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Biomedical subjects

R Rodriguez

Publications and source records attributed to R Rodriguez.

At least 127 records · Page 7Linked to original sources

Cardiac and thoracic vascular injuries: anesthetic considerations.

Heart and thoracic vascular injuries account for 1% to 4% of trauma, but the potential for mortality and morbidity makes preanesthetic evaluation important. A rational management plan initiated from the time the patient is first seen in the emergency room will guide anesthetic management. Our review of 65 patients with cardiac and intrathoracic vascular injuries showed the preoperative evaluation facilitates selection of airway and anesthetic management. Extensive monitoring and placement of large intravenous lines allow prompt detection and treatment of hemodynamic deterioration.

Adult

Sex hormone influences on yawning behavior.

Young male albino rats yawn significantly more than females or castrated males when injected with physostigmine (0.10 mg/kg). Treatment with testosterone (100 micrograms daily) during seven days restores cholinomimetically induced yawning in castrated males, and increases yawning in normal and androgenized females. Treatment with estradiol (200 micrograms daily) during one week does not modify physostigmine induced yawning behavior in castrated males nor in androgenized females.

Animals

Serotonergic modulation of yawning.

Yawning induced by intraperitoneal (IP) injection of physostigmine (0.15 mgKg-1), in infant or adult rats is potentiated by Lu 10-171 (0.5-10 mgKg-1), a selective serotonin uptake inhibiting drug, which, by itself does not induce yawning. This effect is counteracted by metergoline (5-10 mgKg-1, IP) which blocks serotonin postsynaptic receptors. It is suggested that serotonin may exert a positivie modulating effect on yawning.

Animals

A simple, one-step chromatographic procedure for the purification of lysozyme.

A rapid method for the purification of lysozyme (mucopeptide N-acetyl-muramoylhydrolase, EC 3.2.1.17) from hen egg-white has been devised. It was that gel filtration chromatography on agarose columns can be used selectively to purify lysozyme, due to the fact that this protein interacts with the agarose matrix and elutes later than the corresponding total volume for the column. Thus, lysozyme is directly obtained in a relatively pure form and with a high specific activity. In principle, this simple method can be used to prepare lysozymes from other sources.

Animals

A new antiviral agent (P2) in the purpose of treatment of bovine leukemia.

Thirty five cows and heifers, all positive reactors on ID test and all showing persistent lymphocytosis (15 with markedly enlarged lymphatic glands) were divided in 4 experimental groups and treated with P-2, a new antiviral agent, previously shown to be effective for several RNA type viruses. In table are indicated groups, range of dosages of P-2, and variability in WBC and lymphocyte. White blood cells found to be at the lowest level (P less than 0.02) one month after treatment with P-2, a less marked reduction (P less than 0.05) was found when the experiments ended at 7 months. A significant (P less than 0.05) fall in lymphocytes was found one month after treatment but this was not significant at the end of experiment. In 12 animals with lymphosarcomatous disease significant retraction of lymphatic glands. It is not clear whether the sudden drop in WBC and lymphocytes is due to the virostatic effect of drug or an effect of drug per se. New series of experiments will be made to treat BLV with two agents: one virostatic and other cytostatic.

Animals

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

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

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

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