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Biomedical subjects

B Fellström

Publications and source records attributed to B Fellström.

At least 91 records · Page 5Linked to original sources
PubMed1989

Platelet-derived growth factor receptors in the kidney--upregulated expression in inflammation.

Major features of a long-standing inflammation in the kidney are vascular proliferation, glomerulosclerosis, interstitial fibrosis and tubular atrophy, leading to a gradual deterioration of the renal function. In this study we have investigated the expression of B-type receptors for platelet-derived growth factor (PDGF) in frozen sections from normal and inflamed kidneys. Immunohistochemical techniques, employing two monoclonal antibodies specific for PDGF B-type receptors, were used. The specimens investigated were 15 kidneys removed by transplantectomy because of chronic rejection, 20 cases of glomerulonephritis with crescent formation, mesangial proliferation or non-proliferative glomerulonephritis, and six normal kidneys. In parallel we characterized cellular infiltrates and class II transplantation antigen expression in the inflamed kidneys. An enhanced PDGF receptor expression was found on intimal cells and on smooth muscle cells of the proliferating vessels, on glomerular cells in glomeruli with mesangial proliferation, and on fibroblast-like cells in the proximity of clusters of infiltrating macrophages and T-lymphocytes of the interstitial tissue. Induction of PDGF receptor expression may render cells responsive to stimulation by PDGF, released from PDGF-producing cells, such as activated macrophages and from platelets. Our data suggest that PDGF is involved in the proliferation of mesenchymal cells that is seen in rejected kidney transplants and glomerulonephritis.

Antibodies, Monoclonal↗
PubMed1989

Intestinal oxalate and calcium absorption in recurrent renal stone formers and healthy subjects.

The fractional intestinal absorption of oxalate and calcium was investigated by isotope techniques in 20 normal subjects and in 12 idiopathic calcium oxalate stone formers. The greatest amount of 14C-oxalate was excreted during the first six hour period in controls as well as in stone formers. The stone formers had a greater intestinal uptake of oxalate (11 +/- 5.1%) than the controls (6.2 +/- 3.7%; p less than 0.01). There was no significant relationship between the fractional absorption of oxalate and the total urinary oxalate excretion. The stone formers also had a higher fractional uptake of calcium compared to the controls (55 +/- 11% vs. 47 +/- 9.1%; p less than 0.05). There was a positive relationship (r = 0.47) between the urinary excretions of calcium and oxalate in the stone formers. During these conditions no correlation could be demonstrated between the fractional absorptions of oxalate and calcium, neither in the stone formers nor in the controls. In conclusion, patients with recurrent formation of calcium oxalate containing stones appear to have an enhanced intestinal uptake of both oxalate and calcium. This disturbance could be of primary pathogenic importance for their stone forming propensity.

Adult↗
PubMed1989

Circulating T-lymphocyte sub-subsets and NK-like cells in renal transplant patients: patterns associated with rejection.

The patterns of circulating T sub-subset and NK-like cells were monitored in 87 renal transplant patients on a total of 122 occasions. Combinations of monoclonal antibodies were used in two-colour flow cytometric (FACS) analysis to define the major T helper/inducer and T suppressor/cytotoxic subsets and their activated counterparts, the T suppressor inducer and T suppressor effector sub-subsets, NK-like cells and their activated counterparts. In patients with rejection, the proportions of T suppressor inducer and T suppressor effector cells were less and the proportion of activated NK-like cells greater compared with cases exhibiting stable graft function, and these group differences were highly significant. Analysis with stepwise multivariate logistic regression showed that combinations of several functional/activated lymphocyte subsets allow a predictive diagnostic power which is superior to the use of single variables.

Antibodies, Monoclonal↗
PubMed1989

The anti-Leu4 (CD3) monoclonal antibody reacts with proximal tubular cells of the human kidney.

A recent observation that certain kidney tubular cells, especially those in the normal kidney, were positively stained with the anti-Leu4 monoclonal antibody (MoAb) led us to investigate systematically the reactivity of three different anti-CD3 MoAb with a panel of normal human kidneys. Using immunohistochemical and immunofluorescence staining techniques, the anti-Leu4 MoAb was found to react with proximal tubular cells in all eight examined kidneys, while no tubular-cell reactivity was observed with the OKT3 or DAKO-T3 MoAb. In each kidney, however, all three antibodies reacted with a similar number of occasionally encountered T cells. The G11 MoAb, which has been reported to react with a calcium receptor-associated molecule, and the anti-Leu4 MoAb showed almost identical patterns of tubular-cell reactivity. The observed co-distribution of Leu4-expressing structures with a putative Ca2+ sensor in the kidney and the fact that binding of anti-Leu4 to T cells induces Ca2+-mediated signal transduction, warrant further studies on a potential role of Leu4-expressing structures in Ca2+ regulation of proximal tubular cells.

Antibodies, Monoclonal↗
PubMed1989

Dietary habits in renal stone patients compared with healthy subjects.

The dietary habits of renal calcium stone patients were investigated both by dietary history and by 4-day food records and compared with the dietary habits of control subjects, matched on the basis of age, sex, social and professional status. The method using 4-day records seemed to be more precise, judged by the correlation to the urinary output of nutrients. There was no difference in the daily intake of major nutrients between stone formers and controls, but a higher ingestion of vitamin C in controls and a larger consumption of alcohol among stone formers. In contrast to some epidemiological evidence, there were no significant differences in consumption of animal protein when stone formers were matched for social class. Despite a similar total intake of calcium, the stone formers excreted more calcium in the urine, probably reflecting a higher intestinal absorption of calcium. There seem to be only marginally different dietary habits between stone formers and carefully matched control subjects. Differences in the urinary output of minerals and electrolytes are mainly due to variations in gastrointestinal uptake.

Adult↗
PubMed1989

Aluminum removal with hemodialysis, hemofiltration and charcoal hemoperfusion in uremic patients after desferrioxamine infusion. A comparison of efficiency.

In order to compare the effectiveness of aluminum removal in uremic patients during extracorporeal treatment, 17 patients with endstage renal failure were given a desferrioxamine infusion of 40 mg/kg body weight after an ordinary dialysis treatment. Forty-eight hours later 7 patients were treated with hemodialysis, 6 with hemofiltration and 4 with a combination of hemodialysis and hemoperfusion. The clearance of aluminum was measured at different intervals. It was found that the aluminum clearance was 75 +/- 18 ml/min in hemofiltration compared to 30 +/- 10 ml/min in hemodialysis (p less than 0.001). A combination of hemodialysis and hemoperfusion with a charcoal column containing 100 g activated charcoal in series gave a total aluminum clearance of 56 +/- 11 ml/min. The total amount of aluminum in the ultrafiltrate after hemofiltration was found to be approximately 3 times as high (1,728 +/- 156 micrograms) as the total amount of aluminum in the hemodialysis water that had passed a single pass system during a 4-hour dialysis (576 +/- 104 micrograms). Our results indicate that hemofiltration or a combination of hemodialysis and hemoperfusion should be used to remove aluminum in patients with signs of severe aluminum accumulation such as encephalopathy or painful bone disease, because these methods are 2-3 times as effective as ordinary hemodialysis. In patients where aluminum has been accumulated but no severe symptoms occur hemodialysis gives a significant clearance of the aluminum desferrioxamine complex.

Aluminum↗
PubMed1989

Intestinal absorption of oxalate and calcium in patients with jejunoileal bypass.

Jejunoileal bypass (JIB) has been widely performed for treatment of excessive obesity. Formation of calcium oxalate stones is a common side effect. Since, under physiological conditions, the intestinal absorption of calcium and that of oxalate are interrelated, intestinal oxalate and calcium absorption were measured in the present study by isotope techniques in 19 JIB patients and 20 healthy controls. The JIB patients showed pronounced hyperoxaluria and markedly increased absorption of oxalate, with a urinary excretion of 14C-oxalate of 29 +/- 19% (controls 6.2 +/- 3.7%; p less than 0.001). There was a strong correlation between the intestinal absorption and urinary excretion of oxalate in the JIB patients (r = 0.72; p less than 0.001). Furthermore, their oxalate kinetics was altered, with continued urinary excretion of 14C-oxalate for up to 48 hours. The JIB patients also had reduced calcium absorption (36 +/- 9.1% vs. 47 +/- 9.0%; p less than 0.001) and patients with malabsorption of calcium and low urinary calcium had the highest intestinal absorption and urinary excretion of oxalate. It is concluded that hyperoxaluria in JIB patients is due to a significant extent to hyperabsorption of oxalate.

Adult↗
PubMed1989

The relation between urinary tract infections and stone composition in renal stone formers.

During a seven-year period (1975-1981) a total of 1325 patients hospitalized for stone disease were studied as to the occurrence of positive urine cultures. Urinary stones from 535 surgically treated patients were analyzed with infrared spectrophotometry and the relationships between stone composition, level of surgery and bacteriological strains were studied. Positive urinary cultures were found in 34% of the surgically treated patients and in 21% of those not operated upon. Among the surgically treated patients with urinary tract infection (UTI) E. coli was the most frequent microorganism (35%), followed by Proteus (28%). Patients with Proteus infection had the highest frequency of UTI episodes, most of which occurred before hospitalization. There was a higher frequency of magnesium ammonium phosphate (MAP) calculi among patients with Proteus infection than among those with non-Proteus infection, in whom no difference in stone composition was found. Patients infected with E. coli had more phosphate-containing stones (CaP+MAP) than non-infected patients. The highest frequency of oxalate calculi (CaOx+CaOx/CaP) was found among patients without infection. No E. coli infections were seen in male patients with CaP and MAP calculi. MAP stones were most often found in the kidney and oxalate stones in the ureter.

Calcium Oxalate↗
PubMed1988

Induction of B-type receptors for platelet-derived growth factor in vascular inflammation: possible implications for development of vascular proliferative lesions.

Expression of B-type receptors for platelet-derived growth factor (PDGF) in frozen sections of blood vessels from tissues affected by abnormal vascular cell proliferation was investigated by immunohistochemical techniques and compared with expression of these receptors in blood vessels of normal tissues. Receptors were not expressed, or expressed at low levels, in vessels of normal tissues. In contrast, a pronounced expression of PDGF B-type receptors was seen on vascular smooth muscle cells in atherosclerotic plaques, rejected kidneys, and chronic synovitis. These observations suggest induction of PDGF B-type receptors on vascular smooth muscle cells in inflamed tissues, which would render such cells responsive to growth stimulation by PDGF released from captured platelets, or produced locally (eg, by inflammatory cells or smooth muscle cells). Autocrine or paracrine stimulation of cell growth caused by the effect of PDGF on cells with induced receptors may be important in the formation of the proliferative lesions found in atherosclerosis and in certain forms of chronic inflammation.

Antibodies, Monoclonal↗
PubMed1988

Prevention of renal stones by a high fluid intake?

From the physiochemical view on the formation of urolithiasis a high fluid intake, provided it resulted in a high urine volume, should reduce the propensity of crystallization, crystal growth and stone formation. This critical review of the literature, however, demonstrates that there is little epidemiologic support for the hypothesis that a low urine volume is an important risk factor for renal stones in temperate climates. Few clinical studies have attempted to elucidate if a large diuresis can prevent further stone formation in a recurrent renal stone former. In the present study 115 recurrent stone formers were followed for an average period of 6 years without any other treatment than advice about a high fluid intake. The annual recurrence rate was around 23% but there was no difference between those who maintained a high urine volume and those who did not. Thus, the available evidence does not indicate that variations of fluid intake markedly affect stone formation.

Diuresis↗
PubMed1987

Infection-induced urinary calculi and renal failure.

During 1974-1984 altogether 481 patients were treated for end-stage renal disease (ESRD). Eight patients, five women and three men, with chronic pyelonephritis as the primary cause of ESRD, had staghorn urinary calculi as a predisposing factor for renal failure. These eight patients were studied retrospectively concerning epidemiological and bacteriological aspects, the treatment of the stone disease, and the development of uraemia. Anatomical and metabolic abnormalities such as bladder outlet disturbances, primary hyperparathyroidism, phenacetin abuse or metabolic stone disease were found in six patients. The women had all been infected with Proteus mirabilis, whereas the men had been infected with various microorganisms. The average time taken for the development of ESRD, estimated from the first sign of renal impairment, was 7.4 +/- 2.9 (SD) years. Five patients had died before this study commenced. One of the patients still alive was on dialysis treatment. Two patients who were doing well without dialysis were stone free and had sterile urine after successful pyelolithotomy. It is concluded that the prevalence of infectious urinary calculi as a cause of uraemia in patients with ESRD is low. The time taken for uraemia to develop is short in these patients and they often have anatomical abnormalities. Proteus is commonly found in this group of patients. Patients with staghorn calculi, urinary tract infection and impairment of renal function are at risk of developing uraemia.

Aged↗