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Biomedical subjects

P Torres

Publications and source records attributed to P Torres.

At least 73 records · Page 4Linked to original sources

Effects on dogfish haematology and liver composition after acute copper exposure.

1. Dogfish Scyliorhinus canicula was subjected to experimental acute copper pollution. At the lowest concentration no changes were recorded on haemoglobin levels whilst decreases of the erythrocyte number and haematocrit was found. 2. At higher concentrations near to the lethal doses, a general reduction of all blood parameters was observed. 3. Liver composition (protein, glycogen and lipid levels) was not affected by any copper concentration, over the duration of the experiments. 4. Results are discussed in relation to physiological responses of fish, acute concentration and metal action.

Animals↗

Acute toxicity of copper to mediterranean dogfish.

Acute copper toxicity to dogfish (Scyliorhinus canicula) was determined. Median lethal concentrations (LC50) for 24 and 48 hr were respectively 16 and 4 mg/l. These results are compared with those for zinc in dogfish and with the values for copper toxicity in several teleosts obtained by other authors.

Animals↗

Endoscopic cholangiopancreatography in the infant: evaluation of a new prototype pediatric duodenoscope.

The usefulness of a new pediatric duodenoscope PJF in the diagnosis of neonatal cholestasis was studied in 23 infants with ages ranging from 19 to 150 days. In 22 of 23 infants the papilla was cannulated. In 13 of 14 neonates (93%) with neonatal hepatitis, the common bile duct was opacified and biliary atresia was excluded. In one of two neonates with choledochal cyst, the common bile duct was demonstrated. In six of seven neonates (86%) with biliary atresia, only the pancreatic duct was demonstrated and the diagnosis was suspected. Although absence of a common bile duct opacification does not rule out biliary atresia, ERCP with the new duodenoscope proved to be most useful in the diagnosis of normal biliary tree and served to avoid unnecessary surgery in most infants with neonatal cholestasis.

Biliary Atresia↗

Evidence for an HLA-DR4-associated immune-response gene for Mycobacterium tuberculosis. A clue to the pathogenesis of rheumatoid arthritis?

Antigens of Mycobacterium tuberculosis, M leprae, M scrofulaceum, and M vaccae were injected intradermally in 86 caucasoid leprosy patients, and skin responses (measured in mm of induration at 72 h) were analysed in relation to HLA class II phenotypes. HLA-DR4 was associated with high responsiveness to antigens specific to M tuberculosis but not to antigens shared with other mycobacteria (p = 0.0005). Because DR4 is associated with rheumatoid arthritis (RA) and because a role for M tuberculosis antigens has been suggested both in experimentally induced autoimmune arthritis in rats and in RA, the DR4 associated regulation of the immune response to M tuberculosis may be relevant to the pathogenesis of RA.

Arthritis, Rheumatoid↗

Effects of confinement stress and additional zinc treatment on some blood parameters in the dogfish Scyliorhinus canicula.

Several blood parameters were studied in the dogfish Scyliorhinus canicula subjected to different confinement conditions (transport and maintenance) and zinc contamination. Confinement stress significantly decreased erythrocyte counts (RBCC), haematocrit (Ht), haemoglobin (Hb), leucocrit (Lt), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). Mean corpuscular volume (MCV) did not change with this stress and plasma glucose concentration significantly increased. In fish subjected to confinement stress conditions, Zn treatment significantly decreased Hb, MCH and MCHC and plasma glucose concentration. Ht and MCV did not change and Lt and RBCC significantly increased. Results are discussed related to other stress effects and effects of zinc treatment on fish confined in non-stressful conditions.

Animals↗

Prevalence and specificity of the enhancing effect of three types of interleukin 2 on T cell responsiveness in 97 lepromatous leprosy patients of mixed ethnic origin.

Peripheral blood mononuclear cells from 97 predominantly lepromatous leprosy patients and 11 control subjects were tested in a lymphoproliferative assay for response to Mycobacterium leprae (whole and sonicated), and sonicated M. vaccae, M. tuberculosis, and M. scrofulaceum, in the presence and absence of three types of interleukin 2 (IL-2) (crude, purified, and recombinant). IL-2 enhanced the response to sonicated M. tuberculosis and M. leprae organisms more often in patients than in control subjects, but not significantly so and only in a minority of patients. This effect was significantly more common (though still only found in a minority of 46%) using M. leprae organisms as antigen, than when using sonicates of M. leprae (19%) or M. vaccae (19%). However it was nearly as frequent using sonicated M. tuberculosis, or M. scrofulaceum. Thus in only nine patients was the effect specific to M. leprae. Enhancement by IL-2 could not be related to the type of IL-2 used, the dose of antigen, or the amount of endogenous IL-2 released by the cells tested. Similarly it was not related to the extent to which IL-2 caused increased background proliferation in control wells, which occurred to an equal extent using cells from control subjects, nor was it related to the extent of antigen-driven proliferation. The data have also been analysed in relation to duration of disease (50 years to a few weeks) and ethnic origin. No correlations have been revealed. Thus enhancement by IL-2 of the lymphoproliferative response to mycobacterial antigens does occur using cells from lepromatous leprosy patients, but it is found in a minority of patients, it is not specific to M. leprae, and can occur with cells from normal donors.

Antigens, Bacterial↗

Statistical relations of some blood parameters along recovery from imposed stress in dogfish.

Selected blood parameters (arterial pH, O2 and CO2 tensions, oxygen content, bicarbonate and lactate concentrations, haematocrit, haemoglobin, red blood cell count, mean corpuscular haemoglobin, mean corpuscular volume and mean corpuscular haemoglobin concentration), oxygen consumption and ventilatory frequency were measured 0, 3 and 24 hours after cannulation of the dorsal aorta of 22 dogfish. Correlations were calculated between all pairs of variables along the post-operational recovery period. Results are discussed in terms of the integrated dynamics of the recovery process subsequent to handling, anaesthesia and surgery stress. It is suggested that erythrocyte swelling plays an important role in maintaining tissue oxygen supply during recovery from operational procedures.

Anesthesia↗

Equilenin: a specific fluorescent probe for steroid-protein interactions in sex steroid-binding protein.

Equilenin, a naturally fluorescent steroid, has high binding affinity for human sex steroid-binding protein (SBP). At 4 degrees C the equilibrium association constant is approximately 6 X 10(7) M-1. The fluorescence excitation and emission spectra of the steroid-protein complex indicate that both hydrophobic interactions and hydrogen bonding of the 3'-hydroxyl group of the estrogen are important in its binding to the protein. Equilenin has a substantially different 3-dimensional spatial configuration compared with the normally bound androgens, and yet exhibits very tight binding to SBP. This suggests that SBP undergoes a conformational change to accomodate equilenin.

17-Ketosteroids↗