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Biomedical subjects

A García

Publications and source records attributed to A García.

At least 379 records · Page 21Linked to original sources
PubMed1991

99Tcm-HMPAO leucocyte scintigraphy in the diagnosis of bone infection.

The utility of 99Tcm-HMPAO leucocytes has been studied in combination with 99Tcm-MDP bone scanning in the diagnosis of bone infection in a series of 50 patients with a clinical suspicion of bone infection. Thirty-three patients were referred to our Service from the Department of Orthopaedic Surgery (Group A) and seventeen from the Infectious Disease Unit (Group B). A total of 52 lesion sites were studied. The leucocyte and bone studies were performed within four days. The leucocyte scan was obtained at 30-60 min and 4-6 h after i.v. injection of 370 +/- 74 MBq of 99Tcm-HMPAO leucocytes. After confirming the scintigraphic findings, the results obtained were: Group A, 12 true positive, 21 true negative and 2 false positive; and in Group B, 5 true positive, 9 true negative and 4 false negative. The overall sensitivity was 80.9% with a specificity of 93.7%. Although the high bone marrow activity seen with 99Tcm-HMPAO leucocytes may reduce sensitivity, very good results were obtained in bone infection. The use of 99Tcm means great progress in the radiolabelling of white blood cells in terms of availability and better image quality. The combination of 99Tcm-HMPAO leucocytes and 99Tcm-MDP can be recommended as one of the most suitable methods for use in the diagnosis of bone infection, especially in patients with previous bone disease.

Adolescent↗
PubMed1991

Tolerance to aztreonam in patients allergic to beta-lactam antibiotics.

To evaluate the safe use of aztreonam (AZT) in patients allergic to penicillins and other beta-lactam antibiotics we studied 29 patients from a group of subjects allergic to beta-lactams, diagnosed by presenting systemic reactions after skin tests or challenge tests. Skin tests with benzylpenicilloyl (BPO), benzylpenicilloate, benzylpenicillin, ampicillin, amoxicillin, cephamandole and AZT, radioallergosorbent test (RAST) to BPO and AZT, RAST inhibition and challenge tests were performed. One patient was skin test-positive to AZT, another patient was RAST AZT-positive. IgE antibodies were specific to AZT as demonstrated by RAST inhibition studies with AZT coupled to epsilon-amino caproic acid. Nevertheless, AZT was unable to inhibit either a pool of sera or individual sera positive to BPO. Although all our 29 patients tolerated the administration of AZT (including those with skin test or RAST positive) and AZT appears to be safe in these subjects, this does not indicate that all beta-lactam-allergic patients tolerate AZT administration.

Anti-Bacterial Agents↗
PubMed1991

Partial purification of a novel N-ethylmaleimide-activated translational inhibitor from adult rat brain.

A translational inhibitor that is activated by N-ethylmaleimide treatment can be found in the postmicrosomal fraction prepared from the brain of adult rats, but it is almost undetectable in the same fraction prepared from suckling animals. The inhibitor is thermolabile and remains in the supernatant fraction after precipitation at pH 5. During the purification procedure, the inhibitor in its unactivated state binds to the anion exchanger (diethylaminoethyl-cellulose) but not to the cation exchanger (phosphocellulose). Treatment with N-ethylmaleimide increases inhibitor affinity for the cation exchanger, and this chromatographic step purifies the inhibitor by 143-fold. Both the thermolabile nature and the behavior of the inhibitory activity during the different steps of the purification procedure suggest that this activity is most probably due to a protein. Although the addition of initiation factor 2 reverses the inhibition of protein synthesis in the presence of ATP and Mg2+, the inhibitor does not phosphorylate any of the initiation factor subunits "in vitro," which indicates that it does not contain any intrinsic protein kinase activity. However, its presence in both a crude and a purified preparation of a kinase of the alpha subunit of a brain eukaryotic initiation factor increases the phosphorylation of the alpha subunit of the initiation factor. The mechanism of action of this inhibitor is discussed.

Aging↗
PubMed1991

Evaluation of thallium myocardial-perfusion imaging by means of washout parametric images: a simulation study.

A method for the evaluation of myocardial perfusion with 201Tl scintigraphic images is presented. The method is based on making a pixel-by-pixel comparison of the stress and the redistribution images aligned by using bidimensional correlation techniques between the nonpathologic regions of the myocardium. The comparison is made by means of parametric images of the washout, which are evaluated by calculating separately the mean values in the normal and the abnormal regions. The study is carried out on controlled models that contain myocardium, an artifact, and noise. The results show the suitability of the method and confirm the validity of its application to individualized studies of clinical interest.

Computer Simulation↗
PubMed1991

[The cardiac anatomical and functional changes in a group of young type-1 diabetics without microangiopathy].

We study 71 type I diabetics and 25 controls, trying to analyze the anatomical and functional changes due to diabetes. The diabetics, with a mean age of 18.4 +/- 8.2 years, were strictly selected excluding any disease and treatment besides insulin. In 66, and echocardiographic M mode and 2D study was done to calculate wall thickness, cavity dimensions and systolic function indexes; in all, Eco-Doppler analyzing 9 diastolic function indexes. The results showed an increase in septal thickness in diabetics (p less than 0.01 in diastole and less than 0.001 in systole). There was no difference in systolic function or posterior wall thickness, having the diabetics a significant increase of the T 1/2 (p less than 0.001), a decrease of the deceleration of E and the ratio E/A (p less than 0.001). As a group, 12.5% of the diabetics had anatomical abnormalities, and 18.3% diastolic abnormalities at least in two indexes. The only significant correlation was established between the evolution time and the T 1/2 (p less than 0.01). We conclude that in this group of selected diabetics, the anatomical and functional abnormalities found were only imputable to the diabetic abnormality.

Adolescent↗
PubMed1991

[Teicoplanin versus cloxacillin, cloxacillin-gentamycin and vancomycin in the treatment of experimental endocarditis caused by methicillin-sensitive Staphylococcus aureus].

Thirty-three rabbits, (12 in the control group and 21 treated, 5 with teicoplanin, vancomycin and cloxacillin-gentamycin and 6 with cloxacillin alone) with methicillin-sensitive Staphylococcus aureus (MSSA) experimentally induced endocarditis were studied to evaluate the efficacy of teicoplanin and its comparison with cloxacillin, vancomycin and cloxacillin-gentamycin. The rabbits were treated during three days. Mortality, blood cultures at 48 and 72 hours and the number of colonies forming units per gram of vegetation were then evaluated. There was statistically significantly differences between the control group and the 4 treated groups in respect of mortality (p less than 0.001), and blood culture's negativity at 48 and 72 hours (p less than 0.001), but not among the various groups of treatments. The CFU number of the vegetations were also significantly different between control and treatment groups (p less than 0.001). Cloxacillin and the combination cloxacillin-gentamycin lowered the CFU number more than teicoplanin and vancomycin (p less than 0.005). These results, allowed us to conclude than teicoplanin may be used as an alternative of standard treatments in infective endocarditis due to MSSA.

Animals↗
PubMed1991

[Cardiovascular risk factors in an Arab and Hispanic working population].

318 records of male workers, 169 Spanish and 149 Arab were retrospectively studied in 1987 at the "Gabinete de Seguridad e Higiene en el Trabajo" (Council for Safety and Hygiene in the Workplace) in Ceuta in order to prove the hypothesis that 2 different ethnic groups living in the same geographic area have a non-equal distribution of cardiovascular risk factors. The Spanish group showed a higher prevalence in blood hypertension, diabetes, glucose intolerance, obesity and alcohol intake, compared to the Arab group. Smoking and high levels of seric cholesterol were similar in both groups, however, medium levels of seric cholesterol were lower in the Arab group. Family histories of cardiovascular disease were very rare in the latter mentioned group. These observations suggested a major predisposition to ischemic cardiopathy in the Spanish group.

Adolescent↗
PubMed1991

[Prototype of an instrument for retrograde obturation].

Several instruments to carry and put the silver amalgam into de apical foramen for it's posterior condensation without spreading this material over the periodontal tissues, bone and adyacent mucosa, has been designed along the years. This article describes an easier and cheaper way to make an endodontic amalgam carrier by the adaptation between en 18 and 22 mm intravenous catheters into disposable syringes by the use of autopolymerizable acrilic, given the dentist the option of making a very easy instrument, at a low cost which can be used as a commercial endodontic amalgam carrier as well.

Acrylic Resins↗
PubMed1991

[The spontaneous regression of a rhabdomyoma of the right ventricle].

Rhabdomyoma is the most common intracardiac tumor in the newborn. The diagnosis is made by the clinical history and the physical examination, the electrocardiogram, chest X-ray, and the echocardiographic data. It has a poor prognosis, 80% dying in the first year of life because congestive heart failure or sudden death. Rarely, spontaneous regression has been described. We present the case of a newborn diagnosed of tuberous sclerosis, with an echocardiographic image of a rhabdomyoma in the right ventricle with a spontaneous total regression of the tumor 2 years later.

Echocardiography↗
PubMed1990

Acute polyneuropathy in critically ill patients.

We studied five patients in the intensive care unit (ICU) with acute polyneuropathy. All had previously presented severe infectious processes, accompanied by diverse organ failure accompanied by the Adult Respiratory Distress Syndrome (ARDS) in all cases. Two patients died and the three survivors suffered severe motor deficiencies. Electromyographic studies revealed axonal damage which predominantly affected motor neurons. Cerebrospinal fluid was normal in all the patients except one, who showed a moderate increase of lymphocytes. The common causes of polyneuropathy were excluded, but in all cases a nutritional disorder was detected, based on laboratory values of proteins, serum albumin and transferrin. We conclude that polyneuropathy is relatively frequent among critically ill patients and must be closely monitored because of diagnostic difficulties and the repercussions on the progress of these patients. In spite of uncertainties about its cause, it appears to be related to severe infectious processes, ARDS, and nutritional disorders.

Aged↗
PubMed1990

Histamine stimulation of cyclic AMP accumulation in astrocyte-enriched and neuronal primary cultures from rat brain.

Histamine stimulates cyclic AMP accumulation in astrocyte-enriched and neuronal primary cultures from rat brain in the presence of the phosphodiesterase inhibitor isobutylmethylxanthine. The response in the astrocyte cultures (Emax = 304 +/- 44% over basal, EC50 = 43 +/- 5 microM) was much higher than in neuronal cultures (Emax = 24 +/- 2%, EC50 = 14 +/- 7 microM). The histamine effect in astrocytes was competitively inhibited by the H2 antagonists cimetidine (Ki = 1.1 +/- 0.2 microM) and ranitidine (Ki = 46 +/- 10 nM) but was insensitive to the H1 antagonist mepyramine (1 microM). The two selective H2 agonists impromidine and dimaprit behaved as partial agonists and showed relative potencies (139 and 0.5, respectively) consistent with an interaction with H2 receptors. The more selective H1 agonist 2-thiazolylethylamine (0.01-1 mM) did not potentiate the response to impromidine (10 microM). Thus, in contrast to what is generally observed in intact cell preparations from brain, the histamine-induced cyclic AMP accumulation in astroglial cells is mediated solely by H2 receptors. The small effect shown in neuronal cultures also appears to be mediated by H2 receptors.

Animals↗
PubMed1990

[The development of a linear function for stratifying the risk of hospital mortality in acute myocardial infarct].

In spite of conventional treatment in a Coronary Unit, there is a group of patients with acute myocardial infarction who present a high mortality index. A more aggressive attitude (coronariography, angioplasty, and/or emergency coronary bypass) could improve the prognosis in some of these patients but can only be performed in a limited number of centers. In the present work, we have reviewed data obtained from the Emergency Room on 167 patients diagnosed of myocardial infarction. The variables that were correlated to mortality were: age, heart rate, blood pressure, presence of rales, radiologic heart failure cardiomegaly, ventricular extrasystoles in ECG and delay in arrival to hospital. We obtain a lineal function (z = 24.6 X1 - 0.4 X2 + 0.2 X3 + 11) which combining ventricular extrasystoles, diastolic arterial pressure, and heart rate permits to differentiate three risk groups: low, medium and high, associated to hospital mortality rates of 5.7, 36.4 and 83.3%. We suggest the use of a function of this type to select those patients who should be sent to a hospital with facilities for emergency coronary surgery.

Discriminant Analysis↗
PubMed1990

[The prevalence of arrhythmias and repolarization changes in patients with mild or moderate essential hypertension undergoing an exercise test. Their variations with different antihypertensive treatments].

42 mild and moderate hypertensive patients treated with Verapamil, Atenolol and Xipamide were studied. Exercise tests (ET) were performed at the onset and after a month of therapy, in order to detect arrhythmias and repolarization change prevalence of ventricular arrhythmias (VA) was 23.7% and 11.9% for supraventricular arrhythmias (SVA). 45.2% of the exercise tests were considered positive, with a significant correlation with maximum pressure peak. Patients with left ventricular hypertrophy (LVH) showed a significant increase in VA and +ET prevalence (42.1% and 63.2%). After treatment, the prevalence for VA registered a slight decrease and an increase for SVA; these differences not being considered significant. +ET showed a significant decrease in all patients, as well as in those with previous LVH (21.4%, 26.3%). Only atenolol produced a significant decrease in the +ET of patients with previous LVH (75% to 12.5%).

Adult↗
PubMed1990

[The electrocardiographic changes in constrictive pericarditis before and after pericardiectomy. The role of the myocardium in the genesis of preoperative electrocardiographic changes].

We studied 19 patients diagnosed of chronic pericarditis and treated surgically with pericardiectomy, to evaluate the role of the pericardium and myocardium on the preoperative electrocardiogram. Before surgery, there was atrial fibrillation in 17 cases, the P axis was between 0 and +70 and pseudomitral morphology was found in 10 of the 12 cases with normal sinus rhythm. The mean voltage in the QRS complex was (13.8 mm), and the R wave in V5 8.6 mm. The T wave was negative in 17 patients. After surgery there was only a case of atrial fibrillation that converted to normal sinus rhythm; the P wave axis moved to the right between +30 and +150 (p less than 0.002), the pseudomitral morphology of the P changed to normal in 3 cases, the voltage of the QRS increased to 16.7 mm (p less than 0.003) and that of the R wave in V5 to 9.4 mm (p less than 0.001). The T wave became positive in only 3 cases. Because of the persistence of some alterations, we concluded that both components, pericardium and myocardium are important in the changes of the electrocardiogram of constrictive pericarditis.

Adult↗