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Biomedical subjects

B G Danielson

Publications and source records attributed to B G Danielson.

At least 127 records · Page 7Linked to original sources
PubMed1981

Calcium and magnesium metabolism during long-term treatment with thiazides.

The effects of treatment with bendroflumethiazide (2.5 mg twice daily with potassium supplements) on mineral metabolism were evaluated in 111 patients followed for a minimum period of one year. The urinary calcium decreased with approximately 30% irrespective of the pretreatment levels and remained on this lower level during follow-up. This reduction of urinary calcium was associated with a reduction of the intestinal calcium absorption. The serum calcium increased slightly in most of the patients and in 10% of them hypercalcaemia could be demonstrated at some time. In most of these cases the hypercalcaemia was slight and temporary and when sustained rapidly reversed upon withdrawal of therapy. Initially the urinary magnesium excretion increased but after two years' treatment the values were no longer raised. The serum magnesium levels showed a continued decrease during follow-up but in muscle biopsies, performed after three years treatment, no magnesium deficiency was evident. During treatment also the fasting urinary calcium was reduced, suggesting reduced bone resorption, but urinary hydroxyproline was unchanged. The serum PTH levels appeared unchanged during follow-up. Thiazides appear to cause a persisting reduction of calcium excretion, which is compensated by reduced intestinal uptake, whereas parathyroid function is unaffected. Although there was a gradual decline of serum magnesium, magnesium deficiency was not demonstrated.

Adult↗
PubMed1981

Phosphate metabolism in renal stone formers. (II): Relation to renal tubular functions and calcium metabolism.

Patients with idiopathic recurrent calcium nephrolithiasis (n = 57) and controls (n = 16) were investigated regarding the relationship between renal phosphate handling, other renal tubular functions and calcium metabolism. Incomplete renal tubular acidosis (RTA) was disclosed in 13 patients. RTA patients together with stone formers with normal renal acidification capacity (SF) exhibited low values for serum phosphate and renal threshold phosphate concentration (TmP/GFR) compared with controls. TmP/GFR was lower in RTA patients than in stone formers with normal renal acidification. Hypercalciuria of the absorptive type with normal serum PTH and urinary cAMP concentrations was a common finding in both stone patient groups, whereas no patient displayed unequivocal evidence of parathyroid hyperfunction. Fractional excretion of sodium was raised in both SF and RTA patients compared with controls. There was a positive relationship between the fractional excretion of phosphate and sodium in all subjects as a group. TmP/GFR was negatively correlated to fractional excretion of sodium. Twenty-three percent of RTA patients and 8% of SF displayed tubular proteinuria which often was associated with low TmP/GFR levels and enhanced natriuresis. It is concluded that a defective renal tubular phosphate handling is common in calcium stone formers and often associated with signs of other tubular dysfunctions. The altered phosphate handling seems to be unrelated to hypercalciuria.

Adolescent↗
PubMed1981

Phosphate metabolism in renal stone formers. (I): Indices of phosphate handling in calcium stone patients and healthy subjects.

Healthy subjects (n = 112) and patients with recurrent idiopathic calcium nephrolithiasis (n = 44) were evaluated regarding various indices of phosphate handling: serum phosphate concentration, renal tubular reabsorption of phosphate, index of phosphate excretion and renal threshold concentration for phosphate (TmP/GFR). The 24 hour and fasting 2 hour urinary phosphate excretions were similar in the two groups and the index of phosphate excretion was higher in stone formers, but for all the other variables lower mean values were found in the group of stone formers than in the group of normal subjects. The renal tubular capacity for reabsorption of phosphate (as evaluated by the different indices) appeared to decrease with advancing age concomitant with a reduction of the serum phosphate concentration. When age- and sex-matched subjects from the two groups were compared with regard to the phosphate variables lower values were still found in the group of stone forming subjects. This study gives support to earlier observations that renal stone formers tend to waste phosphate by and altered renal handling.

Absorption↗
PubMed1980

Biochemical and clinical effects of the prophylactic treatment of renal calcium stones with magnesium hydroxide.

Prophylactic treatment with magnesium hydroxide ws instituted in 56 consecutive cases with renal calcium stones. The patients had been investigated previously with regard to the magnesium metabolism. The urinary magnesium excretion increased promptly and remained on a higher level during treatment. No changes were observed in the serum or urinary calcium concentrations. Most patients have undergone treatment for at least 2 years and 45 have been free of recurrences of formations of new stones. The mean stone episode rate during treatment was 0.03 stones per year compared to 0.8 stones per year before treatment was instituted. The natural history of stone disease also was followed in 34 patients with stones who had received no prophylactic therapy and 15 have experienced recurrences after 2 years. Therefore, in comparison, treatment with magnesium hydroxide appeared to reduce the recurrence rate. Apart from minor gastrointestinal discomfort no adverse effects were observed during treatment.

Adult↗
PubMed1980

Treatment of recurrent calcium stone formation with cellulose phosphate.

Sodium cellulose phosphate was given to 35 patients for recurrent formation of calcium-containing stones. During therapy urinary calcium decreased by 40% in the first month and remained at this lower level. In addition, urinary magnesium excretion was reduced and the urinary magnesium/calcium ratio remained unaffected. In these patients, who mostly had had calcium oxalate stones, the prophylactic effects of sodium cellulose phosphate was poor, with a 47% recurrence rate after 2 years. This lack of prevention, despite the significant reduction of the urinary calcium, is assumed to be owing to the effects of treatment on magnesium and oxalate metabolism. Side effects were common, mainly consisting of moderate gastrointestinal discomfort, and caused withdrawal of treatment in 8 patients. This fact contributes further to our opinion that sodium cellulose phosphate is not the drug of choice in cases of calcium oxalate stone formation.

Adult↗
PubMed1980

Incidence and clinical importance of renal tubular defects in recurrent renal stone formers.

Renal tubular function was studied in 318 consecutive recurrent renal stone formers. Impaired acidification capacity was found in 19% of the patients, and tubular proteinuria in 13% of the patients. Most of the patients with defective acidification of the urine had the incomplete form of renal tubular acidosis (RTA), rpoximal and distal defects being equally common. The incidence of impaired acidification was much higher in the female (38%) than in the male (13%) stone formers. A further analysis of the clinical picture in patients with acidification defects revealed a more severe stone disease than among other stone formers. Characteristic findings were an early onset, multiple recurrences were an increased need for surgery. Stone analyses showed a high frequency of calcium phosphate stones. Investigations of renal tubular functions appear to be a valuable adjunct in the evaluation of recurrent renal stone disease.

Acid-Base Equilibrium↗
PubMed1980

Zinc in epidermis and dermis in healthy subjects.

Thin tangential skin biopsies were obtained from 40 healthy subjects by a shaving technique. The zinc content in these samples was determined by atomic absorption spectrophotometry. The mean concentration of zinc in epidermis was about 60 micrograms/g and in upper dermis 40 micrograms/g dry weight. The concentration was much higher in the upper than in the lower layer of dermis. There was no correlation between the tissue and serum concentration of zinc. Full awareness of the great risk for contamination is essential and special precautions are mandatory if reproducible results are to be obtained.

Adolescent↗
PubMed1980

Kidney stone disease. Experiences from Uppsala, Sweden.

In summary, several biochemical investigations give valuable information about a possible etiological explanation for the stone formation but to get a more complete picture of the individual stone former, some clinical aspects should be considered such as heredity for stone disease and the age of onset. All these factors are relevant when considering prophylactic treatment to stone formers.

Adult↗
PubMed1980

Magnesium metabolism in renal stone disease.

Magnesium metabolism in 70 consecutive patients with renal stone disease was evaluated and compared with that of a control group matched for age and sex. Serum and urinary magnesium values were not different in the two groups, but magnesium output was greater in males than in females. Stone-formers excreted more calcium in their urine than did controls, and the urinary calcium and magnesium values for both groups were positively correlated. For both groups, the magnesium/calcium ratio in the urine declined with increasing calcium values but was lower in stone-formers than in controls for corresponding calcium values. Intestinal magnesium uptake was the same in both groups. Magnesium deficiency was not evident among stone-formers as assessed by the determination of the magnesium content in muscle specimens or by the retention of an intravenously administered magnesium load. Although stone-formers were not found to display any features of magnesium metabolism that were different from those in the control group, their lower urinary excretion of magnesium in relation to calcium may be a factor in their increased stone-forming propensity.

Adult↗
PubMed1980

Clinical effects of parathyroid surgery in normocalcaemic patients with recurrent renal stones.

Among 52 patients with recurrent renal calcium stones submitted for neck exploration 12 had adenomas, 23 hyperplasia and only 17 histologically normal parathyroid glands. These patients were selected for surgery despite a normal mean value of the total serum calcium concentration because they had, in most cases, indirect evidence of parathyroid hyperfunction such as intermittent hypercalcaemia (in 25 of the patients), hypercalciuria or a pathological response to calcium infusion. It is suggested that the patients with adenomas suffered from primary hyperparathyroidism (HPT), which however did not cause persisting hypercalcaemia. It seems likely that parathyroid hyperplasia either was a mild or an early form of primary HPT or secondary to increased calcium losses. In this study, no single laboratory feature could clearly separate the different groups. None of the patients with adenomas formed any new stone during follow-up (2-7 years) and also 40% of those with hyperplasia appeared to experience benefit from surgery. This benefit was more common in those with occasionally raised serum calcium values. In cases with borderline hypercalcaemia HPT is common and is cured by parathyroidectomy. However, in clinical practice the differential diagnosis may be difficult. In cases without firm evidence of HPT a conservative approach is favoured. Thiazides appear to reduce the stone recurrence rate in most euparathyroid patients and will probably help to unmask borderline HPT in recurrent renal stone formers.

Adenoma↗
PubMed1979

Effects of therapy with bendroflumethiazide in patients with recurrent renal calcium stones.

Forty-four patients with recurrent formation of calcium-containing renal stones were treated with bendroflumethiazide for at least 2 years. Prior to treatment each patient had formed, on average, one stone per year for 8 years; during treatment only 4 patients formed new stones. A reduction in urinary calcium excretion was seen in almost all patients irrespective of their initial urinary calcium level. The apparent clinical benefit was not related to pre-treatment urinary electrolyte levels. Side effects were slight: one patient developed symptomatic hyperuricaemia and in one case sustained hypercalcaemia was found. Long-term treatment with thiazides appears to be a safe and effective method for the prevention of recurrent calcium stones.

Bendroflumethiazide↗
PubMed1979

Magnesium metabolism in healthy subjects.

Magnesium metabolism was studied in 106 apparently healthy subjects aged between 15 and 80 years. The serum magnesium values had a gaussian distribution with a narrow range and with no age or sex dependence. The basal, urinary magnesium excretion was greater in men than in women at all ages and decreased with age. The magnesium and calcium excretions were closely correlated in both sexes. The fractional, gastrointestinal absorption of magnesium, assessed by a newly developed technique using the radionuclide 28Mg, compared favourably with that in earlier balance and tracer studies. The intracellular magnesium content, estimated in muscle specimens obtained by percutaneous biopsies, was not correlated to age or sex. A magnesium-loading test was performed, and the normal range for magnesium retention was calculated. No correlation was demonstrated between different magnesium parameters within the normal range in these subjects.

Adolescent↗