Mehmet Emirzeoglu

Unbiased estimation of the liver volume by the Cavalieri principle using magnetic resonance images

OBJECTIVE It is often useful to know the exact volume of the liver, such as in monitoring the effects of a disease, treatment, dieting regime, training program or surgical application. Some non-invasive methodologies have been previously described which estimate the volume of the liver. However, these preliminary techniques need special software or skilled performers and they are not ideal for daily use in clinical practice. Here, we describe a simple, accurate and practical technique for estimating liver volume without changing the routine magnetic resonance imaging scanning procedure. MATERIALS AND METHODS In this study, five normal livers, obtained from cadavers, were scanned by 0.5 T MR machine, in horizontal and sagittal planes. The consecutive sections, in 10 mm thickness, were used to estimate the whole volume of the liver by means of the Cavalieri principle. The volume estimations were done by three different performers to evaluate the reproducibility. RESULTS There are no statistical differences between the performers and real liver volumes (P > 0.05). There is also high correlation between the estimates of performers and the real liver volume (r = 0.993). CONCLUSION We conclude that the combination of MR imaging with the Cavalieri principle is a non-invasive, direct and unbiased technique that can be safely applied to estimate liver volume with a very moderate workload per individual.

Nitric oxide synthase inhibitors protect cerebellar Purkinje cells from zinc-induced cell loss in adult rat

Zinc is an important trace element in biological systems; however, excessive extracellular zinc could lead to neuronal cell death following ischemia, seizures, and brain trauma. In this study, we investigated whether the intracortical injection of zinc sulphate (200 μg/kg, i.c.) changes total number of Purkinje cells in the cerebellum and whether different types nitric oxide synthase inhibitors, N-(G)-nitro-L-arginine methyl ester (L-NAME), N(omega)-nitro-L-arginine (L-NNA), aminoguanidine and 7-nitroindazole (7-NI), have protective effects against zinc neurotoxicity in Wistar albino rats. Animals were divided into 6 groups: control, zinc, zinc+L-NAME (100 mg/kg, i.p.), zinc+L-NNA (100 mg/kg, i.p.), zinc+7-NI (100 mg/kg, i.p.) and zinc+aminoguanidine (100 mg/kg, i.p.) groups. Total number of Purkinje cells in the cerebellum was estimated using unbiased stereological technique as 318,947 ± 20,549, 123,483 ± 23,762, 206,537 ± 43,128, 178,135 ± 26,635, 193,148 ± 46,104 and 212,910 ± 26,399 in the control, zinc, zinc+L-NAME, zinc+L-NNA, zinc+7-NI and zinc+aminoguanidine groups, respectively (mean ± SD). The number of Purkinje cells in zinc group was significantly lower than that of the other groups (P<0.001). It was found that the nitric oxide synthase inhibitors have neuroprotective effect against zinc neurotoxicity on Purkinje cells. These data show that the inhibition of the nitric oxide synthase could prevent some of the deleterious effects of zinc on Purkinje cells.