Biju,M P; Paulose,C S(Department of Biotechnology, September 27, 1997)
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Abstract:
Kinetic parameters of brain glutamate dehydrogenase (GDH) were compared in the brain
stem, cerebellum and cerebral cortex of three weeks and one year old streptozotocin (STZ)
induced four day diabetic rats with respective controls. A single intrafemoral dose of STZ
(60mg/Kg body weight) was administered to induce diabetes in both age groups. After four days
the blood glucose levels showed a significant increase in the diabetic animals of both age groups
compared with the respective controls. The increase in blood glucose was significant in one year
old compared to the three weeks old diabetic rats. The Vmm of the enzyme was decreased in all
the brain regions studied, of the three weeks old diabetic rats without any significant change in
the Km. In the adult the Vmax of GDH was increased in cerebellum and brain stem but was
unchanged in the cerebral cortex. The K. was unchanged in cerebellum and cerebral cortex but
was increased in the brain stem. These results suggest there may be an important regulatory role
of the glutamate pathway in brain neural network disturbances and neuronal degeneration in
diabetes as a function of age.
Blends of nitrile rubber and reclaimed rubber containing different levels of a
coupling agent, Si 69 (bis(3- triethoxysilyl propyl)(tetrasulphide) were prepared
and the cure characteristic's and mechanical properties were studied. Optimum
loading of Si-69 was found to be a function of blend ratio. 3 phi- of Si 69 in a
70:30. Blend was found to be the optimum combination with respect to the
mechanical properties. The rate and state of cure were also affected bv the
conp/ing agent. Tensile strength, tear strength and abrasion resistance were
improved in the presence of coupling agent. While the state of cure improved,
the cure rate and scorch time decreased with increasing silane content. Ageing
studies showed that the blends containing the coupling agent were inferior to
the unmodified blends.