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An improved unidimensional model of the heat transport and gas diffusion within a porous cometary nucleus is presented, in which the time-dependent gas diffusion equation is coupled with the heat diffusion equation to describe the energy transport due to sublimation and recondensation of volatiles, but is solved independently using a different discrete time step. Also, the erosion of interfaces within the nucleus, due to the sublimation of ices and the removal of dust, is now treated by means of a continuous adaptation of the discrete grid to the interfaces positions, removing numerical stability problems associated with the variation of structure and composition of the discrete layers. The results of this model are then compared with those of another unidimensional model which does not make use of the above-mentioned numerical methods, both computed for the same set of physical parameters describing comet P/Wirtanen, and the effects of the different modelling assumptions on the results are discussed. A new bidimensional model of the heat transport within a porous comet nucleus is presented, and its results are compared with those obtained from the above-mentioned unidimensional model (modified to include the same physics of the bidimensional model). The ability of bidimensional models to better describe the effects of variations in the local physical conditions on the comet activity is then discussed.

What is the ultimate fate of a comet? Excluding impacts with other bodies, two possibilities are foreseen: either long-lasting activity, accompanied by nucleus reduction, or the formation of a stable crust that inhibits dust emission and strongly reduces volatile emissions. In the first case the comet could disintegrate, whereas in the second case it could become dormant or extinct, assuming an asteroidal appearance; in both cases the comet could be reactivated. In this paper we present results of a comet evolution model trying to establish the conditions under which the nucleus becomes dormant or extinct and under which it continues its activity up to the consumption of the icy material. Our nucleus model is composed of a mixture of ices of water, CO 2 , and CO and dust particles. The H 2 O ice can be either amorphous or crystalline; the solid matrix is assumed to be porous. The evolution of the body is determined by the solar energy reaching its surface and by the heat transfer in the interior. The propagation of the heat through the nucleus is modeled by means of the heat transfer and gas diffusion equations, coupled via the condensation–sublimation terms that are seen as sinks or sources of energy and matter, respectively. Particular attention is given to the variations of porosity and to the changes in composition of the superficial layers due to sublimation–condensation phenomena, to gas diffusion processes through the pore system, and to the ejection of dust particles. At the beginning of the evolution of the nucleus the crust is never present and the interior of the comet is not differentiated. We have seen that the evolution can proceed essentially in two ways: (1) if the body is dark and rich in volatiles and the dust grains are fluffy, then the upper layers are usually removed at the same rate at which the CO 2 upper boundary sinks; (2) in the opposite case, sometimes a dusty crust is formed, sometimes not, but in any case the CO 2 interface sinks deeply. We conclude that in the first case the body will remain active for several orbits, while in the second case the gradual reduction of any activity can produce a dormant or extinct comet, maybe with the appearance of an asteroid.

Comet P/Wirtanen is the currently selected target for the international ROSETTA mission, the cornerstone ESA mission to a cometary nucleus that will be launched in 2003. Presently, little is known about this comet, but the successful design of the ROSETTA mission, and in particular of the on-board scientific instruments, requires some preliminary knowledge of the comet's physical parameters, such as surface temperature, percentage of active surface, intensity of gas and dust fluxes, and so on. These quantities cannot be determined through ground-based observations, so predictive models of the thermal evolution and differentiation of a cometary nucleus are needed. A thermal evolution model is applied to a comet on the orbit of P/Wirtanen with the aim of obtaining some of the needed information. The numerical code solves the heat conduction and the gas diffusion equations throughout a spherical, porous comet nucleus made of amorphous H2O ice (the dominant constituent), CO2 ice, CO ice and dust particles of different sizes. The equations are coupled via the source terms, which describe the sublimation and recondensation of ices as latent heat or mass exchanges. Amorphous H2O ice can undergo an exothermal, irreversible phase transition to crystalline form. The ejection of dust is allowed only if the grains have been liberated from ice, when the drag exerted on them by the outflowing gas is stronger than the gravitational pull of the nucleus. The behaviour is simulated of a “P/Wirtanen”-like object, that starting from the Kuiper belt is injected, through multiple close encounters, in the present orbit of P/Wirtanen. This has been done with the aim of predicting the present characteristics of surface condition and emission of this poorly known comet. From the results of the simulations it can be seen that surface activity starts at 2.1 AU with gas emission and then reaches its maximum at the perihelion, where it is accompanied by a strong dust emission; the range of the computed comet surface temperatures is, at the equator and at the perihelion, between 130 and 200 K. Differences between day and night temperatures on the surface of the nucleus can reach 50 K at perihelion, with a consequent variation in the H2O and dust emission rate, but the flux of more volatile ice, like CO2 and CO, is not affected. Such ices can be found at depths varying from a few metres for CO2 to hundreds of metres for CO.

Analysis of long-term dialysis results is the cornerstone of renal replacement therapy evaluation. Elderly patients may be considered a crucial cohort, since subtle differences may be enhanced in a population of lower life expectancy. The aim of the study was an analysis, from the Piedmont Registry of Dialysis and Transplantation, of the results obtained in 1981-1992 (northern Italy, about 4,400,000 inhabitants, 21 dialysis centres, open acceptance since mid-1970s) in patients aged > or = 65 years (475 patients started treatment in 1981-1985, 1026 in 1986-1992). As a first treatment, during the 12 years considered acetate haemodialysis decreased sharply; bicarbonate haemodialysis is currently the standard treatment (68%). Peritoneal dialysis is stable (21%), and haemodiafiltration is increasing (8%). Shifts between treatments are frequent: 15% of elderly patients changed treatment at least once in 1991-1992. Nephroangiosclerosis/ischaemic renal disease, undefined causes and diabetes mellitus are the major causes of end-stage renal disease; 57.3% of patients have high risk conditions in addition to age. In this cohort of patients, mean age of new cases starting dialysis significantly increased in 1986-1992 (72.7 +/- 5.4 years) versus 1981-1985 (71.3 +/- 4.5; P < 0.001). Despite this, survival at 2 years increased significantly from 54.6% in the period 1981-1985 to 59% in the period 1986-1992 (P < 0.05). Even in an ageing dialysis population, therefore, choice of an open dialysis system with easy changes among treatments allowed improvement of survival results; further technical advances may help in maintaining present trends.

In the present multicenter study, 120 pts who had been treated by both hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) for at least 6 months each, were invited to answer questions on 34 matters, to compare symptoms and their well-being while on the two treatments. Patients were invited to choose HD or CAPD and indicate the reasons for their choice. For 28 patients the first treatment was HD and for 92 CAPD. The mean time between the change of therapy and the study was 46±35 months. Their final choices were found to be strictly related to the present treatment (p

A bidimensional explicit finite-difference simulation of a river delta growth, based on Pelnard-Considere continuity equation, considering long-shore sediment transport as given by CERC formula, has been developed and fed by sets of marine events generated by means of a general Markovian-process simulator. The simulation was restricted to the final stage of the sea-beach interaction, remaining it limited, seaward, to the consideration of pairs of values representing wave power and direction of wave motion. This kind of formulation allowed a computationally efficient way to represent persistent phenomena. River sand supply has been modelled by means of a simply stationary stochastic process. The operativeness of the model has been evaluated on some fixed conditions:a) beach length 20 km;b) non-erodible edges;c) river supply in the middle. In general, wave power ranged up to some unit·103 W/m, while sand river supply up to near 7·10−2 m3/s. Some models were left to evolve for 500 y, a time interval in which some significant event should occur. The results show how: 1) for long-time estimations a spatial resolution of 500 m could be a reasonable choice; 2) time step should be kept as small as possible, even in the absence of numerical instability; 3) wave-approaching angles simulation scheme impacts on final delta morphology; 4) sea status persistence strongly influences the final results; 5) even a simple (t/const) time adimensionalization may influence the results when high river sand supply meets low wave power conditions; 6) neglecting on/off-shore sediment transport reflects in a marked triangular equilibrium delta shapes; 7) the cuspate aspect of a river delta could be an indication of a non-erosion-dominated stage or of a growing one. Although for predictive engineering purpose 2D longshore formulations appear to be less attractive than 3D ones, it has been pointed out how some hypotheses can be tested, in an earth science operating context, using either moderate-complexity software or easily avilable computing devices.

The evolution of the subsurface layers of a short-period comet has been studied. The structure and composition of the surface layers due to sublimation recondensation phenomena, to gas diffusion processes through the pore system and to the ejection of dust particles have been investigated in detail. The nucleus has been modelled as a mixture of water ice, CO2 ice and dust in specified proportions. The icy matrix is assumed to be porous and crystalline. The model is based on the solution of two symmetric diffusion equations through the whole nucleus, one describing the transport of matter and the other the transport of heat. These equations are linked by a source term which accounts for production or loss of gas. We assume that the water vapour present in the pore system acts as a perfect gas, and that sublimation and recondensation are instantaneous in order to maintain the local thermodynamic equilibrium between the solid phase and its vapour. Under these assumptions, the source term depends on the variation of the pressure due to vapour diffusion, and on the variation of the saturation pressure of the vapour due to the evolution of the temperature. The diffusion regime, Knudsen or viscous, depends on the mean free path of the molecules of gas through the pore network, considered as a system of cylindrical pipes. The dust particles may be removed from the surface of the nucleus depending on the force balance. The calculations are performed for a nucleus on the orbit of P/Du Toit-Hartley, that was one of the possible targets for the Rosetta mission. Different nucleus compositions with various CO2/H2O ice and dust/ice ratios are investigated. Results are presented on the evolution of the stratigraphy of the nucleus and on the production rates of CO2. H2O and dust particles as a function of the heliocentric distance. Several phenomena are observed, such as the depletion of CO2 ice in the subsurface layers and the possible formation of a dust layer at the nucleus surface.

Conclusion. This short course of therapy with prednis- one and cyclophosphamide has been effective in a Background. IgA nephropathy is associated with a wide spectrum of possible lesions. Therefore, different subset of IgA nephropathy patients with florid glomer- ular changes and major urinary abnormalities, turning responses to anti-inflammatory or immunosuppressive therapies should be expected with acute inflammatory off phlogistic activity and preventing subsequent progression toward renal failure. changes, which are predominantly reversible, and with prevalently sclerotic lesions. Methods. The effects of a combined schedule of pred- nephropathy; renal disease progression nisone and cyclophosphamide was analysed in the specific subset of IgA nephropathy patients with acute inflammatory histologic changes associated with haem- aturia and proteinuria. Two groups of patients, with Introduction similar histologic lesions and clinical presentation, were considered. The first group (12 patients) was treated Due to its wide variability in clinical presentation and within 1 week after renal biopsy; starting with three histologic changes, IgA nephropathy has been defined pulses of methylprednisolone (1 g) followed by oral as a 'microcosmos of glomerular lesions' (1). Some prednisone (0.8 mg/kg body weight for 2 weeks, histologic lesions are irreversible and progress towards 0.6 mg/kg for another 2 weeks, 0.4 mg/kg for an obliteration of glomerular capillaries; others are additional 4 weeks, then slowly tapered by 5 mg each acute inflammatory processes, potentially susceptible month until discontinuation) and 1.5 mg/kg cyclophos- to reversal by means of antiphlogistic and immuno- phamide for 2 months. A second sample of eight suppressive therapies (1,2). Therefore, it is difficult to untreated patients served as a control group. Treated identify truly homogeneous subsets of patients for and untreated patients had diffuse mesangial prolifera- treatment trials (especially if the entry criteria are tion with florid crescents (8-60% in treated and based on a single variable such as urinary protein 10-40% in untreated patients) with mild degree of excretion). This possibly explains the conflicting results glomerular sclerosis and interstitial changes. Basal of reports on corticosteroids and cytotoxic drugs in creatinine (167 mmol/l, range 79-371 vs132 mmol/l, these patients (3). range 79-256) and proteinuria (3.0 g/24 h, 1.0-4.9 vs In order to assess the long-term effects of a combina- 3.3 g/24 h, 1.0-13.7) were not statistically different tion of prednisone and cyclophosphamide on renal between treated and untreated patients respectively. function in a subset of IgA nephropathy patients with Nine treated and six untreated patients were hypertens- acute phlogistic histologic changes associated with ive. Blood pressure treatment did not include ACE- haematuria and proteinuria, two samples of patients inhibitors. with similar histologic lesions and clinical presentation

Background. This study evaluates the association between estimated GFR (eGFR) at the start of dialysis and mortality within Europe. Methods. Renal registries participating in the ERA-EDTA Registry were asked to provide data on serum creatinine recorded 0-4 weeks before the start of dialysis in incident dialysis patients in 1999 and 2003. Within this cohort study, data were available in 11 472 patients from nine national or regional European renal registries. Cox regression analyses were performed to examine the association between GFR estimated by the four-variable MDRD equation (eGFR) and all-cause mortality, using a follow-up through 31 December 2005. Results. In the 2003 data, the mean eGFR was 8.6 ml/min/1.73 m(2). The unadjusted survival analyses showed that an increase in eGFR of 1 ml/min/1.73 m(2) was associated with a higher mortality risk (HR = 1.03; 95% CI: 1.03-1.04) that remained similar after adjustment for age, gender, primary renal disease, treatment modality, country and comorbidity. The findings were consistent across gender, treatment modalities, geographical regions and time periods (2003 versus 1999), but the association between a higher eGFR at the start of dialysis and mortality was the strongest in the youngest age groups and in patients with glomerulonephritis. Analyses at centre level showed that a 10% increase in the percentage of patients starting dialysis at high eGFR levels (>= 10.5 ml/min) was associated with a 22% higher mortality risk (HR = 1.22; 95% CI: 1.18-1.26). Conclusions. This European study showed that a higher eGFR at the start of dialysis was associated with a higher mortality risk. However, an answer to the question when to start dialysis needs to come from randomized controlled trials

Maladjustment at work results from organizational and relational features of the work, the so-called fourth type factors; they include working hours, ways and contents of working activities, and horizontal and vertical business relations. The study reports the percentage of sensed disturbing factors in workers with maladjustment and disaffection at work. Data have been taken from 1382 white collars, 1117 males and 265 females, observed from January 2006 to June 2007 for Health Surveillance. Maladjustment prevalence was higher in females than in males. As individual variables, ageing and family care increased the prevalence of maladjustment among females, whilst a higher prevalence of maladjustment were found in youngest and unmarried males. A very different perception of work harmfulness were found between sexes. As risk factors, female have denounced more wear and tear and authoritarian management; male denounced physical strain.

Tumor necrosis factor (TNF-alpha) and interleukin-1 (IL-1 beta) are cytokines primarily produced by monocytes/macrophages when stimulated by endotoxin, complement-derived anaphylatoxins and the specific antigen. In the present study, the plasma levels of TNF-alpha and IL-1 beta were evaluated before and after hemodialysis with cuprophane membrane (in 9 patients) and hemodiafiltration (in 9 patients) using three high-permeability membranes such as polymethylmethacrylate, polyacrylonitrile (AN-69) and polysulfone. In vitro spontaneous production of TNF-alpha and IL-1 beta was evaluated in the supernatants from short-term cultured monocytes obtained before and after treatment. The predialytic levels of TNF-alpha and IL-1 beta were significantly higher (p less than 0.05) in the uremic population than in 21 healthy subjects taken as controls. The analysis of the uremic population regarding the mode of therapy indicated that in hemodialysis the predialytic plasma levels of TNF-alpha and IL-1 beta did not significantly differ from those of healthy subjects. In contrast, in hemodiafiltration with polymethylmethacrylate and AN-69, but not with polysulfone, the predialytic plasma levels of both cytokines were significantly (p less than 0.05) increased. No significant variation in plasma levels of both cytokines was observed after hemodialysis with cuprophane membranes. Hemodiafiltration with polymethylmethacrylate and AN-69, but not with polysulfone, brought about a consistent reduction in plasma levels of both cytokines. Detectable amounts of TNF-alpha and IL-1 beta were spontaneously produced by peripheral-blood monocytes 6 h after the end of hemodialysis but not of hemodiafiltration. These studies suggest a possible role of TNF-alpha and IL-1 beta in the biocompatibility of different extracorporeal treatments.

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. The present guideline reports evidence of the use of antimicrobial agents for preventing peritonitis in peritoneal dialysis (PD).SR of RCT and RCT on treatments aiming at preventing peritoneal dialysis peritonitis were identified referring to a Cochrane Library and Renal Health Library search (2005 update). Quality of SR and RCT was assessed according to current methodological standards.One SR and 19 RCT were found addressing this issue. Staphylococcus Aureus nasal carriage treatment with mupirocin reduces exit-site and tunnel infections but not peritonitis. Topical gentamicin treatment on the exit site reduces Staphylococcus Aureus infection and peritonitis incidence. Intravenous antibiotics administration prior to catheter placement significantly reduces the risk of early peritonitis but not exit-site and tunnel infections. Oral nistatin associated with antibiotic treatment significantly reduces the incidence of Candida peritonitis. No other prophylaxis measure seems to be effective based on available evidence.In patients on peritoneal dialysis current evidence supports the hypothesis that topical mupirocin reduces the risk of Staphylococcus Aureus peritonitis, intravenous antibiotics prior to catheter placement prevent the risk of early peritonitis, and oral nistatin reduces the risk of Candida peritonitis. Further studies are necessary to test the effectiveness of other interventions.

The current 3rd edition of the Italian Society of Nephrology guidelines has been drawn up to summarize evidence of key intervention issues on the basis of systematic reviews (SR) of randomized trials (RCT) or RCT data only. The present guideline report evidence of catheter-related interventions to prevent peritonitis in peritoneal dialysis (PD).SR of RCT and RCT of catheter-related interventions to prevent peritonitis in PD were identified referring to a Cochrane Library and Renal Health Library search (2005 update).Two SR and 17 RCT were found addressing this issue. Methodological quality of available RCT was suboptimal according to current methodological standards. The use of the Y-set systems with disinfectant and the twin-bag systems was associated with a significantly lower risk of peritonitis. No other catheter-related interventions were found to be of proven efficacy in preventing the risk of peritonitis and exit-site/tunnel infection in PD patients.It is still unknown whether any particular PD catheter design or implantation technique are effective to prevent peritonitis in patients on peritoneal dialysis. Further studies are necessary to test the effectiveness of new interventions.

Aims/hypothesis: Overexpression of the gene encoding phosphoprotein enriched in astrocytes 15 (PEA15), also known as phosphoprotein enriched in diabetes (PED), causes insulin resistance and diabetes in transgenic mice and has been observed in type 2 diabetic individuals. The aim of this study was to investigate whether PEA15 overexpression occurs in individuals at high risk of diabetes and whether it is associated with specific type 2 diabetes subphenotypes. Subjects and methods: We analysed PEA15 expression in euglycaemic first-degree relatives (FDR) of type 2 diabetic subjects. Results: The expression of PEA15 in peripheral blood leucocytes (PBLs) paralleled that in fat and skeletal muscle tissues. In PBLs from the FDR, PEA15 expression was two-fold higher than in euglycaemic individuals with no family history of diabetes (control subjects), both at the protein and the mRNA level (p < 0.001). The expression of PEA15 was comparable in FDR and type 2 diabetic subjects and in each group close to one-third of the subjects expressed PEA15 levels more than 2 SD higher than the mean of control subjects. Subjects with IFG with at least one type 2 diabetes-affected FDR also overexpressed PEA15 (p < 0.05). In all the groups analysed, PEA15 expression was independent of sex and unrelated to age, BMI, waist circumference, systolic and diastolic BP, and fasting cholesterol, triacylglycerol and glucose levels. However, in euglycaemic FDR of type 2 diabetic subjects, PEA15 expression was inversely correlated with insulin sensitivity (r = -557, p = 0.01). Conclusions/interpretation: We conclude that PEA15 overexpression represents a common defect in FDR of patients with type 2 diabetes and is correlated with reduced insulin sensitivity in these individuals.

The Italian Registry of Dialysis and Transplantation (RIDT) collects data concerning patients in renal replacement therapy (RRT) sent from Regional Registries. Until 2003, the data were sent in summary tables. From 2004, each region has been sending patient data as single non-summarized forms (i.e. one record for each patient). This paper summarizes the collection criteria and the ideal method to codify data ensuring that data sent to the RIDT are consistent. This standardization process is necessary to ensure the statistical analyzability of the data and their comparability with data from other registries. Moreover, the standardization process is the initial step in allowing the RIDT to obtain clinical data to transform the registry from an epidemiological registry to a clinical governance instrument.

Assuming/= 75 years old as the age limit to define dialysis in the elderly, the incidence in this group of patients is progressively increasing in most dialysis units, with an annual growth of 8 to 16%, and represents 20 to 33% of the overall population being affected. The prevalence of the elderly dialysis group is also high, 14 to 20%, in the main literature casistics. Vascular nephropathies, 13 to 50%, represent the major cause of end-stage renal disease, followed by diabetes, 11 to 37%. First year survival rate is an acceptable 52 to 82%, whereas the fifth year value is on average 20 %, also due to the high baseline mortality in these patients. The death causes are mainly cardiac related and represent 45% of the overall mortality. The main prognostic factors are frequency and severity of comorbid factors, in addition to nutritional indexes that are particularly important in this age group. Dialysis dose and treatment time are not related to mortality. Haemodialysis and peritoneal dialysis complement each other to allow the best results. The survival rate, however, is usually better with haemodialysis, especially in old diabetic patients and after some years of treatment. Vascular access, intradialytic hypotension, cardiopathy, intestinal bleeding and amyloidotic arthropathy represent the more critical aspects of dialysis in the elderly, while the quality of life is sometimes unexpectedly good.

Appearance of acute renal failure (ARF) in severely burnt patients (GU) is a serious complication. It has a negative prognostic value and almost always develops in the context of multiple organ dysfunction syndrome (MODS) induced by sepsis. Over the last 20 years, according to data available, the mortality rate has been reported to reach about 75%. We have analyzed the initial results obtained in GU patients who were admitted to the Intensive Care Unit of the Burns Center in Turin.Out of 105 GU patients admitted between July 1999 and September 2000 (burned surface area (BSA) 23.8%, range 2-95%, mortality rate 13.7%), 7 patients (6.4%) had complications of ARF requiring extracorporeal dialytic therapy (38 HF sessions lasting 4-6 hours, 2 HF + 12 HDF + 1 UF sessions lasting 8-11 hours).Total BSA of 7 GU patients with ARF was 62.5+/-11.3% (mean +/-SEM). Mortality rate was 71.4% which was due to septic shock and MODS. ARF onset was at 28.4+/-8.4 days from admission. Dialytic treatment started at Crs 2.3+/-0.42 mg/dl, and patients were treated for 7.6+/-3.5 days with a weight loss of 1859+/-161 gr/die. Circuit anticoagulation was obtained by minimal amount of heparin (132.2+/-26.5 U/hour) and no hemorrhagic complications were observed.In GU patients with ARF the dialytic treatment with daily long-lasting convective- diffusive techniques permitted us to achieve a survival and dialytic adequacy similar to those reported with continuous renal replacement therapies; however, mortality rate is high and related to septic shock and MODS.

The aim of the study is to examine the situation of chronic uremia substitutive treatment by means of peritoneal dialysis in Piedmont on December 31, 1997 using data from the Piedmont regional dialysis and transplant register.Starting from the year 1981, data are reported (absolute, per million population, and according to different patient's anagraphic ages) about peritoneal dialysis prevalence and incidence; about basic nephropathies; drop-out from treatment; patient's rehabilitation; complications incidence, particularly peritonitis; patient's survival compared with survival of patients treated, during the same years with extracorporeal techniques.The data demonstrate, during these years, an increase of peritoneal dialysis incidence and prevalence; patients' survival curves, compared with those of patients treated with extracorporeal techniques, are very similar during the first years of treatment and worse afterwards, but never reaching statistical significance.They support Peritoneal Dialysis as a very good kind of substitutive treatment for some years, but this opinion deserves further examination and investigation on a longer period of time.

BACKGROUND: The correlation between symptoms and observed impaired function in functional dyspepsia is still inconsistent. The aims of the study were to obtain a measure of satiety by a meal test; to verify whether this compares with severity of symptoms assessed using a reproducible questionnaire; and to correlate the parameters of satiety test and gastric emptying with all the dyspeptic symptoms. METHODS: Fifty-two functional dyspepsia patients reported their symptoms on a standardized questionnaire that considered belching, bloating, early satiety, epigastric pain and burning, nausea, postprandial fullness and vomiting. They were monitored for gastric emptying of a solid caloric meal using a radionuclide technique and underwent a test to quantify meal-induced satiety by a liquid caloric meal. RESULTS: The number of kilocalories ingested during the satiety test until the occurrence of maximum satiety in healthy subjects was 110% higher than in the dyspeptic group (mean +/- s(mean): 1110 +/- 23 versus 532 +/- 56; P < 0.01). We found a significant positive correlation between gastric emptying rate and kcal of the satiety test (P < 0.01; r = 0.428). Logistic regression showed a significant inverse association between severity of early satiety-coded as absent, mild, moderate or severe, kcal of meal test (P = 0.01), and gastric emptying lag phase (P = 0.03). Bloating was associated directly with t(1/2) of gastric emptying (P = 0.03) and inversely with lag phase (P = 0.02). CONCLUSIONS: The satiety test gives a fine numerical measure of satiety and confirms the results of a symptoms questionnaire. Our study showed an indirect correlation between severity of early satiety--as measured by the satiety test, and gastric emptying rate, as well as an association between bloating and delayed gastric emptying

The need for data bank gathering information in dialysis patients is as old as dialysis. Dialysis Registries presently active are characterized by different policies of data gathering (large vs small number of information) and of use (research vs economical or clinical purposes). Aim of the work was a discussion on the use of a Regional Registry (RPDT, Regional Registry of Dialysis and Transplantation of Piedmont, Italy), gathering since 1981 a wide set of information (about 80 items) on all patients treated in a relatively small area (about 4,300,000 inhabitants).Two researches were selected: the first includes patients treated foror = 20 years by RRT. Cases were identified on the basis of RPDT data and an inquiry regarding all patients was performed, with specific interest on comorbidity. The second includes diabetic patients on regular RRT, a sample of which was further analyzed in high detail.While a Regional Registry, even gathering a wide set of data is unable to answer to the most qualitative questions, such as quality of life, its archives are a powerful tool to identify cases. Furthermore, ad hoc inquiries may represent a way to control quality of data or to test new fields to be studied. In the case of patients with long RRT follow-up, comorbidity questions were tested before being included on RPDT. In the case of a sample of diabetic patients, type of diabetes and cause of ESRD were controlled. This biunivocal relationship between clinical work-up and epidemiological archives may often interest future perspectives.

The aim of this study is to assess the mortality causes in dialysis in the Piedmont Region, using the data of the Dialysis and Transplantation Register (DTR). Data of a 15-year use of the DTR regarding 5519 hospital dialysis admissions were considered. Mortality seems to be particularly due to cardiac causes analyzing, also the incidence of other causes of death such as: cachexia, sudden death and infection causes.

Long survival on dialysis and wide admissions of very old and high risk patients, have focused attention to the problem of vascular access in uremic patients. The situation is critical in the USA, where PTFE/bovine grafts are utilized in about 75% of the cases. conversely, AV fistulas are the main type of access in Piedmont, where their use approaches 90% of the cases, Cimino-Brescia fistulas account for 58% of vascular accesses versus 25% and 9% of proximal AV fistulas and PTFE/bovine grafts, respectively. However, the latter progressively increase as age and time on dialysis increase. Snuff box fistulas are used only for 3% of the cases and this figure is steadily decreasing. In the meanwhile basilic vein superficializations, even if limited in numbers (1%), provided in some centres satisfactory results in term of survival and function. However, the type of access that deserved in the last few years the highest interest is the internal jugular vein cannulation (Canaud/Tesio catheter). In a preliminary series of 51 cannulations in 47 patients, this vascular access was permanent in 28 cases. A possible future routine utilization of jugular vein catheters is advisable in cases where a waiting period (up to a few months) is requested to allow a new fistula to mature or to maintain an empty abdomen in a patient temporarily withdrawn from peritoneal dialysis. Due to the heavy engagement for catheter maintenance and the high number of removals for systemic (9.8%) or skin exit infections (13.7%), a longer stay of indwelling catheters, although actually safe, should be limited to selected cases.

Among the various dermatologic abnormalities that can be associated with advanced chronic renal failure and dialysis therapy, pruritus is certainly the most disturbing disorder. Pruritus is an unpleasant, vexing sensation that provokes an intense desire to scratch. In the past the pruritus was considered from the neurophysiologic point of view as a submodality of pain, but more recent research showed that pain and pruritus are sensations which are carried through different populations of primary sensory neurons. The causes of pruritus in uremic patients are still unknown: xerosis, intradermic microprecipitation of divalent ions, hyperparathyroidism, peripheral neuropathy, allergic reactions and hypersensitivity, histamine and others have been considered as pathogenetic factors. The uncertainty on the causes is in part responsible for the different approach and results, unsatisfactory in many cases. In this paper we will review the neurophysiology, the pathogenesis and the possible therapeutic approaches to uremic pruritus.

The high prevalence of HCV positivity in dialysis patients has recently prompted several studies on this controversial subject. The aim of the study was an evaluation of HCV positivity and of influence on clinical outcome in 2,404 patients on dialysis in Piedmont (Northern Italy Region, about 4,400,000 inhab., 20 Dialysis Centers) at December 1993 (32.7% HCV-positive according to the Regional Registry of Dialysis and Transplantation). As expected, a strong correlation was found with time on dialysis (94.4% in patients with treatment follow-upor = 20 years) and blood transfusions (41.3% HCV positivity in transfused patients versus 22.6% in not transfused ones; p0.0001). Dialysis in a hospital setting is confirmed as at high risk of infection, since HCV positivity was 19.6% in patients always treated by bicarbonate dialysis in hospital versus 8.9% in those treated only by CAPD (start of dialysis in 1992-1993). Despite the high prevalence of HCV positivity, however, death rates for liver disease and for all gastrointestinal causes are very low, regardless of HCV antibody status (1.2% in HCV positive versus 2.3% in HCV negative, NS). Whether this depends upon different clinical features of HCV infection in dialysis patients or merely deflects a relatively short follow-up will be matter of discussion in the future.

At the end of December, 1993, 389 patients treated by means of dialysis for more than 15 years were registered in the Piedmont Dialysis and Transplantation Register; among them, 183 were alive. Characteristics of these patients as age at the beginning of dialytic treatment, casual nephropathies, causes of death, high risk conditions, dialytic schedules, vascular access, hospitalization requirements, rehabilitation, dialysis efficacy, gross mortality, were compared with those of patients treated for a shorter time, concluding that a very long dialytic survival can be achieved with a good clinical and social rehabilitation.

An association between hyperlipidemia and cardiovascular disease is well described in the literature. We conducted an observational study in order to evaluate the lipid profile, the prevalence of hyperlipidemia and its relationship with age, sex, duration of CAPD, peritoneal glucose load (PGL), serum albumin (ALB), serum glucose (GLU), and BMI in a large cohort of uremics undergoing long-term treatment with CAPD. 457 nondiabetic patients (245 males, 212 females; mean age 63.8 +/- 11.9 years; mean duration of CAPD: 41.8 +/- 26.9 months) treated during 1992 in 25 centers participating in the Italian Cooperative Peritoneal Dialysis Study Group (ICPDSG) were studied. The serum lipid parameters evaluated were triglycerides (TG), total cholesterol (CHO), HDL-cholesterol (HDL). Indications given in the New England Journal of Medicine, SI Unit Conversion Guide, 1992, were adopted for normal ranges. In the whole population the evaluation of lipid parameters showed: TG 227.4 +/- 123.3 mg/dl, CHO 232.8 +/- 56.0 mg/dl, HDL 40.7 +/- 12.0 mg/dl. No differences were found between the two sexes with regard to age, BMI, duration of CAPD, distribution of renal diseases, TG, ALB, and GLU; whereas CHO and HDL were significantly lower in males than in females (CHO: 222.2 +/- 53.5 vs. 245.0 +/- 56.5 mg/dl, p0.001; HDL: 39.3 +/- 11.4 vs. 42.6 +/- 12.6 mg/dl, p0.05). The prevalence of hypercholesterolemia was significantly lower in males than in females (19.7 vs. 35.4%; p0.001). The multiple regression analysis indicated that TG were directly correlated to PGL (p0.05), and HDL was inversely correlated with TG (p0.001). The coexistence of the two variables (TG and HDL) may increase the risk of cardiovascular events. Further strategies should therefore be developed to select and manage CAPD patients to reduce the incidence of hyperlipidemia.

CAPD outcomes were compared between a group of 301 diabetic patients (mean age +/- SD, 58.9 +/- 12.7 years, 55.8% males) and a group of 1689 non-diabetic patients (mean age +/- SD 57.8 +/- 14.8 years, 55.9% males) treated in 30 centres participating in the Italian Cooperative Peritoneal Dialysis Study Group from 1980 to 1989, with follow-up observation periods of 444 years (mean +/- SD, 1.48 +/- 1.24) and of 3502 years (mean +/- SD, 2.07 +/- 1.91) respectively. CAPD was the first modality for 87.2% of diabetics and 78.1% of non-diabetics (P0.001). The percentage of patients who needed a partner for CAPD was 45.9% in diabetics and 30.2% in non-diabetics (P0.001). In diabetics compared with non-diabetics, cardiovascular diseases and cachexia were nearly twice and infections other than peritonitis more than three times as frequent in causing death. In diabetics, survival was significantly worse (P0.0001) and the relative risk of death 2.13 times higher (P0.001). The technique survival and the relative risk of drop-out were not significantly different in the two groups. Clinical problems were the most important cause of drop-out among diabetics. The probability and relative risk of drop-out due to peritonitis, as well as of the first peritonitis episode, were not significantly different between the two groups and between diabetics using or not using intraperitoneal insulin. Days per patient year of hospitalization, excluding the first, were 18.4 in diabetics and 14.3 in non-diabetics. CAPD-related problems caused hospitalization in a similar way in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

In recent years, the availability of large epidemiological series allowed identification of biochemical outcome markers in the dialysis population. Interest towards albumin and cholesterol levels is motivated by their easy availability and by the presence of a strong short-term effect on mortality and morbidity. The aim of the study was an analysis of the relationship between albumin and cholesterol levels at start of dialysis and mortality (gross mortality and Kaplan Meier survival curves). Data were obtained from the Piedmont Regional Registry of Dialysis and Transplantation (Northern Italy Region, about 4,400,000 inhab, 20 Dialysis Centers, open acceptance since mid '70, yearly information on 100% of patients) in the period 1981-1990 (4734 patients on file). Only non diabetic patients with follow-up= 1 month, who started treatment in the Region, were selected. Patients with renal function recovery were excluded. Albumin levels were dichotomized at 3.5 g/dl. Cholesterol was stratified into 3 levels (150, 150-250,or = 300 mg/dl). The choice of dividing the study into 2 periods (1980-1985 vs 1986-1990) is due to the fact that 1984 has been the year of switch from acetate to bicarbonate dialysis. Prevalence of albumin and cholesterol under the normal range (22% and 15%) is low and rises with age and presence of high risk conditions. A a good correlation with the risk of death of these biochemical markers (stronger for albumin at least in the short term) was observed. No correlations are found with risk of death and elevated cholesterol levels (low number of cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Death in conditions of cachexia is increasing in potential dialysis patients, as treated cohorts are aging, the mean age of new patients increased and access to treatment is unlimited. The present study analyzes the clinical features of 417 deaths in conditions of cachexia recorded in 1981 to 1990 in the Dialysis and Transplantation Registry of a northern Italian region, Piedmont (about 4,400,000 inhabitants, 20 dialysis centers; 4,734 patients on file at December 31, 1990; yearly information on 100% of the cases). Death in conditions of cachexia increased from 105 cases in the first four years taken into account (1981 to 1984), to 107 in the last two years (1989 to 1990). Prevalence is higher in the elderly (85% of the death over age 60). Most patients (90.5%) were at high clinical risk. To assess whether the frequency of this diagnosis reflected the wide acceptance of elderly patients for dialysis and was a marked of vascular disease, a specific inquiry was conducted about 107 cachectic deaths recorded from 1989 to 1990: 82.5% of the patients had diffused vascular disease, 11.5% were already cachectic when dialysis was initiated, and 66% were in cachexia at least six months before death. Since mean age of patients dying in condition of cachexia increased from 68.8 in the period of 1981 to 1984 to 70.3 years in 1989 to 1990, and mean time on dialysis from 2.8 years in 1981 to 1984 to 70.3 years in 1989 to 1990, the higher prevalence is not likely to be due to lack of care of elderly patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The patient survival (PS) and technique survival (TS) were evaluated in 1990 patients on continuous ambulatory peritoneal dialysis (CAPD) (males: 55.9%, mean age +/- SD: 58.4 +/- 14.8 years), treated in 30 centers participating in the Italian PD Study Group, from 1980 to 1989 (follow-up: 3953 years; mean +/- SD: 2.02 +/- 1.86 years). The total PS was 50.7% at 4 years, compared to 73.3% of patients without clinical high-risk condition (HRC) at the beginning of CAPD. In this group (34.0%) PS was significantly higher (p0.001) compared, respectively, to patients with cardiovascular disease (30.5%), diabetes (13.1%), and ageor = 70 years (11.2%). The percentage of death reached the mean value of 11.3% per year without any statistically significant tendency to variation during the follow-up, despite the increased number of patientsor = 65 years old and those with HRC (p0.001). Cardiovascular diseases (47.3%) and cachexia (17.8%) were the most frequent causes of death, whereas the mortality due to peritonitis showed a progressive increase in patients with peritonitis incidence 1 ep/year (G4) compared to those with0.5 ep/year (G2). Peritonitis (0.68 ep/year) was the most frequent cause of technique failure (30.0%), with clinical complications (18.2%) and peritoneal membrane failure (16.4%) as the second and third causes. The dropout percentage was 8.3% per year with a significant decrease over time (p = 0.012) and a positive correlation with the reduction of peritonitis incidence (p = 0.035). The total TS was 50.1% at 7 years, and it was significantly worse in G4 compared to G2.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact of peritonitis on CAPD results was evaluated in 1990 pts (mean age +/- SD:58.4 +/- 14.8 yrs, 55.9% males), treated in 30 centres participating in Italian PD Study Group, during 1980-89, with an overall observation period of 3953 years (mean +/- SD 24.1 +/- 22.3 months). The incidence of peritonitis decreases from 1.21 (1980-84) to 0.48 (1985-89) ep/year (overall:0.68) with a significant (P0.001) reduction of the probability of developing the first peritonitis episode (FPE) through the same periods. The probability of developing FPE and the relative risk of peritonitis were significantly lower (P0.001) in pts for whom CAPD has been the first treatment (80.1%); on the contrary these parameters did not gain significant difference according to sex, age 65 years, diabetes or cardiovascular disease. As far as the organisms responsible for peritonitis are concerned a significant reduction of S. epid. and an increase of S. aureus, other Gram pos. and Pseudomonas was observed in the second 5-yr periods. Peritonitis episodes caused catheter removal in 8.2% of cases and were associated with catheter infection in 10.8% of cases. Peritonitis accounted for 24.2% of hospitalization causes and for 6.7% and 30.0% of death and of drop-out respectively. The probability of death and drop-out was significantly high (p0.001) in pts with a peritonitis incidence1 ep/year than in those with0.5 ep/year. The probability of drop-out due to peritonitis was not higher in diabetic or older patients.

We studied 1,622 patients who started regular dialysis treatment between 1985 and 1989 in 19 centers from the Italian CAPD Study Group. There were 962 pts (59%) and on HD; 660 pts (41%) on CAPD. CAPD pts were older and had more risk factors at the start than HD pts (p0.0001). Overall patient survival was not statistically different between CAPD and HD at 6 years (42% CAPD; 54% HD). Multivariate analysis (Cox's model) on all population revealed that age and pretreatment risk factors had a statistically significant impact on patient survival (p0.0001), but not the type of dialytic treatment (CAPD or HD). When multivariate analysis was applied separately by treatment modalities, in HD group age and risk factors had the same negative influence on survival (p0.0001) while in CAPD group the influence of age on survival was less significant (p 0.025). This multicenter study carried out with appropriate statistical methods in a large number of pts demonstrates that patients' survival at 6 years is not different on CAPD and HD (despite the worse patient selection on CAPD) and can be even better on CAPD for aged patients.

Ninety patients on dialysis, 241 cadaveric kidney donors and 27 cadaveric kidney recipients with a follow-up of 2 years, have been investigated as for anti-HCV positivity by means of 3 tests. As for patients on dialysis and cadaveric donors, the prevalence was 32 and 4%, respectively. As for transplanted patients, it must be noted that 4 negative recipients from positive donors seroconverted, but without any change in hepatic enzymes, while in 2 or 9 anti-HCV-positive recipients, hepatic enzymes increased after transplantation. Seroconversion in patients transplanted from a negative donor was not significantly different. We conclude that, according to their experience, anti-HCV positivity in the donors is not associated with a significant risk of infection in recipients of cadaveric grafts.

While the efficiency of treatment has been recently related to long-term clinical outcome, the relevance of tolerance on this subject, even on critically ill patients, has seldom been evaluated, for the limited size of single pools on high tolerance dialytic treatments (HTT) and the flux of pts. among treatments. Since 1981, on 2243 pts on files of the Dialytic Piedmont Regional Registry, 1399 treatments on acetate-hemodialysis (HD), 1153 on bicarbonate dialysis (BC) and 249 hemofiltration (HF) were compared by survival analysis (Mantel test) and yearly hospitalization rate (YH), according to age, factors of clinical high risk (HR) and presence of diabetes. BC and HF showed on HR pts. LTS comparable to HD (at 1 yr. 82, 78.3 vs 76.77%) despite the higher age, and the lower proportion of first choice (38.9%, 25% vs. 83.5%) testifying successful treatment of more critical cases. On non HR pts. HF, a less efficient treatment vs BD and AD, showed slightly reduced LTS (95.2% at 1 yr. vs. 98.1 and 97.9%). HY results higher on HF vs. BD on non HR pts. (10.4 vs. 5.3 and 2.1%) but improves on HR pts. (10.7 vs. 12.5%) and is lower than BC on diabetics (8.3 vs. 14.5%) (p less than 0.01).

Primary oxalosis is a rare inborn error of oxalate metabolism. Most cases are discovered in children, but occasionally symptoms begin later in life. Since early deaths in the past were from renal failure, prolonged survival obtained with chronic dialysis allows oxalosis to develop. This paper presents a 38-year-old man with an atypical history of type-I primary hyperoxaluria, not diagnosed until after 5 years of dialysis. Bone biopsy was performed because the biochemical and radiologic features did not seem consistent with a putative diagnosis of secondary hyperparathyroidism. This case emphasizes the clinical heterogeneity of this disorder, and the need for its considerations in the spectrum of dialysis-related bone diseases. It also stresses that bone oxalosis may mimic hyperparathyroidism, especially radiologically. Differential diagnosis is therefore mandatory.