Determination of fructose 2,6-bisphosphate in human lymphocytes is a potential laboratory test in diabetology

The conventional micromethod of fructose 2,6-bisphosphate (F-2,6-P₂) determination is optimized for human peripheral blood lymphocytes. The F-2,6-P₂ content in lymphocytes of healthy subjects is 0.8±0.2 pmol/10⁶ cells or 6.7±1.1 pmol/mg protein. Preliminary findings show a decrease in the F-2,6-P₂ content in lymphocytes from patients with severe diabetes mellitus. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 9, pp. 341–344, September, 1996     

Dynamics of the Reorganization of an Operant Food-Procuring Response during an Increase in the Delay of Reinforcement in Monkeys

Operant activity was studied in monkeys in a situation in which they actively initiated a frequency of pressing a lever to obtain subsequent food reinforcement. Studies addressed the dynamics of relearning when the duration of the lever holding time needed to obtain reinforcement was increased from 1 to 2.5 sec. Studies were performed in three series of experiments with two-month intervals between series. The process whereby the animals solved the food-procuring task when the duration of the operant reaction was increased in conditions of constant sensory stimuli occurred in three stages: 1) emotional reactivity in the form of hyperactivation of operant activity, reflecting a conflict state arising as a result of the dissonance between the completed action and the absence of the expected result; 2) intermediate stabilization, when the outcome of the food-procuring behavior with the reinforcement delay of 2.5 sec coincided with that with the delay of 1 sec; 3) establishment of the desired lever holding time by the time the food reinforcement was presented.     

Lighting in photographic laboratories

Conclusions A method has been developed for testing the nonactinic qualities and illuminating power of lamps. Increase of optical density was examined in relation to time of exposure (from 1 to 10 min), type of light filter (Nos. 107, 117, 118, 124), the use of opalescent glass, a reflector, and other factors. The observer's acuity of vision was tested in the various lights. The best type of light filter was found to be green (No. 124) for the new lamp, and red (No. 107) for the older type.Radiological Research Institute, Moscow. Translated from Meditsinskaya Tekhnika, No. 2, pp. 25–27, March–April, 1969.     

Characteristics of the mitotic cycle of ascites hepatoma 22A cells in the terminal stage of development

The characteristics of growth of ascites heptoma 22A in the terminal stage of development were studied. It was shown by an autoradiographic method that some cells may be in the G₁-or R₁-period for 2 or even 4 days. The mean duration of the G₂-period was 16 h. Of the total number of cells 55–60% were in the greatly lengthened G₁- and R₁-period, 7% in the S-period, and 9% in the G₂-period. The remaining 25–30% of cells evidently had irreversibly left the mitotic cycle, for they did not participate in proliferation in response to stimulation of cell division.Laboratory of Chemical Factors of Regulation of Growth and Cell Division, Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician, of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 10, pp. 479–482, October, 1978.