Morphometric parameters of neurons in reticular nuclei of the brain stem in kittens

Three types of Golgi-stained neurons were discovered in brain stem reticular nuclei of 30-day-old kittens: sparsely branching reticular neurons, those with densely branching dendritic trees, and giant multipolar neurons (Leontovich's classification). Adopting computerized morphometric techniques enabled 23 different parameters to be measured in cells of these types. The measurements taken from the neuronal groups investigated revealed statistically significant differences between them for most parameters. It was concluded from this that each of the neuronal types distinguished has its own morphological identity (or stability). Characteristics of structural differences and properties of differing cell types in reticular nuclei are discussed in relation to their functional properties.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 23, No. 4, pp. 399–409, July–August, 1991.     

A tail length modifier gene discovered in the Japanese wild mice (Mus musculus molossinus)

The presence of the t haplotypes in strains derived from the Japanese wild mice (Mus musculus molossinus) was investigated. Crosses between the T/+ heterozygous short tailed mice and five normal tailed molossinus strains (MOL-ANJ, MOA, MOL-NEM, MOM and Mns) produced no tailless mice, indicating that these strains possess no t haplotype. In contrast, tailless mice were produced by a cross between the T/+ heterozygotes and a MOL-NIS strain. Mating experiments showed that the tailless character was due to an interaction between the T gene and an autosomal recessive gene carried by the MOL-NIS strain that expresses the short tail character under the homozygous condition. We have tentatively named this gene brachyury-interacting tail length modifier (btm). It remains to be investigated whether the btm gene is located in the t complex region or in the other locus.     

Formulation of a flowable liquid concentrate of Bacillus thuringiensis serotype H-14 spores and crystals as mosquito larvicide

Bacillus thuringiensis serotype H-14 spores and crystals, produced in 51 fermenters, were centrifuged and resuspended in emulsified palm olein to give 3.2 x 10(11) colony forming units (cfu)/ml. The suspension was mixed with a cassava-molasses-palm olein-charcoal (CMPC-2) mixture which served as the carrier, adhesive, dispersant and protectant. The final concentration of the formulation was 3.2 x 10(9) cfu/ml. The lethal concentrations capable of killing 50% of the test population (LC50) of CMPC-2 during 0, 1 and 2 years of storage at 32 +/- 4 degrees C were 0.056, 0.058 and 0.058 mg/ml respectively as against 0.054, 0.051 and 0.054 mg/ml for the Institut Pasteur Standard-1978 (IPS-78) during the corresponding period. The chi 2 tests showed that the results were homogeneous at P = 0.05. The relative potencies of the preparations were 964.3, 879.3 and 931 International toxic units (ITU) Aedes aegypti as compared with the 1000 ITU assigned to IPS-78. At 95% confidence limits there was no significant difference between the potencies of CMPC-2 and IPS-78. Field tests showed that CMPC-2 provided between 87.5 and 100% control of natural populations of Aedes spp. and Cutex spp. Sedimentation tests showed that CMPC-2 settled markedly during storage. This, therefore, required that the product be thoroughly shaken before use.     

Microflora of nuclear research reactor pool water

In the course of research done it was concluded that circulation of pool water through the nuclear reactor core produces a bactericidal effect on microflora due to influence of radiation of various types. Contents of microbes returns to the initial level after 2-4 months after circulation was stopped. Microflora of pool water comprises big amount of coccus, G-positive rods and fungi and a lower content of G-negative rods if compared to water which had been used to fill reactor pool. There is an increased number of radioresistant forms with intensified production of catalase and nuclease. Supposedly, presence of these enzymes gives to the microbes certain advances to survive in high-radiation zones.     

Products of mitochondrial protein synthesis in Tetrahymena.

The products of mitochondrial protein synthesis have been investigated in Tetrahymena after labelling with [35S]methionine in the presence of cycloheximide. The labelled proteins were analyzed by sodium dodecyl sulfate slab polyacrylamide gel electrophoresis. We have identified 13 electrophoretically discrete bands as well as 4 other bands with a more variable occurrence. These proteins ranged in apparent molecular weight from 8100 to 57,500. The cycloheximide-resistant incorporation could be blocked with chloramphenicol. The mitochondrial proteins appeared to be in a disaggregated state and were stable to agents such as trichloroacetic acid (hot or cold) and chloroform-methanol. The pattern of proteins was similar following labelling times ranging from 30 min to 3 h.     

Retrovirus-mediated immunosuppression. II. FeLV-UV alters in vitro murine T lymphocyte behavior by reversibly impairing lymphokine secretion

Murine splenocytes and cloned murine T cells were used to study the in vitro immunosuppressive effects of UV-inactivated feline leukemia virus (FeLV-UV) on lymphokine secretion. FeLV-UV can significantly depress the accumulation of IL 2 in cultures of Con A-stimulated C57BL/6 splenocytes and in cultures containing the alloreactive helper T cell clone B6D/2-2m plus Con A. Inhibition of lymphokine accumulation in these cultures could not be attributed to absorption or inactivation of IL 2 by the FeLV-UV or to the FeLV-UV-induced production of substances which interfere with the IL 2 bioassay. Thus, FeLV-UV appears to block production and/or secretion of IL 2 by a direct inhibitory effect on IL 2-secreting murine T lymphocytes. Additional studies indicate that FeLV-UV impairs IL 2 production only if added very soon after lymphocyte contact with lymphokine-inducing agents and that IL 2 secretion resumes when FeLV-UV is removed from the culture. FeLV-UV also impairs accumulation of MAF (interferon-gamma?) in cultures of Con A-stimulated C57BL/6 splenocytes and in cultures containing the alloreactive cytotoxic T lymphocyte clone B6D/2-7c plus Con A. The latter observation again suggests that FeLV-UV impairs lymphokine secretion by a direct effect on lymphokine-producing T lymphocytes. Furthermore, it suggests that FeLV-UV does not selectively impair production of IL 2 nor does it have selective inhibitory effects on helper T cells. Rather, FeLV-UV appears to have a general inhibitory effect on lymphokine production by T lymphocytes. Finally, concentrations of FeLV-UV which suppress MAF production by the CTL clone have little influence on the cytolysis mediated by the same cloned T cell population. Thus, the immunosuppressive influence of FeLV-UV is selective for phenomena associated with induction of new T lymphocyte functions, such as lymphokine secretion, and spares other immune functions already expressed by the same cells.     

Phospholipid turnover during cell-cycle traverse in synchronous Chinese-hamster ovary cells. Mitogenesis without phosphoinositide breakdown.

The turnover of phospholipids was investigated in quiescent serum-starved Chinese-hamster ovary (CHO-K1) cells stimulated to progress through the cell cycle by the addition of dialysed bovine serum. A variety of radiolabelling techniques were employed to study the rapid effects of serum on phospholipids and later events during G1 and S phases of the cell cycle. Pulse-labelling studies using [32P]Pi revealed that there was a stimulation of the synthesis rate of all phospholipids investigated during the initial few hours after serum addition. The greatest stimulation (20-fold) was observed in phosphatidylcholine, and the smallest in the polyphosphoinositides (PPIs). Mock stimulation with serum-free medium caused a similar increase in PPI turnover, but little or no effect on turnover of other phospholipids. This effect could be accounted for by a stimulation of the turnover of cellular ATP pools increasing [32P]ATP specific radioactivity. Late G1 and S phases were associated with a decrease in the rate of synthesis of all phospholipids. Phosphatidic acid was the only phospholipid whose labelling fell below that in mock-stimulated cells during the period of the cell cycle. Stimulation of serum-starved cells that had been prelabelled with myo-[2-3H]inositol caused no change in the amounts of inositol trisphosphate, but both serum-stimulated and mock-stimulated cells exhibited similar small decreases in both inositol bisphosphate and inositol monophosphate, of approx. 30% after 30 s. When cells were serum-stimulated in the presence of 10 mM-Li+, there was no increase in the size of the total inositol phosphate pool. We conclude that mitogenic stimulation and cell-cycle traverse cause profound and complex effects on phospholipid turnover in CHO-K1 cells, but there is no evidence for a role of inositol lipid turnover in the proliferative response to serum in this cell line.     

Correlation between the rate of ethanol elimination and the psychophysiological characteristics of rats

Ethanol elimination from the blood of rats with different psychophysiological features was studied using gas chromatographic head-space analysis in the general complex of tests aimed at determination of ethanol consumption. The selection of animals with different levels of the initial alcohol motivation was performed according to modified Porsolt's method. It was shown that the initial level of predisposition to depression-like states is in a dose-dependent correlation with the high rate of ethanol elimination. This is suggested to be one of the genetic indications which promotes the formation of the initial alcohol motivation and the development of experimental alcoholism.