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Biomedical subjects

I R Wanless

Publications and source records attributed to I R Wanless.

66 records · Page 4Linked to original sources

Sulindac hepatotoxicity.

Two patients who developed painless jaundice while taking sulindac are described. Rechallenge in one case confirmed the association of hepatic damage with sulindac administration. Laboratory data and liver biopsy findings suggested a hepatitis with cholestatic features.

Aged↗

Role of estrogens as promoters of hepatic neoplasia.

The administration of estrogens to humans has been associated with the development of benign and possibly malignant hepatocellular neoplasms. This study was designed to investigate the mechanism of this association. We present a rat model that demonstrates that stilbestrol (DES) and ethinyl estradiol promote the development of hepatic neoplasms in rats previously initiated with diethylnitrosamine (DEN). Eighty male and 12 female Fischer-344 rats were given a single intraperitoneal injection of either DEN (200 mg. per kg. of body weight) or saline. Beginning 4 weeks after injection, the rats were given an estrogen or corn oil twice weekly for up to 50 weeks. Treatments were stopped at the time of sacrifice or 11 to 29 weeks prior to sacrifice. Estrogen treatments included high dose DES (5 mg. per dose), low dose DES (0.5 mg. per dose), and ethinyl estradiol (0.2 mg. per dose). Male and female rats given both DEN and high dose DES developed grossly visible hepatic hyperplastic nodules (mean, 9.1 per liver) after 20 weeks of DES. Nodules also developed if the onset of DES treatment was delayed until 28 weeks after initiation. Rats given DEN alone or DES alone did not develop nodules after 20 weeks. Microscopic hyperplastic foci also developed in rats given DEN plus DES, DES alone, and DEN alone. The foci in rats given DES alone were largely reversible on cessation of estrogen therapy. Mitotic activity in foci and nodules was prominent during estrogen therapy but declined markedly after cessation of therapy. Similar promoting activity of ethinyl estradiol was observed. Low dose DES was not effective in promoting tumor formation. The data indicate that estrogens promote hepatic neoplasia, perhaps by increasing hepatocyte mitotic activity and thereby facilitating the evolution of previously initiated cells into neoplastic clones. Comparison with human disease should be made with caution, especially because the estrogenic dose administered was approximately 200-fold the usual contraceptive dose in humans. However, the analogy between this model and the development of human oral contraceptive-associated hepatic tumors is evident. It is possible that some women have latent "initiated" cells that divide faster than the surrounding hepatocytes in response to estrogens.

Animals↗

Intrahepatic portal vein sclerosis in patients without a history of liver disease. An autopsy study.

Portal fibrosis with portal venous obliteration is characteristic of noncirrhotic portal hypertension, but similar lesions are also commonly seen in patients without clinical evidence of liver disease. Thus, the ability to predict the presence of portal hypertension with histologic criteria will probably depend on a quantitative assessment of liver tissue. The purpose of this study is to provide a quantitative basis in a "normal" population for evaluation of portal vein obliteration. We reviewed 414 consecutive autopsies of patients without known history of alcoholism or clinical liver disease. Intrahepatic portal vein obliteration was graded 0 to III. The grading system was standardized by morphometry on 34 selected cases. The incidence of portal vein lesions increased with age and reached a plateau at about 60 years of age. Lesions were more common in patients who had severe congestive heart failure or arterial thrombosis. These associations suggest that obliterative lesions may be the result of thrombosis in patients with sluggish portal blood flow or hypercoagulability. Portal tract mineral oil deposits may also have a role, because they were found more often than expected in livers with portal sclerosis.

Adult↗

Nodular regenerative hyperplasia of the liver associated with macroglobulinemia. A clue to the pathogenesis.

Nodular regenerative hyperplasia of the liver is an infrequent condition characterized by transformation of the hepatic parenchyma into nodules with only mild fibrosis. Little is known about the etiology except that there is usually an underlying chronic disease, such as Felty's syndrome, which antedates the development of clinical liver disease. It is poorly understood how the associated diseases contribute to the pathogenesis of nodular regenerative hyperplasia. Presented are four cases of nodular regenerative hyperplasia in which macroglobulinemia was also present. This new association suggests to us a hypothesis for the pathogenesis of nodular regenerative hyperplasia. Histologic examination of the livers in these and other cases of nodular regenerative hyperplasia reveals widespread obliteration of the small portal veins. Postmortem angiography of one liver in the present series demonstrated that the nodules were well perfused and that the atrophic areas were poorly perfused with portal blood. This supports the view that atrophy of lobules results from a lack of portal blood supply and that nodules develop from lobules well supplied with portal blood. In each of the clinical conditions associated with nodular regenerative hyperplasia, including macroglobulinemia, inflammatory or thrombotic vascular lesions are found in many organs. Therefore, nodular regenerative hyperplasia may be the hepatic expression of a more widespread vascular disease.

Adult↗

Nodular regenerative hyperplasia of the liver in hematologic disorders: a possible response to obliterative portal venopathy. A morphometric study of nine cases with an hypothesis on the pathogenesis.

Nodular regenerative hyperplasia was found in nine patients who had hematological disease including polycythemia vera, agnogenic myeloid metaplasia, primary thrombocythemia, rheumatoid arthritis with thrombocytosis, multiple myeloma, and erythrocytosis associated with polycystic renal disease. Portal hypertension was suspected in three and features of hypersplenism were present in four. 2. Nodular regenerative hyperplasia occurred in livers which had widespread obliteration of portal vein radicals (obliterative portal venopathy). Morphometric analysis indicated that the portal vein lesions were predominately located in veins up to 0.2 mm in diameter and were significantly more frequent than similar lesions occurring in elderly persons. 3. The following pathogenesis of nodular regenerative hyperplasia is proposed: Thrombi, perhaps largely composed of platelet aggregates formed in the portal venous circulation or spleen, embolize to the liver and results in obliterative vascular lesions. Atrophy and regenerative nodule formation occur in response to the interruption of the portal blood supply.

Adult↗

Effect of chronic alcohol intake on hepatic fibrosis and granulomas in murine schistosomiasis mansoni.

In consideration of the vast prevalence of schistosomiasis and heavy alcohol consumption in many parts of the world, the possibility of an interaction between these two conditions inducing liver disease was studied in mice infected with Schistosoma mansoni. Alcohol consumption significantly reduced by 25% the mean granuloma diameter and by about 60% the extent of fibrous tissue deposition determined chemically as hydroxyproline. DNA, as an expression of the inflammatory and cellular components of the granulomatous reaction in the infected animals, was also significantly reduced by alcohol consumption. These results indicate the need for epidemiological studies in the clinical manifestations and course of schistosomiasis in human alcoholics.

Alcoholism↗

On the pathogenesis of focal nodular hyperplasia of the liver.

Fifty-one focal nodular hyperplasia lesions from 36 patients were examined histologically. Serial sections and three-dimensional models were studied in selected cases. Lesions were multiple in 19% of patients. Thirty-four patients were female. One case had 11 focal nodular hyperplasia lesions and 7 hemangiomata in the liver. Three had astrocytoma and one had anomalous pulmonary venous drainage. Morphometric analysis revealed that the lesions were supplied by an anomalous artery larger than expected for the locale in the liver. This artery branched to form a spider-like structure and was usually not accompanied by a portal vein or duct. Each terminal arterial branch supplied a separate nodule 1 mm in diameter; adjacent nodules coalesced to form the focal nodular hyperplasia lesion. The arterial blood appeared to drain directly into the sinusoids of the nodule. We propose that focal nodular hyperplasia is an hyperplastic response of the hepatic parenchyma to a preexisting arterial spider-like malformation. The frequent coexistence of focal nodular hyperplasia with other vascular and neuroendocrine anomalies suggest that the malformations are developmental in origin. The basic requirement for development of hepatic hyperplasia may be greater blood flow to a region compared to the adjacent parenchyma. This requirement appears to be met in the other forms of nodular transformation of the liver, i.e., nodular regenerative hyperplasia and partial nodular transformation.

Adolescent↗