Search PubMedSearch

Biomedical subjects

R Rodriguez

Publications and source records attributed to R Rodriguez.

At least 163 records · Page 9Linked to original sources

Isolation, characterization, and amino acid sequence of a ubiquitin-like protein from insect eggs.

A protein with a primary structure identical to that of human and bovine ubiquitin has been purified from insect eggs. The isolation, secondary structure, and amino acid sequence of this ubiquitin-like protein are reported. The sequence was determined by automatic Edman degradation of the intact molecule as well as by the manual sequence analysis of the enzymatic cleavage products. The polypeptide has 74 amino acid residues and internal homology regions. Interactions of the protein with peptides results in protective effects against proteolysis. This paper reports for the first time the presence of the ubiquitin molecule in invertebrates.

Amino Acid Sequence

Computed tomography in obstructive jaundice. Part I: The level of obstruction.

Computed tomographic (CT) scans of 67 cases of obstructive jaundice were analyzed to determine the value of CT in detecting the level of obstruction. The cases were divided into four groups by anatomical segments, according to the number of visualized hypodense ringlike structures produced by the dilated bile duct, as seen in axial sections made 1 cm apart. Gallbladder size, dilatation of intrahepatic biliary radicals and the pancreatic duct, visualization of tumor masses, and condition of the bile duct below the obstruction were other variables used to determine the level of obstruction. The overall accuracy of CT in determining the exact level has been 97%. The most reliable indicator is the number of rings, which has excellent correlation with the results of direct cholangiography. The diagnostic value of all other variables is limited to specific cases.

Cholecystography

CT cholangiography: multiplanar reconstruction in obstructive jaundice.

The value of multiplanar reconstruction (MR) in coronal and sagittal planes from axial transverse computed tomography (CT) slices was investigated in cases of obstructive jaundice. The clinical application for this technique lies in its potential to depict the dilated bile duct to the point of obstruction providing a "map" of the biliary tree. We call the technique "CT cholangiography." The images obtained were of good quality in 77.5% of the cases. Coronal planes proved better than sagittal in demonstrating the bile duct. Furthermore, MR added information concerning the cause of obstruction in 27% of the cases. Improvements in technique will refine the method and likely eliminate the need for invasive cholangiography in many cases of obstructive jaundice.

Carcinoma

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