[Miniature thin layer biosensors which are sensitive to glutamate and glutamine]. / Miniatiurnye tonkoplenochnye biosensory, chuvstvitel'nye k glutaminovoi kislote i glutaminu.

Integrated thin film biosensors for simultaneous measurement of L-glutamine and L-glutamate in a micro-flow cell were developed. Due to a novel glutaminase with an activity optimum in the neutral pH range a direct monitoring of glutamine in mammalian cell culture medium could be performed. The glutamine bienzyme sensor was prepared by coimmobilization of glutaminase with glutamate oxidase within a photo patterned poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel membrane. The sensor response is linear in the concentration range of 55 mmol to 10 mmol glutamine/l. Additionally a glutamate biosensor is integrated on the sensor chip for difference measurement of possible glutamate interferences. The sensor chip can be used for at least 300 measurements without any alteration in the performance of its sensors. A new sensor chip with an integrated flow cell provides the possibility of simultaneous measurement of four different parameters at a cell volumina of 1 ml. Completing the microsystem a battery operated surface mounted device (SMD) potentiostat was developed to get a "lab on chip".

[Plica polonica]. / A legyel fürt betegségról.

The author summarizes the essentials and history of the plica polonica disease and describes some of his own experiences in diagnosis and treatment. It is remarkable, that the monographs of the internal medicine and the hungarian monographs of dermatology, with the exception of two, didn't even mention this phenomenon in this century. Besides, no original publications can be found in the hungarian medical literature about this topic. However we can find people with this syndrome in Hungary also at the present time. It can be connected with the increasing ageing and growing poverty in our country.