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Biomedical subjects

M Moreno

Publications and source records attributed to M Moreno.

At least 217 records · Page 12Linked to original sources

Monoclonal antibodies against the flagellar fraction of epimastigotes of Trypanosoma cruzi: immunoprotection against metacyclic trypomastigotes obtained by immunization of mice with an affinity-purified antigen.

Subcellular fractions of Trypanosoma cruzi (epimastigotes) were assayed in their capacity to induce protective or aggressive effects in experimental animals. The flagellar fraction showed the best immunoprotective properties without tissular aggression. Monoclonal antibodies were prepared from mice immunized with this fraction. One of them, FCH-F8-4, was able to neutralize the infectivity of bloodstream trypomastigotes, to produce complement-mediated lysis on cell culture-derived trypomastigotes and to recognize the surface of trypomastigotes and epimastigotes by immunofluorescence. FCH-F8-4 reacted in Western blotting with several epimastigote proteins ranging from 50 to 150 kDa, showing a more intense reactivity with 4 bands while it reacted with two molecules on trypomastigote preparations (15 and 48 kDa). Purified antibody was coupled to CNBr-activated Sepharose and used to purify antigens from epimastigote extracts. These antigens were used to immunize BALB/c mice in the presence of Bordetella pertussis as adjuvant. Animals were protected against a challenge with 10(3) metacyclic forms of T. cruzi (Tulahuén strain). Only 40% of immunized mice presented detectable parasites in blood after challenge. Parasitemia decreased 90% in relation to controls in those animals. Survival of immunized mice was 100% in all immunoprotection experiments. These results suggest that the epitope recognized by FCH-F8-4 present in the purified antigens keeps the protective characteristics of flagellar fraction and could be a candidate for the development of a vaccine against T. cruzi infection.

Animals↗

Oxygen-derived free radicals mediate the cutaneous necrotizing vasculitis induced by epinephrine in endotoxin-primed rabbits.

To assess the possible role of oxygen-derived free radical in the pathogenesis of cutaneous necrotizing vasculitis (Thomas reaction) induced by epinephrine in endotoxin-primed rabbits, animals were treated with superoxide dismutase (intraperitoneal or local), catalase, allopurinol, or ibuprofen 2 h before inducing the reaction. This is done by an earlobe intravenous injection (10 micrograms) of endotoxin followed by an intradermal injection (100 micrograms) of epinephrine in the shaved abdomen; 18-24 h later, a hemorrhagic-necrotic lesion can be observed at the site of the epinephrine injection. The reaction was completely inhibited by superoxide dismutase, catalase, and ibuprofen, while allopurinol afforded only partial protection. Thus, oxyradicals seem to participate in the pathogenesis of this reaction.

Animals↗

[Corynebacterium jeikeium septicemia].

An adult male with non-Hodgkin lymphoma, who had been admitted to the hospital for more than one month and had received previous antibiotic therapy, developed Corynebacterium jeikeium septicemia. The organism was isolated in four blood cultures and it was multirresistant, being only sensitive to vancomycin, ciprofloxacin, norfloxacin and rifampin. The patient improved clinically and was bacteriologically cured with intravenous vancomycin therapy.

Adult↗

[Percutaneous cholecystostomy guided by ultrasonography. A preliminary experience].

Surgical cholecystostomy is a palliative treatment for cholecystitis and distal biliary obstructions when the general condition of the patient does not allow complex techniques. Percutaneous cholecystostomy (PC) guided by ultrasonography is an alternative to that procedure as well as a method of direct access to the biliary tract for diagnostic examinations (bacteriologic study of bile and percutaneous cholangiography). During one year, 9 female patients, mean age 74 (49 to 90) underwent this approach; 5 patients had cholecystitis, 2 were suspicious of biliary sepsis and 2 had angiocholitis. Because of poor general condition, no other approach was possible in any of the cases. There were no relevant complications. All 5 cases of cholecystitis improved after the procedure although 3 patients died within 30 days of causes unrelated to PC. In two cases biliary sepsis was ruled, and the probe was withdrawn, without complications. The two patients with angiocholitis improved significantly; in both cases it was shown that the cause was cholelithiasis: later on, they were treated by different methods (endoscopic sphincterotomy in one case and surgery in the third case). These preliminary results suggest that PC guided by echography should be included as a routine therapeutic and diagnostic method in the management of digestive diseases.

Aged↗

[Transesophageal Doppler echocardiography in the evaluation of cardiac pathology].

Transesophageal echocardiography is one of the most important innovations that have lately turned up for the evaluation of the cardiac patient. This technical approach consists not only of the study of the two dimensional image but of the cardiac flows obtained with pulsed and color Doppler as well, using a gastroscopic probe to which an ultrasonic transducer has been adapted. In this paper we make a revision of the methodology used in our laboratory. We discuss the utility of this technical approach not only for the study of the ambulatory patient but also for the critically ill patient.

Ambulatory Care↗

Effect of glucocorticoids on gastrointestinal emptying in young broilers.

1. The rates of gastrointestinal (GI) emptying of 8- and 15-d-old chickens treated with 17-hydroxycorticosterone was measured using 14C-polyethylene glycol-4000. 2. The rate of progression of intraluminal contents along the GI tract was decreased by 17-hydroxycorticosterone in both 8- and 15-d-old chickens. Glucocorticoid treatment only delayed the rate of progression of intraluminal contents along the large intestine of the older birds. 3. Delayed transit of intraluminal contents could be explained by a precocious maturation of chick GI tract, induced by glucocorticoids. Loss of responsiveness to glucocorticoids occurs during the second week after hatching, except in the large intestine.

17-Hydroxycorticosteroids↗

[Calculation of cardiac output using Doppler echocardiography].

The authors describe the theoretical basis and general methods for calculating Cardiac Output (CO) by Doppler Echocardiography, using triangulation and planimetric methods ro obtain the Average Velocity (AV) of the flows. They point the more advisable Bidimensional Echocardiography views plans for the measurement of aortic, mitral, pulmonary and tricuspid cross sectional areas (CA) used in calculating the respective outputs (CO = CA x AV x cardiac frequency) and the rate Pulmonary Flow/Systemic Flow (PF/SF). They point out the main technological limitations, alternative methods and places for calculating CO in certain situations (Aortic stenosis, Pulmonary stenosis, etc.). They stress that these are alternative methods to the invasive techniques in the clinic Cardiac Pathologies (infants and adults), many of them treated in Intensive Care units, where the prolonged non invasive monitorization of CO is facilitated by the use of the same CA.

Aorta↗

[Valve insufficiency. Evaluation using color Doppler].

Color Doppler is undoubtedly in the last years main breakthrough in the non invasive definition of regurgitant flows. The detection and quantification of the regurgitant streams, the study of their spatial distribution, the appraisal of their relationships, to anatomical structures, meant a new sight of the physiopathology of valvular insufficiencies. Although this method has an immediate quantitative and qualitative clinical diagnostic interest, its limitations and pitfalls need further investigation. This improvement of technical quality of the equipment and the lowering of its price will surely extend its application beyond its actual limits making color Doppler a routine diagnostic tool in the evaluation of the cardiac patient.

Aortic Valve Insufficiency↗

Trypanosoma cruzi: immune response in mice immunized with parasite antigens.

The humoral and cellular immune responses were studied in mice immunized with flagellar fraction (F), F plus Bordetella pertussis as adjuvant (F-Bp), and microsomal (Mc) subcellular fractions from the epimastigote forms of Trypanosoma cruzi. The immune response was studied before and after the challenge with 50 bloodstream forms of T. cruzi, Tulahuén strain. The immunization with F-Bp, but not with Mc or F and Bp separately, protected mice, in terms of parasitemia and mortality, from the challenge with the parasite. Before the challenge, levels of specific antibodies in mice immunized with F-Bp were higher than in mice immunized with F or Mc. Antibody levels 17 days after the infection were similar in the three groups of mice while nonimmunized mice reached lower levels. Early during the infection nonimmunized infected mice lacked delayed-type hypersensitivity (DTH) responses to parasite antigens and to concanavalin A (Con A). Mice immunized with F-Bp, however, presented positive DTH responses to parasite antigens and Con A both, before and after the challenge with T. cruzi. DTH reaction was transferred with spleen cells. Mice immunized with Mc behaved similarly to infected nonimmunized animals in their reactivity to parasite antigens. These results indicated striking differences between protected and nonprotected mice in humoral and cellular immune responses during experimental T. cruzi infection.

Adjuvants, Immunologic↗

Multisaccular aneurysm in a coronary vein graft.

This report describes an unusual multisaccular vein graft aneurysm that developed in a patient who had undergone aortocoronary bypass with a saphenous vein graft. The aneurysm was a complication of an atherosclerotic lesion. This case supports the belief that aortocoronary vein grafts have an increased susceptibility to aneurysm formation.

Journal Article↗

Chagas' disease: humoral response to subcellular fraction of Trypanosoma cruzi in symptomatic and asymptomatic patients.

The capacity of antibodies in serum from individuals with chronic Chagas' disease to react with antigens in different subcellular fractions of Trypanosoma cruzi varied according to the clinical status of the patients. Antibodies in serum of asymptomatic patients were directed mostly against antigens in the citosol of the parasite, whereas in overtly cardiopathic patients antibodies were directed mostly against antigens in the microsomal fractions.

Adult↗

Monoclonal antibodies against the flagellar fraction of epimastigotes of Trypanosoma cruzi: complement-mediated lytic activity against trypomastigotes and passive immunoprotection in mice.

Trypanosoma cruzi, the causative agent of Chagas' disease, is widely spread in Central and South America. The present report describes three monoclonal antibodies (mAbs) directed against the flagellar fraction of epimastigotes (Ffe) of the parasite, Tulahuén strain. The three mAbs were of IgG1 isotype. Indirect immunofluorescence assays revealed that the three mAbs bind to epimastigotes, the FCH-F8-1 and -3 bind to blood trypomastigotes (BT) and FCH-F8-1 is the only one that binds to amastigotes. Three different proteins of the parasite were recognized by the mAbs in immunoprecipitation assays: an 85 kDa of BT with the FCH-F8-1 mAb, a 40 kDa of Ffe with the FCH-F8-2 mAb, and a 90 kDa of Ffe and of BT with the FCH-F8-3 mAb. Positive complement mediated lysis (CML) of BT and metacyclic forms, obtained from the insect vector feces, were shown by the FCH-F8-1, while FCH-F8-3 only showed CML against the metacyclic trypomastigotes. FCH-F8-2 did not mediate any CML activity. Passive transference of the mAbs to BALB/c mice conferred protection, in terms of survival, ranging from 50 (FCH-F8-2 and -3) to 80% (FCH-F8-1) against a challenge with 1 X 10(3) BT. These results suggest that FCH-F8-1 may be a useful tool to purify proteins in order to investigate their role in immunoprotection experiments.

Animals↗

A comparative study of salivary secretion by parotid and mandibular glands of anaesthetized Capra hircus: effect of pilocarpine.

A study was made of basal secretion and the effect of the infusion of pilocarpine on the flow and composition of saliva in the parotid and mandibular glands of the anaesthetized lactating goat. In the parotid gland there was a basal flow (1.6 +/- 0.29 microliter/min) which was not present in the mandibular gland. There is a statistically significant dose-effect relationship between pilocarpine and salivary flow in both glands. Salival composition and its variation with respect to the flow of saliva did not conform to either of the two glands to an exclusive monogastric or ruminant model.

Animals↗

Influence of superior cervical ganglion stimulation frequency on salivary secretion in the rabbit. Comparative study of parotid and mandibular glands.

Saliva secretion in response to the stimulation of the superior cervical ganglion (S.C.G.) at different frequencies (2, 3, 5, 10, 15, 20 Hz) has been studied in anaesthetized rabbits. The differences between the two major glands in this species were analyzed, with respect to the flow response, potassium, amylase and total protein content during the sympathetic stimulation. The stimulation of S.C.G. increased the salivary flow rate at all frequencies, on both parotid and mandibular gland. In the parotid gland the flow and stimulation frequency show a positive linear correlation which does not appear in the mandibular gland. In conclusion, the differences observed in the response to sympathetic stimulation in both glands seem to be due to distinct patterns of sympathetic innervation on different glandular elements.

Animals↗