Biomedical subjects

R Rodriguez

Publications and source records attributed to R Rodriguez.

At least 235 records · Page 13Linked to original sources

PubMed1977

Lysozyme from the insect Ceratitis capitata eggs.

1. Lysozyme from eggs of the Dipterous Ceratitis capitata (Wiedeman) has been purified by ion-exchange chromatography and gel filtration and its physicochemical properties have been investigated. This is the first insect lysozyme characterized so far and it exhibits some properties different to those described for other animal lysozymes. 2. Lysozyme from the insect eggs has a molecular weight of about 23200 and a sedimentation coefficient of 2.4 S. Molecular weight determination by sodium dedecylsulphate gel electrophoresis indicates that the molecule consists of a single polypeptide chain. 3. This lysozyme preparation shows notable stability at acidic pH values and lability at alkline pH values. It shows a single optimum pH at about 6.5.4. Chitinase/muramidase specific activity ratio is around 350 times higher for the insect lysozyme than for the hen egg-white enzyme. 5. The amino-acid composition shows the presence of one tryptophan residue per molecule of enzyme. This fact differentiates the lysozyme from insect eggs from other animal and plant lysozymes. From the amino acid composition, the absorption coefficient and the partial specific volume are calculated. 6. Glycine is the N-terminal residue.

Amino Acids↗

PubMed1976

Patterns of total and ionized calcium and other electrolytes in plasma during and after general surgery.

Thirteen patients were studied during two hours of anaesthesia for abdmonial operations and for an hour post-operatively. Serial venous blood samples were taken for determination of plasma total and ionized calcium, acid-base variables, Na, K, Mg, PO4 total proteins and parathyroid hormone. One group of patients received 5 per cent dextrose/water and the other 5 per cent dextrose in Ringer's solution, at 250 ml per hour. Total and ionized calcium levels decreased toward the end of operation and an hour later, associated with respiratory alkalosis. Parathyroid hormone increased at the end of operation, as an effect of the decreased ionized calcium. The general effect was mild haemodilution with all the other electrolytes decreasing, as did total protein concentration.

Adult↗

PubMed1976

Plasma ionic calcium levels following injection of chloride, gluconate, and gluceptate salts of calcium.

The ionic equivalency of three calcium salts was tested in 15 patients undergoing cardiac surgery with extracorporeal circulation. Of the three salts tested (chloride, gluconate, gluceptate), only calcium chloride showed a reproducible and highly significant relationship between the increase in total calcium and the increase in ionic calcium. It is suggested that extracorporeal circulation may be one clinical situation in which use of a calcium electrode may be of major value. The marked distortion of plasma proteins and pH, the addition of large amounts of citrate, and the differences between various calcium salts indicate that it is probably not possible to predict ionic calcium with assurance and that direct measurement may be necessary for optimal therapy.

Buffers↗

PubMed1975

Primary structure of cytochrome c from the insect Ceratitis capitata.

The complete amino acid sequence of cytochrome c from the Dipterous Ceratitis capitata (serie Acalypterae) has been determined by combining automatic and manual methods of sequence analysis. No overlaps between positions 79 and 80, 86 and 87, 91 and 92 as well as between 99 and 100 were obtained. The alignment of these peptides was done by homology with other sequences of cytochromes c from insects already described. Comparison with the sequences of cytochromes c of other Diptera studied so far shows three changes (positions 50, 60 and 61, according to vertebrate cytochrome c numeration) from the Acalypteran Drosophila melanogaster and five changes (positions 9, 36, 50, 60 and 61) from that of the Calypteran Haematobia irritans.

Amino Acid Sequence↗

PubMed1975