Thymosin-beta 4 gene. Preliminary characterization and expression in tissues, thymic cells, and lymphocytes

A cDNA for rat thymosin-beta 4 was used to investigate the expression of this gene in different tissues, thymic cells, and lymphocytes. Hybridization analysis of total RNA from 13 rat tissues demonstrated the presence of an 800 nucleotides-long mRNA in all the tissues surveyed, with the highest levels in spleen, thymus, and lung. Examination of thymic cells showed that the thymosin-beta 4 gene is predominantly expressed in thymocytes. The thymosin-beta 4 mRNA was also studied in Ig+ and Ig- lymphocytes, being fourfold more abundant in Ig- than Ig+ splenic lymphocytes, whereas similar levels were found in both types of blood cells. The analysis of RNA from T cells at different maturation stages evidenced slight differences in their thymosin-beta 4 mRNA content, indicating that thymosin-beta 4 gene expression is not clearly related to the differentiation process of T cells. All these results do not support the roles for thymosin-beta 4 in cellular immunity and differentiation of lymphoid cells, suggesting a more general function for this peptide. Preliminary characterization of the human beta 4 gene by restriction analysis disclosed a complicated pattern consistent with multiple genes and/or introns. The analysis of genomic DNA from different species ranging from humans to Escherichia coli showed that this gene is only highly conserved in mammals.     

Photoperiodic variations in plasma concentration of testosterone in the rabbit

The photoperiodic variations of testosterone plasmatic levels in male rabbits have been studied. The animals were subjected to the influence of three circadian rhythms: 12/12, 14/10 and 10/14 h of light/darkness. The hormone assay was carried out using an enzymeimmunoassay method (Competitive ELISA). Blood samples were of two different types: seriated and non-seriated, to find if these might be any differences in the results. It is concluded that testosterone plasmatic levels are within physiologic values (0.3-10.0 ng/ml), although differences depending on the light/darkness cycle and on the type of blood extraction are remarkable; for this reason the selection of the circadian rhythm will depend on the experimentation that is to be carried out.     

Certain aspects of so-called post cholecystectomy syndrome

The study involved 126 patients with cholelithiasis. Set of biochemical, radiological, endoscopic, and ultrasound examinations was carried out in these patients. Potential coincidence of clinical symptoms and causes of so-called postcholecystectomy syndrome was the purpose of a 1-year follow-up studies. The significance of the results are discussed.     

Monotherapy with acebutolol in hypertensive diabetic patients

Monotherapy of hypertension with acebutolol in diabetics in daily dose of 200-400 mg for 6 weeks induced only non-significant and practically not acceptable hypotensive effect in groups of patients with hypertension and diabetes type I or type II without nephropathy. No therapeutical effect was observed in hypertension in diabetics type I with nephropathy. Administration of acebutolol to hypertensive diabetic patients with nephropathy resulted in tendency to increase in albuminuria. Values of creatinine clearance did not change at the same time. Also no effect of acebutolol on glycemic or lipid indices was observed. The lack of clear hypotensive effect under studied conditions of acebutolol in diabetic patients contrasted with its significant action in comparative group of hypertensive non-diabetic subjects.     

The role of insulin in the control of triacyglycerol (TG) in the rat skeletal muscles

The role of insulin in the control of triacyglycerol (TG) in different types of skeletal muscle has not been fully recognized so the aim of the present study was to fill this gap. The experiments were carried out on control rats, those fed with olive oil or fed with the oil and treated with insulin and on streptozotocin diabetic animals at rest and there after exercise till exhaustion. The level of TG was measured in the white and red layers of the vastus lateralis, the soleus and the diaphragm. It was found that acute feeding with olive oil had no effect on TG level in either muscle type examined. Insulin administered to rats fed with oil increased TG level in the red vastus. Streptozotocin diabetes caused an increase in TG level in muscles with high oxidative potential. Exercise lowered the level of TG only in the red vastus of the diabetic rats. It is concluded that insulin may increase muscle TG level. Accumulation of TG in muscles of rats with acute diabetes is likely to be a result of the high plasma free fatty acid concentration. Acute insulin deficiency did not affect the muscle TG response to exercise.     

A new spectrophotometric assay for dopachrome tautomerase

The existence of a new enzyme involved in mammalian melanogenesis has been recently reported. The names dopachrome oxidoreductase and dopachrome tautomerase have been proposed for the enzyme. So far, this enzyme has been assayed at 475 nm on the basis of its ability to catalyze dopachrome decoloration. This method presents two major problems, derived from the instability of the substrate (dopachrome): (1) dopachrome must be prepared immediately before use, and (2) the rate of dopachrome decoloration in the absence of the enzyme is not negligible, and, furthermore, is enhanced by non-enzymatic agents. In order to overcome these problems, we present a new procedure that combines: (1) a quantitative, fast and easy way to prepare dopachrome from L-dopa by sodium periodate oxidation; (2) a spectrophotometric method in the UV region, at 308 nm, based on following the absorbance increase due to the enzyme-specific tautomerization of dopachrome to 5,6-dihydroxyindole-2-carboxylic acid as opposed to the absorbance decrease due to the spontaneous decarboxylative transformation of dopachrome into 5,6-dihydroxyindole. The advantages of these methods as compared to the previously used procedures are discussed.     

Environmental influences on the sensitization by drugs measured in peripheral blood lymphocyte chromatin

An "allergo-kinetic" method was introduced, which measures early changes of nuclear chromatin structure of lymphocyte subpopulations. The method is used as an in vitro test for drug allergy. The comparison of data from two sampling places (Budapest-Esztergom) shows the following results: The drug allergy scores (obtained from T-cells) may reflect environmental influences on the population under study. During the 13 months period after Atomic Reactor accident in Chernobyl, both the frequency of severe skin manifestations and that of organ manifestations (without skin lesions) increased. The ratio of negative test results decreased in both of drug allergic patient groups (small town = Esztergom, large city = Budapest)--tendency to polysensibilization. The scores obtained in drug related groups of generalized urticaria and Quincke's oedema increased significantly within 13 months after accident followed by a normalization in the subsequent year.     

Replication banding in the chromosomes of the European eel (Anguilla anguilla)

The chromosomes of the European eel Anguilla anguilla have been analyzed with a replication banding technique from lymphocyte cultures treated with 5-BrdU. This technique allows us to identify with high resolution the individual chromosome pairs and to differentiate classes of chromatin by the order of replication. The replication banding obtained on the chromosomes of European eel can be related with the structural bands described in this species.     

Evaluation of the use of phase-specific gene promoters for the expression of enological enzymes in an industrial wine yeast strain

Summary Genes as POT1, HSP104 and SSA3, which are late expressed in laboratory culture conditions are expressed only during the first few days in microvinifications in wine yeast cells. This effect is probably due to the different growth conditions and leads to useless levels of enzyme activity for a reporter gene. However the ACT1 promoter, which is constitutively expressed in laboratory conditions, produces sufficient amounts of enzyme activity in late fermentation phases.