149 research outputs found

    The Realm and Frontiers of Mycosis Fungoides

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    Objectives Chronic renal failure (CRF) is associated with altered systemic arterial tone and hypertension. Myogenic constriction and endothelium-derived hyperpolarizing factor (EDHF)-dependent relaxation represent major vasoregulatory mechanisms in small systemic arteries. Elevated myogenic response and impaired EDHF might participate in the development of essential hypertension; however, their role in CRF-related hypertension is unknown. We investigated whether myogenic response and EDHF are altered in subtotally nephrectornized (sNX) rats and whether these changes are modifiable by chronic treatment with angiotensin-converting enzyme (ACE) inhibitor. Methods In a pressure arteriograph, myogenic constriction and EDHF-mediated relaxation were evaluated in small mesenteric arteries isolated from male Wistar rats 15 weeks after either sham operation (n = 7) (SHAM), sNX (n = 12) or sNX followed by 9 weeks of treatment with lisinopril (sNX + LIS, 2.5 mg/kg, n = 13). Results Surprisingly, myogenic response was reduced in hypertensive CRF rats (maximal myogenic tone: 37 +/- 2 and 18 +/- 4%, P <0.01; peak myogenic index: -0.80 +/- 0.08 and -0.40 +/- 0.12%/mmHg, P <0.05 in SHAM and sNX respectively). At the same time EDHF-mediated relaxation was also impaired (maximal response: 92 +/- 2 and 77 +/- 5%, P <0.01; pD(2): 6.5 +/- 0.1 and 5.9 +/- 0.1, P <0.05). Both myogenic response and EDHF were inversely related to the severity of renal failure and restored by treatment with lisinopril to levels found in SHAM animals. Conclusion Major constrictive (myogenic) and dilatory (EDHF) mechanisms of small systemic arteries are impaired in hypertensive CRF rats. These alterations do not seem to participate in the development of hypertension, being rather directly related to the severity of renal impairment. Both systemic vascular changes might be restored by renoprotective treatment with ACE inhibitor

    A Markov Model of Gap Occurrence in Continuous Glucose Monitoring Data for Realistic in Silico Clinical Trials

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    Background and objective: Continuous glucose monitoring (CGM) sensors measure interstitial glucose concentration every 1-5 min for days or weeks. New CGM-based diabetes therapies are often tested in in silico clinical trials (ISCTs) using diabetes simulators. Accurate models of CGM sensor inaccuracies and failures could help improve the realism of ISCTs. However, the modeling of CGM failures has not yet been fully addressed in the literature. This work aims to develop a mathematical model of CGM gaps, i.e., occasional portions of missing data generated by temporary sensor errors (e.g., excessive noise or artifacts). Methods: Two datasets containing CGM traces collected in 167 adults and 205 children, respectively, using the Dexcom G6 sensor (Dexcom Inc., San Diego, CA) were used. Four Markov models, of increasing complexity, were designed to describe three main characteristics: number of gaps for each sensor, gap distribution in the monitoring days, and gap duration. Each model was identified on a portion of each dataset (training set). The remaining portion of each dataset (real test set) was used to evaluate model performance through a Monte Carlo simulation approach. Each model was used to generate 100 simulated test sets with the same size as the real test set. The distributions of gap characteristics on the simulated test sets were compared with those observed on the real test set, using the two-sample KolmogorovSmirnov test and the Jensen-Shannon divergence. Results: A six-state Markov model, having two states to describe normal sensor operation and four states to describe gap occurrence, achieved the best results. For this model, the Kolmogorov-Smirnov test found no significant differences between the distribution of simulated and real gap characteristics. Moreover, this model obtained significantly lower Jensen-Shannon divergence values than the other models.Conclusions: A Markov model describing CGM gaps was developed and validated on two real datasets. The model describes well the number of gaps for each sensor, the gap distribution over monitoring days, and the gap durations. Such a model can be integrated into existing diabetes simulators to realistically simulate CGM gaps in ISCTs and thus enable the development of more effective and robust diabetes management strategies.& COPY; 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/

    Simultaneous removal and replacement of the peritoneal catheter in CAPD patient with refractory peritonitis sustained by P. aeruginosa: A case-report

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    Pseudomonas peritonitis is often severe and associated with less than 50% complete cure rate, often requiring catheter removal, and transfer to HD. International guidelines recommend that peritoneal catheter should be removed if peritoneal dialysis (PD) effluent does not clear after 5 days of appropriate antibiotic therapy defining the episode as refractory peritonitis. To avoid the shift to hemodialysis (HD), the simultaneous removal and replacement of the peritoneal catheter (SCR) has been employed to treat recurrent peritonitis or tunnel infections associated with peritonitis, obtaining satisfactory outcomes. However, the use of SCR is still controversial in refractory episodes. At present there is growing evidence that refractory peritonitis can be sustained by bacterial adherence along the intraperitoneal portion of the catheter, especially when Pseudomonas species are involved. We describe a case of refractory peritonitis sustained by P. aeruginosa that after a partial response to antibiotics has been successfully treated by SCR

    patients with hypertensive nephropathy and chronic kidney disease might not benefit from strict blood pressure control

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    Background/Aims: In patients with chronic kidney disease (CKD) strict blood pressure (BP) control is reno-protective. However, renal benefits from BP control might depend also on the etiology of CKD. We investigated if maintenance of BP at target is equally effective in subjects with hypertensive nephropathy (HN+) and in those with other nephropathies (HN-). Methods: We evaluated 148 patients with CKD (stages 3-5) in two visits at least 12 months apart. BP was measured both as office BP and 24h ambulatory blood pressure (ABP). Glomerular filtration rate (eGFR) was estimated with CKD-EPI formula. The slope of eGFR variation (ΔeGFR) was calculated as: (eGFR1-eGFR0)/months of follow up. Results: Cohort characteristics were: HN-(n=82) and HN+ (n=66), age (71±9 vs 74±9 years; p=0.09); prevalence of diabetes (57 vs 43%; p=0.19); average follow up (19±7 vs 21±9 months; p=0.3). HN- and HN+ did not differ regarding both baseline eGFR (34±18 vs 35±14 ml/min; p=0.97) and ΔeGFR (0.00±0.53 vs -0.06±0.35 ml/min/month, p=0.52). The proportion of patients with BP at target at both visits was similar in HN- and HN+ (office BP: HN- 18% and HN+ 27%; p=0.21; ABP: HN- 42% and HN+ 43; p=0.96). In patients with office BP at target at both visits HN- showed a significant improvement of ΔeGFR respect to HN+ (HN-: 0.240 ± 0.395 and HN+: -0.140±0.313 ml/min/ month; p=0.026). In patients with office BP not at target HN- and HN+ did not show any difference in ΔeGFR (HN- 0.00±0.47; HN+ -0.030±0.420 ml/min/month; p=0.66). ABP was not associated with differences in ΔeGFR either if it was at target (HN- 0.104±0.383 and HN+ 0.00±0.476 ml/min/month; p=0.42) or not (HN- -0.057±0.503 and HN+ -0.092±0.325 ml/ min/month; p=0.87). Conclusion: In patients with CKD and HN+ maintenance of BP targets recommended by current guidelines is less reno-protective than it is in HN-

    Spontaneous low-protein intake in older CKD patients: one diet may not fit all

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    BackgroundProtein restriction has been extended to stage 3 chronic kidney disease (CKD) regardless of age in the latest K-DOQI guidelines for the dietary management of patients with CKD. However, in elderly CKD patients there is a tendency to a spontaneous reduction in protein and energy intake that may impair the overall nutritional status. The aim of our study is to assess whether there are differences in malnutrition, exercise capacity and inflammatory status in elderly CKD patients with spontaneously low protein intake (sLPI) compared with patients with normal protein intake (NPI).MethodsWe performed a cross-sectional analysis of 123 incident patients. Malnutrition was assessed using Malnutrition Inflammation Score (MIS) and serum markers; As for physical performance, we used Short Physical Performance Battery (SPPB) and handgrip strength.ResultsWe found that in older patients with advanced CKD, as many as 68% had low spontaneous protein intake, and they were more malnourished evaluated with MIS (25% vs. 10%, p = 0.033), protein-energy wasting (PEW) (43% vs. 14%, p = 0.002) and nPCR (0.63[0.51–0.69] vs. 0.95[0.87–1.1], p &lt; 0.0001). They also had worse body composition, in terms of lower mid-arm muscular circumference (MAMC), fat tissue index (FTI) and higher overhydration (OH). sLPI patients also had higher levels of IL6 (4.6[2.9–8.9] vs. 2.8[0.8–5.1], p = 0.002). Moreover, sLPI patients were frailer (33% vs. 24%, p = 0.037) and had poorer physical performance especially when assessed with (SPPB) (7[5–9] vs. 9[7–10], p = 0.004) and gait test time (6.08 + 2 vs. 7.22 + 2.7, p = 0.04). sLPI was associated with lower physical performance [SPPB OR, 0.79 (0.46–0.97), p = 0.046] and malnutrition [MIS 1.6 (1.05–3.5), p = 0.041] independently from patients’ age and eGFR.ConclusionWe found that in older patients with advanced CKD, up to 68% had low spontaneous protein intake and were frailer, more malnourished and with lower physical performance. These findings emphasize the importance of assessing patients’ needs, and personalized approaches with individual risk–benefit assessments should be sought. To achieve the best possible outcomes, targeted interventions should use all available tools

    Associations of Intact and C-Terminal FGF23 with Inflammatory Markers in Older Patients Affected by Advanced Chronic Kidney Disease

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    Background: In patients with chronic kidney disease (CKD), Fibroblast Growth Factor 23 (FGF23) is markedly increased and has been proposed to interact with systemic inflammation. Methods: In this cross-sectional study, we evaluated the correlations of intact FGF23, c-terminal FGF23, and the FGF23 ratio (c-terminal to intact) with some inflammatory cytokines in 111 elderly patients with advanced CKD not yet in dialysis. Results: Estimated glomerular filtration rate (eGFR) was inversely correlated with intact FGF23 and c-terminal FGF23, as well as with interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), and monocyte chemoattractant protein-1 (MCP-1). Intact FGF23 levels were directly correlated with IL-6 (r = 0.403; p &lt; 0.001) and TNFα (r = 0.401; p &lt; 0.001) while c-terminal FGF23 was directly correlated with MCP-1 (r = 0.264; p = 0.005). The FGF23 ratio was, instead, inversely correlated with IL-6 (r = -0.326; p &lt; 0.001). Multivariate analysis revealed that intact FGF23 was directly associated with TNFα [B = 0.012 (95% CI 0.006, 0.019); p = 0.003] and c-terminal FGF23 was directly associated with MCP-1 [B = 0.001 (95% CI 0.000, 0.002); p = 0.038], while the FGF23 ratio was inversely correlated with IL-6 [B = -0.028 (95% CI -0.047, -0.010); p = 0.002]. Conclusions: Our data demonstrate that, in CKD patients, intact FGF23 and the metabolites deriving from its proteolytic cleavage are differently associated with some inflammatory pathways. In particular, intact FGF23 is mainly associated with IL-6 and TNFα, c-terminal FGF23 with MCP-1, and the FGF23 ratio with IL6

    Bayesian denoising algorithm dealing with colored, non-stationary noise in continuous glucose monitoring timeseries

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    Introduction: The retrospective analysis of continuous glucose monitoring (CGM) timeseries can be hampered by colored and non-stationary measurement noise. Here, we introduce a Bayesian denoising (BD) algorithm to address both autocorrelation of measurement noise and temporal variability of its variance.Methods: BD utilizes adaptive, a-priori models of signal and noise, whose unknown variances are derived on partially-overlapped CGM windows, via smoothing approach based on linear mean square estimation. The CGM signal and noise variability profiles are then reconstructed using a kernel smoother. BD is first assessed on two simulated datasets, DS1 and DS2. On DS1, the effectiveness of accounting for colored noise is evaluated by comparison against a literature algorithm; on DS2, the effectiveness of accounting for the noise variance temporal variability is evaluated by comparison against a Butterworth filter. BD is then evaluated on 15 CGM timeseries measured by the Dexcom G6 (DR).Results: On DS1, BD allows reducing the root-mean-square-error (RMSE) from 8.10 [6.79–9.24] mg/dL to 6.28 [5.47–7.27] mg/dL (median [IQR]); on DS2, RMSE decreases from 6.85 [5.50–8.72] mg/dL to 5.35 [4.48–6.49] mg/dL. On DR, BD performs a reasonable tracking of noise variance variability and a satisfactory denoising.Discussion: The new algorithm effectively addresses the nature of CGM measurement error, outperforming existing denoising algorithms

    Frailty in kidney transplantation: a review on its evaluation, variation and long-term impact

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    The problem of frailty in kidney transplantation is an increasingly discussed topic in the transplant field, partially also generated by the multiple comorbidities by which these patients are affected. The criteria currently used to establish the presence and degree of frailty can be rapidly assessed in clinical practice, even in patients with chronic kidney disease (CKD). The main objectives of this work are: (i) to describe the method of evaluation and the impact that frailty has in patients affected by CKD, (ii) to explore how frailty should be studied in the pre-transplant evaluation, (iii) how frailty changes after a transplant and (iv) the impact frailty has over the long term on the survival of renal transplant patients
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