Determination of nucleation, growth, agglomeration and disruption kinetics from experimental precipitation data: the calcium oxalate system

Zauner, Rudolf; Jones, Alan G.

doi:10.1016/s0009-2509(00)00059-2

Cited by 97 publications

(84 citation statements)

References 24 publications

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“…In this work, this linear relationship was used to calculate the inhibited agglomeration kernel for CaOx at varying citrate concentrations. Again, the value supplied by Zauner and Jones (41) in Table 1 was used as the nominal uninhibited agglomeration rate constant in the absence of citrate.…”

Section: Effect Of Citrate Inhibitionmentioning

confidence: 99%

Prediction of renal crystalline size distributions in space using a PBE analytic model. 2. Effect of dietary countermeasures

Kassemi

Thompson

2016

American Journal of Physiology-Renal Physiology

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is used to assess the efficacy of citrate, pyrophosphate, and augmented fluid intake as dietary countermeasures aimed at reducing the risk of renal stone formation for astronauts. The model uses the measured biochemical profile of the astronauts as input and predicts the steady-state size distribution of the nucleating, growing, and agglomerating renal calculi subject to biochemical changes brought about by administration of these dietary countermeasures. Numerical predictions indicate that an increase in citrate levels beyond its average normal groundbased urinary values is beneficial but only to a limited extent. Unfortunately, results also indicate that any decline in the citrate levels during space travel below its normal urinary values on Earth can easily move the astronaut into the stone-forming risk category. Pyrophosphate is found to be an effective inhibitor since numerical predictions indicate that even at quite small urinary concentrations, it has the potential of shifting the maximum crystal aggregate size to a much smaller and plausibly safer range. Finally, our numerical results predict a decline in urinary volume below 1.5 liters/day can act as a dangerous promoter of renal stone development in microgravity while urinary volume levels of 2.5-3 liters/day can serve as effective space countermeasures.nephrolithiasis; gravity; weightlessness; crystal nucleation; crystal growth; agglomeration; inhibition; dietary countermeasures NEPHROLITHIASIS IS NOT ONLY a problem within the general population on Earth but is also a risk to the astronauts' health and survival during future long-duration missions where exposure to microgravity and other space conditions are likely to increase the risk of renal stone formation. The concern seems to be justified since a recent survey of renal stone formation in US astronauts has revealed 14 recorded postflight episodes (13, 26). Whether on Earth or in space, the development of calcium oxalate (CaOx) renal stones is initiated with nucleation of the sparingly soluble salt from a supersaturated urine as the necessary first step, followed by simultaneous growth and agglomeration of the crystals as two effective stone size-enhancing mechanisms. While the extent of urinary CaOx supersaturation in the nephron changes continuously depending on the level of hydration and the extent of other dietary intake, the urine of most individuals, healthy or stone former, remains supersaturated under normal everyday conditions.The progression from crystal nucleation and growth to a clinical colic situation is not yet well understood, but it is thought to occur by either free-or fixed-particle mechanisms (13, 32). Recent studies by Kim et al. (14) and Evan et al. (7) using advanced endoscopic imaging and comprehensive physiological biopsies suggest three possible free/fixed pathways to stone formation: 1) nucleation and growth on the Randall plaque deposits in the papillae; 2) growth after adherence to a possibly injured section of collecting or Bellini ducts; and 3) homogeneous nucleatio...

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Section: Effect Of Citrate Inhibitionmentioning

confidence: 99%

Prediction of renal crystalline size distributions in space using a PBE analytic model. 2. Effect of dietary countermeasures

Kassemi

Thompson

2016

American Journal of Physiology-Renal Physiology

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“…Recent investigations of the effect of growth rate and stirrer speed on aggregation in precipitation processes are available in the literature (Mumtaz and Hounslow, 2000;Seyssiecq et al, 2000;Zauner and Jones, 2000), resulting in somewhat deviating opinions about the basic principles of the aggregation process. Two particles come together as a result of the orthokinetic collision frequency but the success of aggregation is dependent on growth-controlled cementation.…”

Section: Aggregation Ratesmentioning

confidence: 99%

Growth and aggregation of vaterite in seeded‐batch experiments

Andreassen

Hounslow

2004

AIChE Journal

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“…where K b is the nucleation rate constant for which we use a fitted value for CaOx based on a range of measured nucleation rates reported in the literature (1,3,40). Equation 1 is subject to two important simplifying assumptions.…”

Section: Methodsmentioning

confidence: 99%

“…6 clearly indicate that the impact of agglomeration on the size distiribution of renal calculi is significant. Unfortunately, as was the case with the reaction rate consistent for CaOx, there is also around an order of magnitude scatter in the nominal values of the agglomera- (40). The situation is, again, further exacerbated by the scarcity of data on how the agglomeration constant is altered due to the direct inhibitive effect of certain constituents of urine such as citrate (11).…”

Section: ϫ10mentioning

confidence: 99%

Prediction of renal crystalline size distributions in space using a PBE analytic model. 1. Effect of microgravity-induced biochemical alterations

Kassemi

Thompson

2016

American Journal of Physiology-Renal Physiology

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Numerical results indicate that the model is successful in clearly distinguishing between 1-G normal and 1-G recurrent stone-former subjects based solely on their published 24-h urine biochemical profiles. Numerical case studies further show that the predicted renal calculi size distribution for a microgravity astronaut is closer to that of a recurrent stone former on Earth rather than to a normal subject in 1 G. This interestingly implies that the increase in renal stone risk level in microgravity is relatively more significant for a normal person than a stone former. However, numerical predictions still underscore that the stone-former subject carries by far the highest absolute risk of critical stone formation during space travel.

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Determination of nucleation, growth, agglomeration and disruption kinetics from experimental precipitation data: the calcium oxalate system

Cited by 97 publications

References 24 publications

Prediction of renal crystalline size distributions in space using a PBE analytic model. 2. Effect of dietary countermeasures

Prediction of renal crystalline size distributions in space using a PBE analytic model. 2. Effect of dietary countermeasures

Growth and aggregation of vaterite in seeded‐batch experiments

Prediction of renal crystalline size distributions in space using a PBE analytic model. 1. Effect of microgravity-induced biochemical alterations

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