COVID-19 and kidney: role of SARS-CoV-2 infection in the induction of renal damage

OBJECTIVE

SARS-CoV-2 causes acute respiratory disease, interstitial and alveolar pneumonia, and involves numerous organs and systems such as the kidney, heart, digestive tract, blood, and nervous system. We aimed to evaluate the incidence of renal manifestations in patients diagnosed with COVID-19 infection.

PATIENTS AND METHODS

We performed a monocentric, cross-sectional, observational study, conducted on 114 patients with SARS-CoV-2. Clinical and laboratory parameters [renal function, serum electrolytes, inflammatory state, blood gas analysis, Interleukin 6 (IL-6) and urinalysis] were evaluated. The same values were checked out after two months (T1), however after negativization.

RESULTS

We enrolled 114 patients (59 males) with a mean age of 63.8 ± 13.9 years. We found hematuria in 48 patients (55.8%), proteinuria in 33 patients (38.4%), leukocyturia in 61 patients (70.9%), acute kidney injury (AKI) in 28 patients (24.6%), AKI in chronic kidney disease (CKD) in 24 patients (21.1%). Moreover, we found a significant increase of inflammatory indexes as C Reactive Protein (CRP), lactic dehydrogenase (LDH), alpha 1 and alpha 2 globulins with a subsequent reduction at T1 (p = 0.016, p < 0.001, p = 0.005, p = 0.007; respectively). Hemoglobin and erythrocyte values significantly decreased (p < 0.001, p = 0.003, respectively), and we found lymphopenia (p < 0.001). Also, we found elevated levels of the D-Dimer (p < 0.001) and a significant increase in the International Normalized Ratio (INR) (p = 0.038). We also showed a significant improvement after negativization in oxygen partial pressure (p = 0.001) and oxygen saturation (p < 0.001) and a significant increase in pH (p = 0.018) and bicarbonate concentration (p = 0.042). Moreover, we found a significant increase in IL-6 (p = 0.004). Also, we reported mild hyponatremia and hypokalemia with subsequent significant recovery (p < 0.001, p < 0.001, respectively) and mild hypochloremia with a recovery to the limits of statistical significance (p = 0.053). At the entrance, we found an increase in serum glucose with a significant reduction during recovery (p < 0.001).

CONCLUSIONS

The prevalence of AKI and/or CKD and/or abnormal urinalysis in patients diagnosed with COVID-19 on admission seems to be high and appears as a negative prognostic factor. Urinalysis appears to be very useful in unveiling the potential kidney impairment of COVID-19 patients; therefore, urinalysis could be used to reflect and predict the disease severity. We also recommend a careful evaluation of metabolic alterations, inflammatory states, and electrolytic disorders in COVID-19 patients.

Pancreatitis and pancreatic cancer in patients with type 2 diabetes treated with glucagon-like peptide-1 receptor agonists: an updated meta-analysis of randomized controlled trials

INTRODUCTION

An association between glucagon-like peptide-1 receptor agonists (GLP1-RA) and risk of pancreatitis and pancreatic cancer has been suggested. Since its first description, several new trials (including three cardiovascular outcome trials) have been published, substantially increasing the available data set. This suggests the need for an update of the previous meta-analysis.

EVIDENCE ACQUISITION

A Medline search for GLP-1 receptor agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, or semaglutide) was performed, collecting all randomized clinical trials, with duration ≥52 weeks, enrolling patients with type 2 diabetes, and comparing a GLP-1 receptor agonist with placebo or any other non-GLP-1 receptor agonist drug. The endpoints were pancreatitis, pancreatic cancer reported as serious adverse events. Mantel-Haenszel Odds Ratio (MH-OR) with 95% confidence interval (95% CI) was calculated for all outcomes defined above, on an intention-to-treat basis.

EVIDENCE SYNTHESIS

A total of 43 trials fulfilling inclusion criteria (all reporting data on pancreatitis and pancreatic cancer) was identified. GLP-1 RA showed no association with pancreatitis (MH-OR 1.24 [0.94, 1.64]; P=0.13) and pancreatic cancer (MH-OR 1.28 [0.87, 1.89]; P=0.20).

CONCLUSIONS

No clear evidence of risk for pancreatitis was observed, whereas data on pancreatic cancer are too scarce to draw any conclusion.

Literature review on the cross-link between ocular and renal disease: renin angiotensin aldosterone system is a main actor

OBJECTIVE

Chronic kidney disease (CKD) and ocular disease share several cardiovascular risk factors as well as pathogenetic mechanisms having Renin-Angiotensin-Aldosterone System (RAAS) as main actor. Moreover, kidney and eyes have common genetic and embryonic origin. In this literature review, we present main evidence supporting this association for early identifying diseases affecting both systems and evaluating potential multi-target therapeutic strategies.

MATERIALS AND METHODS

We performed a literature review of the current peer-reviewed English-language randomized controlled studies (RCTs), reference lists of nephrology or ophthalmology textbooks, review articles and relevant studies with ocular or eye and kidney or renal diseases as keywords until March 2020. Prospective and retrospective studies as well as meta-analyses and latest systematic reviews were included.

RESULTS

We evaluated a total of 683 records, finally selecting 119 articles related to ocular and renal diseases. Records were divided into two areas: chronic and acute kidney disease and ocular or eye diseases. Some of the examined studies were discarded for population biases/intervention or deemed unfit.

CONCLUSIONS

Based on our results, we conclude that there is evidence of a clear association between kidney and eye diseases, being this cross-link mainly based on RAAS dysregulation. Our review suggests that it may be useful to screen CKD patients for associated ocular diseases, such as cataract, glaucoma, diabetic retinopathy and age-related macular degeneration. A comprehensive study of CKD and proteinuric patients should include careful eye examination. Renal impairment in young patients should prompt a search for ocular disease, such as TUNA syndrome or oculo-renal syndrome, in particular if family history of concurrent ocular and renal disease is present. Anti-RAAS agents are mostly recommended in patients with renal and ocular impairment.

Screening of QTc interval and global autonomic activity in autosomal dominant polycystic kidney disease and atherosclerotic renal artery stenosis hypertensive patients

OBJECTIVE

Arterial hypertension (AH) represents a major risk factor for cardiovascular disease and is associated to several complications, such as prolonged corrected QT (QTc) interval and impaired heart rate variability (HRV). Secondary causes of AH include autosomal dominant polycystic kidney disease (ADPKD) and atherosclerotic renal artery stenosis (ARAS), both known to be related to arrhythmic risk and autonomic imbalance. The aim of the study is to evaluate whether global autonomic activity and QTc interval differently affect ADPKD and ARAS hypertensive patients.

PATIENTS AND METHODS

An observational study was performed on 59 patients: 16 ADPKD patients and 19 diagnosed with ARAS, compared to 24 healthy controls (HC). All patients underwent clinical evaluation, biochemical lab tests, 24-hour electrocardiogram (ECG) and renal Doppler ultrasound. HRV was assessed through the analysis of 24-hour ECG to detect standard deviation of normal-to-normal RR intervals (SDNN). QTc interval was defined as prolonged when > 440 msec.

RESULTS

SDNN was significantly lower in ADPKD and ARAS patients than HC (p < 0.0001) and no significant differences were found between ADPKD and ARAS patients (p > 0.05). QTc was found significantly higher in ARAS patients than HC (p = 0.001) and in ARAS patients than ADPKD patients (p = 0.004).

CONCLUSIONS

The pathogenesis of hypertension in ADPKD and ARAS patients is related to the activation of the renin angiotensin aldosterone system (RAAS). In ADPKD, cyst enlargement leads to kidney ischemia and renin release, associated to endothelial dysfunction, low nitric oxide and sympathetic tone activation. Differently, reduction in renal perfusion pressure activates RAAS and renal adrenergic nerves in ARAS patients. We can speculate that prolonged QTc interval is more present in ARAS vs. ADPKD hypertensive patients due to a greater activation of RAAS. We suggest adding 24-hour HRV evaluation in association with traditional risk factors in course of ADPKD and ARAS hypertension to better stratify cardiovascular risk in these groups of patients.

Effects of non-invasive ventilation on renal and endothelial function in patients with respiratory failure

OBJECTIVE

Non-invasive positive pressure ventilation (NIV) is now an indispensable safeguard in the management of many pathologies. However, sometimes the positive end-expiratory pressure (PEEP) showed harmful effects on renal function, although effects on renal hemodynamic are unclear. We aimed at evaluating the effects of NIV on renal and endothelial function, in patients with chronic or acute respiratory failure.

PATIENTS AND METHODS

We performed a longitudinal, prospective, interventional study. We enrolled 17 hospitalized and non-hospitalized patients (11 males) with indication to NIV and stable hemodynamic parameters. Patients were treated with NIV and followed up at T0, at T1 (at the end of the NIV cycle) and at T2 (fifteen days after).

RESULTS

17 patients (11 males) with a mean age of 71.94 ± 14.89 years were enrolled. A significant increase in flow mediated dilation (FMD) was found (p = 0.004). We showed a significant improvement, after NIV, in the values of pH (p = 0.0002), pCO2 (p = 0.0001), pO2 (p = 0.04), lactates (p = 0.04), sO2 (p = 0.02) and in the P/F Ratio (p = 0.004). We also showed a significant reduction of serum glucose (p = 0.01) and a significant increase of serum chlorine (p = 0.047), while we did not report a significant increase of creatinine (p = 0.297) or a significant change in diuresis.

CONCLUSIONS

In our study NIV has no significant effects on renal function in patients with respiratory failure. Probably these patients required low PEEP values, which were less harmful to lung parenchyma and not effective on systemic hemodynamic. Furthermore, NIV has improved endothelial function in the short term, likely by reducing oxidative stress, as improvements of the gas-analysis parameters showed. Therefore, NIV could help to reduce cardiovascular risk of patients improving endothelial function.

Pancreatitis and pancreatic cancer in patients with type 2 diabetes treated with glucagon-like peptide-1 receptor agonists: an updated meta-analysis of randomized controlled trials

AIM

An association between Glucagon-Like Peptide-1 Receptor Agonists (GLP1-RA) and risk of pancreatitis and pancreatic cancer has been suggested. Since its first description, several new trials (including three cardiovascular outcome trials) have been published, substantially increasing the available data set. This suggests the need for an update of the previous meta analysis.

MATERIALS AND METHODS

A Medline search for GLP-1 receptor agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, or semaglutide) was performed, collecting all randomized clinical trials, with duration ≥52 weeks, enrolling patients with type 2 diabetes, and comparing a GLP-1 receptor agonist with placebo or any other non-GLP-1 receptor agonist drug. The endpoints were pancreatitis, pancreatic cancer reported as serious adverse events. Mantel-Haenszel odds ratio (MH-OR) with 95% Confidence Interval (95% CI) was calculated for all outcomes defined above, on an intention-to-treat basis.

RESULTS

A total of 43 trials fulfilling inclusion criteria (all reporting data on pancreatitis and pancreatic cancer) was identified. GLP-1 RA showed no association with pancreatitis (MH-OR 1.24 [0.94, 1.64]; p=0,13) and pancreatic cancer (MH-OR 1.28 [0.87, 1.89]; p=0,20).

CONCLUSIONS

No clear evidence of risk for pancreatitis was observed, whereas data on pancreatic cancer are too scarce to draw any conclusion.

Major cardiovascular events, heart failure, and atrial fibrillation in patients treated with glucagon-like peptide-1 receptor agonists: An updated meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Glucagon-like Peptide 1 Receptor Agonists (GLP1-RA) has been associated with a reduction of major cardiovascular events (MACE) and mortality on the basis of the results of cardiovascular outcome trials (CVOT). Several meta-analyses on this issue have been recently published; however, they were all restricted to CVOT, with the exclusion of all studies designed for other endpoints; moreover, other cardiovascular endpoints, such as atrial fibrillation and heart failure have not been fully explored.

METHODS AND RESULTS

A Medline search for GLP-1 receptor agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, or semaglutide) was performed, collecting all randomized clinical trials with a duration ≥52 weeks, enrolling patients with type 2 diabetes, and comparing a GLP-1 receptor agonist with placebo or any other non-GLP-1 receptor agonist drug. We included 43 trials, enrolling 63,134 patients. A significant reduction of MACE (MH-OR 0.87 [0.83, 0.92]), all-cause mortality (MH-OR 0.89 [0.83, 0.96]), and a nonstatistical trend toward reduction of heart failure (MH-OR 0.93 [0.85, 1.01]) was observed - GLP1-RA did not increase the risk of atrial fibrillation (MH-OR 0.94 [0.84, 1.04]).

CONCLUSION

The present meta-analysis confirms the favorable effects of glucagon-like peptide-1 receptor agonists on major cardiovascular events, cardiovascular and all-cause mortality, stroke, and possibly myocardial infarction. Conversely, the effects on heart failure remain uncertain. Available data on atrial fibrillation seems to exclude any major safety issues in this respect.

REGISTRATION NUMBER (PROSPERO)

CRD42018115577.

Cholelithiasis in patients treated with Glucagon-Like Peptide-1 Receptor: An updated meta-analysis of randomized controlled trials

Glucagon-Like Peptide-1 Receptor Agonists (GLP1-RA) has been associated with cholelithiasis in a previous meta-analysis. The publication of new trials suggests the need for an update. We collected trials with GLP1-RA vs. other therapies, calculating Mantel-Haenszel odds ratio (MH-OR, 95%CI). GLP1-RA significantly increased the risk of cholelithiasis (MH-OR 1.28 [1.11, 1.48]).

Hypokalemic rhabdomyolysis: a rare manifestation of primary aldosteronism

Rhabdomyolysis is a rare presentation of hypokalemia, although muscle weakness is a well-known manifestation of hypokalemia. Primary aldosteronism is characterized by hypertension, suppressed plasma renin activity, increased aldosterone excretion and hypokalemia with metabolic alkalosis. Rhabdomyolysis is not common in primary aldosteronism. We present here a 40-year-old woman presenting with rhabdomyolysis accompanied by severe hypokalemia as heralding symptom of primary aldosteronism.

Resistive index and MELD-Na: nephrologic monitoring in cirrhotic patients awaiting liver transplantation

Renal dysfunction in cirrhotic patients is primarily related to disturbances in circulatory function. In decompensated cirrhosis, ascites and water retention are associated with development of dilutional hyponatremia. The arterial resistive index (RI) is a measure of resistance to arterial flow within the renal vascular bed. Hyponatremia is an independent predictor of mortality in patients with ascites. The aim of this study was to evaluate intrarenal RI in end-stage liver disease (ESLD) patients awaiting liver transplantation (LT) and its association with renal and hepatic function as assessed by Model for End-Stage Liver Disease (MELD) and MELD-Na scores. We evaluated 40 cirrhotic patients (23 males, 17 females) awaiting LT from January 2009 to January 2012. Twenty-six of the 40 patients (65%) showed a renal RI ≥ 0.70, the normal value according to standard reported evaluations. Patients with RI ≥ 0.70 showed significantly higher MELD and MELD-Na scores as well as greater higher serum creatinine and lower serum sodium concentrations compared with subject displaying RI <0.70. The most relevant result of our study was the strong association between elevated renal RI in ESLD patients and advanced liver dysfunction, as demonstrated by MELD and MELD-Na scores, hyponatremia, ascites, and acute renal failure episodes. In conclusion, this study suggested that intrarenal RI assessment should be considered in the clinical and nephrologic monitoring of cirrhotic patients awaiting LT.

Oxidative actions of hydrogen peroxide in human gingival and oral periosteal fibroblasts: responses to glutathione and nicotine, relevant to healing in a redox environment

Background

This study aims to validate pro-oxidant actions of nicotine (N), using hydrogen peroxide (H₂O₂) and the antioxidant glutathione (G) in an in vitro model of human gingival fibroblasts (HGF) and human oral periosteal fibroblasts (HPF); radiolabelled androgens are used as biomarkers of redox status. Oxidative stress is an important mediator of inflammatory repair. The androgen metabolite 5α-dihydrotestosterone (DHT) is an effective biomarker of oxidative stress and healing.

Methods

6 Cell-lines of HGF and HPF established in confluent monolayer culture were incubated in Eagle's MEM using 14C-testosterone and 14C-4-androstendione as substrate; in conjunction with effective concentrations of N, G and H₂O₂ established at N250, G3 μg/ml and 3%H₂O₂ w/w, 0.5 μl/ml. Combinations of H₂O₂G and H₂O₂GN were used in order to compare the oxidative effects of N/H₂O₂ and their responses to glutathione. At 24 h, the medium was solvent extracted, evaporated to dryness and subjected to TLC in a benzene/acetone solvent system 4:1 v/v for the separation of metabolites. The separated metabolites were quantified using a radioisotope scanner.

Results

The mean trends of 6 cell-lines for both substrates and each cell type demonstrated that the yield of the main metabolite DHT was significantly reduced by N and H₂O₂ alone (2-fold, n=6; p<0.01). The inhibition caused by H₂O₂ was overcome by the antioxidant glutathione in the combination H₂O₂G, to values similar to those of controls (n=6; p<0.01). It is relevant that when N was added to this neutralized combination, the decrease in yields of DHT triggered by N were comparable to those induced by H₂O₂; and retaining the positive effect of G.

Conclusion

Oxidative stress mediated by H₂O₂ was overcome by glutathione and recurred when nicotine was added, suggestive of a pro- oxidant role for nicotine. Androgen biomarkers are a sensitive index of oxidative stress which affects wound healing.

•

DHT is an effective redox marker in HGF and oral periosteal fibroblasts in vitro.

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Both nicotine and H₂O₂ reduced yields of DHT, indicative of induced oxidative stress.

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Nicotine has oxidative effects that are comparable to those of H₂O₂ mediated by AR.

•

Effects of nicotine and H₂O₂ were reduced by glutathione in HGF and HPF cultures.

•

Redox status is relevant to androgen receptor-mediated inflammatory wound healing.

Long-term interleukin-2 assessment after conversion from a twice-daily to once-daily tacrolimus regimen in stable kidney recipients

Conversion to tacrolimus (Tac) to once daily (Tac-O) formulation is commonly followed by a 20% reduction in Tac trough levels in the first month. It is not associated with modifications of renal function but there is the issue of its effects on inflammatory cytokines and on subclinical rejection. The aim of our study was to evaluate long-term interleukins (IL)-2 profiles in stable renal transplant patients after Tac-O conversion. We enrolled 10 stable kidney transplant patients converted to Tac-O. Tac trough levels, serum creatinine concentrations, glomerular filtration rate using the Modification of Diet in Renal Disease formula, C-reactive protein, IL-2 levels, and clinical assessments were performed monthly for 6 months before and 12 months after conversion. Despite the significant reduction in Tac trough levels, we did not observe alterations suggestive of clinical or subclinical acute rejection.

Liver transplantation: role of immunosuppression, renal dysfunction and cardiovascular risk factors

In the past decades, advances in immunosuppression, organ preservation, surgical techniques and better management of post-transplantation complications have led to improvement in survival of liver transplant patients. Such extended survival of liver graft recipients in their fifties and sixties has resulted in a greater prevalence of complications, in particular chronic kidney (CKD) and cardiovascular diseases (CVD). Renal failure and cardiovascular complications in the setting of liver transplantation are associated to an increase of morbidity and mortality. A 4-fold increased risk of death is reported among patients developing post-transplant CKD, and CVD is the leading cause of death with a functioning allograft, accounting for as much as 30% of post-transplant mortality. The onset is multifactorial, with pre-transplant conditions involved, including pre-transplant renal insufficiency, hepatitis C virus infection and pretransplant diabetes. Acute renal dysfunction in the setting of transplantation is also responsible of post-transplant CKD. Immunosuppressive therapy is primarily responsible for the development of CKD. Metabolic syndrome and its individual components, including diabetes mellitus, systemic hypertension, dyslipidemia, and obesity, are increasingly being identified as closely related to immunosuppressive therapy and actively contribute to cardiovascular morbidity and mortality in transplant patients. Treatment of modifiable risk factors is mandatory aiming to prevent the development and progression of serious complications. Early recognition, prevention and treatment of these conditions may further improve long-term survival after liver transplantation.

Acute renal failure in liver transplant recipients: role of pretransplantation renal function and 1-year follow-up

Chronic renal failure and acute renal failure (CRF and ARF) are common complications after orthotopic liver transplantation (OLT) that adversely affect patient survival. Many factors influence the development of ARF in the OLT setting. In a previous study we reported an association between ARF and the development of CRF at 1 month after OLT. The aims of our study were to evaluate the influence of ARF on short-, middle-, and long-term renal function after OLT and its influence on 1-year survival of patients and grafts. Fourty-four patients who underwent deceased donor OLT between August 2008 and August 2010 were evaluated pretransplantation, in the perioperative period, and at 1, 6, and 12 months posttransplantation. ARF was associated with CRF at 1 month post-OLT, whereas no association was observed at 6 and 12 months post-OLT. The development of CRF at 6 months post-OLT was associated with pre-OLT renal dysfunction and 1 month post-OLT CRF. Four patients died in the ARF group, whereas 3 patients died in the group without ARF. We confirmed ARF to be a predictive event for short-term renal dysfunction. The majority of patients recovered renal function after the first month. Although many pre-, peri-, and post-OLT factors may contribute to the development of posttransplantation CRF, pre-OLT CRF seemed to be the most important risk factor.

Polyomavirus BK replication in liver transplant candidates with normal renal function

Polyomavirus-associated nephropathy (PVAN) has a predilection for kidney rather than for other solid organ transplants such as the liver. Immunosuppression is widely recognized to be a major risk factor for PVAN development. Since end-stage liver disease (ESLD) patients are immunocompromised and immunosuppression is a major cause of BK virus reactivation, we sought to evaluate BK virus replication in patients listed for liver transplantation. From April to October 2010, we enrolled 20 patients listed for liver transplantation. BK virus load was measured by quantitative real-time polymerase chain reaction on plasma and urine samples. Viremia occurred in only 1 among 20 patients. We hypothesized that in ESLD patients, the low prevalence of BK virus infection may be related to the prevalent impairment of antibacterial immunity rather than to the viral-specific one. In BK virus reactivation, not only the immunodepressive state itself, but also the specific immunologic mechanisms involved may have a role.

Model for end-stage liver disease score versus simplified acute physiology score criteria in acute renal failure after liver transplantation

Hepatic function and renal failure are closely related among patients with end-stage liver disease (ESLD) due to splanchnic hemodynamic mechanisms that characterize advanced decompensated cirrhosis. Acute renal failure (ARF) is a frequent complication that occurs immediately post-orthotopic liver transplantation (OLT). The Model for End-stage Liver Disease (MELD) score describes the survival of patients with ESLD awaiting OLT related to the severity of liver disease. The Simplified Acute Physiology Score (SAPS II) is a mortality prediction model that scores the severity of illness among intensive care unit patients. In a previous study we observed an association between ARF post-OLT and a higher MELD score, but it was not clear whether this association depends on the grade of ESLD or on the critical condition of liver transplant patients. The aim of this study was to evaluate the association of ARF with MELD score and/or SAPS II criteria among liver transplant patients. We analyzed 46 patients with ESLD who underwent deceased donor OLT. All patients were evaluated at baseline and in the first 7 days post-OLT. According to the RIFLE classification, the incidence of the worst grade of ARF post-OLT was 19.2%. These patients showed significantly higher MELD scores, while there was no association with systemic parameters related to the critical patient's condition or with the mortality score as evaluated by SAPS II criteria. We confirmed the association between renal failure and hepatic function among liver transplant patients. A more severe degree of hepatic dysfunction before OLT was associated with a greater incidence of ARF that can adversely affect patient survival.

Tacrolimus trough levels and level-to-dose ratio in stable renal transplant patients converted to a once-daily regimen

Numerous evidence has been reported to support a safe 1:1 conversion from the twice-daily tacrolimus (Tac-T) to the once-daily tacrolimus regimen (Tac-O), but frequently there is a reduction in drug trough levels, which has been estimated by some authors to be about 20%. The relationship between Tac-O dosage and trough levels after conversion is not clear. The tacrolimus trough levels-to-dose ratio has been applied to better define the wide variability in doses and blood levels of tacrolimus. The aim of this study was to evaluate tacrolimus trough levels, tacrolimus daily dosage, and tacrolimus level-to-dose ratio during 1 year pre-postconversion follow-up in 31 stable kidney transplant patients who had received Tac-T therapy for over 6 months with stable renal function. They were converted to the same dosage of Tac-O. Patients before and after conversion were their own controls. The trough levels of tacrolimus showed a slight albeit significant reduction after conversion, remaining in the therapeutic range. Nineteen percent underwent an adjustment in total daily dosage after conversion versus 39% before conversion with no significant difference. No significant differences were detected in the total daily dose administered either by tacrolimus level-to-dose ratio before or after conversion. Kidney transplant recipients under Tac-O therapy were safely maintained using the same therapeutic monitoring as when receiving Tac-T.

RIFLE criteria and hepatic function in the assessment of acute renal failure in liver transplantation

Renal dysfunction in cirrhotic patients is primary related to disturbances of circulatory function, triggered by portal hypertension with chronic intrarenal vasoconstriction and hypoperfusion. Pretransplant renal function is an important factor implicated in the development of acute renal failure (ARF) after liver transplantation (OLT), but other factors mostly related to liver function seem to influence the development of ARF. The Acute Dialysis Quality Initiative workgroup developed the RIFLE classification to define ARF. We sought to evaluate the incidence of ARF among patients undergoing OLT, to evaluate the association of ARF with pre-OLT renal and hepatic functions, and to evaluate the influence of ARF on chronic kidney disease (CKD) at 1 month post-OLT. Clinical, renal, hepatic function, and donor risk index data of 24 patients who underwent deceased donor OLT were collected before transplantation, in the perioperative period and in the first month post-OLT. ARF occurred in 37.5% of patients with 56% developing the R grade and 44% the I grade; no patient showed the F grade. An association was observed between ARF and a higher Model for End-Stage Liver Disease (MELD) score and between ARF and a reduced pre-OLT serum albumin. No association was noted between ARF and other pre-OLT parameters. In cirrhotic patients serum creatinine is a bias for renal function assessment and the Modification of Diet in Renal Disease formula overestimates GFR. Post-OLT CKD was present in 6.7% of patients without ARF and in 44.4% of patients with ARF. The R grade developed more frequently among patients with viral cirrhosis. The association of ARF with MELD and hypoalbuminemia may be the result of a close relationship between renal and hepatic functions among cirrhotic patients. Post-OLT CKD may be the result of unrecognized, preexisting CKD and/or the effects of not fully resolved acute damage to an injured kidney.

Meaning of early polyomavirus-BK replication post kidney transplant

Polyomavirus BK (BKV) infection is ubiquitous in the human population. Under immunosuppression, BKV can undergo reactivation resulting in viral replication. What really happens in the early hours posttransplantation is not clearly defined; the meaning of early viremia and viruria is not clear. BKV viremia is considered a marker of infection. The aim of our study was to investigate the prevalence of early BKV infection in kidney transplant patients, to evaluate the relationship to infections at 3 and 6 months and the association with recipient, donor, and graft features. We enrolled 36 kidney transplanted patients from May 2006 to April 2007. BKV load was measured on plasma and urine samples by Q-PCR at 12 hours (T(0)/early) as well as 3 (T(3)) and 6 (T(6)) months thereafter. A high percentage of BKV infections were detectable in the first hours after transplantation (33.3%), which remained unchanged to month 6 post transplantation. Moreover, patients who were positive at T(0) had a high probability of remaining positive thereafter. The number of copies in plasma samples tended to increase at 3 months and to decrease thereafter, whereas the urine viral load tended to steadily increase. Among BKV-positive patients, we identified 2 groups according to viremic state at T(0): 9 patients (group A); who were already positive and remained so to T(6) 5 and 3 patients who turned positive at 3 or at 6 months, respectively (group B). Group A included 75% of positive patients at T(0) and 90% of positive patients at either T(3) or T(6) (P = .007). The most important contribution of our study was to highlight the presence of BKV infection in renal transplant recipients from the first hours posttransplantation. This condition seemed to be the most important risk factor for persistent infection in the first 6 months.

DNA microarrays for identifying fishes

In many cases marine organisms and especially their diverse developmental stages are difficult to identify by morphological characters. DNA-based identification methods offer an analytically powerful addition or even an alternative. In this study, a DNA microarray has been developed to be able to investigate its potential as a tool for the identification of fish species from European seas based on mitochondrial 16S rDNA sequences. Eleven commercially important fish species were selected for a first prototype. Oligonucleotide probes were designed based on the 16S rDNA sequences obtained from 230 individuals of 27 fish species. In addition, more than 1200 sequences of 380 species served as sequence background against which the specificity of the probes was tested in silico. Single target hybridisations with Cy5-labelled, PCR-amplified 16S rDNA fragments from each of the 11 species on microarrays containing the complete set of probes confirmed their suitability. True-positive, fluorescence signals obtained were at least one order of magnitude stronger than false-positive cross-hybridisations. Single nontarget hybridisations resulted in cross-hybridisation signals at approximately 27% of the cases tested, but all of them were at least one order of magnitude lower than true-positive signals. This study demonstrates that the 16S rDNA gene is suitable for designing oligonucleotide probes, which can be used to differentiate 11 fish species. These data are a solid basis for the second step to create a "Fish Chip" for approximately 50 fish species relevant in marine environmental and fisheries research, as well as control of fisheries products.

Response to anti-tumour necrosis factor alpha blockade is associated with reduction of carotid intima-media thickness in patients with active rheumatoid arthritis

OBJECTIVES

To determine whether tumour necrosis factor (TNF)-alpha blockers may reduce carotid intima-media thickness (cIMT) in patients with active rheumatoid arthritis (RA) steadily responsive to such therapy.

METHODS

From 287 consecutive RA patients attending our out-patient clinic and diagnosed on the basis of the American College of Rheumatology (ACR) criteria, 49 without traditional cardiovascular risk factors and meeting the requirements for TNF-alpha blockers therapy were selected. Among them, 39 actually started TNF-alpha blockers, but only 30, who reached at least a response on the ACR 20% improvement criteria at 14 weeks, maintained during the whole year of treatment, were finally considered (group A). The remaining 10/49, homogeneous for age, sex, traditional cardiovascular risk factors, socioeconomic status, disease activity and duration, who did not consent to TNF-alpha-blocker administration, were used as controls (group B). Disease activity score in 44 joints (DAS44), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were evaluated before starting the study, and 3, 6, 12 months thereafter; cIMT was measured by ultrasound before and 12 months thereafter only.

RESULTS

Patients in group A showed a very significant cIMT reduction (P < 0.0001 and P < 0.0001, on the right and left side, respectively), preceded by an early and lasting significant decrease in DAS44, ESR and CRP. Moreover, a significant correlation was found between cIMT and DAS44 (r = 0.435, P < 0.05).

CONCLUSIONS

These results demonstrate that TNF-alpha blockade is associated with cIMT reduction in RA patients steadily responsive to therapy, probably by lowering inflammation.

Molecular and chromosomal analysis of ribosomal cistrons in two cartilaginous fish, Taeniura lymma and Raja montagui (Chondrichthyes, Batoidea)

We used silver nitrate staining, CMA3 and FISH to study the chromosomal localization of both the major ribosomal genes and the nucleolar organizer regions as well as that of the minor ribosomal genes (5S rDNA) in two species of Batoidea, Taeniura lymma (Dasyatidae) and Raja montagui (Rajidae). In both species, all the metaphases examined showed the presence of multiple NOR-bearing sites, while the gene for 5S rRNA proved to be localized on two chromosome pairs. Furthermore, one of the two 5S rDNA sites in T. lymma was shown to be co-localized with the major ribosomal cluster. The presence of multiple nucleolar organizer regions in the two species might be interpreted as being the result of intraspecific polymorphisms, or as a phenomenon of the amplified transposition of mobile elements of the genome. We also determined the nucleotide sequence of the 5S rRNA gene, consisting of 564 bp in R. montagui and 612 bp in T. lymma. We also found TATA-like and (TGC)n trinucleotides, (CA)n dinucleotides and (GTGA)n tetranucleotides, which probably influence gene regulation.

Rapid miocene-pliocene dispersal and evolution of Mediterranean rajid fauna as inferred by mitochondrial gene variation

Rajidae (colloquially known as skates and rays) experienced multiple and parallel adaptive radiations allowing high species diversity and great differences of species composition between regional faunas. Nevertheless, they show considerable conservation of bio-ecological, morphological and reproductive traits. The evolutionary history and dispersal of North-east Atlantic and Mediterranean rajid fauna were investigated throughout the sequence analysis of the control region and 16S rDNA mitochondrial genes. Molecular estimates of divergence times indicated recent origin and rapid dispersal of the present species. Compared with the ancient origin of the family (Late Cretaceous), the present species diversity arose in a relatively narrow time-window (12 Myr) from Middle Miocene to Early Pleistocene, likely by speciation processes related to dramatic geological and climatic events in the Mediterranean. Nucleotide substitution rates and phylogenetic relationships indicated Mediterranean endemic skates derived from sister species with wider distribution during Late Pliocene-Pleistocene. Skate phylogeny and systematics obtained using mitochondrial gene variation were largely consistent with those based on morpho-anatomical data.

Microsatellite DNA variation reveals high gene flow and panmictic populations in the Adriatic shared stocks of the European squid and cuttlefish (Cephalopoda)

In the semienclosed Adriatic Sea, the shared stocks of the cephalopods Loligo vulgaris and Sepia officinalis represent important marine fisheries resources exploited by all coastal countries. The improving of knowledge on the demographic features of these shared stocks is internationally relevant for adopting responsible management and conservation of these marine resources. Analyses of microsatellite variation in geographical samples collected from all parts of the Adriatic Sea were performed using arrays of species-specific di-nucleotide and tri-nucleotide loci. In L. vulgaris the level of genetic variability was consistent with that observed in other loliginid species, whereas the S. officinalis stock showed a microsatellite variation markedly lower than that estimated for the Atlantic and Mediterranean populations collected around the Iberian peninsula. The weak spatial genetic differentiation, the discordant results of the genetic divergence estimators and the lack of any geographical cline in the spatial genetic differences suggest the occurrence of single genetically homogeneous populations within the Adriatic stocks of both species, recommending a coordinated management of the squid and cuttlefish by the Adriatic fishing countries. On the contrary, significant differences detected in temporal replicates of S. officinalis might suggest that allelic frequency can change relating to reproductive behaviour.

Mitochondrial DNA variation, phylogenetic relationships, and evolution of four mediterranean genera of soles (soleidae, pleuronectiformes)

To increase knowledge about the systematics and evolution of Mediterranean soles, we assessed mitochondrial DNA variation, molecular phylogeny, and evolution in eight species from the genera Solea, Microchirus, Monochirus, and Buglossidium by large ribosomal subunit (16S) and cytochrome b (cytb) sequence analysis. Relevant molecular features are the great variation of base composition among species at the third codon in cytb and the heterogeneity of the nucleotide substitution rate. Phylogenies recovered using 16S nucleotide and cytb amino acid sequences agree with those based on morphology in assessing monophyly of Solea species and ancestry of Buglossidium luteum, but they are against the intergeneric differentiation of Microchirus and Monochirus. Conversely, phylogenetic trees based on cytb nucleotide sequences yielded relationships among taxa regardless of their evolutionary histories. The incongruities between morphological and molecular issues suggest the need for reassessing the systematic value of some morphological characters. Approximate estimates of the divergence time of Mediterranean soleid lineages range from 40 to 13 Mya (Oligocene-Miocene), indicating an ancient origin for the group.

Satellite DNA variation in parental and derived unisexual hybrids of Bacillus stick insects (Phasmatodea)

The Bag320 sequence family of satellite DNA (satDNA) has been found in some stick insect taxa: the bisexual Bacillus grandii, the related parthenogen B. atticus and their hybrids with B. rossius. However, under the same experimental conditions, the Bag320 sequences were not found in B. rossius. Bag320 sequences of the clonal hybrid B. whitei (= B. rossius/grandii grandii) intermingled with those of B. grandii in all plotted dendrograms. On the whole, satDNA features (restriction pattern, sequence variation, fluorescent in situ hybridization (FISH)), allozymes and karyology support a relatively recent origin of B. whitei. Our investigations on unisexual hybrids of Bacillus also suggested that their origin and clonal reproduction allow the occurrence of different sequence subsets of limited variability in isolated populations stemming from the hybridization focus.

Comparative Analysis of a Mitochondrial DNA Control Region Fragment Amplified from Three Adriatic Flatfish Species and Molecular Phylogenesis of Pleuronectiformes

: The 5'-end of the mitochondrial control region of three Pleuronectiformes from the Adriatic Sea, Platichthys flesus italicus (Adriatic flounder), Solea vulgaris (common sole), and Solea kleini (Klein's sole), was sequenced and compared with that of six other flatfish species from the families Pleuronectidae and Bothidae. The sequence structures of all flatfishes appear very similar and consist of alternate short segments with low, medium, and high rates of nucleotide substitution. Four conserved 19-bp repeats occur at the beginning of the European and Adriatic flounder sequences. The common occurrence of tandem arrays in fish control regions could be related to a stable secondary structure. Molecular phylogenetic relationships among Pleuronectiformes agree well with previous morphologic data at all taxonomic levels. Molecular analyses could therefore contribute to resolving phylogenetic and taxonomic debates within the Pleuronectiformes.

Species recognition of congeneric acanthocephalans in slider turtles by random-amplified polymorphic DNA (RAPD) markers

Species recognition of acanthocephalans of the genus Neoechinorhynchus (Hamann, 1892) found in the freshwater turtle Trachemys scripta (Wied, 1838) has previously been based primarily on female body and egg morphology. Observed morphological plasticity within and among species may lead to the misclassification of female specimens and leaves males of different species completely indistinguishable. Here, random-amplified polymorphic DNA (RAPD) analysis was used to genetically characterize samples of Neoechinorhynchus pseudemydis (Cable and Hopp, 1954), Neoechinorhynchus emydis (Leidy, 1851), and Neoechinorhynchus emyditoides (Fisher, 1960). Amplifications performed with 3 decamer oligonucleotides showed banding patterns with a few diagnostic fragments that allowed the recognition of N. pseudemydis specimens from those of the N. emydis-N. emyditoides group. No primer gave a species-specific locus that allowed the differentiation of N. emydis from N. emyditoides specimens, suggesting that they could belong to a sole taxon. The species assignment of females of uncertain classification and of males is fully reliable using RAPD markers. Thus, identification of acanthocephalan species by RAPD in the helminth infracommunities could potentially be very useful to determine community structure. RAPD and other polymerase chain reaction-based methods have some practical advantages over multilocus discriminant analysis, such as the ability to use ethanol-stored specimens and small tissue samples of parasites.

The Bag320 satellite DNA family in Bacillus stick insects (Phasmatodea): different rates of molecular evolution of highly repetitive DNA in bisexual and parthenogenic taxa

The Bag320 satellite DNA (satDNA) family was studied in seven populations of the stick insects Bacillus atticus (parthenogenetic, unisexual) and Bacillus grandii (bisexual). It was characterized as widespread in all zymoraces of B. atticus and in all subspecies of B. grandii. The copy number of this satellite is higher in the bisexual B. grandii (15%-20% of the genome) than in the parthenogenetic B. atticus (2%-5% of the genome). The nucleotide sequences of 12 Bag320 clones from B. atticus and 17 from B. grandii differed at 13 characteristic positions by fixed nucleotide substitutions. Thus, nucleotide sequences from both species cluster conspecifically in phylogenetic dendrograms. The nucleotide sequences derived from B. grandii grandii could be clearly discriminated from those of B. grandii benazzii and B. grandii maretimi on the basis of 25 variable sites, although all taxa come from Sicily. In contrast, the Bag320 sequences from B. atticus could not be discriminated accordingly, although they derive from geographically quite distant populations of its three zymoraces (the Italian and Greek B. atticus atticus, the Greek and Turkish B. atticus carius, and the Cyprian B. atticus cyprius). The different rate of evolutionary turnover of the Bag320 satDNA in both species can be related to their different modes of reproduction. This indicates that meiosis and chromosome segregation affect processes in satDNA diversification.

Genome exclusion and gametic DAPI-DNA content in the hybridogenetic Bacillus rossius-grandii benazzii complex (Insecta Phasmatodea)

Among Sicilian stick insects, two hybridogenetic complexes have been discovered: Bacillus rossius-grandii benazzii and B. rossius-grandii grandii, which also produce androgenetic offspring. The egg maturation of the former is analyzed here through DAPI fluorometry, which, besides the assessment of the meiotic stages, also allows their DNA measurements and the analysis of sperm-head evolution into male pronuclei in these polyspermic eggs. Hybridogenetic eggs undergo an extrasynthesis of chromosomes, because two groups of n autobivalents (4C each) are segregated at metaphase 1st; the two groups must correspond to the pure parental species haplosets. Then the grandii chromosomes degenerate (1st polar body), while the rossius chromosomes divide further to produce two groups of n autodiads (2C each); one of them degenerates (2nd polar body), and the other is ready to perform syngamy (female pronucleus). Meanwhile, several B. grandii sperm evolve into male pronuclei by doubling their DNA (from 1C to 2C content) and assuming an interphase nucleus appearance. If regular mixis occurs, the F1 hybrid constitution is restored but, if it fails, a fusion between two sperms may occur, originating fully paternal descendants (natural androgenesis). The genome exclusion mechanism of stick-insect hybridogens appears to be more primitive than those observed in the already known hybridogenetic complexes of Poeciliopsis and Rana esculenta. Unfertilized eggs of hybridogens are capable of self-activation, but the cytology of the related clonally reproducing B. whitei indicates that its parthenogenetic mechanism stems from the hybridization event (hybrid theory) rather than from tychoparthenogenetic potentialities (spontaneous theory).

Rapid assessment of maturation stage and reproductive mode in centrolecytic eggs of stick insects (Phasmatodea) using DAPI stain

A rapid three-step DAPI technique is proposed for detecting meiotic stages and sperm head evolution in yolky, fertilized stick insect eggs, which were difficult to analyze with other methods. Fixed eggs were freed from chorionic envelopes and stained directly in DAPI/PBS solution. After rinsing, eggs were singly squashed in a drop of mounting buffer and examined under a microscope with incident fluorescent illumination. The method was almost uniformly successful, and direct observation of nuclear structures, coupled with fluorometry, allowed easy recognition of bivalents, diads, pronuclei and their DNA content. The DAPI method proposed here appears particularly helpful for investigating unusual reproductive modes in eggs with large amounts of yolk.