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Biomedical subjects

A Boldrini

Publications and source records attributed to A Boldrini.

51 records · Page 3Linked to original sources
PubMed1992

Visual acuity of low- and high-risk neonates and acuity development during the first year.

Binocular grating acuity of 65 neonates was measured using Teller acuity cards. At the time of testing, age corrected for prematurity ranged from -3 weeks to 2 weeks. On the basis of clinical data, serial ultrasound scans and EEG recording newborns were divided into 4 subgroups: fullterm low-risk (FLR, n = 22); preterm low-risk (PLR, n = 20); preterm medium-risk (PMR, n = 9) and preterm high-risk (PHR, n = 14). Mean visual acuity of PLR infants (0.86 cy/deg; S.D. 0.34 oct) was not significantly different from that of FLR newborns (0.80 cy/deg; S.D. 0.71 oct); the lower variability of the PLR infants might possibly be caused by their longer postnatal experience. Within the preterm groups, mean visual acuity of PLR newborns was found to be significantly higher than that of PMR (0.73 cy/deg; S.D. 0.26 oct) and PHR infants (0.73 cy/deg; S.D. 0.35 oct). This difference can not be explained by dissimilarities in postnatal or corrected age. Brain impairment, as documented by US scans and EEG recording could account for these findings. Longitudinal data are needed in order to substantiate these findings and correlate them with later neurological and neuro-imaging outcome. Preliminary results of an ongoing longitudinal study suggest acuity development of most, but not all, PHR infants, in whom a cystic-periventricular leukomalacia had been diagnosed, to be worse than that of low- and medium-risk infants.

Electroencephalography↗
PubMed1990

Endogenous digitalis-like factors: their possible pathophysiological implications with particular regard to the perinatal period.

Endogenous factors with biological and immunological activity similar to cardiac glycoside drugs (endogenous digitalis-like factors; EDLF) have been found in several tissues and body fluids of animals and humans. Detectable EDLF concentrations were found in blood and urine extracts of adults (normal healthy controls, hypertensive patients and salt-loaded healthy subjects), while higher levels were generally observed in plasma samples of pregnant women, newborns, and patients with renal insufficiency. The chemical characteristics of this endogenous factor are, at present, unknown, although it has been suggested that EDLF could be a substance with low molecular weight. Experimental studies and theoretical considerations suggest that EDLF, in addition to the ability to react with antibodies, might also bind to the specific cellular receptor of the cardiac glycosides and thus inhibit the membrane Na+/K(+)-ATPase (sodium pump). Therefore, it has been suggested that EDLF is an endogenous modulator of the membrane sodium-potassium pump, and that it could play a role in the regulation of fluids and electrolytes, in the myocardial muscular tone and also in the pathogenesis of hypertension.

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↗
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

Pharmacological activation of gamma-aminobutyric acid-system blunts prolactin response to mechanical breast stimulation in puerperal women.

To evaluate whether the gamma-aminobutyric acid (GABA)ergic system participates in the control of PRL secretion during the puerperium, different doses of sodium valproate (DPA), a drug that increases endogenous GABA activity, were administered orally to puerperal women who did not wish to breast feed their infants. Two groups of five women were each given DPA in doses of 400 and 800 mg, respectively. PRL levels were measured in plasma samples collected before and after drug administration. Another group of five puerperal women was treated with 800 mg DPA 60 min before mechanical breast stimulation using an electric breast pump for 15 min. Circulating PRL levels were measured in samples obtained before, during, and after breast stimulation. No drug-associated side effects were observed. After placebo administration, no significant variations in plasma PRL levels occurred in any subject. The lower dose of DPA (400 mg) induced a slight decrease in plasma PRL levels, but 800 mg of the drug induced a significant fall (P less than 0.05 vs. baseline values) in PRL, with a maximum percent decrease (68.2 +/- 4%) 180 min after DPA treatment. Mechanical breast stimulation performed after placebo treatment induced a significant increase (P less than 0.01) in plasma PRL levels, with peak values (37 +/- 10% above baseline values) 10 min after the onset of stimulation. When DPA was administered to the same women, a significant decrease (23 +/- 3%) in plasma PRL occurred during breast stimulation. Thereafter, PRL values continued to fall in spite of breast stimulation. PRL levels were significantly decreased after DPA treatment compared to both basal values (P less than 0.01) and the levels found in the same patients during control tests (P less than 0.05). These results demonstrate that enhancement of endogenous GABAergic tone induced by DPA significantly decreases basal PRL levels and blunts PRL release after mechanical breast stimulation. In agreement with animal data, a possible physiological role of GABA in the control of PRL release during puerperium may be suggested.

Adult↗
PubMed1983

The pharmacokinetics of clofoctol in healthy neonates and adults studied by an original HPLC technique.

The pharmacokinetics of clofoctol [(tetramethyl-1,1,3,3,butyl)-4-(dichloro-2,4-benzyl)-2-hydroxy-1-benzene ] was investigated in six healthy newborns and compared with the kinetic parameters of the drug in six healthy adults. The concentration of the drug in plasma was measured by means of an original sensitive HPLC technique. In both neonates and adults treated rectally with clofoctol, the plasmatic peak occurred at the 30th min, although the maximal peak of adults was significantly lower. Kel and T1/2 exhibited a similar pattern, whereas the AUC was about 5 times higher in newborns. The present findings suggest that clofoctol is well absorbed rectally. The higher plasmatic levels of clofoctol in neonates may result from their lower degree of hepatic metabolic activity.

Adult↗
PubMed1980

Neonatal mucolipidosis II (I-cell disease): clinical, radiological and biochemical studies in a case.

Clinical, radiological and biochemical findings are described in a male newborn with mucolipidosis II (I-cell disease). At birth a characteristic somatic picture, skeletal anomalies, vacuolated lymphocytes in peripheral blood, typical signs of a metabolic disorder, were present. The daily excretion of urinary mucopolysaccharides was within normal range, nevertheless an anomalous pattern consisting in a high amount of dermatan sulfate was found. The excretion of urinary sialyl oligosaccharidases was increased. Cultured skin fibroblasts showed the typical "I-cell" phenomenon. The activities of serveral lysosomal enzymes were strikingly increased in serum, but not in leucocytes. No significant variations of acid hydrolase activities were found in the patient's relatives.

Humans↗
PubMedDate not supplied

[Evaluation and treatment of the enuretic child: eight years' experience].

Enuresis is a common functional problem among children which is defined as a complete involuntary voiding of urine at an age which control should be present. Bed wetting generally resolves with increasing age, but the restriction in social life and the psychological secondary problems, so frequent in older patients, justify an appropriate treatment of the problem in the child over seven. At children's Hospital of Florence University an enuresis service exists since 1983, and during these years 541 children applied to the structure. 326 children completed the treatment, among these there were 202 boy and 124 girls with age between 6 and 19. All the patients have been initially helped only with conversation (motivational counseling) and 76 among them (23% of the whole) obtained permanent cure. The remaining 250 children were treated with the conditioning alarm system, always associated to periodic conversation, urine stop exercises and other psychological support (token economy, etc). There were 161 boys and 89 girls: 220 children had nocturnal primary enuresis and 30 secondary. The family history was positive in 77%. The results obtained of this kind of treatment after a follow-up of 6 months, were permanent recovery in 211 children (84%) and failure in 39 patients (16% of the cases). There have been 35 relaxes. Regarding the sex, no significant difference was noted. These positive results with the conditioning devices favor the view that the etiology of primary enuresis is mainly biologic. The bell alarm represents the most effective treatment for nocturnal enuresis included more than seven.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

Carotid surgery under cervical block anesthesia. A simple method of heart and brain protection in high risk patients.

Between January 1, 1985, and December 15, 1987, 60 patients underwent surgery for carotid lesions under local cervical block anesthesia. Sixty-seven reconstruction procedures were performed including 64 endarterectomies and 3 vein bypasses. During the same 3 year period, 938 other reconstruction procedures were carried out under general anesthesia for a total of 1005 procedures. These 60 patients, who accounted for 6.7% of our indications, were selected for surgery under local anesthesia because they were at high risk for cardiac and neurologic complications. As far as staging is concerned, this subgroup of patients included: 14 asymptomatic cases (stage 0), i.e., 21%; 44 transient ischemic attacks (stage I), i.e., 66%; 2 progressive stroke (stage II), i.e., 3%; 7 patients with neurologic sequels (stage III), i.e., 10%. In all 79% of the patients were symptomatic. The asymptomatic patients all presented bilateral tight stenosis sometimes with thrombosis of the contralateral carotid. The technique of local anesthesia and endarterectomy were classic: closing with a bougie to calibrate the lumen, systematic intraoperative arteriography and immediate correction of technical failures (2 times); no death occurred among the patients in stages 0, 1 and II; 1 early asymptomatic occlusion that was not corrected was noted; in one case, a ligation of the carotid was necessary after technical failure, without consequences; one death occurred in stage III after intracerebral hemorrhage. On the basis of our experience local cervical block anesthesia appears to be a simple and reliable method of ensuring intraoperative diagnosis of cerebral ischemia. It eliminates all intraoperative cerebral complications secondary to ischemia and allows a better understanding of the physiopathologic mechanisms underlying perioperative neurologic complications. The absence of neurologic and cardiac complications in this series of very high risk patients enables us to extend eligibility for surgery to include patients with unstable cardiac and cerebral disease.

Aged↗
PubMedDate not supplied

Ultrasound and estradiol plasma levels in threatened abortion.

Ultrasound examination and unconjugated estriol assay were performed in 111 women with threatened abortion between the 6th and the 20th week of pregnancy. In viable pregnancies, fetal echoes and fetal heart movements were always observed by sonar from the 10th week onward and estradiol levels always increased above 30 pg/ml from the 13th week. Both ultrasound and estriol assay showed high percentages of uncertain prognostic indication on pregnancy outcome when examinations were performed during the first weeks of pregnancy. However, in the same period estriol levels higher than 30 pg/ml were always correlated with the favourable outcome of pregnancy, since no abortion occurred in subjects with detectable estriol values. During the second trimester ultrasound and estradiol results were normal in all viable pregnancies, while they were abnormal in 71.4% of pregnancies which failed to continue. Estriol values were always undetectable when fetuses could not be identified by sonar or they were dead. These data seem to demonstrate that both methods have similar prognostic value in patients with threatened abortion. However both sonar examination and estriol levels sometimes failed in predicting subsequent pregnancy interruptions, suggesting that abortions were not related to either fetal or placental alterations.

Abortion, Threatened↗