How habitat factors affect an Aedes mosquitoes driven outbreak at temperate latitudes: The case of the Chikungunya virus in Italy

BACKGROUND

Outbreaks of Aedes-borne diseases in temperate areas are not frequent, and limited in number of cases. We investigate the associations between habitat factors and temperature on individuals' risk of chikungunya (CHIKV) in a non-endemic area by spatially analyzing the data from the 2017 Italian outbreak.

METHODOLOGY/PRINCIPAL FINDINGS

We adopted a case-control study design to analyze the association between land-cover variables, temperature, and human population density with CHIKV cases. The observational unit was the area, at different scales, surrounding the residence of each CHIKV notified case. The statistical analysis was conducted considering the whole dataset and separately for the resort town of Anzio and the metropolitan city of Rome, which were the two main foci of the outbreak. In Rome, a higher probability for the occurrence of CHIKV cases is associated with lower temperature (OR = 0.72; 95% CI: 0.61-0.85) and with cells with higher vegetation coverage and human population density (OR = 1.03; 95% CI: 1.00-1.05). In Anzio, CHIKV case occurrence was positively associated with human population density (OR = 1.03; 95% CI: 1.00-1.06) but not with habitat factors or temperature.

CONCLUSION/SIGNIFICANCE

Using temperature, human population density and vegetation coverage data as drives for CHIKV transmission, our estimates could be instrumental in assessing spatial heterogeneity in the risk of experiencing arboviral diseases in non-endemic temperate areas.

Aedes albopictus bionomics data collection by citizen participation on Procida Island, a promising Mediterranean site for the assessment of innovative and community-based integrated pest management methods

In the last decades, the colonization of Mediterranean Europe and of other temperate regions by Aedes albopictus created an unprecedented nuisance problem in highly infested areas and new public health threats due to the vector competence of the species. The Sterile Insect Technique (SIT) and the Incompatible Insect Technique (IIT) are insecticide-free mosquito-control methods, relying on mass release of irradiated/manipulated males, able to complement existing and only partially effective control tools. The validation of these approaches in the field requires appropriate experimental settings, possibly isolated to avoid mosquito immigration from other infested areas, and preliminary ecological and entomological data. We carried out a 4-year study in the island of Procida (Gulf of Naples, Italy) in strict collaboration with local administrators and citizens to estimate the temporal dynamics, spatial distribution, and population size of Ae. albopictus and the dispersal and survival of irradiated males. We applied ovitrap monitoring, geo-spatial analyses, mark-release-recapture technique, and a citizen-science approach. Results allow to predict the seasonal (from April to October, with peaks of 928-9,757 males/ha) and spatial distribution of the species, highlighting the capacity of Ae. albopictus population of Procida to colonize and maintain high frequencies in urban as well as in sylvatic inhabited environments. Irradiated males shown limited ability to disperse (mean daily distance travelled <60m) and daily survival estimates ranging between 0.80 and 0.95. Overall, the ecological characteristics of the island, the acquired knowledge on Ae. albopictus spatial and temporal distribution, the high human and Ae. albopictus densities and the positive attitude of the resident population in being active parts in innovative mosquito control projects provide the ground for evidence-based planning of the interventions and for the assessment of their effectiveness. In addition, the results highlight the value of creating synergies between research groups, local administrators, and citizens for affordable monitoring (and, in the future, control) of mosquito populations.

Revealing the widespread potential of forests to increase low level cloud cover

Forests play a key role in humanity's current challenge to mitigate climate change thanks to their capacity to sequester carbon. Preserving and expanding forest cover is considered essential to enhance this carbon sink. However, changing the forest cover can further affect the climate system through biophysical effects. One such effect that is seldom studied is how afforestation can alter the cloud regime, which can potentially have repercussions on the hydrological cycle, the surface radiation budget and on planetary albedo itself. Here we provide a global scale assessment of this effect derived from satellite remote sensing observations. We show that for 67% of sampled areas across the world, afforestation would increase low level cloud cover, which should have a cooling effect on the planet. We further reveal a dependency of this effect on forest type, notably in Europe where needleleaf forests generate more clouds than broadleaf forests.

A global association between Covid-19 cases and airborne particulate matter at regional level

Evidences of an association between air pollution and Covid-19 infections are mixed and inconclusive. We conducted an ecological analysis at regional scale of long-term exposure to air-borne particle matter and spread of Covid-19 cases during the first wave of epidemics. Global air pollution and climate data were calculated from satellite earth observation data assimilated into numerical models at 10 km resolution. Main outcome was defined as the cumulative number of cases of Covid-19 in the 14 days following the date when > 10 cumulative cases were reported. Negative binomial mixed effect models were applied to estimate the associations between the outcome and long-term exposure to air pollution at the regional level (PM10, PM2.5), after adjusting for relevant regional and country level covariates and spatial correlation. In total we collected 237,749 Covid-19 cases from 730 regions, 63 countries and 5 continents at May 30, 2020. A 10 μg/m3 increase of pollution level was associated with 8.1% (95% CI 5.4%, 10.5%) and 11.5% (95% CI 7.8%, 14.9%) increases in the number of cases in a 14 days window, for PM2.5 and PM10 respectively. We found an association between Covid-19 cases and air pollution suggestive of a possible causal link among particulate matter levels and incidence of COVID-19.

Global vulnerability of soil ecosystems to erosion

CONTEXT

Soil erosion is one of the main threats driving soil degradation across the globe with important impacts on crop yields, soil biota, biogeochemical cycles, and ultimately human nutrition.

OBJECTIVES

Here, using an empirical model, we present a global and temporally explicit assessment of soil erosion risk according to recent (2001-2013) dynamics of rainfall and vegetation cover change to identify vulnerable areas for soils and soil biodiversity.

METHODS

We used an adaptation of the Universal Soil Loss Equation together with state of the art remote sensing models to create a spatially and temporally explicit global model of soil erosion and soil protection. Finally, we overlaid global maps of soil biodiversity to assess the potential vulnerability of these soil communities to soil erosion.

RESULTS

We show a consistent decline in soil erosion protection over time across terrestrial biomes, which resulted in a global increase of 11.7% in soil erosion rates. Notably, soil erosion risk systematically increased between 2006 and 2013 in relation to the baseline year (2001). Although vegetation cover is central to soil protection, this increase was mostly driven by changes in rainfall erosivity. Globally, soil erosion is expected not only to have an impact on the vulnerability of soil conditions but also on soil biodiversity with 6.4% (for soil macrofauna) and 7.6% (for soil fungi) of these vulnerable areas coinciding with regions with high soil biodiversity.

CONCLUSIONS

Our results indicate that an increasing proportion of soils are degraded globally, affecting not only livelihoods but also potentially degrading local and regional landscapes. Similarly, many degraded regions coincide with and may have impacted high levels of soil biodiversity.

Everolimus vs Mycophenolate Mofetil in Combination With Tacrolimus: A Propensity Score-matched Analysis in Liver Transplantation

BACKGROUND

No trial has investigated the long-term outcome of everolimus (EVR)-incorporating immunosuppression vs tacrolimus (TAC) and mycophenolate mofetil (MMF) after liver transplantation.

MATERIALS AND METHODS

With a propensity score methodology, 178 recipients on TAC and MMF were compared to 178 patients on TAC and EVR.

RESULTS

At a median (interquartile range) follow-up of 45 (46.3) months, the probability of treated biopsy-proven acute rejection, graft loss, and death was 36.6% for MMF and 28.1% for EVR (P = .0891). Treated biopsy-proven acute rejection was numerically lower for EVR (3.3% vs 7.3%, P = .09), while adverse events (70.2% vs 58.9%, P = .02) and drug discontinuations (21.3% vs 11.8%, P = .01) were significantly higher with regard to hypercholesterolemia (P = .001), thrombocytopenia (P = .0062), and edema (P = .0107). Patients on MMF showed more hypertension (P = .0315), tremor (P = .0006), cytomegalovirus infection (P = .0165), and malignancies (P = .0175). EVR was associated with lesser deterioration in mean (SD) renal function at the latest follow-up (-2.2 (1.8) vs -5.1 (3.2) mL/min/1.73 m², t = 3.6, P = .005).

CONCLUSIONS

The efficacy of the combination of TAC and EVR is comparable to that of TAC and MMF. Drug discontinuations and adverse events were higher for patients on EVR, but these latter showed less hypertension, cytomegalovirus infection, and renal dysfunction. The observed reduction in posttransplant malignancies for EVR requires longer follow-up to be confirmed.

Transmission dynamics of the ongoing chikungunya outbreak in Central Italy: from coastal areas to the metropolitan city of Rome, summer 2017

A large chikungunya outbreak is ongoing in Italy, with a main cluster in the Anzio coastal municipality. With preliminary epidemiological data, and a transmission model using mosquito abundance and biting rates, we estimated the basic reproduction number R₀ at 2.07 (95% credible interval: 1.47-2.59) and the first case importation between 21 May and 18 June 2017. Outbreak risk was higher in coastal/rural sites than urban ones. Novel transmission foci could occur up to mid-November.

Salvage of an Octogenarian Liver Graft Using Normothermic Perfusion: A Case Report

Liver transplantation with very old donors is safe, but is associated with an increased incidence of ischemic-type biliary lesions and delayed graft function. Normothermic machine perfusion (NMP) is a novel technique for preservation of liver grafts and has the potential to reduce ischemia-reperfusion injury. A case is reported here of a liver transplantation (LT) with a graft from an 83-year-old brain-dead donor. Procurement was with dual perfusion and en bloc, modified fast technique. Donor kidneys were not transplanted due to severe atherosclerosis and poor perfusion. The liver was shipped to the transplantation center and underwent NMP with a blood-based perfusate. During machine perfusion lactates decreased, vascular flow was stable, and bile production restored, and the graft was considered suitable for transplantation. The postoperative course was uneventful and 4 months after surgery the patient is in good clinical condition with normal liver function. To date, few LTs have been performed with NMP in humans, but its preliminary results are promising. NMP allows functional evaluation of the graft and possibly reduction of post-transplantation complications when extended-criteria donor grafts are used.

Spatial and Temporal Hot Spots of Aedes albopictus Abundance inside and outside a South European Metropolitan Area

Aedes albopictus is a tropical invasive species which in the last decades spread worldwide, also colonizing temperate regions of Europe and US, where it has become a public health concern due to its ability to transmit exotic arboviruses, as well as severe nuisance problems due to its aggressive daytime outdoor biting behaviour. While several studies have been carried out in order to predict the potential limits of the species expansions based on eco-climatic parameters, few studies have so far focused on the specific effects of these variables in shaping its micro-geographic abundance and dynamics. The present study investigated eco-climatic factors affecting Ae. albopictus abundance and dynamics in metropolitan and sub-urban/rural sites in Rome (Italy), which was colonized in 1997 and is nowadays one of the most infested metropolitan areas in Southern Europe. To this aim, longitudinal adult monitoring was carried out along a 70 km-transect across and beyond the most urbanized and densely populated metropolitan area. Two fine scale spatiotemporal datasets (one with reference to a 20m circular buffer around sticky traps used to collect mosquitoes and the second to a 300m circular buffer within each sampling site) were exploited to analyze the effect of climatic and socio-environmental variables on Ae. albopictus abundance and dynamics along the transect. Results showed an association between highly anthropized habitats and high adult abundance both in metropolitan and sub-urban/rural areas, with "small green islands" corresponding to hot spots of abundance in the metropolitan areas only, and a bimodal seasonal dynamics with a second peak of abundance in autumn, due to heavy rains occurring in the preceding weeks in association with permissive temperatures. The results provide useful indications to prioritize public mosquito control measures in temperate urban areas where nuisance, human-mosquito contact and risk of local arbovirus transmission are likely higher, and highlight potential public health risks also after the summer months typically associated with high mosquito densities.

Assessment of the Effectiveness of a Seasonal-Long Insecticide-Based Control Strategy against Aedes albopictus Nuisance in an Urban Area

Seasonal-long larvicide treatments and/or outdoor space-spray applications of insecticides are frequently applied to reduce Aedes albopictus nuisance in urban areas of temperate regions, where the species has become a permanent pest affecting people’s quality of life and health. However, assessments of the effectiveness of sequential interventions is a difficult task, as it requires to take into account the cumulative and combined effect of multiple treatments, as well as the mosquito seasonal dynamics (rather than mosquito abundance before and after single treatments). We here present the results of the effectiveness assessment of a seasonal-long calendar-based control intervention integrating larvicide treatments of street catch basins and night-time adulticide ground spraying in the main University hospital in Rome (Italy). Cage-experiments and an intensive monitoring of wild mosquito abundance in treated and untreated sites were carried out along an entire season. Sticky traps were used to monitor adult abundance and site-specific eco-climatic variations (by recording water left over in each trap), in order to disentangle the effect of insecticide treatments from eco-climatic drivers on mosquito seasonal dynamics. Despite the apparent limited impact of single adulticide sprayings assessed based on mortality in caged and wild mosquitoes, the results of the temporal analysis showed that mosquito seasonal patterns were initially comparable in the two sites, diverged in the absence of diverging eco-climatic conditions and remained stable afterwards. This allowed to attribute the lack of the expected Ae. albopictus population expansion in the treated site to the combined effect of multiple adulticide sprayings and larvicide treatments carried out during the whole season. The approach proposed was proved to be successful to assess effects of seasonal-long control treatments on adult mosquito population dynamics and could represent a valuable instrument to assess the effectiveness of other control interventions, to evaluate their actual cost-benefits and to possibly minimize space-spraying applications to reduce mosquito nuisance.

Due to the considerable nuisance created by the aggressive day-time biting behaviour of the “tiger mosquito,” insecticide treatments are largely employed in urban areas of temperate regions where this tropical species has become a permanent pest. These include treatments of catch basins with lethal products for mosquito larvae and spraying of insecticides against flying adults. Despite the latter having a high environmental impact and not being recommended by health authorities to reduce the nuisance to citizens, they are perceived as the approach providing the greatest benefits. However, this is not fully demonstrated. We showed that a seasonal-long calendar-based control intervention carried out against mosquito larvae and adults in Rome (Italy) was effective in reducing the mosquito abundance in the months when highest densities and nuisance are known to occur. The novel methodological approach followed here facilitates the assessment of the actual effectiveness of control strategies against mosquitoes, which are very rarely assessed due to technical difficulties, high costs and lack of commitments, but are instrumental to optimize control strategies. Should our preliminary indications of a major effect of larvicide treatments be confirmed, the more harmful exploitation of insecticide spraying could be reduced or eliminated.

Efficacy and safety of combination therapy with everolimus and sorafenib for recurrence of hepatocellular carcinoma after liver transplantation

BACKGROUND

Recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) is still associated with a dismal outcome. Combination therapy with everolimus (EVL) and vascular endothelial growth factor inhibitor sorafenib (SORA) is based on the role of both b-Raf and mammalian target of rapamycin/protein kinase B pathways in the pathogenesis of HCC and is being investigated in clinical practice.

METHODS

This was a single-center retrospective analysis on LT recipients with unresectable HCC recurrence and undergoing combination therapy with EVL and SORA. Patients were included if they were switched to EVL+SORA at any time after surgery. Primary endpoint was overall survival (OS) after both LT and recurrence, and response to treatment based on the modified Response Evaluation Criteria in Solid Tumors (mRECIST) in the intention-to-treat (ITT) population. Secondary analysis was safety of combination therapy with EVL and SORA in the population of patients who received ≥1 dose of the study drug.

RESULTS

Seven patients (100% male; median age 53 years [interquartile range (IQR) 9 years]) were considered for analysis. HCC recurrence was diagnosed at a median (IQR) interval since LT of 9 (126) months, and patients were administered EVL+SORA at a median interval since LT of 11 (126) months. Baseline immunosuppression was with tacrolimus (TAC) in 2 patients (28.6%), cyclosporine (CsA) in 2 (28.6%), and EVL monotherapy in 3 (42.8%). At a median (IQR) follow-up of 6.5 (14) months, 5 patients (71.4%) were alive, 4 of them (57.1%) with tumor progression according to the mRECIST criteria. Median (IQR) time to progression was 3.5 (12) months. Two patients died at a median (IQR) follow-up of 5 (1) months owing to tumor progression in 1 patient (14.3%) and sepsis in the other (14.3%). EVL monotherapy was achieved in 6 patients (85.7%), whereas 1patient (14.3%) could not withdraw from calcineurin inhibitor owing to acute rejection. Treatment complications were: hand-foot syndrome in 5 patients (71.4%), hypertension in 1 (14.3%), alopecia in 1 (14.3%), hypothyroidism in 1 (14.3%), diarrhea in 2 (28.6%), pruritus in 1 (14.3%), abdominal pain in 1 (14.3%), rash in 1 (14.3%), asthenia in 3 (42.8%), anorexia in 3 (42.8%), and hoarseness in 2 (28.6%). Adverse events led to temporary SORA discontinuation in 2 patients (28.6%) and to SORA dose reduction in 3 (42.8%).

CONCLUSIONS

Treatment of HCC recurrence after LT with a combination regimen of EVL+ SORA is challenging because of SORA-related complications. Longer follow-up periods and larger series are needed to better capture the impact of such combination treatment on tumor progression and patient survival.

The impact of everolimus on renal function in maintenance liver transplantation

We retrospectively investigated the impact on renal function (RF) of conversion from calcineurin inhibitors (CNI) to everolimus (EVL) monotherapy in orthotopic liver transplant (OLT) recipients. Between January 2006 and July 2007, 70 deceased donor OLT recipients including 51 men and 19 women of overall mean age of 55.9 +/- 11 years were enrolled into a program of conversion to EVL monotherapy at a mean interval of 45 +/- 35.9 months from transplantation (range, 7-192 months). The indication for conversion was deteriorating RF in 64 (91.4%). Efficacy failure was defined as the persistence of CNI, EVL discontinuation, death, graft loss, loss to follow-up, or need for dialysis at 12 months. Twelve months after switching, 53 patients (75.7%) were on EVL monotherapy. Their mean change in creatinine clearance (CrCl) from baseline (day 1 before EVL introduction) to endpoint (12 months) was 5.8 +/- 13.1 mL/min. On univariate and multivariate analyses, the clinical variable correlated with the greatest probability of improvement was the baseline CrCl (P < .0001). Conversion from CNI to EVL monotherapy was successful in 75.7% of cases with improvement in RF correlated with baseline CrCl. These data supported preemptive minimization of CNI in the posttransplant course, seeking to delay the decline in RF.

Use of octogenarian donors for liver transplantation: a survival analysis

Use of very old donors in liver transplantation (LT) is controversial because advanced donor age is associated with a higher risk for graft dysfunction and worse long-term results, especially for hepatitis C virus (HCV)-positive recipients. This was a retrospective, single-center review of primary, ABO-compatible LT performed between 2001 and 2010. Recipients were stratified in four groups based on donor age (<60 years; 60-69 years; 70-79 years and ≥80 years) and their outcomes were compared. A total of 842 patients were included: 348 (41.3%) with donors <60 years; 176 (20.9%) with donors 60-69 years; 233 (27.7%) with donors 70-79 years and 85 (10.1%) with donors ≥80 years. There was no difference across groups in terms of early (≤30 days) graft loss, and graft survival at 1 and 5 years was 90.5% and 78.6% for grafts <60 years; 88.6% and 81.3% for grafts 60-69 years; 87.6% and 75.1% for grafts 70-79 years and 84.7% and 77.1% for grafts ≥80 years (p = 0.065). In the group ≥80 years, the 5-year graft survival was lower for HCV-positive versus HCV-negative recipients (62.4% vs. 85.6%, p = 0.034). Based on our experience, grafts from donors ≥80 years may provide favorable results but require appropriate selection and allocation policies.

Prevention by metformin of alterations induced by chronic exposure to high glucose in human islet beta cells is associated with preserved ATP/ADP ratio

AIM

We have explored whether the insulin secretory defects induced by glucotoxicity in human pancreatic islets could be prevented by metformin and investigated some of the possible mechanisms involved.

METHODS

Human pancreatic islets and INS-1E cells were cultured for 24h with or without high glucose (16.7mM) concentration in the presence or absence of therapeutical concentration of metformin and then glucose-stimulated insulin release, adenine nucleotide levels and mitochondrial complex I and II activities were measured. Islet ultrastructure was analyzed by electron microscopy.

RESULTS

Compared to control islets, human islets cultured with high glucose showed a reduced glucose-stimulated insulin secretion that was associated with lower ATP levels and a lower ATP/ADP ratio. These functional and biochemical defects were significantly prevented by the presence of metformin in the culture medium, that was also able to significantly inhibit the activity of mitochondrial complex I especially in beta cells exposed to high glucose. Ultrastructural observations showed that mitochondrial volume density was significantly increased in high glucose cultured islets. The critical involvement of mitochondria was further supported by the observation of remarkably swollen organelles with dispersed matrix and fragmented cristae. Metformin was able to efficiently prevent the appearance of all these ultrastructural alterations in human islets exposed to high glucose.

CONCLUSIONS

Our results show that the functional, biochemical and ultrastructural abnormalities observed in human islet cells exposed to glucotoxic condition can be significantly prevented by metformin, further highlighting a direct beneficial effect of this drug on the insulin secreting human pancreatic beta cells.

Analysis of patients' needs after liver transplantation in Tuscany: a prevalence study

BACKGROUND

The reorganization of the healthcare system in Tuscany aims at characterizing the hospitals as a place for the treatment of acute patients. This event, together with the improvement of long-term survival after orthotopic liver transplantation (OLT), calls for a management network able to ensure effective continuity of care for patient needs in the posttransplantation period.

MATERIALS AND METHODS

An observational study of prevalence has been carried out with the primary objective to evaluate patients' needs and criticalities both in routine daily life and in urgency in the posttransplantation period and the capacity of the regional health system to support them. A survey, using a semi-structured questionnaire consisting of 27 questions, was administered to all patients resident in Tuscany who underwent transplantation from 2000 to 2010. The survey tool assessed the following: socio-demographic data, personal, family and social difficulties, problems emerged in the clinical routine and urgency, resolution modality, relationships with the general practitioner and the referral specialist, and services the patients would appreciate receiving in their province of residence.

RESULTS

In the study, 346 patients matched the inclusion criteria of the study, 324 gave telephone consent to participate in the survey, and 225 responded (69.4%). The most frequent difficulties were as follows: depression (39.5%), difficulty in returning to work (29.3%), low income (22.6%), lack of self-sufficiency (22.6%), addictions (19.1%) (cigarette smoking 16.4%), 12.4% eating disorders, and 18.9% other difficulties (social isolation, absence of a family network, and so on). The main reasons for dissatisfaction were as follows: difficulty to obtain the required laboratory tests and lack of a reference structure at the local health facility. Few patients have a referral specialists in their area and most of them primarily refer to the Transplant Center even late after the procedure.

DISCUSSION

Early diagnosis of specific conditions (depression, addiction, and eating disorders) should be implemented in the follow-up period and services such as counselling, dietary support, rehabilitation, and social services should be provided locally. An integrated management system between the transplantation center and the local facilities (hospitals, general practitioners, primary care, and laboratories) should be implemented and referral specialized centers should be identified locally.

Organ sharing in the management of acute liver failure

BACKGROUND

Liver transplantation (OLT) for acute liver failure (ALF) is associated with high morbidity and mortality rates in the early posttransplant course. An efficient organ-sharing organization may grant favorable results.

METHODS

This is a retrospective analysis of prospectively collected data on patients wait listed for ALF at a single center. Patients were listed for OLT when matching King's College Criteria. Based on patients' clinical status, ABO-incompatible grafts were used.

RESULTS

From January 2001 to December 2010, 37 patients were wait listed for ALF. Two patients were de-listed (5.4%) for improvement of their clinical conditions; two patients (5.4%) died on the list and 33 (89.2%) underwent OLT. Among these latter, 21 (63.6%) were Italian and 12 (36.4%) were foreign citizens, with four referred from their home country on the basis of international agreements on ALF management. Donors were procured in our region in 10 cases (30.3%), nationally in 22 (66.6%), and outside Italy in 1 (3.1%). Mean time from wait listing to OLT was 1 day (range 0-6), and seven patients received an ABO-incompatible graft. Graft and patient survivals at 1 month, 1 year, and 3 years were 78.8%, 72.7%, 66.5%, and 81.8%, 75.8%, and 72.7%, respectively. Five patients underwent retransplantation: two on postoperative day (POD) 2 for primary nonfunction of the liver graft, two on POD 8 and 95 for hepatic artery thrombosis, and one at 18 months for nonanastomotic biliary stenosis.

CONCLUSIONS

Prompt referral to a OLT center and efficient organ-sharing system play a fundamental role in optimizing the outcome of the patient with ALF. Development of international organ exchange programs might further improve the results for this category of patients. In very selected cases, ABO-incompatible grafts may be a valuable resource.

β-Cell inflammation in human type 2 diabetes and the role of autophagy

β-Cell failure is crucial for the onset and progression of human type 2 diabetes, and a few studies have suggested that inflammation may play a role. Immune cell infiltration has been reported in subpopulations of islets in some cases of human type 2 diabetes, and altered gene expression of a few cytokines and chemokines has been observed in isolated islets and laser captured β-cells from diabetic subjects. Recent observations on the links between inflammation, apoptosis and autophagy are putting the focus on the possibility that modulating the autophagic processes could protect the β-cells from cytotoxicity induced by inflammatory mediators.

In vitro effects of mycophenolic acid on survival, function, and gene expression of pancreatic beta-cells

Post-transplant diabetes mellitus represents an important complication of prolonged immunosuppressive treatment after solid organ transplantation. The immunosuppressive toxicity, responsible for a persistent impairment of glucose metabolism in pancreatic islet-transplanted patients, is mainly attributed to calcineurin inhibitors and steroids, while other immunosuppressive molecules (azathioprine and mycophenolic acid, MPA) are considered not to have a toxic effect. In the present study, in vitro effects of MPA have been investigated in mouse beta-cell lines (βTC-1 and βTC-6) and in purified human pancreatic islets. βTC-1, βTC-6, and human pancreatic islets were exposed to various concentrations of MPA for different times. Consequently, we evaluated the viability, the induction of apoptosis, the glucose-stimulated insulin secretion, and the expression of β-cell function genes (Isl1, Pax6, Glut-2, glucokinase) and apoptosis-related genes (Bax and Bcl2). βTC-1, βTC-6, and human islets treated, respectively, for 48 and 72 h with 15-30 nM MPA showed altered islet architecture, as compared with control cells. We observed for βTC-1 and βTC-6 almost 70% reduction in cell viability; three to sixfold induction of TUNEL/apoptotic-positive cells quantified by FACS analysis. A twofold increase in apoptotic cells was observed in human islets after MPA exposure associated with strong inhibition of glucose-stimulated insulin secretion. Furthermore, we showed significant down-regulation of gene expression of molecules involved in β-cell function and increase rate between Bax/Bcl2. Our data demonstrate that MPA has an in vitro diabetogenic effect interfering at multiple levels with survival and function of murine and human pancreatic β-cells.

A local glucagon-like peptide 1 (GLP-1) system in human pancreatic islets

AIMS/HYPOTHESIS

Glucagon-like peptide 1 (GLP-1) is a major incretin, mainly produced by the intestinal L cells, with beneficial actions on pancreatic beta cells. However, while in vivo only very small amounts of GLP-1 reach the pancreas in bioactive form, some observations indicate that GLP-1 may also be produced in the islets. We performed comprehensive morphological, functional and molecular studies to evaluate the presence and various features of a local GLP-1 system in human pancreatic islet cells, including those from type 2 diabetic patients.

METHODS

The presence of insulin, glucagon, GLP-1, proconvertase (PC) 1/3 and PC2 was determined in human pancreas by immunohistochemistry with confocal microscopy. Islets were isolated from non-diabetic and type 2 diabetic donors. GLP-1 protein abundance was evaluated by immunoblotting and matrix-assisted laser desorption-ionisation-time of flight (MALDI-TOF) mass spectrometry. Single alpha and beta cell suspensions were obtained by enzymatic dissociation and FACS sorting. Glucagon and GLP-1 release were measured in response to nutrients.

RESULTS

Confocal microscopy showed the presence of GLP-1-like and PC1/3 immunoreactivity in subsets of alpha cells, whereas GLP-1 was not observed in beta cells. The presence of GLP-1 in isolated islets was confirmed by immunoblotting, followed by mass spectrometry. Isolated islets and alpha (but not beta) cell fractions released GLP-1, which was regulated by glucose and arginine. PC1/3 (also known as PCSK1) gene expression was shown in alpha cells. GLP-1 release was significantly higher from type 2 diabetic than from non-diabetic isolated islets.

CONCLUSIONS/INTERPRETATION

We have shown the presence of a functionally competent GLP-1 system in human pancreatic islets, which resides in alpha cells and might be modulated by type 2 diabetes.

Evidence for a role of frataxin in pancreatic islets isolated from multi-organ donors with and without type 2 diabetes mellitus

Frataxin (FXN) is a mitochondrial protein involved in iron metabolism and in the modulation of reactive oxygen and/or nitrogen species production. No information is currently available as for the role of frataxin in isolated human pancreatic islets. We studied islets from pancreases of multi-organ donors with (T2DM) and without (Ctrl) Type 2 diabetes mellitus. In these islets, we determined FXN gene and protein expression by qualitative and quantitative Real-Time RT-PCR, nitrotyrosine concentration, and insulin release in response to glucose stimulation (SI). FXN gene and protein were expressed in human islets, though the level of expression was much lower in T2DM islets. The latter also had lower insulin release and higher concentration of nitrotyrosine. A positive correlation was apparent between SI and FXN gene expression, while a negative correlation was found between nitrotyrosine islet concentration and FXN expression. Transfection of Ctrl islets with siRNA FXN caused reduction of FXN expression, increase of nitrotyrosine concentration, and reduction of insulin release. In conclusion, in human pancreatic islets FXN contributes to regulation of oxidative stress and insulin release in response to glucose. In islets from T2DM patients FXN expression is reduced while oxidative stress is increased and insulin release in response to glucose impaired.

Alcohol drinking after liver transplantation is associated with graft injury

AIM

This was a single-center, mixed-design, cross-sectional and retrospective study to assess the performance of the 4-item, self-reported CAGE (Cut down, Annoyed, Guilty, Eye-opener) questionnaire in predicting histology-proven alcohol-related liver graft injury (ARLGI).

METHODS

A total of 316 liver transplant (LT) patients between six months and five years were enrolled. Based on previous research, problem alcohol drinking (PAD) was defined as any score ≥ 1 on the CAGE, while a cut-off of 2 was assumed for alcohol dependence (AD).

RESULTS

Responders were 195, 45 (23.1%) had a CAGE score ≥ 1 and 30 (15.3%) scored ≥ 2. After controlling for confounders, PAD was associated with hyperlipidemia (P=0.01), while AD with a male gender (P=0.01), hyperlipidemia (P=0.03) and alcohol as native diagnosis (P=0.03). PAD and AD were both associated with a significantly higher prevalence of ARLGI, i.e. 53.3% and 63.3%, respectively (P<0.0001). Hepatitis C virus (HCV) patients with PAD showed more steatosis (P=0.04), portal infiltrate (P=0.03), and pericellular/perivenular fibrosis (P=0.02). The likelihood ratios for CAGE scores ranging from 0 to 4 in predicting ARLGI were 0, 5.2, 7.8, 7.8, and 100, respectively.

CONCLUSION

By use of a self-report instrument we found a 23.1% prevalence of PAD and a 15.3% prevalence of AD among LT patients between six months and five years. A variable degree of ARLGI was present in 53.3% of PAD and 63.3% of AD, respectively. HCV patients with PAD had more steatosis, portal inflammation, and pericellular fibrosis. Transplant physicians might improve their ability to predict the probability for ARLGI using the CAGE.

Patient satisfaction among liver transplant recipients: single-center survey

A single-center survey using a semistructured questionnaire was conducted in liver transplantation recipients at discharge after the primary surgery. The objectives of the study were to assess patient satisfaction and to identify critical points that negatively affected their perception of the quality of care received, and to derive information to enable improvement in current standards of care. The questionnaire included 5 sections about quality and 1 section for suggestions. Patients were asked to provide answers on a 5-item Likert scale. Areas assessed included quality of staff, organization, boarding, privacy, and transfer of care. Among 51 recipients, satisfaction was high (>50%) in all areas. Lower satisfaction scores were given for room services, diet, and background music. The most frequently reported area of dissatisfaction (12%) was lack of availability of in-hospital physical rehabilitation programs. Despite overall satisfaction with quality of care, recipients reported lack of appropriate physical rehabilitation programs in the early posttransplantation period.

Unintended transplantation of three organs from an HIV-positive donor: report of the analysis of an adverse event in a regional health care service in Italy

In February 2007, three organs from an human immunodeficiency virus (HIV)-positive donor were transplanted at two hospitals in the Tuscany Regional Health Care Service, owing to a chain of errors during the donation process. The heart-beating donor was a 41-year-old woman who died as a result of head trauma. The patient's history did not highlight any risky behavior. The available data on previous hospital admissions reported a negative result on HIV testing. During the donation process, the result of the lab test performed for evaluation of organ suitability was mistakenly transcribed from positive to negative. This wrong negative result was then included in the donation record without any cross-check. Therefore, the Regional Transplant Center allocated the liver and both kidneys. The patient also donated tissues, and a second laboratory conducted an evaluation of suitability for the tissue banks. During this process, only 5 days after the successful transplantation procedures, the positive HIV result was fed back to the Regional Transplant Center and the previous error discovered. Transplanted patients were immediately assessed and then treated with antiretroviral medications. A national commission soon performed a systems analysis of the adverse event. Besides the active error committed during the manual transcription for the HIV lab test result, the commission also identified technological factors, such as the lack of integration between the lab machine, the laboratory information system (LIS), and the donor record, as well as organizational factors, such as the distribution to two different labs of the suitability evaluation for organs and tissues. Recommendations included: automatic transmission of lab test results from the lab machine to the LIS and to the donor record, centralization of lab tests for suitability evaluation of organs and tissues, a training program to develop a proactive quality and safety culture in the regional network of donation and transplantations.

A common polymorphism in the monocyte chemoattractant protein-1 (MCP-1) gene regulatory region influences MCP-1 expression and function of isolated human pancreatic islets

BACKGROUND AND AIMS

Islet transplantation is an attractive approach to treat type 1 diabetic patients. However, suboptimal islet engraftment still represents an unsolved problem. It has been shown that human islets release monocyte chemoattractant protein-1 (MCP-1), one of the most powerful macrophage chemokines, which may impair the fate of the transplant. The aim of this study was to evaluate the presence and role of MCP-1 in isolated human islets, including genotyping for a common polymorphism.

METHODS

Pancreatic islets were isolated by enzymatic digestion and gradient purification from 41 nondiabetic multiorgan donors. We measured MCP-1 mRNA expression by quantitative real- time reverse-transcriptase polymerization chain reaction, analyzed the MCP-1 single nucleotide polymorphism, -2518 G/A (SNP, rs 1024611) and evaluated glucose-stimulated insulin release (IR; microU/islet/min).

RESULTS

MCP-1 mRNA expression was found in all studied batches of islets. Overall, IR was significantly higher at 16.7 mmol/L than 3.3 mmol/L glucose. We observed a significant negative correlation between MCP-1 mRNA expression and stimulation index (SI). We found that MCP-1 mRNA expression was significantly higher in CC and CT compared with TT genotype groups. Finally, SI was significant lower in the CC with respect to the TT genotype group.

CONCLUSIONS

These data show that MCP-1 gene expression regulated by the -2518 G/A polymorphism, is correlated with glucose-stimulated insulin release. The study of MCP-1 expression and genotype on isolated islets before transplantation may be useful to understand the inflammatory response after infusion of human islets into patients with type 1 diabetes mellitus.

Efficiency of the tissue procurement process: what evaluation tools?

Evaluation of the efficiency of tissue procurement (TP) requires appropriate indicators. We report the results of a survey on all in-hospital deaths in Tuscany performed to identify potential indicators of efficiency with regard to donor identification and evaluation. In January 2004, we established a regional, compulsory, prospective program to monitor all in-hospital deaths in Tuscany. Currently, in Tuscany TP is performed if donors are < or =75 years without evidence of infectious or malignant diseases. Between January 2004 and December 2008, we analyzed data on 75,921 in-hospital deaths, including 50,001 (66.9%) in subjects older than 75 years, while 25,920 (33.1%) were < or =75 years and thus considered for TP. Among the latter cohort, 11,657 (15.3%) presented with clinical contraindication(s), while 14,263 (18.8%) were fit for tissue donation. Of the latter population, tissue donation occurred in 3083 cases (ie, 4% of in-hospital deaths or 11.8% of potential tissue donors). Contraindications to tissue donation were identified in 9861 cases (12.9%) based on clinical files, and in 1796 (2.4%) after interview with the family. There was a great variability by regional hospital in the percent of contraindications identified after the family interview, from a low of 4% to a high of 45%. Based on our experience, implementation of efficiency parameters and improvement of the efficiency of the entire TP process requires compulsory reporting of in-hospital deaths by local transplant coordinators.

G-protein-coupled receptor 40 (GPR40) expression and its regulation in human pancreatic islets: the role of type 2 diabetes and fatty acids

BACKGROUND AND AIMS

GPR40 is a membrane-bound receptor paired with medium and long-chain fatty acids (FFA) as endogenous ligands. Its acute activation potentiates insulin secretion from beta cells, whereas prolonged binding might contribute to the deleterious effects of chronic exposure to FFA. Little information is available on the expression of GPR40 and its regulation in human islets (HI).

MATERIAL AND METHODS

HI were prepared by enzymatic digestion and gradient separation from the pancreas of 20 non-diabetic (Ctrl) and 13 type 2 diabetic (T2DM) multiorgan donors, and functional and molecular studies were then performed.

RESULTS

By qualitative and quantitative PCR experiments, mRNA expression was shown in HI. Both in T2DM islets and in Ctrl islets pre-exposed for 24 h to 1.0 mmol/l FFA (palmitate:oleate, 2:1), GPR40 mRNA expression was significantly reduced (p<0.01) in the T2DM cells as compared to Ctrl cells. A significant positive correlation was found between glucose-stimulated insulin secretion and GPR40 expression.

CONCLUSIONS

These results show the expression of GPR40 in human pancreatic islets which are regulated by FFA. The finding that T2DM islets have a lower GPR40 expression, and the correlation of these genes with insulin secretion, raises the possibility of an involvement of GPR40 in human diabetes beta-cell dysfunction.

Autophagy in human type 2 diabetes pancreatic beta cells

AIMS/HYPOTHESIS

Beta cell loss contributes to type 2 diabetes, with increased apoptosis representing an underlying mechanism. Autophagy, i.e. the physiological degradation of damaged organelles and proteins, may, if altered, be associated with a distinct form of cell death. We studied several features of autophagy in beta cells from type 2 diabetic patients and assessed the role of metabolic perturbation and pharmacological intervention.

METHODS

Pancreatic samples were obtained from organ donors and isolated islets prepared both by collagenase digestion and density gradient centrifugation. Beta cell morphology and morphometry were studied by electron microscopy. Gene expression studies were performed by quantitative RT-PCR.

RESULTS

Using electron microscopy, we observed more dead beta cells in diabetic (2.24 +/- 0.53%) than control (0.66 +/- 0.52%) samples (p < 0.01). Massive vacuole overload (suggesting altered autophagy) was associated with 1.18 +/- 0.54% dead beta cells in type 2 diabetic samples and with 0.36 +/- 0.26% in control samples (p < 0.05). Density volume of autophagic vacuoles and autophagosomes was significantly higher in diabetic beta cells. Unchanged gene expression of beclin-1 and ATG1 (also known as ULK1), and reduced transcription of LAMP2 and cathepsin B and D was observed in type 2 diabetic islets. Exposure of non-diabetic islets to increased NEFA concentration led to a marked increase of vacuole accumulation, together with enhanced beta cell death, which was associated with decreased LAMP2 expression. Metformin ameliorated autophagy alterations in diabetic beta cells and beta cells exposed to NEFA, a process associated with normalisation of LAMP2 expression.

CONCLUSIONS/INTERPRETATION

Beta cells in human type 2 diabetes have signs of altered autophagy, which may contribute to loss of beta cell mass. To preserve beta cell mass in diabetic patients, it may be necessary to target multiple cell-death pathways.

Interregional allocation models for liver transplantation

In light of the persistent donor scarcity, it has been advocated to shift the current region-based allocation model for liver transplantation (OLT) to an interregional one, so as to allow sicker patients on the wait list to obtain timely transplantations. Being convinced that tackling the challenge of organ donor scarcity requires appropriate measures, we have suggested some initiatives to be taken at different levels. First, definition of the real need for OLT, since it is largely unknown to transplant physicians and still represents the starting line for any initiative in the field. Second, we recommend creation of liver transplant care processes organized around the concept of smooth, seamless, and prompt referral of liver disease patients. Third, we suggest continued efforts in the field of deceased donation, so as to reduce the chasm between organ donation and demand and limit the persistent variability among regions. Fourth, we favor patient mobility, so as to expand the opportunity for transplantation for sicker patients. Finally, we seek to improve the efficiency of interregional coordination by prompt referral of extended criteria donors, sicker patients, or patients with rare diseases, so as to expand the opportunity for better donor-to-recipient matching at a national level.

A phase II (PhII) trial of sorafenib (S) in combination with 5-fluorouracil (5FU) continuous infusion (c.i.) in patients (pts) with advanced hepatocellular carcinoma (HCC): Preliminary data

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Background: S, an oral multi-kinase inhibitor that targets Raf-kinase and receptor tyrosine kinases, improved overall survival (OS) and time to progression (TTP) versus placebo in a randomized phase III study in HCC (SHARP study). The safety of S in association with infusional and bolus 5FU regimens was established in a previous PhI study, with no clinically relevant pharmacokinetic interaction between S and 5FU. The present trial was designed to evaluate the safety and efficacy of S with infusional 5FU in HCC pts. Methods: Patients with advanced HCC (not eligible to surgical or locoregional therapies), age≥18 years, Child-Pugh Class A or B, ECOG PS 0–1, without prior systemic treatment for HCC and adequate bone marrow, liver and renal function, were eligible for the study. The primary endpoint is the Disease Control Rate (DCR). Secondary endpoints included response rate, TTP, OS and safety. According to a two-step Simon's model 46 pts were to be accrued. Pts were treated with oral S 400 mg bid continuously and c.i. 5FU 200 mg/sqm/day day 1–14 every 3 weeks. Tumour response was assessed according to RECIST criteria every 9 weeks. Results: Between October 2006 and October 2008 38 pts were enrolled: M-F: 32–6, median age (range): 68(47–83) years, ECOG-PS 0–1: 28–10, Child-Pugh A-B: 35–3, extrahepatic spread: 14 pts, macroscopic vascular invasion: 6 pts. Grade 3/4 (%) toxicities (NCI CTC v 3.0 criteria) included diarrhoea 5/0, stomatitis 21/3, hand foot syndrome 21/0, skin rash 11/0, hypertension 11/0; hyperbilirubinemia 5/3, AST 11/0, ALT 8/0, cardiac toxicity (one cardiac failure, one atrial fibrillation) 5/0 and bleeding (melena) in 3/0. One partial response was observed. Stable disease was obtained in 45% of pts with a median duration of 9.6 months (range 5–18+). Median TTP was 7.6 months (CI 95%=5.3–9.9) and median OS 12.2 months (CI 95%=4.45–19.8). Conclusions: Preliminary results of this PhII study show encouraging disease control rate, TTP and OS in pts with advanced HCC. The S+5FU association is feasible, well tolerated and AEs were predictable and manageable.

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