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Biomedical subjects

R García

Publications and source records attributed to R García.

At least 199 records · Page 11Linked to original sources
PubMed1988

Olive (Olea europea) pollen allergens--I. Immunochemical characterization by immunoblotting, CRIE and immunodetection by a monoclonal antibody.

The pattern of reactivity of the Olea europea crude extract antigens was analysed after electroblotting to nitrocellulose from SDS-PAGE. The antigens contained in the 17, 19 and 42 K bands were most reactive with specific IgE from individual sera. Following immunization with a crude extract, one monoclonal antibody (OL-1) was raised against components which exhibited IgE binding capacity in electroblotting and crossed radioimmunoelectrophoresis (CRIE). Monoclonal antibody OL-1 reacted with the 17 and 19 K antigens and with three arcs of crossed immunoelectrophoresis (CIE), one of which is considered to contain a major allergen by CRIE.

Allergens↗
PubMed1988

Olive (Olea europea) pollen allergens--II. Isolation and characterization of two major antigens.

A dialyzed extract of olive (Olea europea) pollen was fractionated by anion exchange chromatography on DEAE-Sepharose CL-6B using a discontinuous gradient of ammonium bicarbonate. The most important protein allergen was obtained from the 0.3 M fraction after gel filtration on Sephadex G-100 and separation by lentil-lectin Sepharose-4B. The major allergen of olive pollen was contained in the effluent and was designated Olea Antigen I. This material inhibited the RAST activity of 15 patients' sera that were tested. Analytical IEF demonstrated a major band at pH 5.3 and two minor ones at pH 5.6 and 5.0. When these were run into SDS-polyacrylamide gel electrophoresis in a second dimension, all were separated into two bands of mol. wt 17 and 19 K. A second protein, which is the next most important allergen, Olea Antigen II, was obtained from the 0.5 M fraction by chromatofocusing in a 4-7 pH range followed by filtration on Bio-gel P-30. Olea Antigen II had a mol. wt of 8 K as assessed by SDS-PAGE. IEF analysis displayed one main band at pH 3.6 and two minor bands at pH 3.8 and 4.0, respectively. OL-1, an anti-Olea europea monoclonal antibody (MAb) previously reported by us Lauzurica et al. (1988) reacted with the 17 and 19 K antigens from the crude extract and with Olea Antigen I but not with Olea Antigen II.

Allergens↗
PubMed1988

Relationship between glomerular filtration rate and renal blood flow at different levels of protein-induced hyperfiltration in man.

1. We studied the relationship between changes in glomerular filtration rate (GFR) determined as inulin clearance (CIn), and changes in renal blood flow (RBF), determined as p-aminohippurate clearance (CPAH), after the ingestion of a large (1.35 +/- SEM 0.04 g/kg, n = 9), moderate (1.08 +/- 0.03 g/kg, n = 10) or mild (0.55 +/- 0.02 g/kg, n = 8) protein load given as a meat meal. Control subjects (n = 10) received a carbohydrate meal. 2. CIn and CPAH increased after a protein meal. Two hours after eating the test meal, GFR levels were (mean +/- SEM) 160.0 +/- 13.8 (P less than 0.05), 141 +/- 7.69 and 127.8 +/- 9.07 ml/min in the groups that received a large, moderate and mild protein load, respectively. Peak CIn values after the meal were 211.6 +/- SEM 14.92 (P less than 0.001), 177.5 +/- 10.88 (P less than 0.01) and 129.0 +/- 8.72 ml/min after a large, moderate and mild protein load, respectively. 3. At peak GFR levels after the meal, filtration fraction (FF) (CIn X 100/CPAH) increased significantly (P less than 0.02) with the large and with the moderate protein load, but not with the mild protein load. 4. There was a significant (P less than 0.001) positive relationship between increments of FF and increments of CIn, but not CPAH, whether the values were expressed as post-meal/pre-meal ratios or as absolute changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Induction of reversible shock by Escherichia coli lipopolysaccharide in rats. Changes in serum and cell membrane parameters.

Reversible endotoxic shock was induced in adult rats by i.v. injection of Escherichia coli O111:B4 lipopolysaccharide (1.6 mg/100 g). The shock progression was evaluated by measuring serum glucose levels as well as activities of aspartate aminotransferase (GOT) and alkaline phosphatase in serum. A rapid increase of serum glucose levels occurs, after LPS injection, followed by hypoglycaemia (minimum values at 6 h) with progressive reversion to control values. Serum GOT activity increased (twofold) 6 h after endotoxin administration and returned to control values at 72 h. No appreciable changes occurred in serum alkaline phosphatase activity. Endotoxaemia produced a decrease in the cytochrome P-450 levels in all target organs considered: lung, adrenal glands and liver. The progressive decrease in the serum albumin concentration as well as changes of the physical properties of the plasma membranes observed in vivo, can not be explained only by direct interaction of endotoxin with the target organs, underlining the importance of serum mediators in the induction of the shock response.

Adrenal Glands↗
PubMed1988

Evidence of cell-mediated immune contrasuppression in lepromatous leprosy: modulation of a putative T contrasuppressor cell-subset.

Some lepromatous leprosy (LL) patients are characterized by the presence of activated suppressor T cells that specifically inhibit the immune response to Mycobacterium leprae antigens. Immune contrasuppressor (CS) cell activity antagonize suppressor function. Whereas the former function has been extensively studied in leprosy, the latter has not been explored. We studied the peripheral blood mononuclear cells (PBMNC) of 20 patients with leprosy (10 lepromatous and 10 tuberculoid) and six healthy contacts. We found CS-like activity in the PBMNC from some LL patients when assayed in vitro using lepromin as antigen. This CS-like function was found in CD8+, vicia villosa adherent (VV+) T cells. CS-like activity was not detected in PBMNC from either tuberculoid patients or healthy contacts. Pre-treatment of CD8+, VV+ cells with either recombinant IL-2 (5 u/ml) or recombinant interferon-gamma (1,000 u/ml) did not modify significantly their putative CS function. However, in 50% of lepromatous patients the pre-incubation of CD8+, VV+ cells with both lymphokines together increased significantly the CS-like activity. These data suggest that the in vitro immune response to M. leprae in some LL patients can be augmented by either modifying numerically the contrasuppressor T cells or activating them with lymphokines.

Antigens, Bacterial↗
PubMed1988

Urinary prostaglandin E and kallikrein activity in glomerular hyperfiltration induced by a meat meal in man.

Because renal vasodilator systems may be involved in the physiologic response to a protein meal, we studied the relationship of prostaglandin E (PGE) and kallikrein (KE) activity to the renal hemodynamic changes induced by a meat meal. Ten normal subjects on a maintenance diet providing 1 g protein per kg and 100 mmol Na daily were studied before and after a meal of 86 g of meat protein, once without medication, and again after treatment with indomethacin (150 mg daily for 3 days before and 50 mg the morning of the test). A carbohydrate meal of similar caloric, Na and K content was used in control studies. Glomerular filtration rate (GFR, inulin clearance), renal blood flow (RBF, para-aminohippurate [PAH] clearance), PGE and kallikrein urinary excretion were determined. All studies were performed during water diuresis to avoid bladder catheterization. The protein load induced an increase in GFR (ml/min, mean +/- s.e.m.: baseline 107.2 +/- 6.05, peak postmeal 146.4 +/- 6.79, p less than 0.01) and RBF (baseline 529.7 +/- 42.9, postmeal 678.9 +/- 61.9, p less than 0.05). Renal hemodynamic changes were unrelated to changes in urinary PGE and KE excretion. Indomethacin treatment inhibited PGE excretion by 73% during the test meal but did not modify the protein-induced hyperfiltration. Our results suggest that these renal vasodilator systems are not primarily responsible for the hyperfiltration response. In addition, the data show that inhibition of prostaglandin synthesis is not a practical approach to prevent glomerular hyperfiltration in clinical practice.

Adult↗
PubMed1988

Short-term treatment with captopril in hypertension due to acute glomerulonephritis.

We report that the inhibition of the angiotensin converting enzyme is an effective short-term treatment of low-renin hypertension in acute glomerulonephritis (AGN). We treated 9 patients who had AGN with moderate to severe hypertension and suppressed plasma renin activity with 25-50 mg of captopril per os every 6-8 hours. Control of blood pressure was achieved in 1-2 hours and maintained thereafter. Captopril therapy was associated with an increase in plasma renin activity, a decrease in plasma aldosterone and an increase in the urinary excretion of prostaglandin E2 and kallikrein, independent of changes in urine output. Creatinine clearance increased 39.6 +/- SE 15.2% with captopril and decreased in the postcaptopril period, suggesting that captopril exerted a reversible effect on glomerular filtration rate, possibly modifying intrarenal vasoconstriction. Our study shows that rapid control of hypertension in AGN may be obtained with oral inhibition of the angiotension converting enzyme. Stimulation of PGE2 and kinins, as well as angiotensin II blockade appear to contribute to the hypotensive effect of the drug; by inference, the suppressed activity of vasodilator systems seems to play a significant role in the hypertension of AGN.

Acute Disease↗
PubMed1985

Response to acute protein load in kidney donors and in apparently normal postacute glomerulonephritis patients: evidence for glomerular hyperfiltration.

25 kidney donors who had undergone nephrectomy 1-11 years ago, 35 patients followed up for 13 years after poststreptococcal glomerulonephritis, and 44 controls were investigated for their capacity to increase their glomerular filtration rate after an acute oral load of 100-150 g of protein. Their mean baseline creatinine clearances (Ccrl, ml/min +/- SEM) were similar (controls 108.5 +/- 6.1; kidney donors 115.4 +/- 8.54; postacute nephritis 82.0 +/- 6.45), but the postmeal filtration rates (Ccr2) were significantly (p less than 0.05) lower in the two patient groups (kidney donors 137.4 +/- 11.60; postacute nephritis 90.3 +/- 5.30) than in the controls (161.5 +/- 9.39), as was the Ccr2/Ccr1 ratio (p less than 0.01, controls 1.58 +/- SEM 0.10; kidney donors 1.20 +/- 0.07; postacute nephritis 1.18 +/- 0.08). In normal individuals the degree of change was inversely related to the initial creatinine clearance and varied from 135.6% +/- 43.0 when Ccrl was less than 70 ml/min to 32.7% +/- 9.50 when Ccrl was 130 ml/min or higher. This relative response was decreased in kidney donors and postacute nephritis patients. Kidney donors and apparently normal postacute nephritis patients thus have diminished renal reserve capacity.

Acute Disease↗
PubMed1983

Cationic antigens in poststreptococcal glomerulonephritis.

Antigen charge is an important factor in the pathogenesis of experimental immune complex glomerulonephritis. Its potential role in man was investigated in post-streptococcal glomerulonephritis, a disease where the causative agent is known. Cationic, extracellular streptococcal antigens were detected in 8 of 18 renal biopsies from patients with acute poststreptococcal glomerulonephritis (APSGN). The antigen was found mainly in earlier biopsies in which both IgG and IgM were present. Patients' sera taken at the time of biopsy contained antibody to cationic, streptococcal antigens. Cationic moieties are known to have affinity for the glomerular basement membrane and it is possible that the type of antigen described here initiates APSGN via in situ immune complex formation.

Antibodies, Bacterial↗