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Biomedical subjects

E Ferrari

Publications and source records attributed to E Ferrari.

At least 271 records · Page 15Linked to original sources
PubMed1990

Performance and clinical significance of the new fructosamine assay in diabetic patients.

The performance of the assay and the clinical usefulness of a new short-term index (Fructosamine Plus: FP) of metabolic control in diabetes was evaluated. The FP concentration was determined with the Hitachi 704, Cobas Mira, and Cobas Fara analyzers. The "within run" and "between run" CVs were less than 2.67% and less than 4.26%, respectively. The reference interval (determined from data on 125 blood donors) was 191 to 288 mumol/l (mean 240 mumol/l). In poorly controlled diabetic patients FP was significantly higher than in the well controlled ones. Moreover FP was significantly correlated with HbA1c and blood glucose levels. Our preliminary data seem to demonstrate that relating FP to total protein does not improve the clinical value of the new index.

Adult↗
PubMed1989

Calf thymus DNA polymerase delta independent of proliferating cell nuclear antigen (PCNA).

DNA polymerase delta from calf thymus was purified under conditions that minimized proteolysis to a specific activity of 27,000 units/mg. The four step isolation procedure included phosphocellulose, hydroxyapatite, heparin-Sepharose and FPLC-MonoS. This enzyme consists of four polypeptides with Mr of 140, 125, 48 and 40 kilodaltons. Velocity gradient sedimentation in glycerol removed the 48 kDa polypeptide while the other three sedimented with the DNA polymerase activity. The biochemical properties of the three subunit enzyme and the copurification of 3'----5' exonuclease activity were typical for a bona fide DNA polymerase delta. Tryptic peptide analysis showed that the 140 kDa polypeptide was different from the catalytic 180 kDa polypeptide of calf thymus DNA polymerase alpha. Both high Mr polypeptides (140 and 125 kDa) were catalytically active as analysed in an activity gel. Four templates were used by DNA polymerase delta with different preferences, namely poly(dA)/oligo(dT)12-18 much much greater than activated DNA greater than poly(dA-dT) greater than primed single-stranded M13DNA. Calf thymus proliferating cell nuclear antigen (PCNA) could not stimulated this DNA polymerase delta in any step of the isolation procedure. If tested on poly(dA)/oligo(dT)12-18 (base ratio 10:1), PCNA had no stimulatory effect on DNA polymerase delta when tested with low enzyme DNA ratio nor did it change the kinetic behaviour of the enzyme. DNA polymerase delta itself did not contain PCNA. The enzyme had an intrinsic processivity of several thousand bases, when tested either on the homopolymer poly(dA)/oligo(dT)12-18 (base ratio 64:1) or on primed single-stranded M13DNA. Contrary to DNA polymerase alpha, no pausing sites were seen with DNA polymerase delta. Under optimal in vitro replication conditions the enzyme could convert primed single-stranded circular M13 DNA of 7,200 bases to its double-stranded form in less than 10 min. This supports that a PCNA independent DNA polymerase delta exists in calf thymus in addition to a PCNA dependent enzyme (Lee, M.Y.W.T. et al. (1984) Biochemistry 23, 1906-1913).

Animals↗
PubMed1989

Alpha 2-adrenoceptor sensitivity in anorexia nervosa: GH response to clonidine or GHRH stimulation.

Growth hormone (GH) response to clonidine and growth hormone-releasing hormone (GHRH) stimulation, together with baseline somatomedin C (SmC) levels, were examined in parallel in a group of 21 patients with anorexia nervosa (AN) and in 10 controls. In addition, the Hamilton Rating Scale for Depression (HRS) was administered to the patients. Clonidine (2.5 micrograms/kg body weight, iv) induced GH elevations that were not significantly different between patients and controls. In contrast, GHRH (1 microgram/kg body weight, iv) produced a significantly higher GH response in anorectics than in controls. The ratio between GH responses (area under the curve, or AUC) to GHRH and to clonidine was significantly higher in patients than in controls. Baseline SmC levels (6 patients) were significantly lower in anorectics than in controls. Minor depressive symptomatology was present in all patients. When viewed in relation to the GH hyperresponsiveness to GHRH, the apparent normality of the response to clonidine in anorectics reflects the existence of an actual alpha 2-adrenoceptor subsensitivity. As clonidine reportedly acts via release of endogenous GHRH, an excessive, rather than a normal, GH response to clonidine was to be anticipated.

Adolescent↗
PubMed1989

Facial dystonia: clinical features, prognosis and pharmacology in 31 patients.

The natural history and response to different treatments were assessed in 31 consecutive patients with blepharospasm (BS) and/or oromandibular dystonia (OMD). The mean age at onset was 52.4 years and there was a female preponderance of 2.5 to 1. Ocular symptoms preceded the onset of blepharospasm in more than 50% of the affected patients, whereas psychiatric and dental problems prior to the onset of focal dystonia were found in 10% and 13% of the cases respectively. Dystonia elsewhere, mainly in the craniocervical area, was found in 23% of patients and appeared to follow a somatotopic progression. The first 2-3 years of history were crucial for the spread of dystonia to other face and body parts. When OMD was the first symptom, a lower tendency of dystonia to progress elsewhere was observed. A putative cause was found in 14% of patients who showed clinical and radiographic evidence of basal ganglia or rostral brainstem-diencephalon lesions. The response to different drugs was inconsistent although transient improvement was induced by haloperidol in 6 patients, by L-Dopa plus deprenyl in 3 patients, by trihexyphenidyl in 2 patients and by clonazepam in 2 patients. One, apparently spontaneous, remission was observed. Botulinum A toxin was injected in the orbicularis oculi of 8 patients affected by BS: moderate to marked improvement lasting 5 to 30 weeks (mean 14.5 weeks) was achieved in all cases; transient ptosis, lasting 1 to 3 weeks, occurred in 3 cases.

Adult↗
PubMed1989

Evidence for the existence of prejunctional receptor sites for dopamine in the mouse vas deferens.

The present work is focused on the effects of newly developed dopaminergic agonists and antagonists on the field-stimulated vas deferens. Both LY 171555 and SK&F 38393, relatively selective DA2 and DA1 receptor agonists, respectively, produced concentration-dependent inhibition of the field stimulation-evoked contractions in the mouse vas deferens; both compounds did not modify the baseline tone nor the contractile responses to exogenous noradrenaline. Control LY 171555 and SK&F 38393 concentration-response curves, were shifted rightward in a parallel manner in the presence of sulpiride (relatively specific DA2 antagonist) and SCH 23390 (relatively specific DA1 antagonist), respectively. Control concentration-response curves for dopaminergic agonists were not modified in the presence of specific blockers for H1 and H2 histamine receptors, serotonin receptors and alpha 2-adrenoceptors. These preliminary findings are suggestive of the existence of two dopaminergic receptor types both presumably located prejunctionally.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1989

[Clinical aspects, differential diagnosis and evolution of visual epileptic seizures in children].

We studied 13 boys and girls, treated for ictal visual episodes, followed-up in the Center for Epilepsy of the University of Modena. In 10 cases visual symptoms (amaurosis, hallucinations, and illusions) started between 6 and 14 years, associated with occipital EEG anomalies. In 6 cases, EEG abnormalities (sharp-waves, slow waves, spikes, spike-waves) disappeared after eyes opening. In the history of half of our cases, there was no significant antecedent. Normal intelligence and behaviour were present in all cases. Only in one case, CT demonstrated bilateral occipital calcifications. In the other 9, visual ictal symptoms disappeared after antiepileptic treatment. We think that these last cases present the characteristic features of Benign Occipital Epilepsy described by Gastaut (1982-1985). On the basis of our results, we can confirm the existence of this syndrome, even if it is rare. Nevertheless, 3 of our cases with visual symptoms, don't show the typical picture of BOE, and must be diagnostically distinguished from psychiatric disorders, basilar migraine, and other partial epilepsies.

Adolescent↗
PubMed1989

Melatonin and pituitary-gonadal function in disorders of eating behavior.

In order to study the possible relationships between melatonin secretion and pituitary-gonadal function, the circadian rhythm of plasma melatonin, the basal levels of estradiol-17beta and testosterone and the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) response to luteinizing hormone-releasing hormone (LH-RH) stimulation were evaluated in normally cycling healthy women and in two groups of women with menstrual dysfunctions related to eating disorders (19 patients with anorexia nervosa and 16 with primary obesity). The circadian rhythm of plasma melatonin reached statistical significance in anorectic patients but not in obese patients. The mean 24 h melatonin level was significantly higher in anorectic than in obese patients and in control subjects. However, both groups of patients shared some abnormalities of melatonin circadian pattern, such as increased ratio between day and night melatonin levels, abnormal secretory peaks during the light hours and great interindividual variability for timing, amplitude, and duration of melatonin nocturnal peak. A selective impairment of LH secretion was observed in both anorectic and obese patients. By considering together the two groups of patients and controls, a linear inverse correlation between the circadian mesor of plasma melatonin and the basal and LH-RH stimulated LH levels was found. The persistence of a certain melatonin secretion during the light hours in both anorectic and obese patients could play an inhibitory role on the pituitary gonadal function in these subjects.

Adolescent↗
PubMed1989

Effects of diet-therapy on urinary protein excretion albuminuria and renal haemodynamic function in obese diabetic patients with overt nephropathy.

Twenty-four type 1 and type 2 diabetic patients with obesity and overt nephropathy were studied for 12 months after hypocaloric diet change from 1870 to 1410 kcal/day (without changes of protein:carbohydrate ratio). Several parameters were evaluated: arterial blood pressure, blood glucose, fructosamine, HbA1c, proteinuria, albuminuria, glomerular filtration rate (GFR), creatinine clearance, triglycerides, HDL and total cholesterol. A significant reduction of body weight (body mass index from 33 +/- 1.6 to 26 +/- 1.8 kg/m2, P less than 0.001), concomitantly with a decrease of blood pressure levels (P less than 0.002) was demonstrated at the end of the study. Triglyceride (P less than 0.002), HDL (P less than 0.002), HDL (P less than 0.05) and total cholesterol (P less than 0.01) levels were reduced after diet-therapy, while a mild improvement of glycometabolic profile was observed in the same period. A marked decrease of proteinuria (from 1280 +/- 511 to 623 +/- 307 mg/24 h, P less than 0.01) and albuminuria (from 723 +/- 388 to 492 +/- 170 micrograms/min, P less than 0.01), and an improvement of GFR (from 66 +/- 13 to 81 +/- 11 ml/min/1.73 m2, P less than 0.01) and creatinine clearance (from 79 +/- 14 to 91 +/- 13 ml/min, P less than 0.01) was demonstrated after 12 months of diet-treatment. Our data suggest that body weight reduction by hypocaloric diet may delay the progression of clinical nephropathy in obese diabetic patients.

Albuminuria↗
PubMed1988

Replication of single-stranded porcine circovirus DNA by DNA polymerases alpha and delta.

Porcine circovirus is the only mammalian DNA virus so far known to contain a single-stranded circular genome (Tischer et al. (1982) Nature 295, 64-66). Replication of its small viral DNA (1.76 kb) appears to be dependent on cellular enzymes expressed during S-phase of the cell cycle (Tischer et al. (1987) Arch. Virol. 96, 39-57). In this paper we have exploited the porcine circovirus genome to probe for in vitro initiation and elongation of DNA replication by different preparations of calf thymus DNA polymerase alpha and delta as well as by a partially purified preparation from pig thymus. The results indicated that three different purification fractions of calf thymus DNA polymerase alpha and one from pig thymus initiate DNA synthesis at several sites on the porcine circovirus DNA. It appears that the sites at which DNA primase synthesizes primers are not entirely random. Subsequent DNA elongation by a highly purified DNA polymerase alpha holoenzyme which had been isolated by the criterion of replicating single-stranded M13 DNA (Ottiger et al. (1987) Nucleic Acids Res. 15, 4789-4807) is very efficient. Complete conversion to the double-stranded form is obtained in less than 1 min. When the DNA synthesis by DNA polymerase alpha is blocked with the DNA polymerase alpha specific monoclonal antibody SJK 132-20 after initiation by DNA primase, DNA polymerase delta can efficiently replicate from the primers. This in vitro DNA replication system may be used in analogy to the bacteriophage systems in E. coli to study initiation and elongation of DNA replication.

Animals↗
PubMed1988

Do DNA polymerases delta and alpha act coordinately as leading and lagging strand replicases?

The activity ratio of DNA polymerases delta and alpha in calf thymus was found to be invariably 1:1, irrespective of extraction procedure (8 types) and subcellular localization (cytoplasm, nucleus and microsomes). This was established by separation of the two forms by hydroxyapatite chromatography and by their response to specific inhibitors and monoclonal antibodies. This finding supports the dimeric DNA polymerase model [(1980) J. Biol. Chem. 255, 4290-4303], which proposes that DNA polymerases delta and alpha act coordinately as leading and lagging strand enzymes, respectively, at the replication fork.

Adenosine Triphosphate↗
PubMed1988

Haemostatic variables, serum lipid abnormalities and vascular complications in diabetes mellitus: a 5 year follow-up study.

The relationship among blood lipids, haemostatic and fibrinolytic parameters have been evaluated, during a follow-up study, in 27 non-insulin dependent (type II) diabetic patients. Upon recruitment, and in periodical controls, we observed that plasma triglycerides and VLDL levels correlated inversely, and HDL directly, with the fibrinolytic activity of plasma and euglobulin precipitate. Furthermore triglycerides and VLDL correlated directly with Factor VIII antigen (vWFAg). After 5 years in the study, 12 patients (44%) had macroangiopathic complications, and 9 of these subjects showed persistently high levels of triglycerides (above 2.36 mmol/l). These haemostatic and lipid components, however, do not influence the progression of diabetic retinopathy and nephropathy. The alterations of lipid, haemostatic and fibrinolytic parameters and their possible relationships seem to play an important role in the occurrence of diabetic macroangiopathy.

Aged↗
PubMed1988

Plasma beta-endorphin, free fatty acids and blood lipid changes in type 2 (non-insulin dependent) diabetic patients.

A lipolytic activity for beta-endorphin (beta EP) has been recently suggested both in vitro and in vivo. In our study we evaluated the relationship between beta EP and blood lipid pattern in Type 2 (non-insulin dependent) diabetic patients. Plasma beta EP, together with plasma beta-lipotropin (beta LPH), ACTH, cortisol and plasma insulin (IRI), was measured by RIA after silicic acid plasma extraction and Sephedex G-75 column chromatography. Although reduced beta EP (7.12 +/- 3.8 fmol/ml) and increased beta LPH (9.3 +/- 3.7 fmol/ml) levels were found in diabetic patients, compared to controls (8.53 +/- 3.3 fmol/ml, p less than 0.05 and 8.34 +/- 2.6 fmol/ml, p less than 0.05, respectively), higher plasma beta EP concentrations were demonstrated in hyperlipidemic diabetic patients (10.3 +/- 3.9 fmol/ml) than in patients with normal blood lipid pattern (4.85 +/- 1.45 fmol/ml, p less than 0.001). Several positive correlations between beta EP, plasma free fatty acids (r = 0.75, p less than 0.001), triglycerides (r = 0.84, p less than 0.001) and VLDL (r = 0.80, p less than 0.001) were found in our patients independently of overweight, hypoglycemic treatment, plasma IRI levels and of the degree of metabolic control. A higher prevalence of micro- and macrovascular complications was demonstrated in hyperlipidemic than in normolipidemic patients. Blood lipid disorders might therefore be associated with increased plasma beta EP levels in Type 2 diabetes.

Adrenocorticotropic Hormone↗
PubMed1988

Melatonin circadian rhythm in anorexia nervosa and obesity.

The mean 24-hour secretion and circadian rhythm of melatonin were studied in 12 female subjects with anorexia nervosa (AN), 13 massively obese (OB) women, and 9 normal weight healthy volunteers to investigate the relationship between type of feeding behavior and hormonal secretory pattern. Blood samples for melatonin were drawn every 4 hours from 0400 h to 2400 h and every 2 hours from 2400 h to 0400 h. Mean 24-hour melatonin secretion was significantly higher in AN than in OB patients and controls. Melatonin circadian rhythms were disrupted in 8 of the 12 AN patients and in 9 of the 13 OB subjects, with phase-advanced nocturnal rises, abnormal diurnal peaks, or no nocturnal rises. The population mean cosinor analysis validated the existence of a significant circadian rhythm of the hormone in AN but not in OB subjects. No significant correlation between mean 24-hour secretion or type of circadian alterations and degree of weight deficit or excess was observed. The circadian alterations of melatonin in AN and OB may be linked to impaired secretory tonus of noradrenalin in the central nervous system, possibly unrelated to feeding patterns.

Adolescent↗