Effect of neostigmine on contractility of equine pre-ovulatory follicles: An in vitro study.

In this study, the Authors investigated the modulatory effect of three single doses (10-6, 10-5, and 10-4 M) of neostigmine on the spontaneous contractility of equine pre-ovulatory follicles in an isolated organ bath, to establish the relationship between this acetylcholinesterase inhibitor and ovulation, in the mare. The results indicate that neostigmine increases pre-ovulatory contractility in equine follicles at each dose, but in a different manner. Indeed, the rise in contractility induced by neostigmine at 10-6 M and 10-4 M was phasic, while at 10-5 M it was tonic. The data obtained indicate possible implications of these drugs in the pharmacological modulation of equine ovulation.

Oxytocin plus antibiotics: A synergism of potentiation to enhance bovine uterine contractility.

This in vitro study investigates the modulatory effect of three antibiotics (amoxicillin, enrofloxacin, and rifaximin) on contractility of the bovine uterine tissue, in follicular and luteal phases. The evaluation of the effects of these antibiotics (10(-4) M) was performed on oxytocin-induced contractility. The decision to test these antibiotics with the oxytocin (10(-6) M) comes from the reported ability of these combinations of hinder the antibiotic resistance and the formation of bacterial biofilms. The procedures were carried out in isolated organ bath, and the contractile functionality of the strip throughout the experiment was evaluated after a dose of carbachol (10(-5) M). The results demonstrate the different modulatory activity of these antibiotics, on the plateau of contraction induced by oxytocin, in both phases of the estrus cycle. The differing individual antibiotic effects of our testing made it possible to identify, only in some cases. Rifaximin in the follicular phase and enrofloxacin in both phases of the estrous cycle, induced a synergistic enhancement (potentiation) of uterine strip contraction induced by oxytocin. This result is thought important because these associations might enable, in vivo, a simultaneous increase of uterine cleaning and the antimicrobial action on bacteria in planktonic form and of those organized in biofilms.

[MR-angiography with contrast bolus vs digital angiography in peripheral arterial occlusive disease of the legs]. / Angio-RM con bolo di contrasto vs angiografia digitale nella patologia ostruttiva del circolo arterioso periferico degli arti inferiori.

PURPOSE: Aim of our study was to compare MR Angiography and Digital Angiography in the diagnosis of peripheral vascular occlusive disease. MATERIAL AND METHODS: Forty-five patients underwent both MRA and DSA examination of the peripheral arterial district. We employed a 1.5 Tesla MRI unit using 3D FSPGR T1-w sequence on coronal scan plane (TR=5.2 ms; TE=1.5 ms; slice=1.5/3 mm; FOV=48 cm; matrix 384x512; TA=16/24 s), before and after automatic iv injection of Gd-DTPA BMA (0.15/0.3 mmol/kg) with a flow rate of 2 ml/s. We evaluated the vascular district from renal to medio-distal tibial arteries. The acquisition of this arterial district required a semi-automatic movement of the examination table. Qualitative and quantitative analyses were carried out according to MIP reconstructions. DSA evaluation, considered as the gold standard, was performed by trans-femoral access using a 4-5F catheter. RESULTS: The MRA examination detected 246 steno-occlusive lesions while 285 were identified with DSA. No statistically significant differences were found among the various degrees of stenotic lesions detected by the two METHODS. The MRA examination had specificity and sensitivity values of: 100% and 84,8% for the iliac axes; 98,9% and 94,3% for the femoral district; 100% and 84,9% for the popliteal district; 97% and 89% for tibial vessels. CONCLUSIONS: MRA showed a high diagnostic accuracy close to that of DSA. On the basis of our short experience we believe that MRA will be a useful method in the detection of various degrees of peripheral artery occlusive diseases reserving DSA for the therapeutical step.

[Magnetic resonance imaging of hepatic focal lesions: dynamic contrastographic evaluation with gadolinium versus reticulo-endothelial hepato-specific contrast media]. / Risonanza Magnetica delle lesioni focali epatiche: valutazione contrastografica dinamica con gadolinio vs mezzo di contrasto epatospecifico reticolo-endoteliale.

PURPOSE: To compare the potentials of AMI-25 (Endoren) to those of Gadolinium with the dynamic contrast-enhanced technique in the differential diagnosis of focal liver lesions. MATERIAL AND METHODS: Forty patients with at least one focal liver lesion diagnosed at US underwent MRI. We used a 1.5 T unit and employed single-shot half-Fourier T2-weighted FSE and spoiled gradient-echo T1-weighted sequences before and after Gadolinium injection. Multiple acquisitions were obtained during the arterial, portal and delayed phases. Twenty-four to 48 hours later T2*-weighted GRE and SPGR/90 degrees sequences were obtained after AMI-25 administration. In the characterization of solid lesions the gold standard was biopsy performed with a shearing needle; for the diagnosis of angiomas and of 11 metastatic lesions we considered follow-up and clinical data as important diagnostic elements. RESULTS: We found 12 hepatocarcinomas, 14 metastases, 4 cases of focal nodular hyperplasia (FNH), 4 adenomas and 6 angiomas. The diagnosis was correct and confirmed by the conventional examination in all cases but 2 adenomatous lesions and 2 angiomas. Precontrast studies showed slight hyperintensity in 2 of 4 cases of FNH, while the other 2 lesions appeared isointense and were therefore detected only on postcontrast images, where there was contrast agent uptake during the arterial phase and rapid washout. We found only one central scar hyperintense on T2- and hypointense on T1-weighted images. After AMI-25 administration all lesions appeared isointense to surrounding parenchyma on T2* GRE sequences. Adenomas were isointense in the precontrast phase and postcontrast 3 of them showed strong Gadolinium uptake and rapid washout. After AMI-25 two of the 4 lesions were hyperintense while the other two were isointense to the parenchyma. Four of 6 angiomas exhibited a typical pattern characterized by signal hyperintensity on T2-weighted sequences and on AMI-25-enhanced T1- and T2-weighted sequences. Two angiomas were supposed to be of malignant nature but histology showed the presence of a strong fibrotic component. Hepatocarcinomas could be detected on precontrast images. After Gadolinium administration 10 lesions appeared hyperintense in the arterial phase and 2 were hypointense. After AMI-25 all lesions exhibited homogeneous signal hyperintensity and appeared slightly bigger than on Gadolinium-enhanced images. The metastases were only partly demonstrated by MRI. Postgadolinium studies showed 13 lesions with hyperintense signal in the portal phase. AMI-25 administration detected 14 lesions that appeared slightly bigger than on Gadolinium-enhanced images. CONCLUSIONS: AMI-25 can help also in characterizing primary lesions with an atypical signal pattern after contrast agent administration thanks to its intrinsic capability of accumulating in benign lesions. However it remains difficult to characterize well differentiated hepatocarcinomas and adenomas. Finally, AMI-25 improves MR capabilities in detecting secondary lesions and possible satellite nodules.

[Superparamagnetic iron oxide in the differential diagnosis of focal hepatic lesions using a 0.5-tesla magnetic resonance apparatus]. / Ossido di ferro superparamagnetico nella diagnosi differenziale delle lesioni focali epatiche con apparecchio di risonanza magnetica da 0.5 tesla.

INTRODUCTION: We investigated the efficacy of superparamagnetic iron oxide (SPIO) in the characterization of focal liver lesions on MR images by means of quantitative and qualitative analysis. MATERIAL AND METHODS: We examined 60 patients with at least one focal liver lesion on US images. Conventional T1-weighted spin echo (CSE), proton density and T2-weighted MR images were acquired before and after the injection of a SPIO agent (Endorem, slow infusion, 15 micromoles Fe/kg body weight). A qualitative and a quantitative analysis were performed calculating the contrast enhancement rate in different kinds of lesions; the differences were related to the type of sequence statistically using Student's t-test for coupled samples. RESULTS: Excellent correlation was found with biopsy findings in all but two patients who were false positive for hepatocellular carcinoma (scar on cirrhotic liver). T1-weighted sequences after AMI-25 injection were the most specific ones in hemangioma characterization; PD were the most sensitive sequences in the detection and characterization of liver metastases. T2-weighted sequences were helpful only in the detection of focal liver lesions but they were not specific. CONCLUSIONS: In conclusion, SPIO-enhanced MRI is an excellent imaging tool for the differential diagnosis of focal liver lesions, with a good specificity for the differential diagnosis of hemangioma and metastasis. It is also helpful to distinguish benign from malignant lesions.