568 research outputs found

    The Effect of Treatment of Acidosis on Calcium Balance in Patients with Chronic Azotemic Renal Disease

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    Small but statistically significant negative calcium balances were found in each of eight studies in seven patients with chronic azotemic renal disease when stable metabolic acidosis was present. Only small quantities of calcium were excreted in the urine, but fecal calcium excretion equaled or exceeded dietary intake. Complete and continuous correction of acidosis by NaHCO3 therapy reduced both urinary and fecal calcium excretion and produced a daily calcium balance indistinguishable from zero. Apparent acid retention was found throughout the studies during acidosis, despite no further reduction of the serum bicarbonate concentration. The negative calcium balances that accompanied acid retention support the suggestion that slow titration of alkaline bone salts provides an additional buffer reservoir in chronic metabolic acidosis. The treatment of metabolic acidosis prevented further calcium losses but did not induce net calcium retention. It is suggested that the normal homeostatic responses of the body to the alterations in ionized calcium and calcium distribution produced by raising the serum bicarbonate might paradoxically retard the repair of skeletal calcium deficits

    Predicting the safety and efficacy of butter therapy to raise tumour pHe: an integrative modelling study

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    Background: Clinical positron emission tomography imaging has demonstrated the vast majority of human cancers exhibit significantly increased glucose metabolism when compared with adjacent normal tissue, resulting in an acidic tumour microenvironment. Recent studies demonstrated reducing this acidity through systemic buffers significantly inhibits development and growth of metastases in mouse xenografts.\ud \ud Methods: We apply and extend a previously developed mathematical model of blood and tumour buffering to examine the impact of oral administration of bicarbonate buffer in mice, and the potential impact in humans. We recapitulate the experimentally observed tumour pHe effect of buffer therapy, testing a model prediction in vivo in mice. We parameterise the model to humans to determine the translational safety and efficacy, and predict patient subgroups who could have enhanced treatment response, and the most promising combination or alternative buffer therapies.\ud \ud Results: The model predicts a previously unseen potentially dangerous elevation in blood pHe resulting from bicarbonate therapy in mice, which is confirmed by our in vivo experiments. Simulations predict limited efficacy of bicarbonate, especially in humans with more aggressive cancers. We predict buffer therapy would be most effectual: in elderly patients or individuals with renal impairments; in combination with proton production inhibitors (such as dichloroacetate), renal glomular filtration rate inhibitors (such as non-steroidal anti-inflammatory drugs and angiotensin-converting enzyme inhibitors), or with an alternative buffer reagent possessing an optimal pK of 7.1–7.2.\ud \ud Conclusion: Our mathematical model confirms bicarbonate acts as an effective agent to raise tumour pHe, but potentially induces metabolic alkalosis at the high doses necessary for tumour pHe normalisation. We predict use in elderly patients or in combination with proton production inhibitors or buffers with a pK of 7.1–7.2 is most promising

    A prospective evaluation of the predictive value of faecal calprotectin in quiescent Crohn’s disease

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    Background: The faecal calprotectin (FC) test is a non-invasive marker for gastrointestinal inflammation. Aim: To determine whether higher FC levels in individuals with quiescent Crohn’s disease are associated with clinical relapse over the ensuing 12 months.<p></p> Methods: A single centre prospective study was undertaken in Crohn's disease patients in clinical remission attending for routine review. The receiver operating characteristic (ROC) curve for the primary endpoint of clinical relapse by 12 months, based on FC at baseline, was calculated. Kaplan-Meier curves of time to relapse were based on the resulting optimal FC cutoff for predicting relapse.<p></p> Results: Of 97 patients recruited, 92 were either followed up for 12 months without relapsing, or reached the primary endpoint within that period. Of these, 10 (11%) had relapsed by 12 months. The median FC was lower for non-relapsers, 96µg/g (IQR 39-237), than for relapsers, 414µg/g (IQR 259-590), (p=0.005). The area under the ROC curve to predict relapse using FC was 77.4%. An optimal cutoff FC value of 240µg/g to predict relapse of quiescent Crohn’s had sensitivity of 80.0% and specificity of 74.4%. Negative predictive value was 96.8% and positive predictive value was 27.6%. FC≥240μg/g was associated with likelihood of relapse 5.7 (95% CI 1.9-17.3) times higher within 2.3 years than lower values (p=0.002).<p></p> Conclusions: In this prospective dataset, FC appears to be a useful, non-invasive tool to help identify quiescent Crohn’s disease patients at a low risk of relapse over the ensuing 12 months. FC of 240µg/g was the optimal cutoff in this cohort.<p></p&gt

    Budesonide foam versus budesonide enema in active ulcerative proctitis and proctosigmoiditis

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    Background: Rectal budesonide is an effective treatment of active ulcerative proctitis or proctosigmoiditis. Aim: To compare the therapeutic efficacy, tolerability and safety, and patient's preference of budesonide foam vs. budesonide enema. Methods: Patients with active ulcerative proctitis or proctosigmoiditis (clinical activity index >4 and endoscopic index ≥4) were eligible for this double-blind, double-dummy, randomized, multicentre study. They received 2 mg/25 mL budesonide foam and placebo enema (n = 265), or 2 mg/100 mL budesonide enema and placebo foam (n = 268) for 4 weeks. Primary endpoint was clinical remission (clinical activity index ≤4) at the final/withdrawal visit (per protocol). Results: A total of 541 patients were randomized - 533 were evaluable for intention-to-treat analysis and 449 for per protocol analysis. Clinical remission rates (per protocol) were 60% for budesonide foam and 66% for budesonide enema (P = 0.02362 for non-inferiority of foam vs. enema within a predefined non-inferiority margin of 15%). Both formulations were safe and no drug-related serious adverse events were observed. Because of better tolerability and easier application most patients preferred foam (84%). Conclusion: Budesonide foam is as effective as budesonide enema in the treatment of active ulcerative proctitis or proctosigmoiditis. Both budesonide formulations are safe, and most patients prefer foam.publishersversionPeer reviewe

    Low urine pH and acid excretion do not predict bone fractures or the loss of bone mineral density: a prospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>The acid-ash hypothesis, the alkaline diet, and related products are marketed to the general public. Websites, lay literature, and direct mail marketing encourage people to measure their urine pH to assess their health status and their risk of osteoporosis.</p> <p>The objectives of this study were to determine whether 1) low urine pH, or 2) acid excretion in urine [sulfate + chloride + 1.8x phosphate + organic acids] minus [sodium + potassium + 2x calcium + 2x magnesium mEq] in fasting morning urine predict: a) fragility fractures; and b) five-year change of bone mineral density (BMD) in adults.</p> <p>Methods</p> <p>Design: Cohort study: the prospective population-based Canadian Multicentre Osteoporosis Study. Multiple logistic regression was used to examine associations between acid excretion (urine pH and urine acid excretion) in fasting morning with the incidence of fractures (6804 person years). Multiple linear regression was used to examine associations between acid excretion with changes in BMD over 5-years at three sites: lumbar spine, femoral neck, and total hip (n = 651). Potential confounders controlled included: age, gender, family history of osteoporosis, physical activity, smoking, calcium intake, vitamin D status, estrogen status, medications, renal function, urine creatinine, body mass index, and change of body mass index.</p> <p>Results</p> <p>There were no associations between either urine pH or acid excretion and either the incidence of fractures or change of BMD after adjustment for confounders.</p> <p>Conclusion</p> <p>Urine pH and urine acid excretion do not predict osteoporosis risk.</p

    History, epidemiology and regional diversities of urolithiasis

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    Archeological findings give profound evidence that humans have suffered from kidney and bladder stones for centuries. Bladder stones were more prevalent during older ages, but kidney stones became more prevalent during the past 100 years, at least in the more developed countries. Also, treatment options and conservative measures, as well as ‘surgical’ interventions have also been known for a long time. Our current preventive measures are definitively comparable to those of our predecessors. Stone removal, first lithotomy for bladder stones, followed by transurethral methods, was definitively painful and had severe side effects. Then, as now, the incidence of urolithiasis in a given population was dependent on the geographic area, racial distribution, socio-economic status and dietary habits. Changes in the latter factors during the past decades have affected the incidence and also the site and chemical composition of calculi, with calcium oxalate stones being now the most prevalent. Major differences in frequency of other constituents, particularly uric acid and struvite, reflect eating habits and infection risk factors specific to certain populations. Extensive epidemiological observations have emphasized the importance of nutritional factors in the pathogenesis of urolithiasis, and specific dietary advice is, nowadays, often the most appropriate for prevention and treatment of urolithiasis

    Assessing impacts of soil management measures on ecosystem services

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    Only a few studies have quantified and measured ecosystem services (ES) specifically related to soil. To address this gap, we have developed and applied a methodology to assess changes in ecosystem services, based on measured or estimated soil property changes that were stimulated by soil management measures (e.g., mulching, terracing, no-till). We applied the ES assessment methodology in 16 case study sites across Europe representing a high diversity of soil threats and land use systems. Various prevention and remediation measures were trialled, and the changes in manageable soil and other natural capital properties were measured and quantified. An Excel tool facilitated data collection, calculation of changes in ecosystem services, and visualization of measured short-term changes and estimated long-term changes at plot level and for the wider area. With this methodology, we were able to successfully collect and compare data on the impact of land management on 15 different ecosystem services from 26 different measures. Overall, the results are positive in terms of the impacts of the trialled measures on ecosystem services, with 18 out of 26 measures having no decrease in any service at the plot level. Although methodological challenges remain, the ES assessment was shown to be a comprehensive evaluation of the impacts of the trialled measures, and also served as an input to a stakeholder valuation of ecosystem services at local and sub-national level

    Medical treatment of pediatric urolithiasis

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    In recent years the incidence of pediatric stone disease has increased several fold, mostly due to hypercalciuria and hypocitraturia. The goal of medical treatment is to protect the patient from formation of new stones and expansion of existing ones. The non-pharmacological means to address stone disease include high fluid intake and, frequently, modification of nutritional habits. The pharmacological treatment is based on the chemical composition of the stone and the biochemical abnormalities causing its formation; hence, chemical analysis of the stone, urine and blood is of paramount importance and should be done when the first stone is detected. This review discusses the current options of medical treatment of pediatric urolithiasis
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