mTORC1 Inhibitor Rapamycin Inhibits Growth of Cerebral Cavernous Malformation in Adult Mice.

BACKGROUND: Cerebral cavernous malformations (CCMs) are vascular malformations that frequently cause stroke. CCMs arise due to loss of function in one of the genes that encode the CCM complex, a negative regulator of MEKK3-KLF2/4 signaling in vascular endothelial cells. Gain-of-function mutations in PIK3CA (encoding the enzymatic subunit of the PI3K (phosphoinositide 3-kinase) pathway associated with cell growth) synergize with CCM gene loss-of-function to generate rapidly growing lesions. METHODS: We recently developed a model of CCM formation that closely reproduces key events in human CCM formation through inducible CCM loss-of-function and PIK3CA gain-of-function in mature mice. In the present study, we use this model to test the ability of rapamycin, a clinically approved inhibitor of the PI3K effector mTORC1, to treat rapidly growing CCMs. RESULTS: We show that both intraperitoneal and oral administration of rapamycin arrests CCM growth, reduces perilesional iron deposition, and improves vascular perfusion within CCMs. CONCLUSIONS: Our findings further establish this adult CCM model as a valuable preclinical model and support clinical testing of rapamycin to treat rapidly growing human CCMs.

Cavernous Angioma Symptomatic Hemorrhage (CASH) Trial Readiness II: Imaging Biomarkers and Trial Modeling.

Background: Quantitative susceptibility mapping (QSM) and dynamic contrast enhanced quantitative perfusion (DCEQP) MRI sequences assessing iron deposition and vascular permeability were previously correlated with new hemorrhage in cavernous angiomas. We assessed their prospective changes in cavernous angiomas with symptomatic hemorrhage (CASH) in a multisite trial readiness project ( clinicaltrials.gov NCT03652181 ). Methods: Patients with CASH in the prior year, without prior or planned lesion resection or irradiation were enrolled. Mean QSM and DCEQP of CASH lesion were acquired at baseline, and at 1- and 2-year follow-ups. Sensitivity and specificity of biomarker changes were analyzed in relation to predefined lesional symptomatic hemorrhage (SH) or asymptomatic change (AC). Sample size calculations for hypothesized therapeutic effects were conducted. Results: We logged 143 QSM and 130 DCEQP paired annual assessments. Annual QSM change was greater in cases with SH than in cases without SH (p= 0.019). Annual QSM increase by ≥ 6% occurred in 7 of 7 cases (100%) with recurrent SH and in 7 of 10 cases (70%) with AC during the same epoch, and 3.82 times more frequently than clinical events. DCEQP change had lower sensitivity for SH and AC than QSM change, and greater variance. A trial with smallest sample size would detect a 30% difference in QSM annual change in 34 or 42 subjects (one and two-tailed, respectively), power 0.8, alpha 0.05. Conclusions: Assessment of QSM change is feasible and sensitive to recurrent bleeding in CASH. Evaluation of an intervention on QSM percent change may be used as a time-averaged difference between 2 arms using a repeated measures analysis. DCEQP change is associated with lesser sensitivity and higher variability than QSM. These results are the basis of an application for certification by the U.S. F.D.A. of QSM as a biomarker of drug effect in CASH.

Risk of outcomes in a Spanish population with chronic kidney disease.

Objectives: To assess mortality and cardiovascular and renal outcomes among patients with chronic kidney disease (CKD) (primary objective), with a particular focus on heart failure (HF) risk following diagnosis of CKD (secondary objective) in Spain. Methods: We conducted an observational study comprising cross-sectional and longitudinal retrospective analyses using secondary data from electronic health records. For the primary objective, adults with prevalent CKD [estimated glomerular filtration rate (eGFR) <60 or ≥60 mL/min/1.73 m2 with a urine albumin:creatinine ratio (UACR) ≥30 mg/g at the index date (1 January 2017)] were included. For the secondary objective, adults with incident CKD in 2017 were enrolled. Results: In the prevalent population, 46 786 patients with CKD without HF [75.8 ± 14.4 years, eGFR 51.4 ± 10.1 mL/min/1.73 m2; 75.1% on renin-angiotensin system inhibitors (RASis)] and 8391 with CKD and HF (79.4 ± 10.9 years, eGFR 46.4 ± 9.8 mL/min/1.73 m2) were included. In the prevalent population, the risk of all-cause death {hazard ratio [HR] 1.107 [95% confidence interval (CI) 1.064-1.153]}, HF hospitalization [HR 1.439 (95% CI 1.387-1.493)] and UACR progression [HR 1.323 (95% CI 1.182-1.481)] was greater in those patients with CKD and HF versus CKD only. For the incident population, 1594 patients with CKD without HF and 727 with CKD and HF were included. Within 24 months from the CKD diagnosis (with/without HF at baseline), 6.5% of patients developed their first HF hospitalization. Although 60.7% were taking RASis, only 3.4% were at maximal doses and among diabetics, 1.3% were taking sodium-glucose cotransporter-2 inhibitors. Conclusions: The presence of HF among CKD patients markedly increases the risk of outcomes. CKD patients have a high risk of HF, which could be partially related to insufficient treatment.

Follow a recipe to prescribe phosphate during hemodialysis. / Receta para prescribir fósforo durante hemodiálisis.

The addition of phosphorus (P) to the dialysate (LD) in the form of enema Casen® is common practice in patients with hypophosphatemia. The estimation of the amount to be used and the identification of the problems that may can occur are not well defined. As a result of our work we propose a practical approach of how to proceed to increase phosphate concentration in the hemodialysate. We present a reasoned formula to calculate how much enema has to be added and the problems that may arise.

Is it useful to increase dialysate flow rate to improve the delivered Kt?

BACKGROUND: Increasing dialysate flow rates (Qd) from 500 to 800 ml/min has been recommended to increase dialysis efficiency. A few publications show that increasing Qd no longer led to an increase in mass transfer area coefficient (KoA) or Kt/V measurement. Our objectives were: 1) Studying the effect in Kt of using a Qd of 400, 500, 700 ml/min and autoflow (AF) with different modern dialysers. 2) Comparing the effect on Kt of water consumption vs. dialysis time to obtain an individual objective of Kt (Ktobj) adjusted to body surface. METHODS: This is a prospective single-centre study with crossover design. Thirty-one patients were studied and six sessions with each Qd were performed. HD parameters were acquired directly from the monitor display: effective blood flow rate (Qbe), Qd, effective dialysis time (Te) and measured by conductivity monitoring, final Kt. RESULTS: We studied a total of 637 sessions: 178 with 500 ml/min, 173 with 700 ml/min, 160 with AF and 126 with 400 ml/min. Kt rose a 4% comparing 400 with 500 ml/min, and 3% comparing 500 with 700 ml/min. Ktobj was reached in 82.4, 88.2, 88.2 and 94.1% of patients with 400, AF, 500 and 700 ml/min, respectively. We did not find statistical differences between dialysers. The difference between programmed time and Te was 8' when Qd was 400 and 500 ml/min and 8.8' with Qd = 700 ml/min. Calculating an average time loss of eight minutes/session, we can say that a patient loses 24' weekly, 312' monthly and 62.4 hours yearly. Identical Kt could be obtained with Qd of 400 and 500 ml/min, increasing dialysis time 9.1' and saving 20% of dialysate. CONCLUSIONS: Our data suggest that increasing Qd over 400 ml/min for these dialysers offers a limited benefit. Increasing time is a better alternative with demonstrated benefits to the patient and also less water consumption.

Psychosocial factors and adherence to drug treatment in patients on chronic haemodialysis.

BACKGROUND: The daily pill burden in hemodialysis patients is one of the highest reported to date in any chronic disease. The adherence to prescribed treatment has implications on the quality of life, the survival of patients, and the economic cost of their treatment, this being a priority public health issue. OBJECTIVE: To evaluate the adherence to pharmacological treatment examining, among the possible causes of non-adherence, psychosocial factors such as depression, anxiety, cognitive impairment and social support. METHOD: Transversal-observational study of thirty five patients that suffer from chronic renal disease and who are on manteinance hemodialysis, evaluated by self-reported measures. RESULTS: Non-adherent patients have significant higher depression index than adherent patients. Anxiety, cognitive impairment and social support do not show a significant relation with the degree of adherence or compliance with farmacological treatment. CONCLUSIONS: These results suggest that psychological intervention in chronic haemodialysis patients with a severe depression index could increase the degree of fulfillment and general well-being of renal patients.

Transient Brugada-type electrocardiographic abnormalities in renal failure reversed by dialysis.

The Brugada syndrome (BRS) is a hereditary cardiac condition (characteristically with a gene mutation affecting sodium channel function) identified by an elevated terminal portion of the QRS complex (prominent J wave) followed by a descending ST-segment elevation ending in a negative T wave in the right precordial leads, and malignant tachyarrhythmias in patients without demonstrable structural heart disease. We report a patient with a previous history of epilepsy treated with psychotropic drugs (with a sodium channel blocking effect) and chronic renal failure on haemodialysis who developed hyperkalaemia (6.6 mmol/l) and ECG findings resembling BRS. This condition was manifested by the prominent J wave, the coved-type ST-segment elevation and the negative T wave in the right precordial leads. These ECG changes disappeared after haemodialysis when the potassium became normal. Subsequently, a flecainide test did not reproduce ST-segment elevation. We conclude that hyperkalaemia associated with cardiac membrane active drugs may cause ECG changes mimicking the Brugada syndrome.

Synthesis of o,p-EDDHA and its detection as the main impurity in o,o-EDDHA commercial iron chelates.

Ethylenediamine-N,N'bis(o-hydroxyphenyl)acetic acid (o,o-EDDHA) is one of the most efficient iron chelates employed to relieve iron chlorosis in plants. However, the presence of positional isomers of EDDHA in commercial iron chelates has been recently demonstrated, and among them, it has been claimed that ethylenediamine-N(o-hydroxyphenylacetic)-N'(p-hydroxyphenylacetic) acid (o,p-EDDHA) is the main impurity present in EDDHA fertilizers. Here we report the preparation of o,p-EDDHA, a compound whose synthesis had not been previously reported. The synthetic o,p-EDDHA is able to form ferric complexes, and it has been used as a standard in the analysis of the impurities of commercial iron fertilizers. The presence of o,p-EDDHA/Fe(3+) in commercial samples has been unambiguously demonstrated by HPLC.