Giulio Soldani

High Growth Rate of Girls with Precocious Puberty Exposed to Estrogenic Mycotoxins

OBJECTIVE To test the hypothesis that human puberty timing can be advanced by environmental estrogen exposure. STUDY DESIGN We analyzed serum mycoestrogen contamination via high-performance liquid chromatography (HPLC) in 32 girls affected by central precocious puberty (CPP) and in 31 healthy female control subjects. All 32 patients received triptorelin (TR) for more than 12 months after diagnosis. RESULTS Increased serum levels of zearalenone (ZEA; 933.7 +/- 200.3 pg/mL; 95% CI, 723.5-1143.9) and of its congener alpha-zearalenol (106.5 +/- 1.9 pg/mL; 95% CI, 104.5-108.5) contaminated 6 girls with CPP, who were from a bounded Tuscany area. At diagnosis, ZEA levels correlated with patient height (r = 0.906, P < .05) and weight (r = 0.887, P < .05), but not with bone age. In patients who were mycotoxin-positive, height (F = 4.192; P < .01), weight (F = 3.915; P < .01), and height velocity (F = 2.777, P < .05) were higher than patients who were mycotoxin-negative during 12-months TR treatment. Height correlated with weight both in patients who were mycotoxin-positive (r = 0.986, P < .001) and in patients who were mycotoxin-negative (r = 0.994, P < .001). Body mass index, bone age, and gonadal secretion was not different in patient groups before and during TR treatment (P > .05). CONCLUSIONS Mycoestrogenic zearalenone is suspected to be a triggering factor for CPP development in girls. Because of its chemical resemblance to some anabolic agents used in animal breeding, ZEA may also represent a growth promoter in exposed patients.

Gastric antisecretory role and immunohistochemical localization of cannabinoid receptors in the rat stomach

The role of cannabinoid (CB) receptors in the regulation of gastric acid secretion was investigated in the rat by means of functional experiments and by immunohistochemistry. In anaesthetized rats with lumen‐perfused stomach, the non selective CB‐receptor agonist WIN 55,212‐2 (0.30 – 4.00 μmol kg−1, i.v.) and the selective CB1‐receptor agonist HU‐210 (0.03 – 1.50 μmol kg−1, i.v.), dose‐dependently decreased the acid secretion induced by both pentagastrin (30 nmol kg−1 h−1) and 2‐deoxy‐D‐glucose (1.25 mmol kg−1, i.v.). By contrast, neither WIN 55,212‐2 (1 – 4 μmol kg−1, i.v.) nor HU‐210 (0.03 – 1.50 μmol kg−1, i.v.) did modify histamine‐induced acid secretion (20 μmol kg−1 h−1). The selective CB2‐receptor agonist JWH‐015 (3 – 10 μmol kg−1, i.v.) was ineffective. The gastric antisecretory effects of WIN 55,212‐2 and HU‐210 on pentagastrin‐induced acid secretion were prevented by the selective CB1‐receptor antagonist SR141716A (0.65 μmol kg−1, i.v.) and unaffected by the selective CB2‐receptor antagonist SR144528 (0.65 – 2 μmol kg−1, i.v.). Bilateral cervical vagotomy and ganglionic blockade with hexamethonium (10 mg kg−1, i.v., followed by continuous infusion of 10 mg kg−1 h−1) significantly reduced, but not abolished, the maximal inhibitory effect of HU‐210 (0.3 μmol kg−1, i.v.) on pentagastrin‐induced acid secretion; by contrast, pretreatment with atropine (1 mg kg−1, i.v.) did not modify the antisecretory effect of HU‐210. Immunoreactivity to the CB1 receptor was co‐localized with that of the cholinergic marker choline acetyltransferase in neural elements innervating smooth muscle, mucosa and submucosal blood vessels of rat stomach fundus, corpus and antrum. In contrast, CB2 receptor‐like immunoreactivity was not observed. These results indicate that gastric antisecretory effects of cannabinoids in the rat are mediated by suppression of vagal drive to the stomach through activation of CB1 receptors, located on pre‐ and postganglionic cholinergic pathways. However, the ineffectiveness of atropine in reducing the effect of HU‐210 suggests that the release of non cholinergic excitatory neurotransmitters may be regulated by CB1 receptors.

Pharmacokinetics of enrofloxacin in the seabass (Dicentrarchus labrax)

Abstract The plasma kinetics and tissue distribution of enrofloxacin (EF) were investigated in the seabass (Dicentrarchus labrax) after administration by oral gavage and by bath. Plasma and tissue concentrations of EF and of its metabolite ciprofloxacin (CF) were determined by HPLC. After oral treatment (5 mg/kg bw), EF was slowly absorbed and eliminated (Cmax=1.39±0.67 μg/ml at 8 h; T1/2=25 h). EF was distributed efficiently to the extravascular compartment, with concentrations in liver constantly higher than in muscle and skin. Bath treatment (5, 10 or 50 ppm for 4, 8 or 24 h) resulted in plasma and tissue levels that significantly correlated with water drug concentration or time of exposure to medicated water. CF was detected constantly in liver, occasionally in plasma, but never in muscle and skin, suggesting a low degree of metabolic conversion of EF in the seabass. After oral treatment at 5 mg/kg and bath treatment at 50 ppm for 4 h or at 5 ppm for 24 h, ratios between EF peak concentrations in plasma and tissues and MICs of EF against the most common fish pathogens exceeded those indicated as optimal to ensure the bactericidal efficacy of the drug. These dosages of EF are proposed for performing therapeutic trials in the seabass.

An optimized digestion method coupled to electrochemical sensor for the determination of Cd, Cu, Pb and Hg in fish by square wave anodic stripping voltammetry

An optimized digestion method coupled to electrochemical detection to monitor lead, copper, cadmium and mercury in fish tissues was developed. Square wave anodic stripping voltammetry (SWASV) coupled to disposable screen-printed electrodes (SPEs) was employed as fast and sensitive electroanalytical method for heavy metals detection. Different approaches in digestion protocols were assessed. The study was focused on Atlantic hake fillets because of their wide diffusion in the human nutrition. Best results were obtained by digesting fish tissue with hydrogen peroxide/hydrochloric acid mixture coupled to solid phase (SP) purification of the digested material. This combined treatment allowed quantitative extraction from fish tissue (muscle) of the target analytes, with fast execution times, high sensitivity and avoiding organic residues eventually affecting electrochemical measurements. Finally, the method has been validated with reference standard materials such as dogfish muscle (DORM-2) and mussel tissues (NIST 2977).

Measurement of the SαT segment as the most reliable electrocardiogram parameter for the assessment of adriamycin-induced cardiotoxicity in the rat

A new method is described for the assessment of the early cardiotoxic effects of adriamycin and related drugs on rat electrocardiographic parameters. Evidence is presented that during repeated treatment with adriamycin, no changes occur concerning the PR and RR intervals, QTc, or R- and S-wave voltages, whereas significant changes in the QRS complex, R alpha T and alpha TP intervals, and T-wave voltage are detectable. However, the earliest and most consistent electrocardiogram alteration observed during adriamycin treatment is a progressive, irreversible widening of the S alpha T segment. The S alpha T enlargement becomes significant during the first week of treatment and may be detected in all the tracings at all the times examined. The electrocardiogram changes are accompanied by cardiac histological lesions that gradually increase in severity during the study. These results indicate that the measurement of the S alpha T segment provides a rapid, sensitive, and reliable method for the evaluation of electrocardiogram toxicity induced by adriamycin and related anthracyclines in the rat.

Mycotoxin detection in infant formula milks in Italy

After birth, infant formulas constitute an important or often sole food source for infants during the first months of life. In this study, a survey on the presence of aflatoxin M1 (AFM1) and ochratoxin A (OTA) in the 14 leading brands of infant formulas marketed in Italy was conducted. Mycotoxins were determined by immunoaffinity column clean-up and high-performance liquid chromatography (HPLC) with fluorescence detection. AFM1 was found in two of 185 samples, but at levels below the European legislation limit of 25 ng l−1. OTA was detected in 133 (72%) samples (range = 35.1–689.5 ng l−1). It has been observed that OTA contamination was 80% in the ready-to-use preparations and 63% in the powdered samples. The Scientific Committee for Food (SCF) reviewed the toxicology on OTA and concluded that it would be prudent to reduce exposure to OTA ensuring that exposure is towards the lower end of the range of tolerable daily intakes of 1.2–14 ng kg−1 body weight day−1. OTA was also evaluated by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and a provisional tolerable weekly intake (PTWI) of 100 ng kg−1 body weight was established. The OTA levels in pre-term ready-to-use infant formulas were sufficient to cause a higher OTA intake than the suggested TDI. The results point out the need to perform controls for prevention programmes especially when attempting to identify risk markers of the infant feed quality.

THE PLASMA KINETICS AND TISSUE DISTRIBUTION OF ENROFLOXACIN AND ITS METABOLITE CIPROFLOXACIN IN THE MUSCOVY DUCK

Intorre, L., Mengozzi, G., Bertini, S., Bagliacca, M., Luchetti, E. and Soldani, G., 1997. The plasma kinetics and tissue distribution of enrofloxacin and its metabolite ciprofloxacin in the Muscovy duck. Veterinary Research Communications, 21 (2), 127-136

Antimicrobial susceptibility of Staphylococcus intermedius and Staphylococcus schleiferi isolated from dogs.

The susceptibility to 23 antimicrobial agents was determined in 114 isolates of Staphylococcus intermedius and eight isolates of Staphylococcus schleiferi of canine origin. Overall, 73% of S. intermedius isolates and 37.5% of S. schleiferi isolates were susceptible to all the 23 antimicrobials tested. The large majority of S. intermedius strains retained susceptibility to antimicrobials currently employed in treatment of pyoderma (cephalosporins, cotrimoxazole and association amoxicillin-clavulanic acid) as well as to those effective against staphylococci (fusidic acid, rifampicin and fluoroquinolones). Resistance in S. intermedius was observed mainly against macrolides, chloramphenicol and lincosamides, while S. schleiferi isolates retained susceptibility to all antimicrobials except three of six fluoroquinolones. Although, our results confirm susceptibility to antimicrobials currently employed in pyoderma treatment, the several different resistance patterns observed for S. intermedius emphasize the importance of antimicrobial susceptibility testing of canine staphylococci to choose the most appropriate treatment of infections and to allow the prudent use of antimicrobial drugs in companion animals.

Action of catecholamines on release of acetylcholine from human taenia coli

Abstract The amount of acetylcholine released from longitudinal strips of human taenia coli increased with frequency of stimulation; in contrast there was an inverse relationship between stimulation rate and output per stimulus. The reduction of acetylcholine release by tetrodotoxin was greater during stimulation than at rest. Noradrenaline 1 × 10−6 g/ml (but not isoprenaline 1 × 10−6 g/ml) reduced significantly acetylcholine release from preparations stimulated at a frequency of 2/sec. No effect was observed on the resting release. It was concluded that in human taenia coli catecholamines modulate the activity of cholinergic neurons probably through α-receptors.

Effects of galanin on smooth muscle and mucosa of porcine jejunum.

The enteric neuropeptide galanin (GAL) increased the amplitude of spontaneous contractions in longitudinally oriented muscle strips and inhibited short-circuit current (Isc) elevations induced by transmural electrical stimulation (ES) of mucosal sheets from porcine jejunum in vitro. GAL-induced contractions (GAL EC50 = 9 nmol/l) were maximally 25% of those elicited by 10 mumol/l carbamylcholine and remained unaffected by atropine, tetrodotoxin, or tachyphylaxis to substance P. The presynaptic Ca2+ channel blocker, omega-conotoxin (0.1 mumol/l), inhibited GAL-induced contractions by 66%. GAL attenuated mucosal Isc elevations induced by ES with an IC50 = 13 nmol/l and at 0.1 mumol/l produced rapid decreases in basal Isc averaging 8 +/- 2 microA cm-1 in 77% of tissues examined. The alpha-adrenoceptor blocker phentolamine or the opiate antagonist naloxone did not alter tissue Isc responses to GAL. These results suggest that GAL modulates neuronal activity linked to secretomotor function in the porcine small intestine.