First isolation of Trypanosoma theileri in Sicilian cattle.
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Biomedical subjects
Publications and source records attributed to A Greco.
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Isoprostanes are prostaglandin-like compounds which are formed by free radical catalysed peroxidation of arachidonic acid esterified in membrane phospholipids. They are emerging as a new class of sensitive, specific and reliable markers of in vivo lipid peroxidation and oxidative damage. Since their initial description of in 1990, the rapid development of analytical methods for isoprostane measurement has allowed to overcome some of the pitfalls of the previous and most widely used methods of assessing free radical injury. Here, we summarise the current knowledge on these novel class lipid peroxidation products and the advantages of monitoring their formation to better define the involvement of oxidative stress in neurological diseases. Although the literature data are still not abundant, they indicate that in vivo or post mortem cerebrospinal fluid and brain tissue levels of isoprostane are increased in some diseases such as multiple sclerosis, Alzheimer's disease, Huntington's disease, and Creutzfeldt-Jakob disease.
The levels of 2 arachidonic acid metabolites formed either by enzymatic activity of cyclooxygenase, i.e. prostaglandin E2 (PGE2), or by free radical-catalyzed peroxidation, i.e. F2-isoprostane 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha), were measured in the CSF of subjects with sporadic and familial Creutzfeldt-Jakob disease (CJD) and in brain homogenates of scrapie-infected mice. The CSF levels of both metabolites were increased in sporadic CJD (n = 52) and familial CJD (n = 10) patients when compared with a group of patients with noninflammatory disorders. Similarly, PGE2 and 8-epi-PGF2alpha levels were higher in brain homogenates obtained from C57BL/6J mice infected with the ME7 scrapie strain than in brain homogenates from control animals. As PGE2 is 1 of the most abundant prostaglandins released during inflammation and 8-epi-PGF2alpha is a quantitative marker of lipid peroxidation, our results provide in vivo biochemical evidence for the occurrence of inflammation and oxidative stress in human and experimental transmissible spongiform encephalopathies (TSEs), a concept so far based mainly on histopathological and in vitro evidence. Interestingly, in sporadic CJD patients, high CSF levels of PGE2, but not 8-epi-PGF2alpha, correlated with short survival time, suggesting that the inflammatory response correlates with the clinical duration of disease.
The BK virus (BKV) belongs to the family of the polyoma group, which contains three species: JC, which is responsible for progressive multifocal leukoencephalopathy in acquired immunodeficiency syndrome (AIDS); simian virus 40 (SV40), which is a simian virus of little pathologic significance in humans; and BKV, which is usually not pathogenic and is found in the urine of asymptomatic individuals. Recently BKV has been reported to cause symptomatic infection in renal transplant patients. The authors report a rare case of a 14-year-old boy with AIDS who developed a BKV infection of the lung and kidney that progressed to diffuse alveolar damage and death. The infected type II pneumocytes in the lung and the tubular epithelial cells in the kidney showed large, homogenous purple intranuclear inclusions. The absence of necrosis and destruction made it possible to distinguish BKV infection from herpes simplex. The size of the infected cells and the lack of a halo around the nuclear inclusion helped rule out cytomegalovirus as the cause of infection. Electron microscopy detected the presence of 40-nm intranuclear viral particles compatible with BKV, and in situ hybridization established the diagnosis.
PURPOSE: To evaluate gadobenate dimeglumine (Gd-BOPTA) for dynamic and delayed magnetic resonance (MR) imaging of focal liver lesions. MATERIALS AND METHODS: In 126 of 214 patients, MR imaging was performed before Gd-BOPTA administration, immediately after bolus administration of a 0.05- mmol/kg dose of Gd-BOPTA, and 60-120 minutes after an additional intravenously infused 0.05-mmol/kg dose. In 88 patients, imaging was performed before and 60-120 minutes after a single, intravenously infused 0.1-mmol/kg dose. T1- and T2-weighted spin-echo and T1-weighted gradient-echo images were acquired. On-site and blinded off-site reviewers prospectively evaluated all images. Intraoperative ultrasonography, computed tomography (CT) during arterial portography, and/or CT with iodized oil served as the reference methods in 110 patients. RESULTS: Significantly more lesions were detected on combined pre- and postcontrast images compared with on precontrast images alone (P <. 01). All reviewers reported a decreased mean size of the smallest detected lesion and improved lesion conspicuity on postcontrast images. All on-site reviewers and two off-site reviewers reported increased overall diagnostic confidence (P <.01). Additional lesion characterization information was provided on up to 109 (59%) of 184 delayed images and for up to 50 (42%) of 118 patients in whom dynamic images were assessed. Gd-BOPTA would have helped change the diagnosis in 99 (47%) of 209 cases and affected patient treatment in 408 (23%) of 209 cases. CONCLUSION: Gd-BOPTA increases liver lesion conspicuity and detectability and aids in the characterization of lesions.
We identified more than 30 studies on the association between exposure to maternal tobacco smoke during pregnancy and cancer in childhood. We combined their results in meta-analyses based on a random effects model. The results of the meta-analyses suggest a small increase in risk of all neoplasms [relative risk (RR) 1.10; 95% confidence interval (CI), 1.03-1.19; based on 12 studies], but not of specific neoplasms such as leukemia (RR 1.05; CI, 0.82-1.34; 8 studies) and central nervous system tumors (RR 1.04; CI, 0.92-1. 18; 12 studies). Results for other specific neoplasms were sparse, but the available data did not suggest a strong association for any type of tumor. No clear evidence of dose response was present in the studies that addressed this issue. The results on exposure to maternal tobacco smoke before or after pregnancy are too sparse to allow a conclusion. The results on exposure to paternal tobacco smoke suggest an association with brain tumors (RR 1.22; CI, 1.05-1. 40; based on 10 studies) and lymphomas (RR 2.08; CI, 1.08-3.98; 4 studies). The data are too sparse for the other neoplasms, although the results of a few recent large studies are compatible with a weak carcinogenic effect of paternal smoke. For exposure from either maternal or paternal smoke, bias and confounding cannot yet be ruled out. Further studies are needed to confirm the hypothesis that parental tobacco smoke, from the father in particular, is a risk factor of childhood cancer. Results on the risk of lung cancer in adulthood and childhood passive smoking exposure are available from 11 studies: they do not provide evidence of an increased risk (summary RR 0.91; CI, 0.80-1.05).
OBJECTIVE: We evaluated the extent to which hepatic lesion characterization and detection is improved by using gadobenate dimeglumine for enhancement of MR images. MATERIALS AND METHODS: Eighty-six patients were imaged before gadobenate dimeglumine administration, immediately after the 2 mL/sec bolus administration of a 0.05 mmol/kg dose (dynamic imaging), and at 60-120 min after the IV infusion at 10 mL/min of a further 0.05 nmol/kg dose (delayed imaging). The accuracy for lesion characterization was assessed for a total of 107 lesions. Sensitivity for lesion detection was assessed for a total of 149 lesions detected on either intra-operative sonography, iodized oil CT, CT during arterial portography, or follow-up contrast-enhanced CT as the gold standard. RESULTS: The accuracy in differentiating benign from malignant liver lesions increased from 75% and 82% (the findings of two observers) on unenhanced images alone, to 89% and 80% on dynamic images alone (p<0.001, p = 0.8), and to 90.7% when combining the unenhanced and dynamic image sets (p<0.001, p = 0.023). Delayed images did not further improve accuracy (90% and 91%; p = 0.002, p< 0.05). A similar trend was apparent in terms of accuracy for specific diagnosis: values ranged from 49% and 62% on unenhanced images alone, to 76% and 70% on combined unenhanced and dynamic images (p<0.001, p = 0.06), and to 75% and 70% on inclusion of delayed images (p<0.001, p = 0.12). The sensitivity for lesion detection increased from 77% and 81% on unenhanced images alone, to 87% and 85% on combined unenhanced and dynamic images (p = 0.001, p = 0.267), and to 92% and 89% when all images were considered (p<0.001, p = 0.01). CONCLUSION: Contrast-enhanced dynamic MR imaging with gadobenate dimeglumine significantly increases sensitivity and accuracy over unenhanced imaging for the characterization of focal hepatic lesions, and delayed MR imaging contributes to the improved detection of lesions.
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Ureteral endoprostheses can be complicated by incrustations, sometimes making it impossible to withdraw the stent. A case in which the use of cistolithotripsy and of extracorporeal shock-wave lithotripsy (ESWL) allowed withdrawal of a double J ureteral stent with large incrustations is reported. The stent was placed 3 years before. Epidemiology, aetiology and therapeutic aspects of encrusted ureteral stents are discussed.
The CSF level of the isoprostane 8-epi-prostaglandin (PG)-F2alpha (a reliable marker of oxidative stress in vivo) was three times higher in subjects with definite MS than in a benchmark group of subjects with other neurologic diseases. This increase was not correlated with that of PGE2 levels, measured as an index of cyclooxygenase activity, and was much lower in steroid-treated patients. The levels of 8-epi-PGF2alpha were moderately correlated with the degree of disability.
1. Our aim was to assess whether ATP-induced inward currents in microglia are due to a single or more than one purinergic receptor. The ATP dose-response curve showed two components, whose presence might be due to the activation of high and low affinity receptors. 2. The P2Z/P2X7 specific receptor agonist benzoylbenzoyl-ATP (Bz-ATP) and some P2 receptor agonists were tested. The rank order of potency was Bz-ATP >> ATP = 2-methylthio-ATP (2-MeSATP) > alpha, beta-methylene ATP (alpha,beta-meATP) >= ADP. beta, gamma-MethyleneATP (beta,gamma-meATP), UTP and adenosine were ineffective. 3. The non-specific P2 receptor antagonist suramin antagonized by 92 +/- 2 % the inward current induced by 100 microM ATP, and by 51 +/- 8 and 68 +/- 6 % those induced by 3 mM ATP and 100 microM Bz-ATP, respectively. The P2Z/P2X7 antagonist oxidized ATP (oATP) almost abolished the inward current induced by 3 mM ATP or Bz-ATP, but was ineffective against 100 microM ATP. 4. Inward currents induced by low ATP concentrations (<= 100 microM) were generally followed by an almost complete and irreversible desensitization, while those elicited by ATP >= 1 mM showed only a partial decline. Interestingly, the inward current induced by 100 microM 2-MeSATP showed a large desensitization, while that induced by Bz-ATP did not. 5. In voltage-ramp experiments, the 100 microM ATP-induced current exhibited a slight inward rectification more visible at negative potentials, while the 3 mM ATP-induced current did not. 6. ATP induced a fast and large increase in [Ca2+] that promptly recovered in the continuous presence of low ATP doses, but did not recover in high ATP doses. As with desensitization, the response to Bz-ATP mimicked that of high doses of ATP. 7. When Ca2+ mobilization due to P2Y receptors was blocked by thapsigargin-induced Ca2+ depletion or by pertussis toxin treatment, 10 microM ATP was still able to induce a Ca2+ transient, which represented the contribution of the Ca2+ influx induced by P2X receptors 8. In conclusion, the inward currents and a fraction of the Ca2+ transients induced by ATP in microglia are due to at least two ATP-sensitive receptor channel types, whose different properties and sensitivity to ATP may be associated with different functional roles.
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We report a fetus with radiological features of the four established types of short rib-polydactyly syndrome (SRPS). The phenotype of this fetus supports the previously suggested hypothesis that the different subtypes of the short rib and polydactyly syndrome are not single entities, but rather, part of a continuous spectrum with variable expressivity.
1. Activated microglial cells are believed to play an active role in most brain pathologies, during which they can contribute to host defence and repair but also to the establishment of tissue damage. These actions are largely mediated by microglial secretory products, among which are prostaglandins (PGs) and nitric oxide (NO). 2. The anti-inflammatory protein, lipocortin 1 (LC1) was reported to have neuroprotective action and to be induced by glucocorticoids in several brain structures, with a preferential expression in microglia. In this paper we tested whether the neuroprotective effect of LC1 could be explained by an inhibitory effect on microglial activation. 3. We have previously shown that bacterial endotoxin (LPS) strongly stimulates PGE2 and NO production in rat primary microglial cultures, by inducing the expression of the key enzymes cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), respectively. 4. Dexamethasone (DEX, 1-100 nM) and LC1-derived N-terminus peptide (peptide Ac2-26, 1-100 microg ml(-1)) dose-dependently inhibited the production of both PGE2 and NO from LPS-stimulated microglia. The inhibitory effects of DEX on NO and of the peptide on NO and PGE2 synthesis were partially abrogated by a specific antiserum, raised against the N-terminus of human LC1. The peptide Ac2-26 did not affect arachidonic acid release from control and LPS-stimulated microglial cultures. 5. Western blot experiments showed that the LPS-induced expression of COX-2 and iNOS was effectively down-regulated by DEX (100 nM) and peptide Ac2-26 (100 microg ml(-1)). 6. In conclusion, our findings support the hypothesis that LC1 may foster neuroprotection by limiting microglial activation, through autocrine and paracrine mechanisms.
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Tyrosine kinase NTRK1 is expressed in neural and nonneuronal tissues. Like RET, NTRK1 is often activated by rearrangements that involve one of at least five other genes in papillary thyroid carcinoma (PTC). Because of similarities in involvement of the two tyrosine kinases RET (rearranged during transfection) and NTRK1 in the pathogenesis of PTC, the obvious parallels between RET and NTRK1 and between PTC and medullary thyroid carcinoma (MTC), NTRK1 seemed to be an excellent candidate gene to play a role in the genesis of MTC. Single-strand conformational polymorphism analysis of 16 exons of NTRK1, from 31 sporadic MTC, revealed variants in five exons (exons 4 and 14-17). Sequence analysis demonstrated one sequence variant each in exons 4, 14, 16, and 17, and four different variants in exon 15. Differential restriction enzyme digestion specific for each variant confirmed the sequencing results. All variants were also present in the corresponding germline DNA. Interestingly, the sequence variants at codon 604 (c1810C>T) and codon 613 (c1838G>T) ofexon 15 always occurred together and might represent linkage disequilibrium. The frequencies of the sequence variants in germline DNA from patients with sporadic MTC did not differ significantly from those in a race-matched control group. Although we did not find any somatic mutations of NTRK1 in sporadic MTC, the single-strand conformational polymorphism conditions reported here, together with the knowledge of the frequency of various sequence variants, may help in future mutation analyses of DNA from other neural and nonneural tissues.
Mesoidial tumours are rare benign lesions which may occur wherever mesenchymal tissues are present with an incidence of between 1.5% and 5%. Above all, leiomyomas affect females affect females aged between 30 and 50 years old and show a preference for the uterus (most frequently observed site) and the digestive and urinary tracts, in particular the vescica. Their etiology is still controversial, but the hypothesis of tumoral growth following an altered response to hormone stimulation (spt. Estrogens) appears to be the most credible. Development is mainly endovescical (63%), but extravescical (30%) and intramural cases are not rare; the site and dimensions (mean 6 cm) influence the symptoms, the type of surgery and the prognosis. In intravescical cases the most commonplace symptoms include obstructive urination, including pre-urination delay, a feeling of incomplete emptying, diurnal pollakiuria; these are followed by irritative symptoms (dysuria, burning) and micro-macroscopic hematuria. They are often asymptomatic in other cases. Diagnosis is based on instrumental diagnosis, in particular ultrasonography using a suprapubic and/or transvaginal approach, which gives an hypoechogenic image covered by a thin hyperechogenic line of mucosa. Diagnosis can also be made using CAT and, in some cases, MR for a better definition of the site, dimensions and ratios. Urethrocystoscopy is essential in asymptomatic cases and allows biopsy to be performed in uncertain cases. Treatment is surgical using a transurethral approach in endovescical cases with limited dimensions or open surgery in others. Depending on timely treatment, prognosis is good owing to the low number of recidivations.
Nephrogenic adenoma is a benign epithelial tumour localised at the level of the urothelium and caused by metaplasia of the urothelium following prolonged aggressive stimulation over time, for example trauma or chronic urinary infection. Even a diverticulum, in whatever site it is localised, is subject to an increased risk of neoplastic transformation of the urothelium. It above all affects male subjects, with a male/female ratio of 3:1 over the age of 20, which is inverted in younger subjects. The most frequently affected site is the vescical trigonum in 72% of cases, followed by the pelvic tract of the ureter (19%) and urethra. The majority of patients is asymptomatic or reports aspecific symptoms: the most frequent picture is macroscopic hematuria, owing to the rich vascularisation of the tumour. This is followed by irritative type signs such as pollakiuria, strangury, posturination dripping and sometimes painful tenesmus. Differential diagnosis is necessary for pale cell adenocarcinoma, parauretral cysts and Gartner duct's cysts which may be associated with urethral diverticulum, localised on the bottom, and rarely symptomatic. Diagnosis is based on retrograde urethrography, cystography and endoscopic tests, with biopsy if necessary. NMR provides further details regarding the site, localisation and benign or malignant nature of the lesion. Treatment is surgical: endoscopic (transurethral) if the dimension are limited, or traditional using a suprapubic or transvaginal route if it is associated with diverticulum. Prognosis is discrete and depends on the timeliness with which the factors predisposing metaplasia are eliminated.