Human bladder urine oxygen content: Implications for urinary tract diseases

Giannakopoulos, X; Evangelou, Angelos; Kalfakakou, Vasiliki; Grammeniatis, E.; Papandropoulos, I.; Charalambopoulos, K.

doi:10.1007/bf02551103

Cited by 41 publications

(36 citation statements)

References 10 publications

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“…There is a single report in literature showing that pelvic urine pO2 closely reflects renal medullary pO2 in humans 21 . While measuring pelvic pO2 will necessitate invasive measurements, data exists suggesting that freshly voided urine could be used to monitor relative changes in urine pO2 22 . Continuous monitoring of bladder urine pO2 has been shown to be feasible in patients undergoing cardiac bypass procedures 23 .…”

Section: Discussionmentioning

confidence: 99%

Effect of Iodinated Contrast Medium in Diabetic Rat Kidneys as Evaluated by Blood-Oxygenation-Level–Dependent Magnetic Resonance Imaging and Urinary Neutrophil Gelatinase-Associated Lipocalin

Lü

Franklin

et al. 2015

Investigative Radiology

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Objectives To assess if streptozotocin (STZ) induced diabetic rats develop iodinated contrast induced acute kidney injury (CIAKI). The intra-renal R2* (= 1/ T2*) was evaluated continuously before-during-after contrast administration. Renal injury was confirmed by urinary neutrophil gelatinase-associated lipocalin (uNGAL) measurements. Materials and Methods Six Sprague-Dawley rats were administered STZ to induce diabetes (Group 1). R2* was measured before, during, and after administration of iodixanol. R2* readings were sampled from four renal regions: inner medulla, inner stripe of outer medulla (ISOM), outer stripe of outer medulla, and cortex. Peak R2* and initial up-slope of R2* increase following iodinated contrast were calculated. Data from 12 non-diabetic rats pre-treated with nitric oxide synthase and prostaglandin inhibitors to induce susceptibility to CIAKI (pre-treatment model) from a previous study were re-analyzed for peak R2* and initial up-slope of R2* increase following contrast. Six of these animals received saline (Group 2) and the other six received furosemide (Group 3) prior to idoxianol. Results Peak R2* and initial up-slope of R2* increase were used as BOLD response parameters. R2* in ISOM were comparable in all three groups prior to administration of furosemide. Except for the furosemide group, ISOM showed a rapid increase in R2* immediately following contrast administration. Unlike the L-NAME & indomethacin treated groups, the diabetic group showed a quick reversal of R2* towards baseline measurements after contrast administration. Urinary NGAL indicated significant increase in diabetic rats 4 hours following contrast administration. The observed trends with peak R2* and initial up-slope of R2* increase in renal ISOM were in agreement with those of uNGAL. Conclusion The STZ induced diabetic rat may be suitable for studying the effects of iodinated contrast on renal oxygenation status and may mimic human condition closer than the pre-treatment model described before. The peak R2* value and initial up-slope of R2* in ISOM appear to be effective MRI markers to predict renal injury following administration of an iodinated contrast agent.

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Section: Discussionmentioning

confidence: 99%

Effect of Iodinated Contrast Medium in Diabetic Rat Kidneys as Evaluated by Blood-Oxygenation-Level–Dependent Magnetic Resonance Imaging and Urinary Neutrophil Gelatinase-Associated Lipocalin

Lü

Franklin

et al. 2015

Investigative Radiology

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“…Traces of superoxide dismutase are present in urine (56): this enzyme, as well as the acidic pH of urine, should facilitate dismutation of O !¡ 2 to H 2 O 2 (1). The pO 2 of urine within the bladder is below that of ambient air (57,58) and so the rate of H 2 O 2 generation in urine may well increase upon voiding. Nevertheless, the high levels of H 2 O 2 that are detected in some urine samples ( Table 1) strongly suggest that at least some H 2 O 2 generation occurs within the bladder.…”

Section: The Urogenital Systemmentioning

confidence: 99%

Hydrogen Peroxide. Ubiquitous in Cell Culture and In vivo?

Halliwell¹,

Clément²,

Ramalingam³

et al. 2000

IUBMB Life

143

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Hydrogen peroxide (H2O2) is widely regarded as a cytotoxic agent whose levels must be minimized by the action of antioxidant defence enzymes. In fact, H2O2 is poorly reactive in the absence of transition metal ions. Exposure of certain human tissues to H2O2 may be greater than is commonly supposed; levels of H2O2 in the human body may be controlled not only by catabolism but also by excretion, and H2O2 could play a role in the regulation of renal function and as an antibacterial agent in the urine. Cell culture is a widely used method for the investigation of "physiological" processes such as signal transduction and regulation of gene expression, but chemical reactions involving cell culture media are rarely considered. Addition of reducing agents to commonly used cell-culture media can lead to generation of substantial amounts of H2O2. Some or all of the reported effects of ascorbic acid and polyphenolic compounds (e.g., quercetin, catechin, epigallocatechin, epigallocatechin gallate) on cells in culture may be due to H2O2 generation by interaction of these compounds with cell culture media.

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“…The stone holder is filled with tap water (c ¼ 7.2 mg=l O 2 ) to simulate in vivo cavitation conditions in the vicinity of the stone [25]. After stones are treated with 250 shocks at 1 Hz, the fragments are collected and dried for 24 h in an oven at 40°C.…”

Section: Stone Comminutionmentioning

confidence: 99%

Bubble Proliferation or Dissolution of Cavitation Nuclei in the Beam Path of a Shock-Wave Lithotripter

et al. 2015

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It is hypothesized that the decreased treatment efficiency in contemporary shock-wave lithotripters is related to tensile wave attenuation due to cavitation in the prefocal beam path. Utilizing high-speed imaging of the beam path and focal pressure waveform measurements, tensile attenuation is associated with bubble proliferation. By systematically testing different combinations of pulse-repetition frequency and gas concentration, we modulate the bubble-dissolution time to identify which conditions lead to bubble proliferation and show that reducing bubble proliferation in the beam path significantly improves acoustic transmission and stone comminution efficiency in vitro. In addition to experiments, a bubbleproliferation model is developed that takes gas diffusion across the bubble wall and bubble fragmentation into account. By aligning the model with experimental observations, the number of daughter bubbles produced after a single lithotripter bubble collapse is estimated to be in the range of 253 ∼ 510. This finding is on the same order of magnitude with previous measurements of an isolated bubble collapse in a lithotripter field by Williams [BJU Int. 102, 1681 (2008)], and this estimate improves the general understanding of lithotripsy bubble dynamics in the beam path.

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Human bladder urine oxygen content: Implications for urinary tract diseases

Cited by 41 publications

References 10 publications

Effect of Iodinated Contrast Medium in Diabetic Rat Kidneys as Evaluated by Blood-Oxygenation-Level–Dependent Magnetic Resonance Imaging and Urinary Neutrophil Gelatinase-Associated Lipocalin

Effect of Iodinated Contrast Medium in Diabetic Rat Kidneys as Evaluated by Blood-Oxygenation-Level–Dependent Magnetic Resonance Imaging and Urinary Neutrophil Gelatinase-Associated Lipocalin

Hydrogen Peroxide. Ubiquitous in Cell Culture and In vivo?

Bubble Proliferation or Dissolution of Cavitation Nuclei in the Beam Path of a Shock-Wave Lithotripter

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