26 research outputs found

    Geographical variation in shell shape of the pod razor shell Ensis siliqua (Bivalvia: Pharidae)

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    The present study assessed the existence of variation in the shell shape of the pod razor shell (Ensis siliqua) throughout its distributional range in the north- eastern Atlantic. Shells of E. siliqua caught at seven collecting sites (three in Portugal, three in Spain and one in Ireland) were studied by geometric morphometric methods, using both landmark- and contour-based methods. Both approaches (landmarks inside the valves and shell outline) discriminated the shells from Aveiro (centre of Portugal) and Strangford Lough (Ireland) from those caught in the nearby localities (remaining Portuguese and Spanish sites,maximum distance of 550 km by sea). Landmark analysis revealed that shells from Aveiro were more similar to shells from Ireland (*1,500 km far away). Contour anal- ysis revealed that shells from Aveiro had a shape with a comparatively larger height-to-width ratio, whereas shells from Ireland showed a slightly more curved outline than in the remaining sites. Landmark- and contour-based methods provided coherent complementary information, confirming the usefulness of geometric morphometric analyses for discerning differences in shell shape among populations of E. siliqua. A brief review of previous applications of geometric morphometric methods to modern bivalve spe- cies is also provided.The authors would like to thank Dr. Dai Roberts and Adele Cromie for providing samples of pod razor shells from Ireland. This study was funded by Community Initiative Programmes (INTERREG-IIIB, Atlantic Area) Sustainable HARvesting of Ensis (090–SHARE) and Towards Integrated Management of Ensis Stocks (206–TIMES) from the European Community. Marta M. Rufino and Paulo Vasconcelos benefited from postdoctoral grants (SFRH/BPD/14935/2004 and SFRH/BPD/26348/2006, respectively) awarded by the Fundação para a Ciência e Tecnologia (FCT—Portugal). Finally, the authors acknowledge three anonymous referees for valuable comments and suggestions that greatly improved the revised manuscript.publishe

    Cryoglobulinemia in HCVAb+ patients on chronic hemodialysis

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    Objective: Striking evidence of HCV infection has been found in mixed cryoglobulinemia (MC) and HCV has been hypothesized to be the causative agent of this disease. To assess the association of C virus infection and cryoglobulinemia we studied cryoglobulin levels in 66 patients on maintenance hemodyalisis who were selected on the basis of HCVAb positivity and not because they were affected by liver disease. The control group was made up of 45 patients also on hemodyalisis but without HCV infection. Results: Circulating cryoglobulins were found in 34 (52%) of 66 HCV+ patients: the cryocrit was 5% in 2 patients. The cryoglobulins were classified by immunofixation as type II in 8 and type III in 8 others; identification was not possible in 18 cases. In the HCVAb- control group untypable cryoglobulins were detected in 9% of the patients at <1% by volume. No correlation was found between these data and the liver disease detected by biohumoral tests. Conclusions: Our data confirm the close link between HCV infection and cryoglobulins; the prevalence of circulating cryoglobulins in uremic HCVAb+ patients is very close to that found in HCV-related liver disease

    Early kidney-pancreas transplantation in type 1 diabetics prevents hemodialysis.

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    BACKGROUND: The life-expectancy of type 1 diabetics (T1D) on dialysis is still shorter than that of non-diabetics. Pancreas transplantation (PT) in its different modalities should be considered as a life-saving procedure. METHODS: We analyzed our referral activity of T1D to PT from 1992. Since 2002, we have created a kidney and diabetes out-patient clinic devoted to the prevention of diabetic nephropathy and to the early referral of suitable T1D to combined kidney- pancreas transplantation (KPT) and isolated pancreas (PTA). RESULTS: In the last 14 yrs, 25 T1D underwent KP in our district (620000 inhabitants). At the beginning, KPT was performed abroad, but then the borders were closed. After stopping in the mid 1990s, KP activity restarted addressing preemptive KPT and PTA. Currently, only one patient is on dialysis while awaiting KPT. Four T1D were evaluated and excluded from the list on medical grounds; two patients are on the list and a further two patients are currently under evaluation. CONCLUSIONS: The implementation of a cooperative network among dialysis and transplant centers, supported by devoted out-patient clinics allowed the effective prevention of the dialysis requirement in T1D. Out-patient clinics devoted to diabetic nephropathy should play a pro-active role in preemptive KP, including the 'new' option of islet transplantation according to the Edmonton protocol

    Pazienti HCV+ in lista d'attesa per trapianto renale. Analisi retrospettiva dei dati relativi alla popolazione dei pazienti affetti da epatite C in lista d'attesa per trapianto di rene in ambito AIRT

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    BACKGROUND: HCV infection in hemodialysis is still a matter of debate from an epidemiological and clinical point of view. Evaluation criteria for HCV-infected patients as transplant candidates are still not adequately standardized. Aims of the present study were to investigate: 1. the percentage of HCV positive patients on the waiting list of three Italian regions belonging to the Associazione InterRegionale Trapianti (AIRT); 2. to analyze the clinical approach in the evaluation of these patients in the attempt to define national guidelines for their pre- and post-transplant management. PATIENTS: We evaluated 2045 uremic patients on the waiting lists of four transplant centers (Bari, Bologna, Modena, Novara) belonging to AIRT at 31/12/2002. RESULTS: The overall prevalence of HCV positive patients was 14.2%, with a peak in the Puglia waiting list. The most common screening tests were AST and ALT serum levels and viral load (HCV RNA). Although there is a clear evidence that histological parameters are the main diagnostic and prognostic markers, a liver biopsy was performed in only 9.5% of patients. An even smaller percentage of HCV-infected patients underwent anti-viral therapy. CONCLUSIONS: Our retrospective analysis evidenced the need to improve common clinical strategies in approaching HCV-infected canditates to renal transplantation in the attempt to improve their post-transplant outcome

    Malignant neoplasia and kidney transplantation. Retrospective analysis of data on the population having kidney transplantation with de novo neoplasia in the setting of the AIRT

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    BACKGROUND: In transplanted patients undergoing immunossuppressive therapy the incidence of malignant neoplasia is 3-4 times higher than in the general population. Aim of the present study was to evaluate the prevalence of different tumours and the links between modulation of immunosuppressive therapy and patient and graft survival. PATIENTS: We evaluated 2029 kidney-transplanted patients from four Transplant Centres (Bari, Bologna, Modena, Novara) belonging to the Associazione InterRegionale Trapianti (AIRT). RESULTS: The incidence of neoplastic disease after transplantation was 3.9% in our population with a median time between transplantation and clinical onset of 23 months. We demonstrated a significant difference in the geographical distribution of different tumours. We did not observe any correlation with specific immunosuppressive drugs. Finally, dramatic reduction of the immunosuppression levels did not modify either the patients' or the graft's survival. CONCLUSIONS: Several factors can influence the post-transplant onset of neoplastic diseases with immunosuppressive therapy playing a pivotal role. The implementation of a National Registry would be the first step in an attempt to optimise immunosuppression in this particular group of patient's

    Shining new light on dark percepts: visual sensations induced by TMS

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    Phosphenes induced by transcranial magnetic stimulation (TMS) are sensations of light, whereas a missing region in the visual field induced by TMS is generally referred to as a scotoma. It is believed that phosphenes are caused by neural excitation, while scotomas are due to neural inhibition. In light of the recent literature it might, however, be surmised that both phenomena are the result of neural noise injected into the cortex by TMS and that the likelihood of perceiving the two kinds of percepts depends on the state of the cortex at the time of stimulation. In the present study, TMS was applied over the left occipital cortex under different background conditions (Experiments 1-2) and using different TMS intensities (Experiment 3). Behavioral responses indicate the visual system processes luminance in a standardized manner, as lighter percepts were reacted to faster than darker percepts; this effect, however, did not extend to percept size. Our results suggest that phenomenological characteristics of artificial visual percepts are in line with the proposed effects of TMS as the induction of random neural noise interfering with the neural dynamics (the state of the cortex) at the time of stimulation
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