Massive invasion of exotic Barbus barbus and introgressive hybridization with endemic Barbus plebejus in Northern Italy: where, how and why?

Biological invasions and introgressive hybridization are major drivers for the decline of native freshwater fish. However, the magnitude of the problem across a native species range, the mechanisms shaping introgression as well as invader's dispersal and the relative role of biological invasions in the light of multiple environmental stressors are rarely described. Here, we report extensive (N = 665) mtDNA sequence and (N = 692) microsatellite genotypic data of 32 Northern Adriatic sites aimed to unravel the invasion of the European Barbus barbus in Italy and the hybridization and decline of the endemic B. plebejus. We highlight an exceptionally fast breakthrough of B. barbus within the Po River basin, leading to widespread introgressive hybridization with the endemic B. plebejus within few generations. In contrast, adjacent drainage systems are still unaffected from B. barbus invasion. We show that barriers to migration are inefficient to halt the invasion process and that propagule pressure, and not environmental quality, is the major driver responsible for B. barbus success. Both introgressive hybridization and invader's dispersal are facilitated by ongoing fisheries management practices. Therefore, immediate changes in fisheries management (i.e. stocking and translocation measures) and a detailed conservation plan, focussed on remnant purebred B. plebejus populations, are urgently needed.

Basal Ganglia involvement in Wernicke encephalopathy: report of 2 cases.

We present the neuroimaging and clinical findings in 2 nonalcoholic adult patients with WE as assessed by MR imaging. The first patient presented with gait ataxia and changes in consciousness. MR imaging disclosed bilateral lesions in the dorsal striatum and cerebellum. None of the regions typically affected in WE were involved. The second patient showed symmetric lesions in the posterior putamen associated with the alterations frequently and infrequently found WE.

Diagnostic features of real-time contrast-enhanced ultrasound in focal nodular hyperplasia of the liver.

PURPOSE: The typical appearance of focal nodular hyperplasia (FNH) in radiological contrast techniques (helical CT or MRI) includes homogeneous enhancement in the arterial phase, but the exact timing for the best visualization of this pattern is unknown. The aim of the present study was to assess the ultrasound pattern of FNH with special attention to real-time contrast-enhanced ultrasonography (CEUS) appearance and specifically to the timing of perfusion patterns. MATERIALS AND METHODS: 72 patients (60 females, 12 males) with a total of 90 FNH nodules with a diameter ranging from 8 to 100 mm (mean +/- SD, 40.6 +/- 21.5 mm) were examined continuously for at least 4 minutes using CnTI and CPS methods (ESAOTE, Genoa, Italy and Acuson-Siemens) after bolus injection of SonoVue (BRACCO, Milan, Italy). RESULTS: 87 of 90 nodules showed the typical coin-like hyperechogenicity in the arterial phase. The remaining three nodules were all in the same patient and were diagnosed as FNH after resection. Contrast started to appear within the lesions after a mean of 15.7 +/- 4.6 seconds (range 7 - 27 s) and reached peak signal intensity, with the greatest differentiation between the lesion and the surrounding parenchyma, at around 22.6 +/- 7.0 seconds (range 14 - 72 s). In the late phase, 65 lesions (72.2 %) became isoechoic (after a mean of 80.8 +/- 85.7 s, range 20 - 300 s), 22 (24.4 %) slightly hyperechoic and 3 (3.3 %) faintly hypoechoic. CONCLUSION: FNH shows a typical homogeneous hyperechoic pattern during the arterial phase in real-time CEUS which disappears slowly on average but occasionally even as soon as 20 seconds after contrast injection. If the first scans are taken later than 20 seconds after injection (which is still considered to be a full arterial phase), the ultrasound hyperechogenicity may be missed in some cases. Real-time study of these lesions is therefore strongly recommended to avoid possible false-negative results.

Otoacoustic detection of risk of early hearing loss in ears with normal audiograms: a 3-year follow-up study.

INTRODUCTION: Distortion product otoacoustic emissions (DPOAEs) are known to represent the contractile amplifier function of cochlear outer hair cells. It is known that low or absent DPOAEs are associated with hearing loss on audiograms. However, low DPOAEs can also be found associated with normal audiograms. It is unknown whether low DPOAEs in normal hearing ears are risk markers for subsequent early hearing loss when subjects are exposed to noise. MATERIALS AND METHODS: A 3-year follow-up study was carried out on a population of pilots aged 20-40 years (n=521). Data collection consisted of tonal audiograms, DPOAEs measurements with a calculation of an index of abnormality (the IaDPOAE). Of the 521 pilots enrolled, 350 (67%) had follow-up data 3 years later. In pilots with normal audiograms (n=219, all frequencies=10dB HL), we observed the occurrence of hearing threshold shifts after 3 years depending on whether the IaDPOAE was initially high (group 1) or low (group 2). We used this index to test the hypothesis that reduced DPOAEs levels are potential ear vulnerability biomarkers in apparent normal hearing ears. After a 3-year follow-up, the initial IaDPOAE in normal hearing subjects was correlated with final noise-induced hearing threshold shifts at high frequencies (p<0.01). The occurrence of abnormal audiograms was significantly higher in group 1 compared to group 2 (p=0.003). In group 1, 13% of audiograms were found with at least one frequency 25dB HL compared to 3% of audiograms in group 2. In both groups, impairments occurred at high frequencies and hearing in the 4kHz frequency range was significantly more impaired in group 1 (p=0.035). Group 1 was associated with a relative risk of 2.29 (95% CI 1.26-4.16, p=0.005) of sustaining early hearing loss. There was no significant differences between groups for age and noise exposure. DISCUSSION: In adults with a normal audiogram, ear vulnerability to noise could be elicited by the use of objective DPOAE measurements. A high IaDPOAE that corresponded to reduced DPOAE levels constitutes a risk for early hearing loss. This study emphasised the interest of DPOAE measurements in public health and occupational noise prevention policies. The IaDPOAE calculation may also be interesting for clinicians because no DPOAE index of abnormality is currently available.

Role of real-time contrast-enhanced ultrasound in the assessment of metastatic portal vein thrombosis.

Patients with liver disease or systemic pathology are more prone to develop portal vein thrombosis. Non-neoplastic thrombosis is characterised by absence of intrathrombotic perfusion, corresponding to marked hypoechogenicity at contrast-enhanced ultrasound. We report two cases of portal vein thrombosis in which contrast-enhanced ultrasound showed marked hypoechogenicity in the late phase. This late phase perfusional contrast pattern is consistent with non-neoplastic thrombosis, but is actually similar to that of metastatic liver lesions. Echo-guided needle biopsy indeed yielded histological results consistent with carcinoma. Repeated contrast-enhanced ultrasound showed presence of intratumoural perfusion in the arterial phase, suggestive of the neoplastic nature of the thrombus. Our cases suggest that CEUS with second generation contrast agents in patients with portal thrombosis should include the evaluation of both arterial and portal phases in order to provide accurate non-invasive diagnosis of metastatic portal vein thrombosis.

Diagnosis and management of hepatic focal nodular hyperplasia.

Focal nodular hyperplasia (FNH) is the second most common benign tumor of the liver, after hemangioma. It is generally found incidentally and is most common in reproductive-aged women, but it also affects males and can be diagnosed at any age. Patients are rarely symptomatic, but FNH sometimes causes epigastric or right upper quadrant pain. The main clinical task is to differentiate it from other hypervascular hepatic lesions such as hepatic adenoma, hepatocellular carcinoma, or hypervascular metastases, but invasive diagnostic procedures can generally be avoided with the appropriate use of imaging techniques. Magnetic resonance (MR) imaging is more sensitive and specific than conventional ultrasonography (US) or computed tomography (CT), but Doppler US and contrast-enhanced US (CEUS) can greatly improve the accuracy in the diagnosis of FNH. Once a correct diagnosis has been made, in most cases there is no indication for surgery, and treatment includes conservative clinical follow-up in asymptomatic patients.

Transcranial magnetic stimulation shows impaired transcallosal inhibition in Marchiafava-Bignami syndrome.

A case of Marchiafava-Bignami (MB) syndrome with selective callosal involvement was evaluated by clinical examination and magnetic resonance imaging (MRI) in the acute phase and 6 months after the onset of symptoms; at the same time, the corticospinally and transcallosally mediated effects elicited by transcranial magnetic stimulation (TMS) were investigated. The first MRI study showed the presence of extensive abnormal signal intensity throughout the entire corpus callosum. After high-dose corticosteroid administration her symptoms rapidly resolved, in parallel with the reversion of MRI changes, except for severe cognitive impairment. Follow-up TMS examination revealed persistent transcallosal inhibition (TI) abnormalities. This report indicates that the measurement of TI during the course of MB syndrome is useful for evaluating functional changes to the corpus callosum, including their evaluation with time and after treatment and for elucidating the pathophysiology of MB syndrome.

Transient ischaemic attacks in two cases of internal carotid artery hypoplasia.

Congenital anomalies of the internal carotid arteries (ICA) and cerebral arteries have not been frequently reported. Moreover, in the literature there is no clear association between hypoplastic carotid and cerebral vessel systems and the occurrence of cerebral ischaemia. We report two cases of unilateral hypoplasia of the ICA affecting two young patients suffering from an episode of minor stroke and from recurrent transient ischaemic attacks, respectively. Congenital variations in the configuration and size of the carotid and cerebral arteries should not always be considered benign conditions and may predispose to cerebral ischaemia in young adults.

Fitz-Hugh-Curtis-syndrome mimicking acute cholecystitis: value of new ultrasound findings in the differential diagnosis.

Fitz-Hugh-Curtis is a rare syndrome characterised by perihepatitis following pelvic inflammatory disease. We report the case of a patient with a right ovarian teratoma, abnormal liver tests and pain in the right abdomen and shoulder, initially attributed to an acalculous cholecystitis. Before gynaecological surgery, a repeat ultrasound scan found several small avascular peritoneal masses at the upper dome of the liver, not reported in the initial examination. This prompted laparoscopic exploration of the subdiaphragmatic space, and the final diagnosis of Fitz-Hugh-Curtis-syndrome was made. Such ultrasound finding appears to be a new diagnostic feature of this syndrome.

Preoperative chemoradiotherapy for oesophageal cancer: a systematic review and meta-analysis.

BACKGROUND: The benefit of neoadjuvant chemoradiotherapy in oesophageal cancer has been extensively studied but data on survival are still equivocal. OBJECTIVE: To assess the effectiveness of chemoradiotherapy followed by surgery in the reduction of mortality in patients with resectable oesophageal cancer. METHODS: Computerised bibliographic searches of MEDLINE and CANCERLIT (1970-2002) were supplemented with hand searches of reference lists. STUDY SELECTION: Studies were included if they were randomised controlled trials (RCTs) comparing preoperative chemoradiotherapy plus surgery with surgery alone, and if they included patients with resectable histologically proven oesophageal cancer without metastatic disease. Six eligible RCTs were identified and included in the meta-analysis. DATA EXTRACTION: Data on study populations, interventions, and outcomes were extracted from each RCT according to the intention to treat method by three independent observers and combined using the DerSimonian and Laird method. RESULTS: Chemoradiotherapy plus surgery compared with surgery alone significantly reduced the three year mortality rate (odds ratio (OR) 0.53 (95% confidence interval (CI) 0.31-0.93); p = 0.03) (number needed to treat = 10). Pathological examination showed that preoperative chemoradiotherapy downstaged the tumour (that is, less advanced stage at pathological examination at the time of surgery) compared with surgery alone (OR 0.43 (95% CI 0.26-0.72); p = 0.001). The risk for postoperative mortality was higher in the chemoradiotherapy plus surgery group (OR 2.10 (95% CI 1.18-3.73); p = 0.01). CONCLUSIONS: In patients with resectable oesophageal cancer, chemoradiotherapy plus surgery significantly reduces three year mortality compared with surgery alone. However, postoperative mortality was significantly increased by neoadjuvant chemoradiotherapy. Further large scale multicentre RCTs may prove useful to substantiate the benefit on overall survival.

Review article: medical treatment of severe ulcerative colitis.

Severe colitis is a life-threatening complication of ulcerative colitis. Early recognition of the severity of the colitis and intensive treatment and monitoring have all contributed to improved outcome. Since their introduction in 1950s, corticosteroids are the first line therapy for severe active ulcerative colitis (UC). Several prognostic parameters (such as stools movement per day, C-reactive protein, increased amount of intestinal gas or small bowel dilation, hypoalbuminemia, fever etc) help the physician to quickly introduce cyclosporin or to refer the patient to the surgeon. This decision requires a careful evaluation of the patient and a medical /surgical team. Infliximab seems to be a promising drug but more controlled trial are needed.

The effect of transient intestinal ischemia on inflammatory parameters.

BACKGROUND AND AIMS: To determine the early biological changes occurring in intestinal ischemia in vivo. PATIENTS AND METHODS: We studied the effects of acute transient intestinal ischemia in 15 patients undergoing elective open surgery for the treatment of abdominal subrenal aortic aneurysm induced by clamping of the aorta at subrenal level and above the branching of the inferior mesenteric artery. Blocking the blood flow results in hypoperfusion of the inferior mesenteric artery and then to rectal mucosal ischemia. RESULTS: With the introduction of a mucosal ischemic period the basal intestinal mucosal pH decreased during ischemia, and showed a rapid increase during reperfusion to the level preceding ischemia. Parameters were evaluated in blood taken from inferior mesenteric vein. A rectal dialysis was put into the rectum to evaluate eicosanoid concentrations in rectal fluid collected before and during clamping and after declamping. Significant enhancement in plasma level of xanthine, a marker for tissue damage, was observed during reperfusion. Interleukin-6 levels were significantly elevated from 11.28+/-3.4 pg/ml (preischemic) to 109+/-85.9 pg/ml (ischemic) and to 189.33+/-120.24 pg/ml (reperfusion); and tromboxane B(2) levels from 141.57+/-51.20 pg/ml preoperation to 473.01+/-319.01 pg/ml during the surgical procedure. CONCLUSION: These observations indicate that even transient ischemia modifies the inflammatory pattern.

Probiotics--role in inflammatory bowel disease.

The aetiology of inflammatory bowel disease is still unclean. Whilst a specific pathogen agent associated with these diseases has not been found, the rationale for probiotic therapy in inflammatory bowel disease is based on convincing evidence involving intestinal bacteria in their pathogenesis. Encouraging results have been obtained with probiotic therapy in several animal models of experimental colitis. The administration of highly concentrated probiotic preparations represents a valid approach both for the prevention of pouchitis onset and relapses. The encouraging results obtained in ulcerative colitis and Crohn's disease need to be further assessed in large double-blind trials.

Review article: monitoring activity in ulcerative colitis.

The monitoring of patients with ulcerative colitis is easier than in patients with Crohn's disease for several reasons: the severity of symptoms and activity of inflammation tend to run parallel in ulcerative colitis when involvement of the large bowel is more extensive. The easy accessibility of the colonic mucosa by endoscopic and histologic examination provides further information concerning the degree of inflammation. In severe attacks, the patient must be admitted to hospital and monitored carefully. Clinical and laboratory parameters (such as daily stools, CRP, fever, haemoglobin, albumin, etc.) and plain abdominal X-ray are useful in monitoring the activity of the disease and to predict the outcome. In mild to moderate attacks, endoscopic and histologic evaluation are the best methods for choosing the appropriate treatment and for assessing response.

Review article: treatment of mild to moderate ulcerative colitis and pouchitis.

The meta-analyses of published trials have shown topical therapy with 5-aminosalicylic acid (5-ASA) to be the treatment of choice in active distal ulcerative colitis. Oral aminosalicylates are effective for both distal and extensive ulcerative colitis, but in distal colitis the rates of improvement and remission are usually lower than those reported for rectal 5-ASA therapy. An alternative to 5-ASA therapy is represented by the new steroids; budesonide and beclometasone dipropionate (BDP) enemas, the most extensively studied, have been shown to be as effective as conventional steroids but with a significantly lower inhibition of plasma cortisol. Patients who do not respond to 5-ASA or new steroids should be treated with oral steroids. Azathioprine or 6-mercaptopurine may be effective in patients who do not respond or cannot be weaned off steroids. Treatment of pouchitis is largely empirical and few controlled studies have been carried-out. Antibiotics are the treatment of choice and most patients make a good response to metronidazole or ciprofloxacin. Chronic refractory pouchitis may benefit from a prolonged course of a combination of antibiotics. Highly concentrated probiotics (VSL#3) are effective both for the prevention of pouchitis onset and the prevention of relapses.

Review article: the management of refractory Crohn's disease.

Refractoriness to conventional therapy is a common and intriguing problem in Crohn's disease patients. At the present time there is no agreement on its definition and several mechanisms are involved in its determination. Immunosuppressors, such as azathioprine (AZA), 6-mercaptopurine (6MP) and methotrexate (MTX) are effective drugs for controlling the inflammatory process and avoid chronic glucocorticosteroid treatment and its related side-effects. Recently, the introduction of tumour necrosis factor antibodies (infliximab) has dramatically changed the natural history of Crohn's disease and its therapeutic approach. Several studies have determined the efficacy, mechanisms and safety of infliximab. However, this molecular approach has also left several questions unanswered about the mechanisms of refractoriness, possible concomitant treatments and long-term safety and efficacy.

Effect of probiotic strains on interleukin 8 production by HT29/19A cells.

OBJECTIVES: Promising results from clinical studies on the effect of probiotics as maintenance therapy in inflammatory bowel disease and in the prevention of onset of pouchitis ask for studies to unravel the still poorly understood mechanism of action of probiotics. METHODS: To evaluate whether the probiotic bacteria that were used in the clinical studies (VSL#3, Escherichia coli Nissle 1917, and Lactobacillus GG) are able to induce chemokine production in epithelial cells, HT29/19A monolayers were incubated with cell debris and cell extract fractions of single strains of the probiotic bacteria in doses ranging from 10(3) to 10(9) colony-forming units/ml for 32 h. Supernatants were measured for interleukin 8 by ELISA. RESULTS: Lactobacilli and bifidobacteria strains from VSL#3 and Lactobacillus GG did not induce interleukin 8, whereas both cell debris and cell extracts from E. coli Nissle 1917 induced interleukin 8 production in a dose-dependent way. Cell extracts from streptococcal strains induced interleukin 8 when applied at high concentrations. CONCLUSIONS: Probiotic Gram-positive bacteria did not induce interleukin 8, whereas the nonpathogenic, Gram-negative E. coli Nissle 1917 strain induced interleukin 8 in a dose-dependent way in this culture model. These results suggest that probiotic Gram-positive bacteria and E. coli Nissle 1917 may exert their beneficial effects on the host by a different mechanism of action.

Oral bacteriotherapy as maintenance treatment in patients with chronic pouchitis: a double-blind, placebo-controlled trial.

BACKGROUND & AIMS: Pouchitis is the major long-term complication after ileal pouch-anal anastomosis for ulcerative colitis. Most patients have relapsing disease, and no maintenance treatment study has been performed. We evaluated the efficacy of a probiotic preparation (VSL#3) containing 5 x 10(11) per gram of viable lyophilized bacteria of 4 strains of lactobacilli, 3 strains of bifidobacteria, and 1 strain of Streptococcus salivarius subsp. thermophilus compared with placebo in maintenance of remission of chronic pouchitis. METHODS: Forty patients in clinical and endoscopic remission were randomized to receive either VSL#3, 6 g/day, or an identical placebo for 9 months. Patients were assessed clinically every month and endoscopically and histologically every 2 months or in the case of a relapse. Fecal samples were collected for stool culture before and after antibiotic treatment and each month during maintenance treatment. RESULTS: Three patients (15%) in the VSL#3 group had relapses within the 9-month follow-up period, compared with 20 (100%) in the placebo group (P < 0.001). Fecal concentration of lactobacilli, bifidobacteria, and S. thermophilus increased significantly from baseline levels only in the VSL#3-treated group (P < 0.01). CONCLUSIONS: These results suggest that oral administration of this new probiotic preparation is effective in preventing flare-ups of chronic pouchitis.