Is hepatitis C more aggressive in renal transplant patients than in patients with end-stage renal disease?

BACKGROUND: The eventual impact of immunosuppression on the natural history of hepatitis C virus (HCV) infection in patients with end-stage renal disease (ESRD) is still unknown because of the lack of comparative data for HCV-infected patients with ESRD and renal transplant patients. The aim of this study was to compare the biochemical and histological characteristics of chronic HCV infection in renal transplants patients and ESRD patients undergoing hemodialysis. METHODS: Thirty-eight renal transplant patients and 38 ESRD patients undergoing hemodialysis who were chronically infected with HCV and were matched for gender, age at infection, and estimated time of infection were included in the study. The groups were compared regarding laboratory and histological variables. RESULTS: Renal transplant patients showed similar alanine aminotransferase and higher gamma-glutamyltransferase levels (P = 0.05) when compared with ESRD patients. Comparative analysis of histological variables revealed a higher proportion of cases with septal fibrosis (P = 0.04) and confluent necrosis (P = 0.01) among transplant-recipient patients. No difference between groups was observed regarding the intensity of portal and periportal inflammatory infiltrates. Steatosis was more prevalent among transplant-recipient patients (P < 0.001). There was no difference between groups regarding the prevalence of lymphoid aggregates or bile duct injury. CONCLUSION: Renal transplant patients had a larger proportion of cases with septal fibrosis and confluent necrosis than did ESRD patients, suggesting that renal transplantation might modify the natural history of hepatitis C in ESRD patients, leading to a more aggressive liver disease.     

Independent effects of circulating glucose,insulin and NEFA on cardiac triacylglycerol accumulation and myocardial insulin resistance in a swine model

Aims/hypothesis

Cardiac steatosis and myocardial insulin resistance elevate the risk of cardiac complications in obesity and diabetes. We aimed to disentangle the effects of circulating glucose, insulin and NEFA on myocardial triacylglycerol (TG) content and myocardial glucose uptake.

Methods

Twenty-two pigs were stratified according to four protocols: low NEFA?+?low insulin (nicotinic acid), high NEFA?+?low insulin (fasting) and high insulin?+?low NEFA?±?high glucose (hyperinsulinaemia–hyperglycaemia or hyperinsulinaemia–euglycaemia). Positron emission tomography, [U-¹³C]palmitate enrichment techniques and tissue biopsies were used to assess myocardial metabolism. Heart rate and rate–pressure product (RPP) were monitored.

Results

Myocardial glucose extraction was increased by NEFA suppression and was similar in the hyperinsulinaemia–hypergylcaemia, hyperinsulinaemia–euglycaemia and nicotinic acid groups. Hyperglycaemia enhanced myocardial glucose uptake due to a mass action. Myocardial TG content was greatest in the fasting group, whereas hyperinsulinaemia had a mild effect. Heart rate and RPP increased in hyperinsulinaemia–euglycaemia, in which cardiac glycogen content was reduced. Heart rate correlated with myocardial TG and glycogen content.

Conclusions/interpretation

Elevated NEFA levels represent a powerful, self-sufficient promoter of cardiac TG accumulation and are a downregulator of myocardial glucose uptake, indicating that the focus of treatment should be to ‘normalise’ adipose tissue function to lower the risk of cardiac TG accumulation and myocardial insulin resistance. The observation that hyperinsulinaemia and nicotinic acid led to myocardial fuel deprivation provides a potential explanation for the cardiovascular outcomes reported in recent intensive glucose-lowering and NEFA-lowering clinical trials.     

Which is the best catheter to perform atrial fibrillation ablation? A comparison between standard ThermoCool,SmartTouch, and Surround Flow catheters

Introduction

Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). The SmartTouch catheter (STc) provides information about catheter tip to tissue contact force (CF). The Surround Flow catheter (SFc) provides a uniform cooling of the tip during ablation. We sought to analyze the impact of STc and SFc on CA of paroxysmal AF in terms of feasibility and acute efficacy.

Methods and results

Sixty-three patients (mean age 57.6?±?9.8 years, 53 males) with paroxysmal AF underwent pulmonary veins (PVs) antral isolation, by using standard ThermoCool catheter (TCc) in 21, STc in 21, and SFc in 21. Total procedural, fluoroscopy, and radiofrequency (RF) delivery times; percentage of persistently deconnected PVs after 30 min; and percentage of isolated PVs at the end of the procedure were measured. The use of both STc and SFc obtained a reduction of fluoroscopy time (TCc 34?±?18 min, STc 20?±?10 min, p?<?0.001; SFc 21?±?13 min, p?=?0.02 vs TCc) and RF time (TCc 41?±?13 min, STc 30?±?14 min, p?=?0.013; SFc 30?±?9 min, p?<?0.01 vs TCc). The use of STc resulted in a reduction of procedural time (TCc 181?±?53 min, STc 140?±?53 min, p?<?0.001; SFc 170?±?51 min, p?=?NS vs TCc). The percentage of isolated PVs was comparable between groups (TCc 96 % vs STc 98 % vs SFc 96 %; p?=?NS). The percentage of deconnected PVs at 30 min was lower in TCc (89 %) than in STc (95 %) and in SFc (95 %) group (p?<?0.05).

Conclusions

Both STc and SFc allowed a simplification of CA of paroxysmal AF. In addition, they reduced early PVs reconnection.

Condensed abstract

Sixty-three patients with paroxysmal AF underwent ablation by standard ThermoCool, SmartTouch, or Surround Flow catheter. Both the SmartTouch and the Surround Flow significantly reduced radiofrequency and fluoroscopy times, as well as pulmonary veins reconnection rate at 30 min. Moreover, the SmartTouch reduced overall duration of the procedure.     

Earliest Videofluoromanometric Pharyngeal Signs of Dysphagia in ALS Patients

The aim of this study was to find whether there are manometric pharyngeal changes that may have diagnostic and prognostic relevance in the amyotrophic lateral sclerosis (ALS) patient who does not show changes in contrast-medium oropharyngeal transit in a videofluoroscopic swallowing study. Ten ALS patients, with an ALS Severity Scale Score of at least 7, no need to change dietary habit, no aspiration and/or penetration, and no other changes in contrast-medium oropharyngeal transit, were collected from our institution’s database of videofluoromanometric swallowing studies. They were included in the study together with a group of 11 healthy volunteers. For each subject, 12 manometric items—7 for the pharyngeal phase and 5 for UES functionality—were evaluated. Statistically significant differences between the ALS patients and the healthy volunteers were found for pharyngeal contraction time of the upper region (median = 1,120, range = 880–1,420 vs. median = 970, range = 800–1,140), pharyngeal contraction time of the intermediate region (median = 1140, range = 960–1,360 vs. median = 770, range = 280–1,180), pharyngeal contraction time of the lower region (median = 1,320, range = 920–1,760 vs. median = 800, range = 620–1,780), and residual pressure after the relaxation of the UES (median = 2.2, range = ?20.2 to 27.8 vs. median = ?5.7, range = ?2.9 to 8.4). A videofluoromanometric swallowing study may show an increase in the pharyngeal contraction time and in residual pressure after relaxation of the UES in ALS patients without videofluoroscopic changes in contrast-medium oropharyngeal transit.     

Indomethacin has a potent antiviral activity against SARS coronavirus

Severe acute respiratory syndrome (SARS) is a newly emerging, highly transmissible and fatal disease caused by a previously unknown coronavirus (SARS-CoV). Existing in non-identified animal reservoirs, SARS-CoV continues to represent a threat to humans because there is no effective specific antiviral therapy for coronavirus infections. OBJECTIVES: Starting from the observation that cyclopentenone cyclooxygenase (COX) metabolites are active against several RNA viruses, we investigated the effect of the COX inhibitor indomethacin on coronavirus replication. METHODS: Work involving infectious SARS-CoV was performed in biosafety level 3 facilities. SARS-CoV was grown in monkey VERO cells and human lung epithelial A549 cells, while canine coronavirus (CCoV) was grown in A72 canine cells. Antiviral activity was analysed by determining infective virus titres by TCID50, viral RNA synthesis by Northern blot analysis and real-time RT-PCR, and viral protein synthesis by SDS-PAGE analysis after 35S-methionine-labelling. Antiviral efficacy in vivo was determined by evaluating virus titres in CCoV-infected dogs treated orally with 1 mg/kg body weight indomethacin (INDO). RESULTS: Unexpectedly, we found that INDO has a potent direct antiviral activity against the coronaviruses SARS-CoV and CCoV. INDO does not affect coronavirus binding or entry into host cells, but acts by blocking viral RNA synthesis at cytoprotective doses. This effect is independent of cyclooxygenase inhibition. INDO's potent antiviral activity (>1,000-fold reduction in virus yield) was confirmed in vivo in CCoV-infected dogs. CONCLUSIONS: The results identify INDO as a potent inhibitor of coronavirus replication and suggest that, having both anti-inflammatory and antiviral activity, INDO could be beneficial in SARS therapy.     

Thyroid function and structure are affected in childhood obesity

OBJECTIVE: Alterations in thyroid function are reported in obesity, although no relevant data exist on the thyroid structure of these patients and the frequency of autoimmunity. The aim of our study was to evaluate the involvement of the thyroid gland in a large group of obese children. DESIGN: This was a cross-sectional study. METHODS: The study was conducted between March 2004 and December 2007 in 186 overweight and obese children. In all subjects, serum free T(3), free T(4), TSH, antithyroid antibodies, and a thyroid ultrasound were assessed. A total ot 40 healthy children matched for age and of normal weight for height served as controls. RESULTS: A total of 23 children (12.4%) showed antithyroid antibodies and an ultrasound pattern suggestive of Hashimoto's thyroiditis (group A). Of them, 20 (10.8%) showed antithyroid antibodies and normal ultrasound (group B). A total of 70 subjects (37.6%) showed absent antithyroid antibodies and an ultrasound pattern suggestive of Hashimoto's thyroiditis (group C), and 73 children (39.2%) showed no thyroid antibodies with normal ultrasound (group D). TSH was higher in groups A and C compared with groups B and C, and controls (P < 0.05). Mean free T(4) was lower in group B (P < 0.05) than in controls, whereas free T(3) was higher in group C than in controls (P < 0.05). TSH and body mass index sd scores were significantly correlated in group C (P < 0.001), and TSH was also significantly associated with the degree of thyroid structure alterations (P < 0.05). CONCLUSION: Obese children frequently show alterations of thyroid structure and function that are not completely explained by the presence of an autoimmune involvement.     

Three‐Dimensional Sonography of Placental Mesenchymal Dysplasia and Its Differential Diagnosis

Objective. Placental mesenchymal dysplasia (PMD) is an uncommon vascular anomaly of the placenta characterized by mesenchymal stem villous hyperplasia. Its main sonographic feature is a thickened placenta with hypoechoic areas, and an accurate sonographic diagnosis is challenging. The aim of this study was to report 2 cases of PMD and discuss the differential diagnosis of its sonographic features. Methods. Cases of placental masses were studied by 2‐dimensional (2D), 3‐dimensional (3D), and color Doppler imaging. Results. In case 1, a thick placenta with multiple hypoechoic areas was noted at 13 weeks' gestation. At 19 weeks, the multicystic area, clearly demarcated from a normal‐looking placenta, measured 6.5 × 8.5 cm and enlarged gradually. The patient gave birth to a 625‐g female neonate after spontaneous labor at almost 26 weeks' gestation. In case 2, a first sonographic examination at 25 weeks' gestation revealed a thickened placenta with hypoechoic areas and a fetus with a single umbilical artery and a ventricular septal defect. At 27 weeks, the abnormal area of the placenta measured 14.5 × 7.5 cm. At 32 weeks' gestation, a caesarean delivery was performed because of a nonreassuring fetal heart tracing, and a 1415‐g female neonate was delivered. Both cases were evaluated by 2D, 3D, and color Doppler imaging, and the pathologic features of both placentas were consistent with PMD. Conclusions. Placental mesenchymal dysplasia should be considered in the differential diagnosis of every placental mass, especially in cases of multicystic placental lesion with lack of high‐velocity signals inside the lesion, and a normal karyotype.     

High Prevalence of qnr Genes in Commensal Enterobacteria from Healthy Children in Peru and Bolivia

A remarkable prevalence of qnrB (54%) and, at a lower level, of qnrS (14%) was discovered in pools of commensal enterobacteria from 310 healthy children living in Peru and Bolivia, using a metagenomic approach. Analysis of randomly selected enterobacterial pools revealed that qnrB was mainly carried by Escherichia coli and qnrS by Klebsiella pneumoniae. Investigation of 11 qnrB-positive isolates and 9 qnrS-positive isolates revealed the presence of plasmid-borne qnrB19 (n = 8), qnrB2 (n = 2), qnrB10 (n = 1), and qnrS1 (n = 9) genes.Several plasmid-mediated quinolone resistance (PMQR) mechanisms have been discovered during the past decade, including Qnr proteins, QepA transporters, and the acetyltransferase AAC(6′)-Ib-cr (11, 13). Qnr proteins, the first discovered PMQR mechanism, are small pentapeptide repeat proteins that bind and protect type II DNA topoisomerases from inhibition by fluoroquinolones (17-19). Different lineages of Qnr proteins have been described (QnrA, QnrB, QnrS, and, more recently, QnrC and QnrD), with several allelic variants known for some of them (3, 9, 11, 20). qnr-like genes have also been detected on chromosomes from both gram-negative and gram-positive bacteria (9), and, recently, as class 1 integron gene cassettes in the chromosome of Vibrio cholerae (7). Although Qnr proteins only determine a moderate reduction of quinolone susceptibility, this may favor the selection of additional resistance mechanisms leading to higher-level quinolone resistance of clinical significance, and the dissemination of qnr genes and other PMQR determinants is believed to be an important promoter for evolution of quinolone resistance (11-13).qnr genes have been reported worldwide, especially in enterobacteria. However, they have mostly been investigated in clinical isolates with specific resistance traits (e.g., quinolone resistance or extended-spectrum β-lactamase phenotype) (11 and references therein), while their prevalence in commensal bacteria remains largely unknown. In this study, we investigated the prevalence of qnr genes in commensal enterobacteria from healthy children by a PCR-based metagenomic approach. We also tested a simplified dot blot DNA hybridization method as a less-labor-intensive and expensive tool to perform the metagenomic analysis.The analysis was carried out on commensal enterobacterial pools from 310 healthy children, ages 6 to 72 months, living in four urban areas of Latin America: two in Peru (Moyobamba, San Martin Department; and Yurimaguas, Loreto Department) and two in Bolivia (Camiri, Santa Cruz Department; and Villa Montes, Tarija Department). The enterobacterial pools, consisting of the bacterial growth obtained by plating fecal samples (one sample per child) onto MacConkey agar (MCA) plates (Oxoid, Milan, Italy), were randomly selected among samples (n = 3,193) obtained during a survey performed in 2005 in the same areas (1) and stored at −70°C. A loopful of each pool was plated on an MCA plate supplemented with 0.12 μg/ml ciprofloxacin (MCA-CIP). This ciprofloxacin concentration was used for screening purposes since (i) it was lower than MICs usually exhibited by enterobacterial strains harboring qnr genes as the sole quinolone resistance mechanism (reference 11 and references therein), while being higher than the wild-type MIC distribution for Escherichia coli and Klebsiella pneumoniae (http://www.escmid.org/research_projects/eucast/); (ii) a similar ciprofloxacin MIC threshold has previously been used for screening of qnr-positive bacteria (4, 8, 14, 15, 21). In case of growth onto MCA-CIP, a loopful of bacteria was directly used for total DNA extraction (10), and about 100 ng of metagenomic DNA was used as template in PCRs (50 μl) to detect the presence of qnr genes. Primers and conditions for PCR amplification of qnr genes were described previously in references 14 (qnrA and qnrS) and 2 (qnrB). Controls for qnr genes were kindly provided by Patrice Nordmann and Laurent Poirel (Université Paris-Sud, K.-Bicêtre, France). The specificity of the PCR products was confirmed by partial sequence analysis of randomly selected amplicons (Macrogen, Seoul, Korea).The presence of qnr genes in the enterobacterial pools was also investigated by dot blot DNA hybridization using a rapid method, essentially as described by Srinivasan et al. (16). Briefly, a loopful of the bacterial growth on MCA-CIP was transferred to 150 μl of lysis solution (0.4 N NaOH, 10 mM EDTA) and incubated at 70°C for 2 h. The bacterial lysate (100 μl) was directly blotted onto Hybond-N+ nylon membranes (Amersham Bioscience, Buckinghamshire, United Kingdom) using a BIO-dot microfiltration apparatus (Bio-Rad Laboratories, Milan, Italy). Nylon membranes were washed twice with 2× SSC (1× SSC is 0.15 M NaCl plus 0.015 M sodium citrate), fixed by UV light, and hybridized with digoxigenin-dUTP (DIG)-labeled qnr probes (generated by PCR using the positive controls, as described above) using the DIG system according to the manufacturer''s instructions (Roche Diagnostics SpA, Milan, Italy).Growth of enterobacterial pools on MCA-CIP was observed with 275 of 310 samples (89%). Analysis of the metagenomes prepared from this bacterial growth by PCR revealed overall positivities of 54% for qnrB and 14% for qnrS, while qnrA was not detected (Table ​(Table1).1). Dot blotting showed signals of variable intensity (Fig. ​(Fig.1)1) and an overall lower detection sensitivity, but results were fully consistent with those of PCR (i.e., all positive samples in the dot blot, including weak signals, were also positive by PCR) (Table ​(Table1).1). This evidently reflected a variable copy number of target genes in the metagenomic DNA from various samples, with a number of cases in which the amount of target genes could only be detected by the more sensitive gene amplification approach.Open in a separate windowFIG. 1.Nylon membrane prepared with bacterial lysates, hybridized with DIG-labeled qnrB probe. All positive signals, including the weakest ones, were positive in PCR experiments. Positive and negative controls (C+ and C−, respectively) are indicated by arrows.

TABLE 1.

Prevalence of qnr genes in commensal enterobacteria from 310 healthy children living in Peru and Bolivia^a