PROGNOSIS IN LIVER CIRRHOSIS BY COX'S PROPORTIONAL HAZARD REGRESSION MODEL.

M. Casaril, R. Micciolo °, G.B. Gabriell i , G. Bellisola and R. Corrocher. Istituto di Patologia Speciale Medica o Clinica Medica - Universit& di Verona - I taly.

To asses the prognostic value of clinical and laboratory data in l iver cirrhosis we stat is t i - cally analyzed 36 variables of 151 patients followed up t i l l 8 years; the reference variable was "time of survival" from the f i rs t admission in our hospital. In a f i rs t step we analyzed by log rank test the data of 98 patients (68 males, 30 females) 43 of which died within ob- servation period (study group) obtaining 10 variables prognostically significant as single ones (ascites, albumin, globulins, cholinesterase, cholesterol, gamma-GT, total bi l irubin, PTT, Na and Ca) and 3 with a significant trend (age, WBC and K). To understand the joint ef- fect of variables on survival those prognostically useful by log rank test were analyzed by Cox's proportional hazard regression model. This procedure showed that a set of only 7 va- riables supplies all the prognostic information (WBC, K, globulins, previous history of l i - ver disease had a positive correlation with survival, Ca had a negative one while choleste- rol and age had a non-linear correlation). From estimated regression coefficents a "risk score" for each patient was obtained, allowing to determine risk classes with stat ist ical ly different observed survival. To confirm the pro- gnostic value of this score and external validation was performed computing risk scores of 53 subsequent different patients (control group), again obtaining a good agreement between predicted and observed survival.

IN VITRO FIBROBLAST CULTURES FROM NORMAL HUMAN LIVER

A.Casini,E.Banchetti,G.Dini^,C.Surrenti.Department of Clinical Pathophisiology, Gastroenterology Unit and ^Department of Pathology,University of Florence,Florence,Italy.

In this paper we characterize in vitro cultures of fibroblasts derived from explants of normal human liver according to their morphology and ability to synthetize components of connective tlssue.Human liver samples were obtained from surgical biopsies of normal adult donors and placed in a sterile tube containing medium.Liver tissue was then cut into fine pieces,placed in tissue culture dishes and covered with square glass cover slips.Explants were performed in

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in medium with 20% FCS at 37 C in a 5% CO 2 atmosphere.Subcultures were obtained by trypslnlz = tion.The morphology of cultured cells was observed by phase-contrast and electron microscopy (EM).For transmission EM cells were fixed in 2.5% glutaraldehyde,postfixed with 1.33% osmium tetroxide and then embedded in Epon mixture.Ultrathln sections were examined in a Philips 300 TEM.Speciflc antibodies against collagen type IV,V0fibronectin and laminin were used at 1:150 diluition:cells were incubated for lh at room temperature with antiserum or control serum, washed with PBS and incubated with PA-colloidal gold(l:20).Cells grew out around the explants

34~2.1 days after the start of cultivation. Cultures consisted mainly of spindle-shaped cells resembling fibroblasts.They did not produce factor VIII,as judged by negative immunoperoxidase staining.On EM these cells exhibited many features typical of fibroblasts.They had an irregu = lar elongated shape and contained a single large ovoid nucleus.The ribosomes bound to the endoplasmic reticulum were arranged in whlrls.The Golgl complex was well developed. Many lyso = somes were seen in the cytoplasm containing electron-dense material.Abundant filaments were randomly dispersed or organized in bundles in the cytoplasm and in the distal ends of cells. A filamentous material was observed around and between the cells.On immunogold EM fibronectin, laminin,collagen type IV and V were detected associated with cell surface membrane and with

extracellular filamentous structures.

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