Yaacov Baruch

Effect of vascular endothelial growth factor on hepatic regenerative activity following partial hepatectomy in rats

BACKGROUND/AIMS Vascular endothelial growth factor (VEGF) is an angiogenic factor with a growth-promoting effect that is thought to be restricted to vascular endothelial cells. Its essential role during liver regeneration has yet to be determined. The aim of this study was to document the effect of exogenous VEGF administration on liver regeneration in rats undergoing submaximal hepatic resections. METHODS Adult male Sprague-Dawley rats (n = 4/group) undergoing 30% partial hepatectomy were administered 200 ng VEGF165 intravenously and were sacrificed at 24, 36, and 48 h postoperatively. Liver regeneration was monitored by measuring the restituted liver mass, proliferating cell nuclear antigen (PCNA) immunostaining, and hepatic PCNA protein by Western blot. RESULTS Changes in restituted liver mass 48 h postsurgery were more prominent, but did not differ statistically between VEGF-treated and control rats (47% vs. 29%; p<0.06). Nevertheless, PCNA immunostaining showed increased labeling index of hepatocytes, apparent at 36 and 48 h after partial hepatectomy (38% vs. 18% [p<0.041 and 42% vs. 11% [p<0.021], respectively). Hepatic PCNA proteins measured by Western blot showed a 3-fold increase in VEGF-treated rats 48 h postsurgery compared with controls (p<0.01). CONCLUSION Exogenous VEGF administration early after partial hepatectomy stimulates liver regeneration in rats. Whether or not VEGF165 is a direct mitogen for hepatocytes remains to be determined.

Growth hormone-stimulated insulin-like growth factor (IGF) I and IGF-binding protein-3 in liver cirrhosis

BACKGROUND/AIMS The aim of this study was to evaluate the livers potential to generate insulin-like growth factor (IGF) I and IGF-binding protein-3 (IGFBP-3), following stimulation by human recombinant growth hormone, as a possible marker for liver functional reserve in patients with liver cirrhosis. METHODS In a pilot study, 15 patients (mean age 56 years) with postnecrotic liver cirrhosis were divided into two groups according to disease severity (Child-Pugh score): Group 1 (n=8) with scores of 5-8 and Group 2 (n=7) with scores of 9-12. Five age-matched healthy subjects served as controls. Human recombinant growth hormone (0.06 mg/kg) was administered subcutaneously on 2 consecutive days. Serum levels of IGF-I and IGFBP-3 were measured before and up to 48 h after human recombinant growth hormone injection. Nutritional status was assessed by the creatinine-height index and was compared to lymphocyte count, body mass index, and muscle arm circumference. RESULTS Baseline IGF-I levels were significantly lower in patients with cirrhosis than in controls, while no differences were noted between the two patient groups. IGF-I levels increased significantly after rhGH administration to the healthy controls, to a lower degree in Group 1, while no change occurred in Group 2. IGF-I levels at 24 h and beyond correlated significantly with the nutritional status, the Child-Pugh score, and the basal levels of GH-binding protein and IGFBP-3. IGFBP-3 serum levels did not change after rhGH stimulation. CONCLUSIONS IGF-I generation after GH stimulation may provide a new dimension in the assessment of liver function and nutritional status in patients with liver cirrhosis.

Case Report: Severe cholestatic jaundice induced by Epstein‐Barr virus infection in the elderly

Infectious mononucleosis due to Epstein‐Barr virus (EBV) is almost always a self‐limited disease, most commonly seen in young adults. Hepatitis is a well‐recognized complication of EBV infection that usually resolves spontaneously. Jaundice occasionally results from the unusual complication of autoimmune haemolytic anaemia rather than hepatitis. We report a 60‐year‐old man with severe cholestatic jaundice whose history, liver histology and laboratory findings suggested EBV infection. He also developed significant jaundice related to his hepatitis, but not to autoimmune haemolysis, a situation that led to diagnostic delay. Costly diagnostic laboratory tests and invasive procedures were performed to rule out a malignant extrahepatic biliary obstruction. Physicians need to be aware of this complication and EBV infection should be included in the differential diagnosis of cholestatic jaundice in the elderly.

Prognostic value of generation of growth hormone-stimulated insulin-like growth factor-I (IGF-I) and its binding protein-3 in patients with compensated and decompensated liver cirrhosis.

Our aim was to study the prognostic value ofgrowth hormone (GH)-stimulated insulin-like growthfactor-I (IGF-I) and IGF-binding protein-3 (IGFBP-3)generation in patients with compensated [group 1 (N = 8) with a Child-Pugh (CP) score of 5-8] anddecompensated postnecrotic liver cirrhosis [group 2 (N= 7) with a CP score of 9-12]. Serum levels of IGF-I,GH-binding protein (GHBP), and IGFBP-3 were measuredbefore and 24 hr after a single subcutaneous injectionof recombinant human GH (rhGH, 0.14 units/kg). Patients(mean age 56 years) were followed prospectively forthree years. Six patients (40%) died during the follow-up period, of whom half had a CP score<9. Mean serum IGF-I levels 24 hr after rhGHinjection (group 1 vs group 2, 17.4 ± 6.8 vs 7.4± 0.7 nmol/liter) predicted survival with 93%accuracy. Levels <10 nmol/liter portended a poorprognosis, with 15% survival at one year, whereas levels>10 nmol/liter had a 100% survival rate at one andtwo years, respectively. Baseline IGF-I (9.98 ± 2.0 vs 6.38 ± 0.8 nmol/liter), GHBP (9.2± 3 vs 5.7 ± 0.8%/50 μl), and IGFBP-3serum levels at baseline (1.7 ± 0.3 vs 0.86± 0.2 mg/liter) and at 24 hr (2.04 ± 0.38vs 0.99 ± 0.3 mg/liter) did not add to the predictive value ofstimulated IGF-I levels at 24 hr and were less accuratein predicting the outcome in comparison to CP score(80%). We conclude that stimulated IGF-1 < 10nmol/liter may be a true predictor of a negative prognosisin patients with liver cirrhosis.

Basic fibroblast growth factor is hepatotropic for rat liver in regeneration.

A role for fibroblast growth factor in liver regeneration has recently been suggested. In this study we followed the intravenous delivery of recombinant human [125I]basic fibroblast growth factor to the liver of rats following 68% partial hepatectomy. The concentration of [125I]basic fibroblast growth factor was higher in the liver (mean +/- SD, 6.8 +/- 0.89% of injected dose) and the kidney (6.7 +/- 0.2%) of sham-operated rats than in the spleen (2.8 +/- 0.45%). It increased threefold in the liver only, soon after 68% partial hepatectomy (20.3 +/- 5.3%, p < 0.001), and remained high for the first 24 h. We also studied the effect of basic fibroblast growth factor injection on the rate of [3H]thymidine incorporation into liver DNA in rats subjected to either 21% or 68% partial hepatectomy. A significant increase was seen after intramesenteric injection of 500 ng basic fibroblast growth factor into rats subjected to 21% partial hepatectomy (23.5 +/- 7.3 cpm/micrograms DNA) compared to saline-injected rats (14.5 +/- 6.4 cpm/micrograms DNA, p = 0.034). A dose of 5000-25,000 ng injected into a peripheral vein resulted in higher thymidine incorporation than in saline-injected control rats (36.9 +/- 12.7 and 9.7 +/- 6.1 cpm/micrograms DNA, respectively; p < 0.0001). No significant effect was seen after 68% partial hepatectomy. Autoradiography showed that the hepatocytes were the predominant labelled cells early after hepatectomy and basic fibroblast growth factor injection. We conclude that basic fibroblast growth factor uptake by the liver is increased after 68% partial hepatectomy and that basic fibroblast growth factor is mitogenic to liver parenchymal cells early after 21% partial hepatectomy.

The liver: a large endocrine gland

?“” LIVER IS the central organ in the growth hormone/insulin-like growth factor (GH-IGF) axis, and the acid-labile subunit (ALS) is one important component of that system in humans. The ALS is linked to the far end of the GH-IGF axis and is an integral constituent in the formation of the 150-kDa IGF/insulin-like growth factor binding protein-3 (IGFBP-3) complex that transports most (95%) of the IGF-I in the circulation and determines its bioavailability to tissues (1,2). The ternary complex (IGF-I, IGFBP-3, ALS) has an important function: to prevent the hypoglycemic effect of IGFs, prolong their biological half-life, and prevent cross-endothelial transport of IGFs. The ALS was first identified when the 150-kDa ternary complex was found to dissociate into a 7.5kDa IGF fraction and a 50-kDa IGFBP-3 fraction after acidification (3). The physiology, biology, and pharmacology of ALS and other parameters of the GH axis are very important in health and disease. In their study in this issue of the Journal, Moller et al. (4) report on low ALS levels in adults that correlate with liver dysfunction. By performing hemodynamic studies they show that the liver predominantly secretes ALS, but that some contribution from extrahepatic tissue may exist. Similar observations have been made in in vivo studies in rats (5). mRNA expression of ALS in tissues other than the liver have been shown by an in situ hybridization technique (6). The binding proteins such as ALS, produced in tissues other than the liver, could account for a paracrine effect or local need as compared with the endocrine function of the liver. In liver cirrhosis, ALS serum levels are decreased and participate in the extreme alterations that occur in the GH-IGF axis in this state. Liver cirrhosis is characterized as one of the GHresistant states, whereby GH serum levels are high in the presence of low IGF serum levels (7-9). Other

The need for liver transplantation: a nationwide estimate based on consensus review

Orthotopic liver transplantation (OLT) is widely practised in developed countries. The procedure is costly, the supply of donor organs limited, and it is not known how many patients need transplantation. A community-wide estimate of the needs for OLT was performed over two years in all general hospitals in Israel. Records of 1851 patients with liver disease were screened to identify those who might eventually need OLT. The annual estimate of transplantation needs in the country was 10-15.5 per million population, with equal numbers of males and females. The addition of patients with nonreformed alcoholism and end-stage liver disease, originally set as an exclusion criteria, would have added 20% to this estimate. 37% of potential candidates were under 40 years of age at diagnosis, and about 50% were 55-64 years old. Almost 80% of patients had cirrhosis of the liver and 13.6% had fulminant hepatitis. These findings provide a basis for a national plan of OLT in Israel, and similar studies might be useful in other countries.

Von Willebrand factor in plasma and in liver tissue after partial hepatectomy in the rat

BACKGROUND/AIMS Von Willebrand factor (vWf) is found in high levels in plasma of patients with acute and chronic liver disease. The role of vWf in liver injury and repair is unknown. We studied the effect of liver mass and remodeling on plasma and tissue vWf after partial hepatectomy. METHODS Rats were sacrificed postoperatively at intervals ranging from 60 min to 5 days, and vWf plasma levels were measured by enzyme-linked immunosorbent assay, using rabbit anti-human vWf, and by immunoperoxidase on cryosections, using rabbit anti-vWf/factor VIII. Northern blot hybridization was prepared with a complementary DNA specific to human vWf. RESULTS vWf plasma levels increased early after sham operation and after 70% partial hepatectomy. The highest levels were reached at 24 h, remaining high for 5 days. Immunostaining showed intense staining of sinusoidal lining cells 4 h after partial hepatectomy, remaining so for 5 days. Non-significant changes in overall liver messenger RNA expression of vWf were seen over 5 days in sham operation and partial hepatectomy. CONCLUSIONS After partial hepatectomy, plasma vWf is increased, probably due to both acute-phase reaction and decreased degradation. An increase in sinusoidal vWf immunostaining may suggest a role for this factor in tissue remodeling.

Spontaneous pulsatility and pharmacokinectics of growth hormone in liver cirrhotic patients

BACKGROUND/AIMS Liver cirrhosis is characterized by high serum growth hormone levels and low serum insulin-like growth factor I and growth hormone-binding protein levels. The present study was designed to characterize the serum profile of growth hormone and growth hormone pharmacokinetics in postnecrotic liver cirrhosis, correlating it with liver function and nutritional states. METHODS Fifteen patients were grouped by the Child-Pugh score (group 1, score of 5 to 8; group 2, score of 9 to 12). Five healthy subjects served as controls. Nutritional status was assessed by the creatinine-height index. Baseline growth hormone, insulin-like growth factor, and growth hormone binding protein were measured, and growth hormone pharmacokinetics was followed for 48 h after administration of subcutaneous recombinant human growth hormone (0.06 mg/kg). RESULTS Trough serum growth hormone (microg/l) was higher in both patient groups (5.3+/-3.6) than in controls (1.0+/-0.3; p<0.01). More pulses were recorded in cirrhotic patients, and mean pulse amplitude (microg/l) was higher in cirrhotic patients than in controls (p<0.01). After subcutaneous recombinant human growth hormone injection, maximal growth hormone was higher in cirrhotic patients and the area under the curve over 24 h was greater (626+/-120) than in controls (330+/-54; p<0.01). Single regression analysis showed a weak correlation of both the Child-Pugh score and the creatinine-height index with the pharmacokinetic parameters. CONCLUSIONS Due to decreased growth hormone clearance, patients with liver cirrhosis have increased trough and peak serum growth hormone levels, as well as lower serum growth hormone binding protein and insulin-like growth factor. Recombinant human growth hormone pharmacokinetics are typical of a high hepatic extraction substance administered to patients with liver disease and portal hypertension, and this may be relevant to the further use of growth hormone therapy.

Metformin-induced mixed hepatocellular and cholestatic hepatic injury: case report and literature review

Introduction Metformin is a first-line drug choice for the treatment of type 2 diabetes mellitus (DM-2). Metformin-induced hepatotoxicity has rarely been reported. We report on a case of metformin-induced mixed hepatocellular and cholestatic liver injury in an elderly patient with DM-2 as well as review and summarize case reports of metformin hepatotoxicity available in English on the PubMed database. Case After receiving metformin 850 mg/day for 2 weeks, a 78-year-old male presented with a 10-day history of abdominal pain, vomiting, diarrhea, and jaundice. Laboratory analysis showed severe hepatocellular and cholestatic hepatic injury. Other causes for acute liver injury were ruled out. Discontinuation of metformin treatment led to significant subjective improvement after 1 week, and all hepatic abnormalities resolved by 2 months. Conclusion Metformin is an important drug for the treatment of DM-2, which is also used for treatment of patients with fatty liver. It can, however, induce hepatocellular and cholestatic hepatic injury; both physicians and patients should be aware of this potential side effect.