Renal and Genitourinary Concerns

Jones, Jeffrey A.; Pietrzyk, Robert A.; Whitson, Peggy A.

doi:10.1007/978-0-387-68164-1_13

Cited by 11 publications

(13 citation statements)

References 23 publications

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“…The physiological, environmental, and dietary conditions imposed by space travel and weightlessness have a considerable potential for increasing the risk of renal stone development (11,26,(37)(38)(39)40). CaOx stones account for ϳ85% of the clinical occurrences of nephrolithiasis on Earth, and the majority of the 14 stones developed by the astronauts postflight (13,26,33).…”

mentioning

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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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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“…But the most common renal stone and a main component in stones of mixed composition is CaOx as it accounts for almost 85% of the clinical occurrences of nephrolithiasis. Four out of the six kidney stones of known composition developed by the astronauts have also been CaOx [5]. In this paper, we will present a combined transport-kinetics model for the growth of CaOx crystals.…”

Section: Introductionmentioning

confidence: 99%

A combined transport-kinetics model for the growth of renal calculi

Kassemi

Brock

Nemeth

2011

Journal of Crystal Growth

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“…Astronauts are at an increased risk of forming kidney stones because of bone demineralization, dehydration, stasis, and alkalinization of urine that occur in spaceflight (Jones et al 2008; Sibonga et al 2008). While generally innocuous in the kidney, a stone often causes debilitating pain as it passes, and even worse, may become obstructive, which could lead to sepsis, urinary tract infection, renal failure, or even death (Glowacki et al 1992; Pearle et al 2005; Scales et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Effect of Carbon Dioxide on the Twinkling Artifact in Ultrasound Imaging of Kidney Stones: A Pilot Study

Simon

Wang

Cunitz

et al. 2017

Ultrasound in Medicine & Biology

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Bone demineralization, dehydration, and stasis put astronauts at an increased risk of forming kidney stones in space. The color-Doppler ultrasound “twinkling artifact”, which highlights kidney stones with color, can make stones readily detectable with ultrasound; however our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. Upon exposing pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9–25 minutes and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling from exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles.

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Renal and Genitourinary Concerns

Cited by 11 publications

References 23 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

A combined transport-kinetics model for the growth of renal calculi

Effect of Carbon Dioxide on the Twinkling Artifact in Ultrasound Imaging of Kidney Stones: A Pilot Study

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