Biochemistry and experimental biology最新文献

1. Pronase action on ventral nerve cord ganglia in Bombyx mori L. larvae has been studied from different points of view. 2. Microelectrode penetration in the nervous cell is facilitated by exposure of the tissue to the enzyme. 3. Ultrastructural observations show that pronase action affects mainly the fibrous sheath of the tissue, leading to a partial desheathing of the ganglion. 4. Pronase treatment does not affect significantly the ionic concentrations in the nerve cord.

In this note we described the E.L.I.S.A. test, applied to diagnostic of Toxoplasmosis, at short period of reaction. The reading has been made with naked eye. The examined sera have been previously titred to the Dye test. The authors have been able to establish the antigenic dilution as well as the short period of the best reaction to carry on the E.L.I.S.A.

Literature fully reports that a polyunsaturated fatty acids suitability reduces cholesterolaemia levels. Many authors regard as very useful for the same purpose phospholipid intakes; certainly this event requires LCAT availability too. In this work we have tried to check EFA, phospholipid and different mixtures of both effects on rat's cholesterolaemia. The research was divided in two tests (3 days long the first, 60 days long the second); the best results for mentioned steroid control, were not proportional as one could suppose, but the effect was positive only for a particular range of mixtures. The achieved results may be explained with an extremely favourable substrata availability, both for quality and amount.

A radioisotopic method for a rapid assay of adenosine deaminase in human lymphocytes is proposed here. [2-3H] adenosine, as substrate, has been employed for the enzymatic assay. The products of reaction have been resolved by thin layer chromatography on PEI cellulose. The plates were developed with distilled water and inosine spots absorbing in the U.V. were eluted with 0.1 N HCl. The eluates obtained from the inosine spots were employed for radioactive measurements.

Codeine sulfate which is obtained from opium or made by methylating morphine has been found to induce a number of anomalies in the meiotic chromosomes of S. fossilis. Feulgen technique was undertaken for experimental studies. At high doses abnormal metaphases, agglutination, achromatic lesions, some breaks and chromosomal scattering were evident. However, the frequency of abnormal metaphases was high amongst the rearrangements. The susceptibility of meiotic metaphase during peak period of breeding is indicative of inhibition in the division activity.

Effect of partial hepatectomy and administration of actinomycin D to partially hepatectomized dogs was studied on the amounts of serum and betalipoprotein phospholipids and incorporation of NaH2 32PO4 into various phospholipid at various periods after surgery. Partial hepatectomy generally did not affect the amounts of various phospholipids as compared to the sham operated controls, though the values in experimental dogs were lower than the control. Actinomycin D did not affect serum and betalipoprotein phospholipids as compared to the sham operated controls. Partial hepatectomy reduced the incorporation of NaH2 32PO4 into all phospholipid components of serum and betalipoprotein as compared to sham operated controls. However, administration of actinomycin D to partially hepatectomized dogs stimulated the incorporation of NaH2 32PO4 into all serum and betalipoprotein phospholipid components, being more prominent in the case of lysophosphatidyl-choline as compared to the partially hepatectomized dogs.

The glycogen has been isolated from buffalo (Bos Bubalus bubalis) liver, purified several-fold, and characterized to compare with rabbit and oyster glycogen. Once-purified buffalo glycogen has been found to contain 1.3% protein, 0.16% nitrogen, 0.69% phosphorous, no lipids, and nucleic acids sufficient to cause absorption at 260 mu. The buffalo glycogen may be used as a potential substitute for rabbit and oyster glycogen after two-or three- purifications and a treatment with DEAE-cellulose.

Biopsy of the finger tip in 42 cases of cirrhosis of the liver showed: a) aspecific changes in type II, group B AVA's, with pictures characterized by unusual perisegmentary neofibrillopoiesis; b) areas of fibrinoid necrosis, indicative of the general participation of connective tissue in the cirrhogenic process.

The general kinetic parameters of IMP:NAD+ oxidoreductase, were investigated at 37 degrees C in normal human serum. These included substrate - velocity relationship, Km (IMP), Km (NAD), as well as the effect of temperature and pH on the kinetics of the reaction. Optimum conditions of IMP, NAD+ oxidoreductase in serum of normal Iraqi individuals at 37 degrees C were investigated. The optimum IMP concentration was found to be 0.6166 mM and the optimum NAD+ concentration was 6.28 mM, while the optimum pH for the reaction was found to be 8.3. The enzyme shows low stability even when the sera were incubated at low temperature. The activity of the enzyme is proportional to the serum concentration and its optimal temperature for the reaction was 37 degrees C. The enzyme was found to be inhibited by XMP, GMP competitively with Ki values of 0.0724 mM and 0.1583 mM respectively. The inhibition by thyroid hormone (T4) was studied giving a Ki value of 2.25 X 10(-6) mM. The mechanism of enzyme action was found to follow ordered sequential mechanism.