Oval cell proliferation in cirrhosis in rats. An experimental study.

AIM: Oval cells are liver stem cells involved in liver regeneration following liver damage. Previous studies have shown that pretreatment with a hepatocyte inhibitor is required to allow full oval cell activation. This study investigates whether oval cells develop and proliferate in a model of experimental liver fibrosis without pretreatment with a known hepatocyte inhibitor. METHODS: The study comprised 66 male Wistar rats divided into two groups: A (n = 6): controls; and B (n = 60): CCl(4) injection (intraperitoneally 2 mL/kg bodyweight 1:1 volume in corn oil twice weekly). Rats were sacrificed at four, eight and 12 weeks. Liver tissues were evaluated for the degree of fibrosis (Masson's trichrome), cell proliferation (Ki67 antigen), expression of alpha-fetoprotein (AFP) mRNA (RT-PCR and in situ hybridization), AFP protein (Western blot) and cytokeratin-19. Cells with morphologic features of oval cells that were cytokeratin 19 (CK19)+ and AFP mRNA+ were scored in morphometric analysis. RESULTS: Oval cells were present in all 66 specimens; their percentage was higher in group B compared to group A (P < 0.001). AFP mRNA and protein expression increased as fibrosis advanced. Similarly, the numbers of CK19+, AFP mRNA+ and Ki67+ oval cells were higher in advanced fibrosis stages. CONCLUSION: This study demonstrates that oval cells develop and proliferate in a model of experimental liver fibrosis without pretreatment with a known hepatocytic inhibitor. However, further research is warranted in order to identify the exact molecular mechanisms involved in this process.

AngioJet rheolytic thrombectomy versus local intrapulmonary thrombolysis in massive pulmonary embolism: a retrospective data analysis.

PURPOSE: To compare the efficacy of full-dose local intrapulmonary thrombolysis (LIT) versus AngioJet rheolytic thrombectomy (ART) in the treatment of massive pulmonary embolism. METHODS: A retrospective review was conducted of 8 consecutive patients (5 women; mean age 66.0+/-5.9 years, range 56-74) who underwent LIT with high-dose intrapulmonary urokinase (4400 IU/kg over 10 minutes followed by a 2000-IU/kg/h infusion) and a subsequent 6 consecutive patients (4 men; mean age of 59.2+/-17.0 years, range 26-69) who underwent ART plus adjunctive low-dose urokinase infusions (100,000 IU) until hemodynamic recovery was achieved. Pre and postprocedural Miller scores were calculated, and relative Miller score improvement, total urokinase doses, and duration of therapy were compared. RESULTS: Hemodynamic stability was restored in all 8 LIT patients and in 5 (83%) of the 6 ART patients; 1 (16.7%) patient died during the ART procedure due to recurrent MPE. In the LIT group, the mean Miller score prior to intervention was 17.38+/-2.67, which was reduced to 6.13+/-1.46 after the intervention (p<0.0001) compared to scores of 18.83+/-2.86 and 6.83+/-2.79, respectively, in the ART group (p<0.0001). The mean urokinase dose was 2.07+/-0.44 million IU in the LIT group versus 0.70+/-0.36 million IU in the ART group (p<0.0001). The mean duration of therapy was 11.45+/-2.94 hours in the LIT group versus 3.37+/-1.41 hours in the ART group (p<0.0001). No significant difference in relative Miller score improvement was observed. CONCLUSION: By accelerating the fragmentation of thrombus, ART plus adjunctive low-dose urokinase seems to be more rapidly effective compared to LIT. ART achieves both rapid cardiovascular relief and reduces the dose of thrombolytic agent necessary in patients with massive pulmonary embolism.

Extracranial internal carotid artery aneurysms: report of a ruptured case and review of the literature.

Aneurysms of the extracranial carotid arteries (ECAA) are extremely rare. Schechter et al. [1] documented 835 cases in the literature up to 1977. One hundred and sixteen cases of ECAA have been documented in the Chinese literature since 1981, suggesting a higher prevalence of carotid aneurysmal disease in China than in the West. Four percent of all peripheral artery aneurysms are reported to be ECAA [2]. Those arising from the internal carotid artery (EICAA) are even more rare. Two recent reviews [3, 4] reported 24 and 25 cases of EICAA during 21 and 17 years, respectively, the majority of them is treated surgically. Our literature review revealed only a few true EICAA managed endovascularly, but none of them with a covered stent. We describe a rare such case of ruptured atherosclerotic EICAA which was treated percutaneously.