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Biomedical subjects

A Clerico

Publications and source records attributed to A Clerico.

At least 127 records · Page 7Linked to original sources
PubMed1986

Correlation between endogenous digoxin-like immunoreactivity and 3H-ouabain displacement on erythrocyte membranes in extracts of human plasma.

The existence of endogenous cardiac glycoside-like compounds and their property of being recognized by anti-digoxin antibodies is still a matter of controversy. In order to investigate this problem, endogenous digoxin-like immunoreactivity (measured by RIA) and digitalis-like radioreceptor activity (measured by displacement of 3H-ouabain from erythrocyte membranes) were assessed in plasma extracts of normal adults, pregnant women and newborns. These three groups were chosen because of their known widely different levels of digoxin-like immunoreactivity. Compared to adults, newborns and pregnant women had significantly higher levels not only of immunoreactivity but also of displacement of 3H-ouabain binding, the latter being due, according to Scatchard analysis, to a decrease of the affinity of ouabain to its cellular receptor rather than to its maximal binding capacity. Furthermore, immunoreactivity and binding displacement correlated significantly. Our data indicate that one (or more) compounds with cardiac glycoside-like properties (both immunological and at the receptor level) are present in the plasma of newborns and pregnant women, and confirm the idea that radioimmunological methods may be useful in studying endogenous inhibitors of the sodium pump.

Adult↗
PubMed1986

Correlations between digoxin-like immunoreactivity and electrolyte values in urinary samples of newborns.

Elevated levels of a group of substances with digoxin-like immunoreactivity (DLIS) are present in biological fluids of newborns. These endogenous substances could also have the biological properties of cardiac glycosides, such as natriuretic and vasoconstrictor activity. Therefore, DLIS could be involved in electrolyte and volume regulation in infants. We measured DLIS, electrolyte (Na+, K+, Cl-) and creatinine concentrations in 157 urine samples collected from full-term and preterm infants, with the aim to establish if a correlation exists between the urinary DLIS levels and the respective values of these electrolytes. Significant and positive correlations were found between the urinary concentrations of DLIS and electrolytes. In addition, electrolyte values correlated significantly between themselves. DLIS, K+ and Cl- values correlated positively with urinary creatinine concentrations (n = 142). A significant multiple correlation was found among DLIS concentrations and creatinine and Cl- values. We also studied the DLIS concentrations in serum samples collected at birth in peripheral blood of the mothers and in umbilical cord and gastric aspirate of 5 full-term infants. We observed that DLIS values in newborns are significantly higher than the respective values of the mothers. In conclusion, our data do not demonstrate a clear relationship between DLIS and electrolyte concentrations in urine samples of newborns. Further investigations are necessary to elucidate the biochemical and physiological properties of DLIS.

Adolescent↗
PubMed1986

Acute hypotensive effect of calcium antagonists and endogenous digitalis-like immunoreactivity in human essential hypertension.

Evidence has been provided on the increased presence, in essential hypertension, of endogenous digitalis-like factor(s) [DLIS, digoxin-like immunoreactive substance(s)] able to cross-react with antidigoxin antibodies and to inhibit the membrane-bound sodium-potassium pump. An inhibition of the sodium pump could lead, in smooth muscle cells, to an increase of intracellular calcium ions and to an increase of total peripheral resistances. In this study the relation between plasma levels of DLIS and the acute hypotensive effect of a calcium antagonist (nifedipine) has been evaluated in a group of borderline to severe hypertensive patients and in a control group of normotensive subjects. The results obtained confirm that the hypotensive effect of nifedipine is related to pretreatment blood pressure and show, only in hypertensive patients, a significant relation of DLIS with both pretreatment blood pressure and blood pressure decrement induced by nifedipine. These findings are compatible with a possible role of DLIS in modulating cellular calcium handling.

Adult↗
PubMed1985

Modifications in the concentrations of circulating myoglobin after treatment with low doses of adriamycin.

The modifications in the concentration of circulating myoglobin have been studied by means of a radioimmunoassay in 15 cancer patients undergoing polychemotherapy including adriamycin. In 8 patients significant increases in myoglobin levels were found after injection of low doses of the drug (25-50 mg/m2). Moreover, a disturbance of the normal biorhythm of the protein was evident in 12 patients. Creatine kinase-MB was evaluated by means of a radioimmunoassay, but there was no relation between an increase in the isoenzyme and an increase in myoglobin. No ECG modifications were detected. These data indicate that the measurement of myoglobin may offer an indication of myocardial or skeletal muscle damage caused by adriamycin.

Adult↗
PubMed1985

11p13 deletion and reduced RBC catalase in a patient with aniridia, glaucoma and bilateral Wilms' tumor.

A rare case of a one-year-old child with Wilms' tumor, aniridia and glaucoma is described, in whom bone marrow chromosome analysis showed the presence of an interstitial microdeletion on the short arm of chromosome 11, presumably involving the p13 band. Research of the enzyme activity of RBC catalase showed a 40% reduction. This finding is compatible with the loss of the 11p13 band which contains the gene coding this enzyme. 11p13 deletion in Wilms' tumor and 13q interstitial deletion in retinoblastoma provide a rare case of prezygotic chromosome abnormality, which may be considered to have a determinant role in the tumor etiopathogenesis.

Catalase↗
PubMed1985

Macro serum CK-BB in a woman with severe primary hypothyroidism.

We report the case of a woman with severe hypothyroidism and without concomitant myocardial damage, in whom elevated CK-MB values were measured by radioimmunological and enzymatic methods before and after thyroid replacement therapy. The patient's CK-MB activity was shown to be actually due to an atypical CK band between CK-MM and CK-MB (also termed "macro CK" or "idiopathic serum CK-BB").

Aged↗
PubMed1985

Chromatographic characterization of endogenous digoxin-like immunoreactive substances present in serum and urine of infants using gel filtration with Sephadex G 25.

We assayed digoxin-like immunoreactivity in the serum of 19 healthy neonates (blood sample from umbilical cord), not receiving digoxin therapy, using a solid-phase radioimmunological method. In addition, urinary concentrations of a digoxin-like immunoreactive substance (DLIS) were assayed throughout the first 10 weeks of extrauterine life in 50 healthy infants. The mean (+/- SD) serum DLIS concentration obtained was 211 +/- 60 ng/l digoxin equivalents (d.e.) while, in the urinary samples of the first day of life, the mean concentration was 818 +/- 560 ng/l d.e. (n = 20). These DLIS values in infants were higher (about 5- to 10-fold) than those previously observed in adults. In addition, urinary DLIS values were very high in the first week of life and fell quite rapidly in the next weeks of life. We used serum and urine pools from neonates for gel filtration experiments using a Sephadex G 25 column. In the urine sample we found some immunoreactive peaks eluted at the end and after the region of salts, while the chromatographic profiles of the serum pool showed only a major peak eluted with the peak of proteins. After boiling, the same serum pool showed an elution pattern characterized by a smaller immunoreactive peak eluted with that of proteins and by other peaks similar to those observed for the urine sample. Our study demonstrated that a substance or more substances which cross-react with digoxin-specific antibodies are present in blood and urine of healthy infants. In addition, our chromatographic studies indicate that DLIS is probably a low molecular weight substance(s) which circulate(s) in blood bound to a higher molecular weight molecule.

Chromatography, Gel↗
PubMed1984

Evaluation of a new radioimmunological assay for the determination of the B subunit of creatine kinase enzyme.

We used a new radioimmunological (RIA) kit for the assay of B subunit of creatine kinase enzyme (CK). This RIA system uses a specific antisera against the B subunit as ligant, human CK-BB labelled with 125I as tracer, and purified human CK-BB isoenzyme as standard. The mean (+/- SD) sensitivity obtained was 0.25 +/- 0.16 ng/tube and the between assay variability was about 9-10%. Serum levels of 113 normal subjects was not normally distributed. The 95% of values was found below 5 ng/ml. This new RIA is usefull in clinical practice when serum levels of CK-BB isoenzyme must be determined. This method is quickly and it is characterized by a good degree of precision, but the CK-MB isoenzyme cross-reacts for about 40% in this RIA system. Therefore, for the clinical diagnosis by means of this RIA it is necessary to rule out the concomitant elevations of serum CK-MB values.

Creatine Kinase↗
PubMed1984

Apparent free cortisol concentrations in patients with anorexia nervosa at different stages of the disease.

We have measured the total cortisol concentration (TC) and the apparent free cortisol concentration (AFCC) in plasma samples of 17 patients with anorexia nervosa (AN) at different stages of the disease, in basal conditions and after suppression test. We measured free cortisol values directly by a RIA method in dialyzed plasma samples after an equilibrium dialysis system. We have found significantly elevated TC and AFCC values in basal conditions and after suppression test only in the group of patients in the severe stage of the disease. In addition, a significant (p less than 0.05) correlation existed between percent loss of ideal body weight TC and AFCC values after suppression test. Our results suggest that the hypothalamus-pituitary-adrenal axis may be grossly impaired only in the severe stage of AN.

Adolescent↗
PubMed1984

Detection of hypothyroid myopathy by measurement of various serum muscle markers--myoglobin, creatine kinase, lactate dehydrogenase and their isoenzymes. Correlations with thyroid hormone levels (free and total) and clinical usefulness.

An accurate and close follow-up of serum levels of thyroid hormones and various muscle markers (myoglobin, creatine kinase and its isoenzymes CK-MB and CK-BB, lactic dehydrogenase, alpha-hydroxybutyric dehydrogenase, etc.) was carried out in 10 hypothyroid patients on replacement therapy. The main muscle markers, creatine kinase and myoglobin, were elevated respectively in 9 and 6 subjects. In 1 male significant CK-MB traces were measured, while in 1 woman significant CK-BB amounts were assayed. Significant correlations between patients' thyroid hormones and the levels of the muscle parameters were found. The rate of normalization of thyroid hormones and muscle markers in relation to replacement therapy was also studied. Myoglobin and creatine kinase have proved to be the best indicators of the hypothyroid myopathy, since they are sensitive for the early detection of muscle involvement due to the metabolic disorder and are closely correlated to the metabolic conditions of patients.

Adolescent↗
PubMed1984

Elevated free cortisol plasma levels in patients with prostatic carcinoma undergoing treatment with estrogens.

The total cortisol concentration (TCC), the percentage of free cortisol (%FC) and the apparent free plasma cortisol concentration (AFCC) have been determined in plasma samples of 9 patients affected by prostatic carcinoma undergoing treatment with estrogens measured by an equilibrium dialysis system and a radioimmunological method. The values found in this group of patients were compared to those obtained in 9 untreated control patients and in normal healthy persons. The mean TCC values found in treated patients were significantly higher than in the controls, both in basal condition (circadian rhythm) and after dynamic tests, while the mean %FC values were significantly lower than the controls except for the results obtained after an ACTH stimulation test. The mean AFCC values in treated patients were elevated both in basal condition and after the dexamethasone suppression test (DST), but the difference between the two groups of patients was statistically significant only after DST. This study demonstrates that patients with prostatic carcinoma undergoing treatment with estrogens can have markedly increased free plasma cortisol levels with an impairment of the hypothalamus-pituitary-adrenal axis.

Adrenocorticotropic Hormone↗
PubMed1984

Digoxin-like immunoreactivity in normal human plasma and urine, as detected by a solid-phase radioimmunoassay.

Reports on the presence of digoxin-like immunoreactive substance(s) (DLIS) in the plasma and urine of several animal species and a few human test subjects prompted us to undertake to confirm the presence of DLIS in plasma and urine of normal persons and to investigate some characteristics of this antibody-DLIS binding. For this purpose we used a modified radioimmunoassay kit involving antidigoxin antibody-coated test tubes and 125I-labeled digoxin to measure DLIS in urine and concentrated plasma of ostensibly healthy subjects. In 12 separate experiments with plasma the mean sensitivity was 5.12 (SD 1.11) pg per tube, expressed as digoxin. There was no significant cross reactivity with human serum albumin in concentrations up to 200 g/L. The mean DLIS value (in digoxin equivalents) for plasma from 24 normal subjects was 33.58 (SD 14.24) ng/L. Its mean concentration in urine from five subjects was 315.00 (SD 91.38) ng/L.

Adult↗
PubMed1982

Circadian variations of serum myoglobin levels in normal subjects and patients with polymyositis.

Circadian variations in myoglobin levels were determined in 18 normal volunteers and in 10 patients with active polymyositis. In all the controls and in 9 of the 10 patients, serum myoglobin concentrations were highest at 9 am, fell significantly during the day to reach a nadir between 6 and 12 pm, remained constant until midnight, and then rose again at 3 am. The percent differences between the highest and lowest values ranged from 21-66%. This pattern was observed in both untreated patients and patients receiving 6-methyl-prednisolone, which was given either in a single dose at 8 am or in divided doses (8 am and 8 pm). These data demonstrate that the time of sample collection must be taken into account when myoglobin levels are used as a marker of muscle damage.

Adult↗