CALLUS INDUCTION, PLANT-REGENERATION AND CHROMOSOMAL VARIATIONS IN BARLEY

Callus cultures were induced on mature embryo mesocotyl explants in Hordeum vulgare cv. Zafer-160. The callus induction ratio was 54% in Murashige-Skoog (MS) medium supplemented with 1 mg 1(-1) 2,4-dichlorophenoxyacetic acid (2,4-D). After transfer at 22, 45, 360, 540 days of culture to MS medium containing lower concentrations of 2,4-D (0.5, 0.1, 0.01 mg 1(-1)) or MS medium lacking 2,4-D, 45-day-old callus cultures showed somatic embryogenesis. The optimum 2,4-D concentration for somatic embryogenesis was 0.01 mg 1(-1). Callus cultures of 360 days showed regeneration via both somatic embryogenesis and organogenesis under the same conditions. Abnormalities in both number and structure of chromosomes increased with the age of calli. This phenomenon might be related to the loss of regeneration ability in 540-day-old calli. In-vitro regenerated plantlets gave rise to normal-looking plants after their transfer to soil. Regenerated plants had the normal diploid chromosome number (2n = 14) in their root tips

Acinar Cell Ultrastructure After Taurine Treatment in Rat Acute Necrotizing Pancreatitis

Objective: To evaluate the organelle-based changes in acinar cells in experimental acute necrotizing pancreatitis (ANP) after taurine treatment and the association of electron microscopic findings with histopathological changes and oxidative stress markers. Methods: The study was performed in February 2005 at Gulhane School of Medicine and Hecettepe University, Turkey. Forty-five rats were divided into 3 groups. Acute necrotizing pancreatitis was induced in groups II and III. Groups I and II were treated with saline and Group III with taurine 1000 mg/kg/day, i.p, for 48 hours. Histopathological and ultrastructural examinations were determined using one-way analysis of variance and Kruskal-Wallis tests. Results: Histopathologic findings improved significantly after taurine treatment. Degree of injury in rough and smooth endoplasmic reticulums, Golgi apparatus, mitochondria and nucleus of acinar cells also decreased with taurine in correlation with biochemical and histological results. Conclusion: Taurine improves acinar cell organelle structure, and ultrastructural recovery in ANP reflects histological improvement.Wo