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V Gazit

Publications and source records attributed to V Gazit.

3 recordsLinked to original sources
PubMed2003

Cysteine-induced hypoglycemic brain damage: an alternative mechanism to excitotoxicity.

Central neural damage caused by L-cysteine (L-Cys) was first reported more than 30 years ago. Nevertheless, the exact mechanisms of L-Cys-mediated neurotoxicity are still unclear. Preliminary study in mice demonstrated that, following L-Cys injection, animals developed tachypnea, tremor, convulsions, and death in conjunction with documented hypoglycemia. The aim of the present study was to further investigate the mechanism of L-Cys-mediated hypoglycemic effect and neural damage. Neonatal ICR mice (n=6) were injected with L-Cys (0.5-1.5 mg/g body weight [BW]), and their blood glucose and insulin levels were determined up to 90 min following the injection. Experiments were repeated in chemically (streptozotocin [STZ]) pancreatectomized animals. Brain histology was assessed. Mice injected with L-Cys exhibited dose-dependent neurotoxicity and higher mortality as compared with controls. L-Cys (1.2-1.5 mg/g BW) caused severe hypoglycemia (glucose<42 mg/dl) ( P<0.001). In STZ-treated (diabetic) animals, L-Cys (1.5 mg/g BW) increased plasma insulin levels 2.3-fold and decreased serum glucose levels by 50% ( P<0.01). Brain histology revealed destruction of as much as 51% of hippocampal neurons in the L-Cys-treated mice but not in the glucose-resuscitated animals. These findings suggest that L-Cys injection can cause pronounced hypoglycemia and central neural damage which is glucose reversible. Since L-Cys is chemically different from the other excitatory amino acids (glutamate and aspartate), L-Cys-mediated neurotoxicity may be connected to its hypoglycemic effect.

Animals↗
PubMed1999

Contaminant eluted from solid-phase plasmid affinity-purification protocol columns is not found using liquid-phase methods and can be prevented.

The preparation of high quality plasmid DNA is a necessary requirement for most molecular biology applications. We compared four different large plasmid preparation protocols, which were based on either a liquid-phase approach (Triton lysis) or purification of alkaline lysis bacterial extracts followed by supercoiled plasmid purification on affinity columns. Two host Escherichia coli strains, JM 109 and INValphaF', were used to grow the test plasmids for comparison of product plasmid DNA produced from the four different plasmid isolation methods. While the DNA grown in E. coli strain JM109, prepared by liquid-phase Triton lysis was appropriately restricted by 12 restriction enzymes, this was not the case for any of the JM109-grown DNA purified by any of the affinity column solid-phase approaches. In contrast to this, when the plasmid DNA was grown in E. coli strain INValphaF', most restriction enzymes cut DNA appropriately, irregardless of the plasmid preparation protocol used. It seems that an impurity commonly eluted with the DNA from all three of the solid-phase DNA columns had an equal effect on the above enzymes using the common host strain JM109, but not strain INValphaF'.

Chromatography, Affinity↗