Urine selenium level in healthy adult population

The level of urine selenium in healthy adult population, 230 persons, was examined. Persons were selected regarding sex, ages, and smoking habits. No differences versus these observations have been found. For a total, group values are 16.96 Se nmol/creatinine mmol, SD=5.44. It is possible from a single-void specimen to express daily excretion of selenium.     

Progress since the first international symposium: ‘Genetic aspects of plant mineral nutrition’, Beograd, 1982, and perspectives of future research

Summary The paper discusses the problems of genetic aspects of plant mineral nutrition in the light of the results presented at the First and Second Symposia on ‘Genetic Aspects of Plant Mineral Nutrition’ organized in Beograd in 1982 and Madison in 1985, respectively. On the basis of the results, future directions of research are discussed. The papers deal with the concentration and content of mineral nutrients in different genotypes, physiological and biochemical aspects of the genetic specificity of plant mineral nutrition, relations between plant genotypes and nitrogen fixing micro-organism strains, as well as with some related problems which have been investigated to a lesser extent. Particular attention is paid to papers and problems referring to genetic and breeding research work linked with genetic aspects of plant mineral nutrition as well as the possibilities of developing new cultivars requiring certain soil and mineral nutrition conditions for their cultivation.     

The temporal region and the supramastoid ridge in mesolithic skulls from Padina in the Iron Gate Gorge of the Danube

Studies of the morphological features of the temporal region of mesolithic skulls from Padina in the Iron Gate Gorge of the Danube revealed a very prominent and large supramastoid ridge which is the most striking feature in skulls of both sexes. Mastoid processes were larger in male skulls, but in 25% of the cases there was an overlap between the size of the processes in male and female specimens. The mastoid ridge was prominent in both sexes. The digastric fossa was always well defined in both sexes and in the two thirds of the skull specimens it was deep. The posterior root of the zygoma was prominent in all the skulls, but it was better developed in the male specimens. The parietotemporal suture in both sexes rises above the level of the pterion. There were no morphological or anthropometrical differences between the left and the right side of individual skulls outside the limits of natural asymmetry. All these morphological characteristics of the temporal region may help in racial and sexual diagnosis of the Mesolithic skulls from the Iron Gate Gorge.     

Frequency of the ΔF508 deletion and G551D,R553X and G542X mutations in Yugoslav CF patients

Summary A study was undertaken to find the frequency of the F508 deletion and those of the G551D, R553X and G524X mutations among the mainly Slavic population of Serbia, Bosnia, Herzegovina, and Montenegro and compare the frequencies determined with those in other European populations. The F508 mutation was found to account for about 70% of CF genes in central Jugoslavia, where its frequency is significantly higher than elsewhere in Southern European populations.     

Radiation chemistry of a multicomponent aqueous system relevant to chemistry of cometary nuclei

Summary We have examined a water-dominated multicomponent system after irradiation in the multimegarad dose range with gamma rays from a⁶⁰Co source at both 77 and 310 K. The constituents were simple organic compounds in the proportions in which they appear in a dense interstellar cloud: HCN/CH₃OH/CH₃CN/C₂H₅CN/HCOOH=10.60.20.10.05. The total amounts were adjusted to correspond to a carbon to nitrogen ratio of 1.8 and a water content of about 50% in a cometary nucleus where the dust to volatiles ratio is 1; the total amount of CN-bearing compounds was taken to correspond to 0.4% of the cometary mass. In experiments at 310 K about 40 radiolytic products are identified, among them aldehydes and amino and carboxylic acids. Abundant polymeric material (M_w up to 80,000 daltons) is formed. The basic aspects of radiolysis of the liquid system are present also at 77 K, although at radiation-chemical yields that are lower by one to two orders of magnitude. We have considered the relevance of the present findings to the chemistry of a liquid-water core and the icy layers of a cometary nucleus.     

Radiation chemistry of an aqueous solution of glycine: compounds of interest to chemical evolution studies

Summary We have examined the radiolysis of an O₂-free aqueous solution of glycine at absorbed doses of⁶⁰Co gamma-radiation of up to 20 Mrad. At least 20 compounds are formed during radiolysis, among them several amino acids, an oligoamine, and the nitrogen-free polymers (M_w28,000 daltons). When dicyandiamide is present in the solution of glycine, various nitrogen-containing products, including some polymers (M_w12,000 daltons), are synthesized along with radiolytic products of glycine; polyglycines are not formed. We have determined the radiation-chemical yields of radiolytic-product formation and of decomposition of glycine, and have considered possible free-radical reactions leading to the radiation-induced changes observed.     

Sex differences in the response of rats to drugs affecting GABAergic transmission

The administration of diazepam 1.0 mg/kg decreased the level of plasma corticosterone in female but not in male Wistar rats. Picrotoxin, another drug affecting GABAergic transmission, also brought about an increase of plasma corticosterone in both sexes. However, in order to achieve a plasma corticosterone increase of similar magnitude (more than 500%) a threefold higher dose of picrotoxin had to be given to males. When the convulsive properties of picrotoxin were tested, it became evident that the dose of picrotoxin (2.5 mg/kg) which was subconvulsive in male was almost 100% convulsive in female rats. The existing sex differences in the response of rats to drugs affecting GABAergic transmission might have possible implications in the treatment of GABA system dysfunction.     

Action of neurotensin on size, composition, and growth of pancreas and stomach in the rat

Since the gastrointestinal peptide neurotensin has a stimulatory effect on the secretion of the exocrine pancreas and an inhibitory effect on secretion and motility of the stomach, we investigated whether chronic parenteral administration of neurotensin would affect pancreatic and gastric growth. We therefore infused synthetic neurotensin subcutaneously (dose, 43 and 282 pmol X kg-1 X min-1) in 20 Wistar rats for 2 weeks using Alzet osmotic minipumps and compared pancreatic weight, DNA, RNA, protein, lipase, amylase, pancreatic polypeptide and insulin with these parameters in 10 control rats from the same litter with subcutaneously implanted plastic cylinders approximately the size of the minipumps. In another experiment, synthetic neurotensin (836 pmol X kg-1) was injected intraperitoneally three times a day for 3 days in 12 rats. Thereafter, we measured pancreatic DNA and in vitro incorporation of [3H]thymidine into pancreatic DNA. These effects were compared with the actions of caerulein and normal saline. Long term infusion of the high neurotensin dose induced an increase of pancreatic weight (control: 0.87 g, neurotensin: 1.02 g) and of DNA (control: 2.5 micrograms; neurotensin: 3.5 micrograms) and pancreatic polypeptide (control: 2.4 ng; neurotensin: 7.4 ng) contents, whereas pancreatic protein, RNA, amylase and lipase contents were not stimulated. In relation to DNA, these parameters even were significantly depressed. Insulin remained unchanged. Intraperitoneal injection of neurotensin induced an increase of pancreatic DNA content and stimulated [3H]thymidine incorporation into DNA (control: 11 000 dpm/g; neurotensin: 15 800 dpm/g pancreas). Moreover, long-term neurotensin infusion with the high dose led to a rise in protein concentration and an increase in the thickness of the gastric antrum; antral DNA concentration was insignificantly stimulated. Parenteral neurotensin in the doses and at the times administered, led therefore, to hyperplasia of the pancreas and induced growth of the gastric antrum. It is concluded that neurotensin can act as a trophic factor on pancreas and gastric antrum of the rat. It remains to be determined whether this represents a physiological effect of neurotensin.