PMID- 15981006
OWN - NLM
STAT- MEDLINE
DCOM- 20060104
LR  - 20181113
IS  - 0300-5623 (Print)
IS  - 0300-5623 (Linking)
VI  - 33
IP  - 4
DP  - 2005 Aug
TI  - Factors modulating the pH at which calcium and magnesium phosphates precipitate 
      from human urine.
PG  - 254-60
AB  - The factors controlling the rate at which crystalline bacterial biofilms develop 
      on indwelling bladder catheters are poorly understood. It is known that normally 
      the pH of voided urine (pHv) is lower than the pH at which calcium and magnesium 
      phosphates come out of urine solution (pHn). In patients who develop infections 
      with urease producing bacteria, however, the pHv rises above the pHn and 
      precipitation of the phosphates occurs in the urine and the biofilm. The aim of 
      this study was to examine ways of manipulating the pHn of urine so that more of 
      its calcium and magnesium remain in solution under alkaline conditions. The 
      experimental data show that pHn can be elevated by decreasing the calcium, 
      magnesium and phosphate concentrations. Increasing the fluid intake of a human 
      subject so that the urinary calcium fell from 120 mg/l to 25 mg/l, for example, 
      resulted in the pHn increasing from 6.48 to 8.22. The addition of citrate to 
      urine also produced a rise in the pHn. The daily consumption of 500 ml of fresh 
      orange juice increased urinary citrate concentrations from 0.35 to around 1.21 
      mg/ml and the pHn rose from 7.24 to 8.2. The pHn of urine is thus a highly 
      variable parameter. It can be manipulated by controlling the urinary 
      concentrations of magnesium, calcium, phosphate and citrate ions. We suggest that 
      increasing fluid intake with citrate containing drinks would reduce the extent of 
      encrustation on catheters in patients infected with urease producing bacteria.
FAU - Suller, M T E
AU  - Suller MT
AD  - Faculty of Applied Sciences, University of the West of England, Coldharbour Lane, 
      Bristol, BS161QY, UK. marc.suller@uwe.ac.uk
FAU - Anthony, V J
AU  - Anthony VJ
FAU - Mathur, S
AU  - Mathur S
FAU - Feneley, R C L
AU  - Feneley RC
FAU - Greenman, J
AU  - Greenman J
FAU - Stickler, D J
AU  - Stickler DJ
LA  - eng
PT  - Journal Article
PL  - Germany
TA  - Urol Res
JT  - Urological research
JID - 0364311
RN  - 0 (Calcium Phosphates)
RN  - 0 (Magnesium Compounds)
RN  - 0 (Phosphates)
RN  - 2968PHW8QP (Citric Acid)
RN  - 453COF7817 (magnesium phosphate)
RN  - 97Z1WI3NDX (calcium phosphate)
SB  - IM
MH  - Adult
MH  - Bacteria/*growth & development
MH  - Biofilms
MH  - Calcium Phosphates/*chemistry/urine
MH  - Catheters, Indwelling/*microbiology
MH  - Chemical Precipitation
MH  - Citric Acid/pharmacology
MH  - Drinking
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Magnesium Compounds/*chemistry/urine
MH  - Male
MH  - Phosphates/*chemistry/urine
MH  - Urinary Catheterization/*adverse effects
MH  - Urine/*chemistry
EDAT- 2005/06/28 09:00
MHDA- 2006/01/05 09:00
CRDT- 2005/06/28 09:00
PHST- 2005/06/28 09:00 [pubmed]
PHST- 2006/01/05 09:00 [medline]
PHST- 2005/06/28 09:00 [entrez]
AID - 10.1007/s00240-004-0458-y [doi]
PST - ppublish
SO  - Urol Res. 2005 Aug;33(4):254-60. doi: 10.1007/s00240-004-0458-y.