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Biomedical subjects

M Miltényi

Publications and source records attributed to M Miltényi.

At least 19 recordsLinked to original sources
PubMed1998

Reproducibility of erythrocyte sodium-lithium countertransport activity and ambulatory blood pressure measurements in type 1 diabetes mellitus.

We aimed to study the reproducibility of sodium-lithium countertransport [SLCT] activity and ambulatory blood pressure monitoring [ABPM] in type 1 diabetes. We did this by performing repeated measurements of SLCT activity and ABPM in 11 recent-onset diabetic children and in 11 patients with longer duration of diabetes. Both parameters were related to microalbuminuria. In the older group of diabetic children a significant correlation [r = 0.78; P<0.005] in SLCT activity between the first and second study was observed [514.3+/-186.4 vs 491.0+/-148.0 micromol/l erythrocytes/h]. Diurnal systolic and diastolic blood pressure were comparable at both time points within the same group of diabetic children [in group 1: 102.6+/-6.1 vs 108.6+/-7.6 mmHg N.S.; in group 2: 113.4+/-10.6 vs 114.0+/-7.8 mmHg N.S. Diastolic blood pressure in group 1: 57.4+/-4.8 vs 65.7+/-6.9 mmHg N.S., in group 2: 70.6+/-9.1 vs 68.5+/-5.3 mmHg N.S.]. Moreover, there was a significant correlation in both diurnal and nocturnal systolic blood pressure between the first and second study in the whole diabetic population. Both SLCT activity and blood pressure values obtained by ABPM were found to be reproducible individual characteristic markers in type 1 diabetic children.

Adolescent↗
PubMed1997

Renal excretion of endothelin in children.

Endothelin (ET) is a peptide with profound vasoconstrictive potential. First isolated from porcine endothelial cell supernatant, it is produced also by smooth muscle, epithelial and circulating cells. Besides vasoconstriction, a wide spectrum of biological activities of ET (via activation of membrane receptors) has been described. These include regulation of other hormones and neurotransmitters, cellular growth and proliferation, bronchoconstriction, and, in the kidney, natriuresis and water diuresis. ET exerts its effects mainly in an autocrine and paracrine fashion. A high concentration of ET is found in urine, compared with plasma originating mainly from the kidney itself. In this review we focus on the role of urinary excretion of ET in children. ET excretion was determined under different physiological and pathological conditions. In premature infants and newborns, the daily excretion of ET (corrected for body surface) was higher than in older children; it was constant, and comparable to the values in healthy adults after the age of 2 years. Renal ET excretion correlated positively with urine flow in both healthy and sick children. Conditions with tubular and/or collecting duct cell damage, such as severe hypoxia, hemolytic-uremic syndrome, renal transplantation, diabetes mellitus, chronic renal failure, and contrast media cytotoxicity were characterized by elevated urinary excretion of ET. In conclusion, the renal excretion of ET is influenced by several factors, probably reflecting the intrarenal ET production. ET has a low specificity with regard to renal injury.

Adolescent↗
PubMed1996

Elevated urinary excretion of endothelin in insulin-dependent diabetes mellitus: no influence of physical exercise.

The urinary excretion of endothelin was measured by radioimmunoassay in children with diabetes mellitus in metabolically stable condition before and after ergometric exercise. Apparently healthy children served as normal controls. The excretion of endothelin, calculated for 24h and the ratio of endothelin/creatinine in urine were also significantly higher in diabetic children compared to normal controls. Physical exercise had no influence on renal endothelin excretion. In diabetic children the volume of diuresis was higher compared to controls. Physical exercise had no influence on diuresis. In a previous study we found a positive correlation between diureses and endothelin excretion. Therefore, the increased endothelin excretion in the diabetic patients may be at least partially the consequence of the higher diuresis values. It cannot be excluded, however, that it may be a sign of altered renal function as well. Furthermore, the present study suggests that in patients with diabetes mellitus elevated sympathetic nerve activity as a result of physical activity does not influence renal endothelin production.

Adolescent↗
PubMed1995

Urinary calcium and oxalate excretion in children.

We have established normal values for calcium/creatinine (Ca/Cr) and oxalate/creatinine (Ox/Cr) ratios in 25 infants (aged 1-7 days) and 391 children (aged 1 month to 14.5 years) and compared these with values obtained in 137 children with post-glomerular haematuria and 27 with nephrolithiasis. Oxalate was measured by ion chromatography. Nomograms of Marshall and Robertson were used to calculate urine saturation to calcium oxalate. The Ca/Cr ratio was normally distributed whereas the Ox/Cr ratio had a log-normal distribution. The molar ratio of Ca/Cr was the lowest in the first days of life and the highest between 7 month and 1.5 years (mean +/- SD = 0.39 +/- 0.28 mmol/mmol). Following a slight decrease it stabilised by the age of 6 years (0.34 +/- 0.19 mmol/mmol). The highest Ox/Cr values were measured during the 1st month of life [geometric mean 133 (range 61-280) mumol/mmol], followed by a gradual decrease until 11 years of age [mean 24 (range 6-82) mumol/mmol]. Thirty-six haematuric children had hypercalciuria (26%), 23 had absorptive hypercalciuria, 13 renal type. Children with absorptive hypercalciuria on a calcium-restricted diet had significantly higher oxalate excretion than those with renal hypercalciuria and the control group [38 (range 28-49) vs. 22 (range 16-29) and 23 (range 22-27) mumol/mol respectively, P < 0.01]. Calcium oxalate urine saturation of stone patients was higher than that of patients with haematuria and the normal population (1.18 +/- 0.05 vs. 1.06 +/- 0.03, P < 0.03 and 0.84 +/- 0.03, P < 0.001 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Association of relative nocturnal hypertension and autonomic neuropathy in insulin-dependent diabetic children.

Twenty-four hour BP and heart rate measurements were carried out in fourteen newly diagnosed-, and in twenty-eight diabetics with 5-13 years of duration; and in eight healthy control children. Mean arterial BP rose at night in five-, fell slightly (less than 10%) in five- and fall markedly (more than 10%) in eighteen diabetics with longer duration of the disease. The diurnal-nocturnal difference of mean arterial pressure was significantly lower in the groups with nocturnal BP rise and slight nocturnal BP fall, compared to the control group (< 0.001; p < 0.01, respectively). The diurnal-nocturnal differences of heart rates were significantly lower in diabetics with relative "nocturnal hypertension" compared to the control group (p < 0.05). The presence of subclinical signs of diabetic autonomic neuropathy was significantly higher in patients with nocturnal BP rise and slight nocturnal BP fall compared to patients with marked nocturnal BP fall and newly diagnosed diabetics (chi squared p = 0.02 and p = 0.01, respectively). In conclusion, the prevalence of autonomic symptoms in diabetic children could be related to change in diurnal/nocturnal arterial BP, however longitudinal studies of ABPM are needed to define, whether patients with abnormal BP profiles are candidates for the development of diabetic vascular disease.

Adolescent↗
PubMed1994

Endothelin excretion during ketoacidosis does not correlate with tubular dysfunction.

Urinary excretion of endothelin was measured by radioimmunoassay in children with diabetes mellitus during severe ketoacidosis and 12 days later when blood pH and blood glucose concentrations were normal. Metabolically stable diabetic children served as controls. Results from apparently healthy children without diabetes mellitus were used as normal values. Renal tubular injury was evaluated by the urinary excretion of the proximal tubular marker alpha 1-microglobulin and the distal tubular marker Tamm-Horsfall protein (THP). During ketoacidosis we detected a decreased glomerular filtration rate associated with highly significant changes in the excretion of alpha 1-microglobulin, indicating proximal tubular damage, and THP, suggesting disturbance of cells of the ascending loop of Henle. The daily excretion of endothelin was unaltered but the ratio of endothelin/creatinine or endothelin excretion/creatinine clearance were significantly enhanced. In conclusion, we could demonstrate that, despite a proximal and distal tubular cell dysfunction, endothelin excretion is not elevated during ketoacidosis. The increased endothelin excretion when related to creatinine clearance may be a consequence of disturbed proximal tubular function or dysfunction of the renal medulla.

Adolescent↗
PubMed1994

Relative nocturnal hypertension in children with insulin-dependent diabetes mellitus.

Twenty-four-hour blood pressure and heart rate measurements were carried out in 14 newly diagnosed diabetics and in 28 diabetics with 5-13 years' duration of the disease; 8 healthy children were used as controls. Mean arterial blood pressure increased at night in 5, decreased slightly (less than 10%) in 5 and decreased markedly (more than 10%) in 18 diabetics with longer duration of the disease. The diurnal-nocturnal differences in heart rates were significantly lower in diabetics with relative "nocturnal hypertension" compared to the control group (p < 0.05). A significant negative correlation was found between maximal arterial blood pressure during physical exercise and the diurnal-nocturnal differences in mean arterial blood pressure in diabetics (r = -0.58; p < 0.02). In conclusion, we found elevated nocturnal blood pressure in a subgroup of children with longer duration of diabetes and without increased albumin excretion. However, longitudinal studies of blood pressure profiles are needed to identify the candidates for diabetic vasculopathy among diabetic children.

Adolescent↗
PubMed1994

24 hour blood pressure monitoring in healthy and hypertensive children.

24 Hour ambulatory blood pressure monitoring (ABPM) was performed to provide data on the normal daily blood pressure of healthy schoolchildren and on patients with hypertension. The subjects studied were 123 healthy schoolchildren with a mean (SD) age of 12.5 (1.6) years (range 9.5-14.5 years), 24 children with borderline or mild hypertension, 17 with renal hypertension and normal renal function, 10 with chronic renal failure, and six with a renal allograft. In eight children with definite renal disease a second measurement was performed after treatment modification. The monitor used for ABPM was validated with a mercury column manometer. The mean (SD) of the signed differences of the blood pressure measured by the two methods was -0.19 (1.75) mmHg for the systolic and -0.21 (2.11) mmHg for the diastolic blood pressure (n = 60). Normal values for daytime and night time blood pressure were determined for those aged 10-14 years. The mean (SD) blood pressure of the 123 children was 109 (7)/66 (8) mmHg (systolic/diastolic) for the daytime and 96 (8)/52 (7) mmHg at night time. Of the 24 children with borderline or mild hypertension 14 had a raised blood pressure on ABPM. The circadian rhythm was disturbed in three children of this group. Even children with normal daytime blood pressure had significantly higher systolic blood pressure in the night when compared with the controls. The incidence of disturbed circadian rhythm was higher in the groups with renal hypertension (4/17 in the subgroup with normal renal function, 5/16 in the group with renal failure and/or transplantation). All children undergoing a second ABPM measurement had a lower average blood pressure after treatment adjustment. ABPM measurements were reproducible and accurate. The method provided new data on the physiological circadian variation of blood pressure in healthy children. It proved to be a helpful tool in the diagnosis of hypertension, particularly in the detection of cases of disturbance of the circadian rhythm of blood pressure pattern and individual adjustment of treatment.

Adolescent↗
PubMed1994

Sympathetic-adrenergic activity and acid-base regulation under acute physical stress in type I (insulin-dependent) diabetic children.

To evaluate the efficacy of the acute-physical-stress response, plasma catecholamine and lactate levels, serum electrolytes, fructosamine, blood glucose and acid-base status were measured in insulin-dependent diabetes mellitus (IDDM) children and the data compared to those of healthy controls. Four groups were studied: group 1, healthy controls; group 2, newly diagnosed diabetic patients with an IDDM duration of 2-4 weeks; group 3, with an IDDM duration of 5-7 years; group 4, with an IDDM duration of 10-13 years. According to their fructosamine levels, IDDM children were in a well-controlled metabolic state. The physical stress was induced by 1.5-1.7 W/kg/10 min bicycle ergometer determined by a target pulse rate of 170/min. IDDM children exhibited pronounced lactic acidosis under stress (pH: group 2, 7.27 +/- 0.07; group 3, 7.28 +/- 0.05; group 4, 7.20 +/- 0.04, vs. group 1; 7.34 +/- 0.03). Baseline plasma norepinephrine and epinephrine levels showed a significant decrease parallel to the duration of IDDM. Stress induced an increase in the concentration of norepinephrine in each group, but the elevation was significantly higher in the IDDM children versus the controls. A significant negative correlation was found between pH and maximal plasma norepinephrine levels (y = 7.3-0.006x, r = -0.46, p < 0.02). Stress resulted in blood glucose elevation in 13 patients regardless of their pre-exercise blood glucose levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗
PubMed1993

Hydrochlorothiazide treatment of children with hypercalciuria: effects and side effects.

Urinary excretion of calcium and the changes in serum cholesterol fractions were investigated in 15 children with renal hypercalciuria, following 3-month hydrochlorothiazide (HCT) treatment (daily dose 1 mg/kg). Urinary calcium excretion (expressed as the ratio of calcium to creatinine) reached its lowest value after 2 weeks. It was still below the initial value at the end of the 3rd month of treatment (0.84 +/- 0.06, 0.29 +/- 0.03 and 0.6 +/- 0.09 mmol/mmol, respectively). A significant rise in the total serum cholesterol level (4.64 +/- 0.23 vs. 4.25 +/- 0.18 mmol/l before treatment, P < 0.01) and the low-density lipoprotein (LDL)-cholesterol fraction (2.6 +/- 0.24 vs. 2.31 +/- 0.31 before treatment, P < 0.01) was observed at the end of the 3rd month, while high-density lipoprotein (HDL)-cholesterol was slightly decreased. A significant elevation of the LDL/HDL ratio was also observed (from 1.76 +/- 0.17 to 2.2 +/- 0.17, P < 0.001), indicating an increase in the atherogenic cholesterol fractions. The risks and benefits of the thiazide therapy should be considered before starting long-term treatment of children with hypercalciuria and haematuria or renal stone disease.

Adolescent↗
PubMed1992

[Selective vitamin B12 absorption disorder (Imerslund-Gräsbeck syndrome)].

The authors present a case of Imerslund-Gräsbeck syndrome, i. e. a familial megaloblastic anemia with proteinuria. The disease is due to congenital, selective malabsorption of vitamin B12. The subnormal absorption of vitamin B12 is not altered by orally given intrinsic factor, but parenteral vitamin B12 therapy results in complete recovery. Approximately 150 cases have been described in literature, the authors' case is the first in Hungary.

Anemia, Megaloblastic↗
PubMed1992

Autosomal recessive acrorenal syndrome.

We describe two sibs with tetraectrodactyly and oligomeganephronic renal hypoplasia. The parents were unaffected. This syndrome of apparently autosomal recessive origin appears to be the first Mendelian form of the acrorenal developmental field defect identified so far.

Child, Preschool↗
PubMed1991

Changes in plasma and urinary amino acid levels during diabetic ketoacidosis in children.

Plasma and urinary concentrations of different amino acids were investigated during diabetic ketoacidosis (DKA) and 12, 24, 72 hours after initiation of therapy. In DKA, plasma concentration of glutamic acid, aspartic acid, valine, leucine and isoleucine significantly increased while that of asparagine and glutamine decreased compared to levels in well-controlled diabetic patients. The urinary excretion of branched-chain amino acids, histidine, serine and threonine was elevated while those of glutamic acid, glutamine, glycine and taurine were reduced. Among the different amino acids, histidine excretion had the highest variability. A strong correlation was found between the urinary excretion of several amino acids and that of the beta-2-microglobulin characterizing tubular dysfunction. Changes in the excretion of different amino acids reflect the altered metabolic state and renal function due to DKA.

Adolescent↗
PubMed1991

Urinary catecholamine in children with diabetic ketoacidosis.

Urinary excretion of norepinephrine, epinephrine and dopamine was investigated in children with diabetic ketoacidosis. Besides pronounced hyperglycemia and metabolic acidosis, severe hypovolemia was also observed. At the onset of the study, urinary excretion of norepinephrine, epinephrine and dopamine was markedly elevated. Fluid replacement decreased urinary catecholamine excretion. Norepinephrine: 996 +/- 97 vs. 253 +/- 29; dopamine: 5,108 +/- 480 vs. 3,175 +/- 715; epinephrine: 402 +/- 81 vs. 77 +/- 200 pmol/min/1.73 m2. During ketoacidosis, there was a significant negative correlation between urinary norepinephrine excretion and endogenous creatinine clearance. Urinary output of both norepinephrine and dopamine correlated significantly with diuresis, while sodium excretion only correlated with dopamine excretion. Our data suggest that in diabetic ketoacidosis increased urinary excretion of norepinephrine may participate in renal hypoperfusion and hypofiltration. Elevated renal dopamine production contributes to sodium loss, characteristic for diabetic ketoacidosis.

Adolescent↗
PubMed1990

[Follow-up of blood and urinary amino acid concentrations in diabetic ketoacidosis in children].

Plasma and urinary concentrations of amino acids were investigated during diabetic ketoacidosis (DKA) and 12, 24, 72 hours after initiation of therapy. In DKA plasma concentration of glutamic acid, asparaginic acid, valine, leucine and isoleucine significantly increased while that of asparagine and glutamine decreased compared to levels in well controlled diabetic patients. Despite the elevated urinary excretion of branched chain amino acids, histidine, serine and threonine, urinary excretion and clearance of glutamic acid, glutamine, glycine and taurine were reduced. Among the different amino acids histidine excretion had the highest variability. Strong correlation was found between the urinary excretion of several amino acids and that of the beta-2-microglobulin characterizing tubular dysfunction. Changes in the excretion of different amino acids reflect the altered metabolic state and renal function due to diabetic ketoacidosis.

Adolescent↗
PubMed1990

Urinary prostaglandins in hyperglycaemic ketoacidosis of type I diabetes mellitus.

Urinary excretion of various renal prostaglandins was measured by radioimmunoassay and gas chromatography-mass spectrometry in children who had different degrees of metabolic control. Excretion in PGE2 in diabetic children was twice control values irrespective of the presence or absence of diabetic ketoacidosis (DKA). The urinary excretion of PGF2 alpha was significantly increased in diabetic children with ketoacidosis, but not when diabetes was well controlled. The excretion of 13, 14 dihydro-15-keto PGE2, the major metabolite of circulating PGE2, was increased in all diabetic children, and was most elevated in ketoacidosis when it averaged 10 times basal excretion. Urinary excretion of PGF2 alpha and of 6-keto-PGF1 alpha, the metabolite of PGI2, was approximately doubled in DKA compared with values from healthy subjects. Excretion of PGE2 was twice control values in children with stable diabetes, whereas the equivalent value for TXB2, the metabolite of the active vasoconstrictor TXA2, was reduced by approximately 50%. We suggest that the increased excretion of prostacyclin metabolite may result from a protective biological action on the kidney opposing other vasoconstrictor hormone activity. PGE2 appears not to be involved in this process. The highly elevated excretion of PGE2 metabolite may represent an activation of systemic PGE metabolism during DKA.

Adolescent↗
PubMed1990

Reduced glomerular filtration and elevated urinary protein excretion in diabetic ketoacidosis.

Glomerular filtration rate (GFR) was measured by two methods in 9 children with diabetic ketoacidosis (DKA), directly by true creatinine clearance and indirectly by means of serum beta-2-microglobulin levels. We found significantly reduced GFR in the first hours of DKA. The rapid improvement in GFR after fluid and electrolyte replacement indicates that volume depletion is the major cause of low filtration rate. In spite of the reduced GFR we observed pronounced albuminuria and low molecular weight (LMW) proteinuria. We conclude that the pathological albuminuria and microalbuminuria in DKA are caused not by glomerular hyperfiltration but by tubular dysfunction.

Adolescent↗