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Biomedical subjects

A Efthimiadis

Publications and source records attributed to A Efthimiadis.

At least 37 records · Page 2Linked to original sources
PubMed1998

Induced sputum, bronchoalveolar lavage and blood from mild asthmatics: inflammatory cells, lymphocyte subsets and soluble markers compared.

Airway inflammation in asthma can be measured directly by invasive bronchoalveolar lavage (BAL), directly and relatively noninvasively by induced sputum and indirectly from peripheral blood. We compared cellular and fluid phase indices of inflammation in induced sputum, BAL and blood from 11 adults with mild stable asthma. On one day, induced sputum selected from saliva was collected and on the next, blood and BAL. Median results of sputum compared with BAL showed a higher number of nonsquamous cells (53 versus 0.8 x 10(6) cells x mL(-1), p=0.003), more neutrophils (34.3 versus 1.0%, p<0.001), CD4+ and CD19+ T-cells (76.5 versus 54.7%, p=0.01 and 5.2 versus 1.1%, p=0.03, respectively), fewer macrophages (603 versus 95.0%, p=0.002) and markedly higher levels of eosinophil cationic protein (ECP) (264 versus 2.0 microg x L(-1), p<0.001), tryptase (17.6 versus 2.2 UI x L(-1), p<0.001) and fibrinogen (1,400 versus 150 microg x L(-1), p=0.001). Sputum and BAL neutrophils and CD4+ T-cells were strongly correlated. Sputum and BAL differed from blood by having higher proportions of T-cells (94.9 and 98.9% versus 87.7%, p=0.002) and lower proportions of CD19+ T-lymphocytes (p=0.04 and 0.006). Sputum also differed from blood by having higher proportions of CD4+ T-cells (76.5 versus 51.4%, p=0.001), lower proportions of CD8+ cells (24.0 versus 403%, p=0.04) and a higher CD4+/CD8+ ratio (3.3 versus 1.4, p=0.01). We conclude that in mild asthmatics, sputum, bronchoalveolar lavage and blood measure different compartments of inflammation. Induced selected sputum has the advantage over bronchoalveolar lavage of higher density of cell recovery and stronger signal for fluid-phase markers.

Adult↗
PubMed1997

Measuring airway inflammation in asthma: eosinophils and eosinophilic cationic protein in induced sputum compared with peripheral blood.

BACKGROUND: Airway eosinophilic inflammation is a characteristic feature of asthma. This can be assessed directly by measurement of eosinophils and eosinophilic cationic protein (ECP) in sputum or indirectly by measurement of the same markers in blood. We investigated the performance of these markers of airway eosinophilic inflammation in a population of patients with asthma compared with control subjects and the extent to which the markers differed. METHODS: In a cross-sectional study, subject characteristics were documented on day 1 and induced sputum and blood samples were obtained on day 2. Nineteen patients with asthma and 20 control subjects (10 healthy subjects and 10 smokers with nonobstructive bronchitis) were consecutively enrolled in the study. Sputum (selected from saliva) and blood samples were processed by persons blind to the clinical details. Results are presented as median values (minimum-maximum); differences were measured by Mann-Whitney U test. The accuracy of the tests (sensitivity and specificity) was measured by plotting the data in receiver-operating characteristic (ROC) curves and comparing the areas under the curve for each marker. RESULTS: Patients with asthma in comparison with control subjects had a higher proportion of sputum eosinophils (5.2% [0.2% to 93%] vs 0.3% [0% to 1.7%], p < 0.001), higher numbers of blood eosinophils (350.0 x 10(6)/L [144.0 to 1520.0 x 10(6)/L] vs 155.0 x 10(6)/L [34.0 to 426.0 x 10(6)/L], p = 0.003), and higher levels of ECP in sputum (1040.0 micrograms/L [76.8 to 32,000.0 micrograms/L] vs 455.3 micrograms/L [54.4 to 1280.0 micrograms/L], p = 0.001) but not in serum (25.0 micrograms/L [5.6 to 52.4 micrograms/L] vs 16.5 micrograms/L [3.3 to 36.0 micrograms/L], p = 0.08). Markers of airway inflammation in induced sputum and blood samples were correlated with clinical and physiologic variables. The area under the ROC curve showed that eosinophils in sputum (0.90) are significantly more accurate markers than blood eosinophils (0.72) and serum ECP (0.67) (p = 0.02). Although the area under the ROC curve for sputum ECP was greater than those for blood eosinophils and serum ECP, the differences could have occurred by chance (p > or = 0.1). CONCLUSION: We conclude that the proportion of eosinophils in sputum is a more accurate marker of asthmatic airway inflammation than the proportions of blood eosinophils or serum ECP.

Adult↗
PubMed1997

Markers of inflammation in induced sputum in acute bronchitis caused by Chlamydia pneumoniae.

Little is known of the inflammatory characteristics of acute infections of the respiratory tract caused by virus and unusual bacteria such as Chlamydia pneumoniae. A case is reported in whom inflammatory indices in sputum were used to investigate, for the first time, the airway inflammation during an episode of acute bronchitis caused by C pneumoniae. The patient presented with a dry cough of five days duration. C pneumoniae was identified by polymerase chain reaction (PCR) in a nasopharyngeal swab collected on day 5. Virological studies were negative. Clinical and inflammatory indices in induced sputum were measured on days 6, 8, and 11. The cough cleared spontaneously by day 11. Forced expiratory volume in one second was normal throughout. Sputum findings identified intense airway inflammation characterised by increased total cell and lymphocyte counts followed by an increase in neutrophils and a decrease in the CD4/CD8 ratio, activation of CD8 lymphocytes, and exudation as indicated by an increase in fluid phase fibrinogen. These observations suggest that sputum might be useful to monitor an inflammatory/immune response of the airway in acute infections.

Acute Disease↗
PubMed1997

Sputum in severe exacerbations of asthma: kinetics of inflammatory indices after prednisone treatment.

We have investigated the time-course of symptoms, forced expiratory volume in one second (FEV1), and the airway inflammatory changes in sputum selected from saliva and blood of 10 patients with severe exacerbation of asthma betwen presentation and after 1, 2, 3, 7, and 21 days of treatment. The sputum was induced by a modified standard protocol, and we examined its safety. The severe exacerbation of asthma was defined by the presence of nocturnal symptoms disturbing sleep and/or the need for inhaled short acting beta2-agonist > or = 8 puffs/d and an FEV1 after bronchodilator < 60% of predicted. The treatment consisted of additional prednisone 30 mg daily for 5 d followed by reduction to zero by day 10. Abnormal findings [median (interquartile range)] in spontaneous and induced sputum included low viability of cells [52.0 (34.0)%]; eosinophilia [20.0 (16.4)%]; many free eosinophil granules; and increased levels of fluid-phase ECP [1960 (9204) microg/L], fibrinogen [6045 (10720) microg/L], and IL-5 [160 (212) pg/ml]. Peripheral blood eosinophils [10.4 (7.6)%] and ECP levels [34.0 (35.0) microg/L] were increased. After treatment, symptoms, FEV1, blood eosinophilia, and serum ECP improved in the first 24 h. Sputum eosinophils and ECP did not improve until 48 h and fibrinogen not until 7 d. The improvement in sputum eosinophils and ECP levels was correlated with improvement of FEV1 and in fluid-phase IL-5. Thirty sputum inductions were performed safely in the majority with inhaled isotonic or 3% saline (23.3% or 63.3%, respectively) over a short duration (mean 8.4 min). The patients who had a fall in FEV1 of > or = 10% (10 occasions) after induction differed from those with a fall of < 10% only in the amount of inhaled beta2-agonist used by the patients in the preceding 24 h [8.0 (5.0) versus 4.0 (3.0) puffs/d, p = 0.01]. The results suggest that spontaneous or induced sputum can be used safely to follow the kinetics of effects of antiinflammatory treatment in a severe exacerbation of asthma. The clinical and blood indices improve before those in sputum, raising the possibility that examination of sputum is a better guide in these patients to follow the effects of treatment.

Adolescent↗
PubMed1997

Induced sputum cell and fluid-phase indices of inflammation: comparison of treatment with dithiothreitol vs phosphate-buffered saline.

Treatment of sputum with dithiothreitol (DTT) gives reliable measurements of cellular and fluid-phase markers of airway inflammation. We investigated the extent to which DTT treatment influences these measurements as compared with phosphate-buffered saline (PBS). Hypertonic saline-induced sputum, collected from 20 asthmatic subjects, was examined within 2 h. All portions which looked more solid (less fluid) than saliva were collected from the expectorate. The selected sputum was then divided into two portions: one treated with one volume of DTT and one volume of PBS, the other with two volumes of PBS. The filtrates were assessed blind for total and differential cell count, viability, and fluid-phase eosinophil cationic protein (ECP), fibrinogen, interleukin (IL)-5 and IL-8. Sputum treated with DTT compared with PBS had lower proportions of viable cells (median 66 versus 74%; p=0.003). In contrast, DTT-treated sputum had higher total cell counts (median 8.8 vs 2.8 x 10(6) mL(-1); p<0.001) and levels of ECP (median 1340 vs 584 mg x L(-1); p<0.001) The measurements were similar with respect to the proportion of eosinophils, neutrophils, lymphocytes, macrophages, and fluid-phase fibrinogen, IL-5 and IL-8. We conclude that dithiothreitol disperses cells more effectively and that this might account for the higher levels of eosinophil cationic protein. Dithiothreitol may affect cell viability, but the changes are not relevant with respect to cell counts. Additionally, dithiothreitol does not seem to influence the other measurements performed.

Adolescent↗
PubMed1996

Elevated B cells in sputum of asthmatics. Close correlation with eosinophils.

Sputum examination is a useful noninvasive method to study airway inflammation. We investigated the reproducibility and validity of the measurements of lymphocyte subsets in the sputum of 11 stable patients with asthma and 10 nonasthmatic smokers. Sputum was dispersed with 0.1% dithiothreitol. A differential cell count was made with Wright's stain. Aliquots were stained with antibodies to CD19 (B cells), CD3 (T cells), CD4 (helper), CD8 (suppressor), and the activation marker CD25 (IL2 receptor) on T-cell subsets and were assayed by flow cytometry. Sputum from patients with asthma compared with nonasthmatic subjects had more eosinophils (mean +/- SEM, 32.5 +/- 8.5 versus 1.3 +/- 0.5%, p < 0.01) and a higher proportion of lymphocytes that were B cells (16.2 +/- 3.2 versus 4.0 +/- 1.0%, p < 0.01), and these correlated closely with the eosinophils (r = 0.8, p < 0.01). Patients with asthma also had more activated T-helper cells (39.3 +/- 4.6 versus 9.0 +/- 9.0%, p = 0.05), but the comparison was limited to two smokers because of macrophage autofluorescence. The repeatability of measurements of helper T-cells (R = 0.94), suppressor T cells (R = 0.88), and activated helper T cells (R = 0.77) was good; repeatability of measurements of T and B cells could not be examined because these were reciprocals of each other. Asthmatic sputum has different lymphocyte profiles than sputum from nonasthmatic smoking control subjects. The results demonstrate a potential importance of antibody-producing lymphocytes in the airway and their relation to sputum eosinophilia in asthma.

Adult↗
PubMed1996

Indices of airway inflammation in induced sputum: reproducibility and validity of cell and fluid-phase measurements.

Methods to examine sputum for indices of airway inflammation are evolving. We have examined the repeatability and the validity of an improved method to measure sputum cells and fluid-phase eosinophil cationic protein (ECP), major basic protein (MBP), eosinophil-derived neurotoxin (EDN), albumin, fibrinogen, tryptase, and interleukin-5 (IL-5). Sputum was induced with hypertonic saline twice within 6 d in 10 healthy subjects, 19 stable asthmatics, and 10 smokers with nonobstructive bronchitis. The method included the processing of freshly expectorated sputum separated from saliva, treatment with a fixed proportion of dithiothreitol 0.1% followed by Dulbecco's phosphate-buffered saline, making cytospins, and collecting the supernatant. The reproducibility of measurements, calculated by the intraclass correlation coefficient, was high for all indices measured with the exception of total cell counts and proportion of lymphocytes. Asthmatics, in comparison with healthy subjects and smokers with bronchitis, had a higher proportion of sputum eosinophils (median percent 5.2 versus 0.5 and 0.3), metachromatic cells (0.3 versus 0.07 and 0.08), ECP (1,040 micrograms/L versus 288 and 352), MBP (1,176 micrograms/L versus 304 and 160), and EDN (1,512 micrograms/L versus 448 and 272). Asthmatics differed from healthy subjects, but not from smokers with bronchitis, in the proportion of neutrophils (46.9% versus 24.1%), albumin (704 versus 288 micrograms/mL), and fibrinogen (2,080 versus 440 ng/mL). Smokers with bronchitis showed a trend for a higher neutrophil count and levels of albumin and fibrinogen than healthy subjects. The proportion of sputum eosinophils correlated positively with ECP, MBP, EDN, albumin and fibrinogen levels, and metachromatic cell counts correlated with tryptase. In asthmatics, IL-5 correlated with eosinophil counts. There was a significant negative correlation between sputum indices and expiratory flows and methacholine PC20. Thus, the methods of measuring cell and fluid phase markers in induced sputum used in this study are reproducible and valid. They can therefore be used to reliably measure these indices of airway inflammation.

Adult↗
PubMed1996

Spontaneous and induced sputum to measure indices of airway inflammation in asthma.

Inhalation of hypertonic saline to induce sputum may alter cells and fluid-phase markers in sputum. We have compared indices of inflammation in sputum produced spontaneously with sputum induced by an aerosol of hypertonic saline. Twenty-three asthmatics produced spontaneous followed by induced sputum on the same day. The sputum specimen was separated from saliva within 2 h, dispersed with dithiothreitol (DTT) and processed to obtain cytospins and supernatant. The statistical power to detect a 20% difference in sputum parameters was > 90%. Results are expressed as median and interquartile range [IQR]. Induced sputum had a higher proportion of viable cells (77.0 [19.0] versus 47.0 [38.0]%, p < 0.001), less squamous cell contamination (1.0 [1.2] versus 1.8 [34.0]%, p < 0.001) and better quality cytospins (score of 8.0 [4.0] versus 4.0 [2.0], p < 0.001). It also had lower fluid-phase levels of eosinophil cationic protein (ECP) (1,358 [1,102] versus 1,574 [2,479] microg/L) and fibrinogen (1,560.0 [3,130.0] versus 4,350.0 [5,970.0] ng/ml) but only the latter was significantly different (p = 0.02). Induced sputum was similar to spontaneous sputum in weight (200.0 [219.0] versus 270.0 [227.0] mg), total cell count (3.3 [4.1] versus 3.5 [4.5] x 10(6)/ml), proportion of nonsquamous cells, and levels of tryptase. The agreement between induced and spontaneous measurements was good, but fluid-phase levels were affected by the low viability of some spontaneous samples. We conclude that for the indices measured in asthmatic subjects, induced sputum separated from saliva is similar to lower respiratory secretions expectorated spontaneously and has the advantage of better cell viability.

Adult↗
PubMed1996

Effect of salmeterol compared with beclomethasone on allergen-induced asthmatic and inflammatory responses.

Salmeterol is a selective long-acting beta 2-agonist bronchodilator considered to have added anti-inflammatory effects, but this is controversial. We investigated the effects of a single dose of salmeterol, 100 micrograms, on the physiological and inflammatory responses to inhaled allergen and compared these with the effects of a single dose of beclomethasone, 500 micrograms, and of placebo. Eight atopic adults with mild stable asthma, treated only with inhaled short-acting beta 2-agonist when needed, attended the laboratory sequentially for screening tests, two single-blind control inhalation tests preceded 30 min by placebo or salmeterol and three allergen inhalation tests preceded by placebo, salmeterol or beclomethasone double-blind in random order. Airway responsiveness to methacholine (assessed as the provocative concentration of methacholine producing 20% fall in forced expiratory volume in one second (PC20)), induced sputum eosinophils, blood eosinophils and serum eosinophil cationic protein (ECP) were examined before and 7-48 h after treatment. The statistical power to detect twofold changes in blood and sputum parameters was > or = 90%. Salmeterol inhaled before allergen challenge completely prevented the early asthmatic response, late asthmatic response and fall in methacholine PC20 at 24 h, and produced additional bronchodilatation. These effects were similar to those obtained by the inhalation of a single dose of salmeterol before the control inhalation test, and significantly better than those observed after a single dose of beclomethasone inhaled before the allergen test. Beclomethasone had no effect on the early asthmatic response or on the fall in methacholine PC20 at 24 h but partially inhibited the late asthmatic response. Neither salmeterol nor beclomethasone had any significant effect on sputum or blood inflammatory changes 7-48 h after allergen inhalation. In conclusion, whilst salmeterol had no demonstrable anti-inflammatory action in sputum after allergen challenge in asthma, neither did a single dose of the positive anti-inflammatory control, beclomethasone. The latter result excludes a more positive judgement on the possible anti-inflammatory action of salmeterol. However, the results do indicate that potent functional effects of a single dose of salmeterol can mask the airway inflammatory cell influx caused by inhaled allergen.

Administration, Inhalation↗
PubMed1996

Measurement of inflammatory indices in induced sputum: effects of selection of sputum to minimize salivary contamination.

Sputum examination is being used increasingly as a noninvasive method to assess airway inflammation. Expectorated sputum has variable contamination with saliva. Methods of processing have included the selection of portions of the sample considered to be representative of pulmonary origin versus use of the whole specimen, which is confounded by varying volumes of saliva. We compared cell profiles and eosinophilic cationic protein (ECP) concentration in sputum selected from the expectorate and in the usually discarded residual portion to determine to what degree salivary contamination is minimized and if the results are representative of lower respiratory secretions. Sputum was induced with hypertonic saline in six healthy and nine asthmatic subjects. All portions considered to be of pure lower respiratory tract origin were selected from the residual. The selected and residual portions were treated with dithiothreitol, total cell counts and cell viability were obtained, cytospins were made for differential cell counts and supernatant was collected for ECP assay. Selected portions of the specimens, in comparison with the residual portion showed: little squamous cell contamination (median 1.2 vs 70%; p < 0.001); higher total cell counts.mL-1 (5.1 vs 0.5 x 10(6) cells.mL-1; p < 0.001); higher number of viable nonsquamous cells per sample (1.9 vs 0.6 x 10(6) cells; p < 0.001); higher slide quality score (7 vs 4; p < 0.001); and higher levels of ECP (768 vs 136 micrograms.L-1; p < 0.001). There were no differences in the differential cell counts of eosinophils (1.3 vs 3.8%), neutrophils (44 vs 32%), and lymphocytes (0.6 vs 0.6%). While the proportion of macrophages was lower (36 vs 54%; p < 0.05), the absolute number (41 vs 19 x 10(4) cells; p < 0.05) was higher in the selected portion. In summary, selection of all portions of induced sputum from the expectorate minimized the confounding influence of saliva. Loss of nonsquamous cells in the residual portion was variable but usually less than one third of those in the selected portion. With one exception, this loss had little influence on the differential counts of inflammatory cells. Similar observations apply to eosinophilic cationic protein levels. We conclude that, in healthy subjects and treated asthmatics, inflammatory markers in the selected portion of the expectorate can be used to represent those in the lower respiratory tract in general.

Adult↗
PubMed1995

Immunopathogenic mechanisms in hypertension.

There is a growing interest in immunologically-mediated lesions in the cardiovascular system, as there has been evidence that there are antimitochondrial antibodies (AMA) in patients with hypertrophic cardiomyopathy or hypertensives with left ventricular hypertrophy (LVH). We have also very recently published findings from our laboratory that hypertensives with LVH have a considerable quantity of anticardiac antibodies (ACA) in their serum. The aim of this study was to investigate the possible involvement of autoimmune mechanisms in the pathogenesis and evolution of hypertensive disease. Three groups of subjects were included in the study. Group A comprised 37 patients (20 men, 17 women, mean age 50.5 +/- 8.5 years) with mild to moderate essential hypertension, 19 without echocardiographic evidence of LVH, and 18 with LVH. Group B comprised 10 patients (6 men, 4 women, mean age 45.1 +/- 8.7 years) with secondary hypertension. The control group (C) comprised 15 normotensive subjects (8 men, 7 women, mean age 47.7 +/- 8.7 years). Cellular immunity against arterial wall antigen was studied in all subjects by means of migration inhibitory factor (MIF) against relevant antigen preparation. Sera from Group A and C subjects were tested for the presence of autoantibodies against both specific (myocardial) and nonspecific antigens, by means of the indirect immunofluorescence technique. Eighty per cent of patients with essential hypertension showed a positive cellular response (MIF) against an arterial wall antigen compared to the patients with secondary hypertension or the control group. Moreover, patients with essential hypertension and LVH had the highest incidence of specific (anticardiac, ACA) and nonspecific autoantibodies and the highest C3c and C4 complement component levels compared to patients without LVH or the control group. Most of the ACA positive patients were also AMA positive, while the ACA negative patients were AMA negative as well. Defects in cell-mediated immunity against arterial wall antigen(s) may be the cause or the effect of hypertension. On the basis of our findings that there was no delayed type hypersensitivity response to arterial wall antigen(s) in the patients with secondary hypertension, we suggest that, in some cases of essential hypertension, delayed hypersensitivity reactions possibly contribute to the pathogenesis of hypertension. Autoimmune mechanisms are discussed on the basis of common epitopes shared between heart and arterial tissue.

Autoantibodies↗
PubMed1995

The predictive value of troponin T in patients who underwent an extracardiac surgery operation.

UNLABELLED: Purpose of the study is the research of the diagnostic value of the determination of Troponin T in relation with the other cardiac enzymes in patients who underwent extracardiac surgery operation. METHODS: 42 pts (M = 24, F = 18, mean age 51.7 +/- 17 years) who underwent a surgery operation were studies. For all pts serum enzyme CPK, CPK MB, SGOT and Troponin T was determined 24 hours before and after the operation. RESULTS: increased value of CPK was observed in all patients. In 14.3% of pts was found abnormal value of CPK. In 1 pt CPK MB was found increased. In no one of the above pts was observed an increased value of Tr-T. No one of the pts had ECG changes and clinical symptoms indicative of ischemic heart disease. CONCLUSIONS: these results suggest that the determination of Tr-T in serum is more useful diagnostic index for myocardial cell injury in pts who underwent an extracardiac surgery because is not detected in skeletal muscle injury.

Aspartate Aminotransferases↗
PubMed1993

Hemodynamic and biochemical changes after chronic administration of cilazapril to hypertensive patients.

The study describes the changes in basic hemodynamic parameters after long-term antihypertensive therapy with cilazapril--a new ACE inhibitor lacking a sulfhydryl group--in hypertensive patients and the drug effects on renal function, glucose tolerance and lipid metabolism. 30 patients (18 males, 12 females, mean age: 53.3 +/- 18 years) with mild to moderate essential hypertension were studied. The following determinations were performed in patients, before and after 4.5 months of cilazapril monotherapy at a dose of 5 mg/24 h: (a) antihypertensive action of the drug (arterial pressure at rest and during a 24-hour recording); drug effects on left ventricular (LV) mass index; its contractility indexes (%FS, EF) and the left atrial emptying index were studied by means of echocardiography; (b) plasma insulin concentration during oral glucose tolerance tests, in the fasting state, after the administration of 75 g glucose per os, as well as the changes in the insulinogenic index and the 6-keto-PGF1 alpha/TXB2 ratio, and (c) drug effect on renal function (urea, creatinine, uric acid, plasma electrolytes), blood lipid profile (total cholesterol, triglycerides, HDL-CH) and serum transaminases. Long-term drug administration exhibits an effective antihypertensive action, without causing reflex tachycardia and also reduces the LV mass index without affecting its EF, while improving its diastolic function. It does not significantly affect the various biochemical parameters, and achieves glucose regulation, both in the fasting state and after glucose loading, with a decrease in the insulinogenic index, and simultaneously increases the 6-keto-PGF1 alpha/TXB2 ratio. The existence of a direct cause-effect relationship between the changes in the above hormone systems is possible.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Alterations of first derivative of apexcardiogram indices during induced changes of heart rate.

UNLABELLED: The aim of this study is to investigate the effects of HR changes, induced by a variety of causes, on left ventricular performance as assessed by the first derivative of apexcardiogram indices. Ten males, mean age 29.6 +/- 8.1 years, without evidence of heart disease were studied. In all subjects tachycardia was induced by 1) administration of atropine (1 mg bolus IV), 2) administration of isoprenaline (0.5-0.25 micrograms/min IV) and 3) treadmill exercise test according to Bruce protocol. The blood pressure (BP) was determined before and every 60 sec during each test. Drawings of the first derivative of apexcardiogram were obtained before and at the peak of HR and the indices a/b, ef/ZN and b/ef were determined. RESULTS: the increase of HR was similar (about 30% from baseline) in each test. Exercise test caused more pronounced increase of BP compared to the administration of isoprenaline while administration of atropine was not followed by significant changes of BP. Administration of isoprenaline caused similar but more vigorous alterations of the first derivative of apexcardiogram indices (significant increase of b/ef and decrease of a/b and ef/ZN indices) compared with the exercise test. Administration of atropine caused no significant changes of these indices. CONCLUSIONS: in this study it was found that the effects of various causes of tachycardia on LV performance, as assessed by the indices studied, are not uniform; this may reflect different mechanisms involved in the induction of tachycardia by different causes. These results suggest that the alterations of the indices assessed in this study can detect dysfunction(s) of the LV; it is also possible that the type of alteration induced, could provide information regarding causal relationships of this impairment.

Adult↗
PubMed1990

Neonatal myasthenia gravis: antigenic specificities of antibodies in sera from mothers and their infants.

Transient neonatal myasthenia gravis (MG) is a human model of passively transferred MG. In an effort to understand the characteristics of the most pathogenic antibodies in MG, we studied the fine antigenic specificities of anti-AChR antibodies in sera from 21 MG mothers (nine of which had transiently transferred the disease) and 17 of their infants. Although in a few cases significant differences in antibody specificities were observed between mothers and infants, whether myasthenic or not, generally the antigenic specificities of the antibodies in sera from infants were very similar to those of their mothers. Furthermore, no characteristic differences were detected between the antibody repertoires of mothers who transferred the disease and those who did not.

Antibodies, Monoclonal↗
PubMed1988

Fine antigenic specificities of antibodies in sera from patients with D-penicillamine-induced myasthenia gravis.

A small fraction of patients with rheumatoid arthritis and other diseases on D-penicillamine treatment may develop antibodies against the acetylcholine receptor (AChR) and symptoms of myasthenia gravis (MG). The mechanism leading to this phenomenon is not known. We have studied the fine antigenic specificities of the anti-AChR antibodies in 19 D-penicillamine-induced MG (pen-MG) patients and compared them with those of antibodies from 204 idiopathic MG patients (the data for 122 obtained from earlier experiments). Antigenic specificities of the circulating antibodies were determined by the capacity of monoclonal antibodies (MoAbs), against certain determinants on the AChR, to inhibit binding of the serum antibodies to the AChR. Monoclonal antibodies against alpha, beta and gamma subunits were used. The anti-AChR antibody patterns of pen-MG patients were very similar to those of idiopathic MG patients. Antibodies to the main immunogenic region, which is located on the extracellular surface of the alpha-subunit, were the predominant group. The variations of antibody specificities in serial sera collected from individual patients at different times were usually small, as were those of idiopathic MG. These results strongly suggest that the antibody repertoire in the sera of idiopathic and pen-MG patients is very similar.

Adult↗