenon has revealed time and temperature dependency, pH optima near neutrality, and inhibition by sodium EDTA and serummin addition, collagen breakdown has been found to be quantitatively related to the state of aggregation of the substrate, being more marked in reconstituted collagen gels than in collagen in solutionma typical pattern of animal collagenase degradation of native collagen into two fragments designated as TC-A and TC-B has been observed under certain conditions. It is concluded that the degradation of native collagen in neutral salt solution is due to a specific collagenase, and that this enzyme probably remains bound to collagen throughout the process of extraction and partial purification. Experiments with gelatin suggest that, in addition to collagenase, a nonspecific proteolytic activity may also be present in collagen preparations.

Two antigenically different types of macrophages.

Summary Using stimulated rat peritoneal macrophages, a specific antimacrophage antibody has been prepared in rabbits. Immunofluorescent studies reveal that the antigen(s) is present in free, and absent in fixed, phagocytic cells in the rat. The antigen(s) has also been identified in free macrophages of guinea pigs, mice, and rabbits. Fixed macrophages in the same animal species are consistently negative. The results indicate that free macrophages are antigenically different from fixed phagocytic cells, and that the antigen(s) lacks species specificity.

Colchicine, serum albumin, and alkaline phosphatase.

Excerpt To the editor: Although colchicine has been used in humans for several centuries as an anti-inflammatory agent in acute gout, its pharmacologic properties as well as its metabolism and toxi...

Further studies on the humoral factor(s) of experimental hypersplenism

Abstract The urine of rats with methylcellulose-hypersplenism contains a humoral factor or factors [HF(s)] which are capable of inducing persistent thrombocytopenia when given orally to normal rats. In contrast to methylcellulose-induced thrombocytopenia, the thrombocytopenia induced by HF(s) is not dependent on the spleen, and once established it becomes independent of HF(s) administration. In this paper experiments are reported that suggest that renal elimination and/or gastrointestinal absorption of the circulating factor responsible for thrombocytopenia in methylcellulose-hypersplenic rats is accompanied by such modifications of the factor that, without losing its thrombocytopenic effect, it becomes capable of inducing normal rats to continue forming it indefinitely. Furthermore, it is confirmed that the spleen is not necessary for this phenomenon nor for the thrombocytopenia, which appears to be due to inhibition of platelet maturation and/or release in the bone marrow.