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Biomedical subjects

H G Tiselius

Publications and source records attributed to H G Tiselius.

At least 19 recordsLinked to original sources
PubMed1992

The effects of a single evening dose of alkaline citrate on urine composition and calcium stone formation.

The effects on urine composition and pH of a single evening dose of alkaline potassium sodium citrate were studied in healthy subjects and recurrent calcium oxalate stone formers. This treatment resulted in a prompt and significantly increased urinary pH with a duration until 10 a.m. the next day and a reduced risk of calcium oxalate crystallization between 10 p.m. and 10 a.m. In a retrospective study alkaline citrate was given in a single evening dose of 3.75 or 5 gm. to 55 patients with calcium oxalate stone disease and a total dose of 5.0 or 7.5 gm. was administered 2 or 3 times daily in 17 patients. The mean plus or minus standard deviation for duration of treatment was 3.5 +/- 1.7 years. Significantly reduced stone formation was recorded only in those on the evening dose regimen, which was associated with significant improvement of urine composition. Patients who continued to form new stones or who had growth of residual stones despite treatment also had improved urine composition but the calcium excretion and the calcium/citrate quotient remained elevated. In 4 patients with new stone formation calcium phosphate was the major component and calcium excretion was high but the concomitant increased citrate excretion resulted in a calcium/citrate quotient that was only slightly elevated. In patients forming calcium oxalate stones the only abnormality was a high calcium/citrate quotient. Because of favorable biochemical and clinical effects as well as good patient compliance with a single evening dose of alkaline citrate, this regimen appears to be an attractive alternative for long-term prevention of recurrent calcium stone formation.

Adult↗
PubMed1992

Calcium oxalate crystallization properties in urine with different specific electrical conductivities.

The relationship between the degree of urine dilution and the risk of calcium oxalate crystallization was studied in 32 urine samples collected from stone formers and normal subjects during an 8-hour period between 10 p.m. and 6 a.m., and in 4-hour urine samples collected during 24-hour periods from 6 patients with calcium stone disease. The risk of calcium oxalate crystallization was analyzed in terms of the increase in oxalate concentration required for a standardized precipitation of crystals of calcium oxalate. The degree of urine dilution was determined with a new instrument (urimho) designed for measuring the concentration, in terms of specific electrical conductivity, in urine samples of droplet size. With this device urine concentration can be expressed in urimho values between 1 and 5. There was a good correlation between recordings of specific electrical conductivity performed with the new device and with a conventional conductivity meter. There was a statistically significant positive correlation between urimho values and calcium oxalate crystallization. Calcium oxalate crystallization greater than 1.3 was not observed in any sample with a urimho value of 2 but it was noted in 31% of the samples with urimho values greater than 2. A positive relationship was also recorded between the urine pH and the urimho level, which is noteworthy because there was an inverse relationship between urine pH and calcium oxalate crystallization. A pH greater than 6 was observed in 78% of the samples with a urimho value of 2 but it was noted in only 27% of the samples with urimho readings between 3 and 5. A considerable variation in the response in urinary flow to ingested volumes was recorded. Therefore, monitoring of urine dilution by means of a sample device like the urimho might be of great help for patients with calcium stone disease in an effort to prevent recurrent stone formation by urine dilution, provided a urimho value of less than 3 can be maintained.

Calcium↗
PubMed1992

Extracorporeal shock wave lithotripsy of bile duct stones: a single institution experience.

Extracorporeal shock wave lithotripsy treatment with Dornier HM3 or MPL 9000 machines was applied in 37 patients with problematic bile duct stones. General anaesthesia was not required. After one extracorporeal shock wave lithotripsy session 14/37 patients (38%) were spontaneously stone free, and additional endoscopic extraction (eight of 37) and retreatments with extracorporeal shock wave lithotripsy (seven cases) increased the stone free rate to 29/37 (78%). In three patients with intrahepatic stones, the bile ducts could not be evaluated decisively at cholangiography and ultrasonography, but they were all symptom free at 15 to 38 months follow up. If these three patients are added to the radiologically stone free patients, the overall clinical success rate was 32/37 (86%). There were no serious complications, hospital admissions, or 30 day mortality as a result of extracorporeal shock wave lithotripsy or endoscopic procedures. It is concluded that extracorporeal shock wave lithotripsy is a valuable adjunct to the non-surgical treatment of bile duct stones.

Aged↗
PubMed1992

Clinical significance of phosphate in calcium oxalate renal stones.

We analysed calcium, magnesium, oxalate, citrate, urate and creatinine in urine and calculated risk factors in patients who had formed stones composed of calcium oxalate, and calcium phosphate, alone or as a mixture. Patients producing pure calcium oxalate stones (less than 0.1% phosphate) had a higher oxalate, and lower calcium excretion than stone-free subjects and patients forming other stone types. In contrast, patients producing calcium oxalate stones containing phosphate, even in trace amounts (greater than 0.1%) had no increase in oxalate excretion, but a higher calcium excretion than stone-free subjects. We could not correlate any computed variable (e.g. AP(CaOx) index) to stone composition. We conclude that pure CaOx stones may be the result of a high oxalate excretion, and that other calcium containing stones may have another and probably more complex aetiology, including primary precipitation of calcium phosphates.

Calcium Oxalate↗
PubMed1992

Cost effectiveness of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy for medium-sized kidney stones. A randomised clinical trial.

To evaluate percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (ESWL) for their clinical effects, their cost effectiveness, their complication rates, and the patients' experiences, 55 consecutive patients were randomised to have one or other operation between October 1986 and October 1988. Six patients were excluded, 21 were treated with PNL and 28 with ESWL as primary treatment. Mean hospital stay and length of treatment were longer for PNL than for ESWL. Since 1 July 1987 all patients having ESWL have been treated without anaesthesia (n = 15), whereas epidural anaesthesia was used for all PNL. Slightly more of the ESWL patients experienced some pain during treatment. Minor complications or pain were more common after ESWL during the first 10 days after discharge from hospital. If patients with stone fragments of 4 mm or less were regarded as having a successful outcome, the success rates after one year were 94% for PNL and 77% for ESWL. The overall total cost was lower for ESWL than for PNL, the cost per successfully treated patient being 2172 pounds for PNL and 1810 pounds for ESWL. Medium sized kidney stones (6-30 mm, or 2-3 stones of 20 mm or less) can be efficiently and cheaply treated by both PNL and ESWL, though the cost of ESWL is lower. Even if effects other than cost (such as complications and patients' experience) are borne in mind, ESWL was superior to PNL for this group of patients.

Cost-Benefit Analysis↗
PubMed1991

Inhibition of calcium oxalate crystallization by urinary macromolecules.

The crystallization of calcium oxalate (CaOx) was determined in dialyzed urine samples collected between 0600 and 1000 hours from 18 normal men, 10 normal women and 13 men and 10 women with CaOx stone disease. Each urine samples was supersaturated by the addition of calcium chloride and sodium oxalate, and CaOx crystallization was followed by quantification of the [14C]-oxalate remaining in solution for 30 min after supersaturation of the sample. The rate of crystallization was compared with that in physiological saline. The surface area delimited by the urine and saline curves was used to express the inhibition of CaOx crystallization by urinary macromolecules (IUMM). The IUMM was significantly higher in urine from normal women than in that from stone-forming women (P less than 0.05), normal men (P less than 0.005), and stone-forming men (P less than 0.02). However, there were no significant differences between stone-forming men and stone-forming women, nor was IUMM higher in normal men than in stone-forming men. A high concentration of inhibitors might protect women from CaOx stone formation and be one factor explaining the lower stone-formation rate in women. Although low values were more predominate in normal men than in normal women, there were no significant differences between the groups when the inhibition was corrected for differences in urinary volumes.

Calcium Oxalate↗
PubMed1991

Anesthesia-free in situ extracorporeal shock wave lithotripsy of ureteral stones.

Stones in the proximal, mid and distal ureter in 375 consecutive patients were treated with extracorporeal shock wave lithotripsy (ESWL) in a technically unmodified Dornier HM3 lithotriptor without regional or general anesthesia. Adequate followup was available in 162 patients with proximal, 62 with mid and 146 with distal ureteral stones. The fraction of patients with stone-free ureters within 3 months after ESWL was 96, 97 and 97%, respectively. Of all patients only 13 (3.6%) had residual stones or fragments in the ureter after 3 months. The average number of ESWL sessions was 1.34 for all patients, and 1.36, 1.45 and 1.38 for those with proximal, mid and distal ureteral stones, respectively. A ureteral catheter with saline irrigation was used whenever it was possible to insert a ureteral catheter. Only 15 stones were pushed up to the kidney during catheterization and all other stones were treated in situ. There were more retreatments in patients in whom the stone had not been bypassed by a catheter at the initial ESWL session. During at least 1 treatment session 238 patients had a ureteral catheter with the tip above the stone. Approximately half of all patients were treated after only premedication with pethidine and diazepam, and cutaneous half of all patients were treated after only premedication with pethidine and diazepam, and cutaneous anesthesia with an anesthetic cream containing lidocaine-prilocaine (for proximal and mid ureteral stones). Small supplements of pethidine and diazepam were given to the other patients during the ESWL session. In situ ESWL of ureteral stones as described is a convenient, efficient and attractive procedure that, applied in a consequent manner, theoretically might result in a successful outcome in up to 98% of the patients.

Adult↗
PubMed1991

Aspects on estimation of the risk of calcium oxalate crystallization in urine.

A previously formulated simplified estimate of the ion activity product of calcium oxalate, AP(CaOx) index, was modified in order to better correspond numerically to the ion activity product obtained by computed iterative approximation with the EQUIL 2 program. The new index, AP(CaOx) index EQ, was given the following form for a 4-hour urine: 1.9 x Ca(0.84) x Ox x Mg-(0.12) x Cit-(0.22) x V-(1.03), where the excretion of calcium, oxalate (Ox), magnesium and citrate (Cit) was expressed in millimoles excreted during the period, and urine volume (V) in liters. There was a good correlation between AP(CaOx) index and AP(CaOx) index EQ (r = 0.98). A standardized index calculated for a 24-hour urine volume of 1.5 liters, AP(CaOx) index EQ(s), was significantly higher in stoneforming men (p less than 0.001) and women (p less than 0.001) than in normal subjects. The mean ion activity products of CaOx at the start of crystallization in salt solutions and dialyzed urine were 2.74 +/- 0.25 x 10(-8) and 3.50 +/- 0.33 x 10(-8) (mol/l)2, respectively. In the urine from normal subjects, AP(CaOx) index EQ at the point of crystallization was 4.3 +/- 1.1 and in the urine from stone formers 2.8 +/- 0.5 (p less than 0.001). From calculation of AP(CaOx) index EQ in hourly collected urine, it was assumed that the risk of exceeding the level where crystallization starts during periods with the highest supersaturation can be anticipated when the 24-hour AP(CaOx) index EQ value exceeds 2.0.

Calcium Oxalate↗
PubMed1990

Effects of different doses of alkaline citrate on urine composition and crystallization of calcium oxalate.

Prophylactic treatment with alkaline citrate in patients with recurrent calcium oxalate (CaOx) stone disease results in reduced CaOx supersaturation and increased urinary citrate. The effects of a single evening dose were compared with those of two and three daily doses in six recurrent CaOx stone formers with hypercalciuria, hypocitraturia or raised calcium/citrate quotients. While on a standardized hospital diet the patients were given 7.5 g (28 mmol) of sodium potassium citrate (URALYT-U) in one, two, and three doses. Fractional urine collections during 24 hours were analyzed for pH, composition, and crystallization risk (CR). All dosage regimens had favourable effects on urinary calcium, citrate, calcium/citrate quotients, and CaOx-CR. The most sustained effect was recorded with three divided doses. Single evening doses resulted in the most pronounced effects between 22.00-06.00 h, thereby counteracting the increased risk of CaOx crystallization during that period. In terms of 24h urine composition the best effect was recorded with alkaline citrate administered three times daily, but because of the favourable response by a single evening dose between 22.00-06.00 h the assumption was made that this dosage regimen might be sufficient to reduce the risk of CaOx crystallization and stone formation. However, the validity of such an assumption can only be established by long-term clinical studies.

Calcium Oxalate↗
PubMed1990

Effects of urinary macromolecules on the crystallization of calcium oxalate.

The macromolecular fraction of urine with a molecular weight above 3,000 was isolated by dialysis. In the dialysed urine the rate of calcium oxalate (CaOx) crystallization was reduced both in the presence and absence of CaOx seed crystals. There was a clear relationship between crystallization and the relative concentration of the dialysed urine, with the highest crystallization propensity at the lowest concentration of macromolecules. Dilution of dialysed urine also affected crystal size distribution, with a predominance of small (2.8-4.5 microns) crystals in 100% dialysed urine and of large (5.6-14.0 microns) crystals in 5% dialysed urine. This is consistent with a macromolecular inhibition of both crystal growth and aggregation. Analysis of the crystal size distribution 120 min after supersaturation of whole urine to a level at which approximately 100 crystals in the size interval 3.5-5 microns were detected in a Coulter counter surprisingly disclosed a higher mean crystal volume in urine samples from normal subjects than from stone formers. This gives support to the assumptions that macromolecules might be of importance during the initial phase of CaOx crystallization and that urine from stone formers and normal subjects might be different in this respect.

Calcium Oxalate↗
PubMed1990

Recurrences during a 10-year follow-up after first renal stone episode.

Each of 92 patients in a Swedish district served by only one hospital had been treated for their first renal stone in 1977 and was evaluated 10 years later. Recurrent stone formation during the observation period was observed in 26% of the patients, with no difference between men and women. Of all the patients who had sought medical advice in 1977 because of urinary stone colic, 51% were experiencing their first stone episode. Ten years later 37% of the original patients were still classified as single stone formers. The recorded recurrence rate was lower than that previously reported in the literature.

Adult↗
PubMed1990

Studies on the crystallization of magnesium ammonium phosphate in urine.

The crystallization of magnesium ammonium phosphate (MAP) was studied in salt solutions and dialysed urine at similar levels of MAP supersaturation. At pH levels of 7.1 or higher crystallization occurred to the same extent in solutions with and without urinary macromolecules. Whereas crystals in the size range 3.5-5 microns were observed in the salt solution at pH 7.0, this was not so in dialysed urine. When the crystal size distribution was determined after 30 min larger crystals were observed in dialysed urine, indicating a promoting effect by urinary macromolecules on the formation of MAP crystals. A modified AP(MAP) index was formulated based on calculations with the EQUIL 2 programme in order to improve the relationship between this simplified estimate and the ion-activity product of MAP (APMAP). This index had the following form: [formula: see text] for 24-h values of magnesium (Mg), ammonium (NH4), phosphate (P), pH and urine volume (V). The APMAP required for the formation of 2,000 crystals in the size range 3.5-5 microns varied between 226 x 10(-15) and 293 x 10(-15) (mmol/l)2 in dialysed urine. An experimental system was designed based on the measurement of pH during the addition of NH4OH. At the point assumed to correspond to the start of crystallization, AP(MAP) index values between 409 and 903 were recorded. Such a test might provide useful information on the crystallization properties in urine.

Crystallization↗
PubMed1990

Long-term acidification of urine in patients treated for infected renal stones.

The effects of ammonium chloride, methenamine hippurate and ascorbic acid on urinary pH was studied in 14 normal subjects. A statistically significant reduction of urinary pH was recorded with ammonium chloride in daily doses of 1.5 and 3 g, but not with 2 g of methenamine hippurate or 1.8 g of ascorbic acid. Long-term treatment with ammonium chloride in doses between 1.5 and 3 g was given to 11 patients in order to reduce the risk of new stone formation or growth of fragments remaining after disintegration of infected renal stones. Biochemical stone analyses showed struvite in 9 of the treated stones, and urine cultures verified the presence of urease-producing bacteria in 10 patients. Apart from ammonium chloride, the patients were treated with antibiotics, in 4 patients continuously and in the others during periods from 2 to 34 months. The patients were followed for an average period of 32 months. No adverse reactions were recorded with the dosage used. Initially, 6 patients were stone-free, whereas 5 had residual stone fragments with a largest diameter ranging from 4 to 20 mm. At follow-up, 2 patients were still stone-free, and of 5 patients with residual fragments 1 showed stable disease and 3 an improved stone situation. In 5 patients, 3 of whom had residual stone fragments, antibiotic treatment had been interrupted without infectious relapse.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

How are urine composition and stone disease affected by therapeutic measures at an outpatient stone clinic?

Urine composition in terms of calcium oxalate (CaOx) supersaturation was studied in 802 patients with calcium stone disease before any intervention and during follow-up. Supersaturation was expressed as the AP(CaOx) index, a simplified estimate of the ion activity product of CaOx, and a similar index calculated for a 24-hour urine volume of 1.5 liters the AP(CaOx) index(s). The AP(CaOx) index was significantly reduced in men with and without medical treatment who remained stone-free during follow-up (p less than 0.001), but not in men who continued to form stones. For the AP(CaOx) index(s), a significant reduction was observed only in patients on medical treatment without new stone formation (p less than 0.01). In women, significantly lower AP(CaOx) index values were recorded in recurrent as well as non-recurrent stone formers on medical treatment, whereas in the group without medical treatment and without recurrences the difference did not reach a statistically significant level. This was similar to the effect on the AP(CaOx) index(s) in non-recurrent women with medical treatment. The small number of women with recurrences might have influenced the result. Significantly reduced levels of the AP(CaOx) index were recorded for patients given thiazide, thiazide + magnesium, magnesium, and alkaline citrate. The AP(CaOx) index(s) was reduced in patients given thiazide + magnesium, magnesium, and alkaline citrate. Comparison between the effects on urine composition and clinical response showed that the reduced CaOx supersaturation observed with thiazide, thiazide + magnesium, and alkaline citrate, corresponded to a low rate of stone formation during follow-up. The inefficiency of allopurinol and orthophosphate in affecting urine supersaturation was reflected in a higher recurrence rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Allopurinol↗
PubMed1990

Evaluation of a system for classification of stones and their sites in kidneys treated with extracorporeal shock wave lithotripsy.

The results of treatment with extracorporeal shock wave lithotripsy (ESWL) were recorded in 1067 patients with renal calculi during their first admission to hospital. All treatments were performed in an unmodified Dornier HM3 lithotripter according to the original recommendations whereby the generator voltage was usually set between 18 and 23 kV. The stones in kidneys treated with ESWL alone were first classified into four different types (A. B. C. D) and after which a further subgrouping was carried out according to the number and sites of stones in the renal pelvis or calyces. The number of shock-waves. the energy index. the duration of treatment, and length of hospital stay as well as the therapeutic results after four weeks and six months were recorded for the different subgroups. An approximate estimate of the stone volume was calculated from measurements on a plain abdominal radiograph. The mean stone volume, number of shock waves, energy index, duration of treatment, and length of hospital stay increased progressively and significantly from group A to group D. The stone volumes and the energy indexes in the different subgroups within each type were distributed around levels that clearly differed between the types. Although minor variations were observed similar patterns also were recorded for the retreatment rate, the total duration of treatment, and the length of hospital stay. The therapeutic result, expressed as satisfactory disintegration, showed roughly similar results within each group but, as expected, the success rate decreased when more complicated stones were treated. Although stones located in the renal pelvis were often bigger than calyceal stones, the former seemed to disintegrate more easily.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗
PubMed1990

Extracorporeal shock-wave lithotripsy of bile-duct stones. Initial Swedish experience.

Fifteen patients with mean age 74 (range 34-94) years were treated with extracorporeal shock-wave lithotripsy (ESWL) for bile-duct stones (intrahepatic in 4 cases) following failure of surgical or endoscopic treatment. A Dornier HM3 lithotriptor was used, and in all cases the ESWL session was preceded by establishment of external biliary drainage (endoscopic nasobiliary in 9, percutaneous transhepatic in 2 and a surgical T-tube in 4 cases) for radiologic positioning of stone. Endoscopic (14 cases) or surgical (1 case) sphincterotomy was done to facilitate spontaneous passage or endoscopic removal of fragments after ESWL. General anesthesia was not needed during the average 50 (range 25-65) min required for performance of ESWL. The number of delivered discharges was 750 to 2,100 and the generator voltage varied from 14 to 17 kV. Disintegration of stone was good in 12 cases and partial in two. Ten patients remain stone-free, five after spontaneous passage, and five after endoscopic extraction of fragments. There were few complications. ESWL may be useful in high-risk patients with failed endoscopic treatment of bile-duct stones and for management of intrahepatic stones.

Adult↗
PubMed1989

The effects of citrate on hydroxyapatite induced calcium oxalate crystallization and on the formation of calcium phosphate crystals.

The addition of different amounts of hydroxyapatite crystals (HAP) to a solution, metastably supersaturated with respect to calcium oxalate (CaOx) resulted in heterogenous crystallization at seed concentrations exceeding 0.2 mmol/l. The induction period varied between 1 and more than 8 h with the shortest period for a seed concentration of 2 mmol/l. Addition to the system of 1 and 2% of whole urine and citrate in concentrations corresponding to approximately 1% of that found in normal urine inhibited the crystallization for as long as 4 h. In a system supersaturated with respect to calcium phosphate (CaP) the total number of crystals was markedly reduced by citrate concentrations exceeding 0.5 mmol/l. The fractions of medium sized and large crystals were sharply reduced and small crystals predominated at higher citrate concentrations. This might indicate effects of citrate on both crystal growth and crystal aggregation. We conclude that increased citrate concentrations during treatment with alkali leads to a significant inhibition of CaOx growth on HAP as well as to a prevention of the formation of large CaP crystals from solutions supersaturated with respect to CaP.

Calcium Oxalate↗