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T Tulassay

Publications and source records attributed to T Tulassay.

At least 37 records · Page 2Linked to original sources
PubMed2001

Effect of low birth weight on adrenal steroids and carbohydrate metabolism in early adulthood.

AIM: Data are inconsistent whether hyperinsulinemia might be associated with adrenal hyperandrogenism in young adults born with low birth weight (LBW). METHOD: We investigated the insulin and adrenal steroid production of 70 young LBW adults [33 women (birth weight: 1,795 +/- 435 g) and 37 men (birth weight: 1,832 +/- 337 g)]. Their results were compared to those of 30 controls (14 men, 16 women), born with normal weight. RESULTS: In LBW women, we measured higher basal DHEA (33.5 +/- 13.1 vs. 23.6 +/- 8.7 nmol/l, p < 0.05), DHEAS (8.0 +/- 2.3 vs. 6.3 +/- 2.1 micromol/l, p < 0.05), androstenedione (8.3 +/- 2.8 vs. 6.0 +/- 2.2 nmol/l, p < 0.05) and cortisol (0.25 +/- 0.07 vs. 0.20 +/- 0.07 micromol/l, p < 0.05) levels and higher insulin response during oral glucose tolerance test (log.AUCins: 2.62 +/- 0.06 vs. 2.57 +/- 0.03, p < 0.05). DHEA levels correlated with fasting insulin levels (r = 0.45, p < 0.01) and insulin response (r = 0.33, p < 0.05). In LBW men, higher cortisol (0.27 +/- 0.06 vs. 0.22 +/- 0.06 micromol/l, p < 0.01) and SHBG (18.4 +/- 10.4 vs. 12.7 +/- 5.9 nmol/l, p < 0.05) levels were found. CONCLUSIONS: Our results suggest that modest hypercortisolism is present in young LBW adults. While the endocrine sequel of hypercortisolism raised insulin response and hyperandrogenism is detectable in apparently healthy young LBW women, it is absent in young LBW men. This suggests that gender-dependent mechanisms might play a role in the development of insulin resistance in LBW adults.

17-alpha-Hydroxyprogesterone↗
PubMed2000

[Low birth weight, adrenal and sex hormones and their correlation with carbohydrate metabolism and cardiovascular physiology, investigated in young adulthood] .

It is known that the prevalence of cardiovascular diseases, hypertension, noninsulin dependent diabetes mellitus and dyslipidemia in the late adulthood are in connection with intrauterine retardation, characterized by low birth weight. One possible explanation of this phenomenon is the abnormality of hypothalamus-hypophysis-adrenal cortex axis due to the accelerated growth. The authors investigated the steroid levels of young adults; whom birth weight were under 2500 g, and examined the relationship between hormone levels and some parameters of glucose metabolism and cardiovascular system. 75 subjects (43 female and 32 male patients, mean age: 19.6 and 19.8 years, respectively; range 18-22 ys) with low birth weight and without any sign of chronic disease, and 30 healthy, age-matched controls with normal birth weight were investigated. The basal serum cortisol, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), androstenedione (AD), 17-hydroxyprogesterone (17OHP), estradiol (OE), sex-hormone binding globulin (SHBG), FSH, LH and insulin levels were determined. Moreover, oral glucose tolerance test with 75 g glucose (OGTT), impedance cardiography as well as ambulatory blood pressure monitoring were done by all subjects. In both sexes in subjects with low birth weight the mean serum cortisol level was significantly higher, than in the normal controls. In female patients the serum DHEA, DHEAS, AD, and 17OHP levels were significantly higher than in the controls. Moreover, among these females a relationship was found between the elevations of adrenal and gonadal steroids and hyperinsulinemia, characterized by increased insulin response during OGTT. In male subjects a significant correlation was found between serum cortisol levels and systolic blood pressure and heart rate. In females there was a positive relationship between serum DHEA and heart rate. Summarized, the basic abnormality in patients with low birth weight seems to be a relative hypercortisolism, and in females because of hyperinsulinemia exists a mild hyperandrogenism as well. The hypercortisolism may cause cardiovascular abnormalities in males directly, while in females indirectly through the hyperinsulinemia and hyperandrogenism. These subtle abnormalities can be detected when no clinical signs present themselves, in young adulthood, giving the opportunity of taking preventive actions.

17-alpha-Hydroxyprogesterone↗
PubMed2000

Higher osteocalcin levels and cross-links excretion in young men born with low birth weight.

As the result of accelerated growth, the final height of infants born with low birth weight (LBW) is near to the normal. Limited data are available about the bone density and bone turnover just after completion of skeletal development. We have investigated the bone turnover and bone density in 49 apparently healthy young LBW men (age 19-21 years; 21 born small for gestational age (SGA) and 28 appropriate for gestational age (AGA)) and in 16 age-matched controls. Bone mineral density of lumbar spine, femoral neck, and radius midshaft, the markers of calcium homeostasis, biochemical parameters of bone turnover as serum osteocalcin (OC), and urinary pyridinoline (PYD) and deoxypyridinoline (DPD) levels were measured. Bone mineral densities of LBW subjects were not altered. Serum calcium (SGA: 2.44+/-0.15; AGA:2.41+/-0.17, control: 2.25+/-0.09 mmol/liter, P < 0.05), OC (SGA:23.4+/-9.9; AGA:20.8+/-7.6; control:13.3+/-4.6 ng/ml, P < 0.01), total alkaline phosphatase (AP) (SGA:201+/-61; AGA:193+/-81, control: 117+/-34 IU/liter, P < 0.01), and urinary DPD/creat (ln.values: SGA:3.10+/-0.48; AGA:3.17+/-0.46; control:2.58+/-0.57 nmol/mmol, P < 0.05) were higher, whereas fractional excretion of calcium (SGA:0.94+/-0.470; AGA: 1.03+/-0.51, control:1.31+/-0.75%, P < 0.05) was lower in both SGA and AGA groups. PTH and 25OHD were not different. Significant correlation was obtained between seCa, OC, AP, DPD and birth weight of the subjects, but feCa correlated inversely to the birth weight. It was concluded that the bone turnover of LBW men is accelerated, but well balanced in young adulthood. Further investigation is needed to describe the possible link between accelerated bone turnover and hormonal homeostasis of LBW subjects.

Absorptiometry, Photon↗
PubMed2000

Normal kidney function and elevated natriuresis in young men born with low birth weight.

The aim of our study was to characterize renal function and its relationship to blood pressure in healthy young Caucasian men born with a birth weight under 2,500 g (LBW). Urinary protein patterns, N-acetylglucosamine and gamma-glutamyltransferase activities, fractional sodium and potassium excretions, glomerular filtration rate, blood pressure, and erythrocyte Na+/K+-ATPase activities were determined in 65 subjects, of whom 49 were born with LBW. Signs of glomerular or tubular damage were not detected in the LBW population. However, the blood pressure and the renal sodium excretion were inversely correlated to the subjects' birth weight and were higher in LBW subjects than in controls. In contrast, the erythrocyte Na+/K+-ATPase activities were lower in LBW subjects. An inverse correlation was detected between the subjects' Na+/K+-ATPase activities and the renal sodium excretion or blood pressure. In summary, our results suggest that: (1) in young LBW Caucasian males signs of early glomerular and tubular impairment are not present; (2) the elevated renal sodium excretion may be a result of higher blood pressure; (3) the alteration of Na+/K+-ATPase activity might play a role either in the elevation of blood pressure and/or in the enhanced natriuresis of LBW subjects.

Adult↗
PubMed2000

Bone metabolism and mineral density following renal transplantation.

AIM: To study bone turnover following renal transplantation using a panel of biochemical markers and to correlate the results with both areal and volumetric bone mineral density (BMD). PATIENTS: A total of 31 patients aged 18.1 years were transplanted 5.4 years before this study. Control patients (n = 31) were age and gender matched. METHODS: In addition to measurement of biochemical markers, BMD was measured by single photon absorptiometry and peripheral quantitative computed tomography on the non-dominant radius. RESULTS: Patients had reduced glomerular filtration rate, raised concentrations of serum phosphate, serum procollagene type I carboxy terminal propeptide, osteocalcin, and serum procollagene type I cross linked carboxy terminal telopeptide. The differences were still significant if only patients with normal intact parathyroid hormone were considered. BMD single photon absorptiometry Z score for age was significantly decreased. Following standardisation for height the differences were no longer present. With volumetric techniques patients had normal trabecular but decreased cortical and total BMD compared to age matched controls, but there was no difference from height matched controls. CONCLUSION: Markers of bone turnover are increased following renal transplantation. However, the biochemical analysis did not allow conclusions to be drawn on the bone mineral content. BMD single photon absorptiometry Z score corrected for height and BMD measured by quantitative computed tomography compared to height matched controls were normal in paediatric renal transplantation patients. Height matched controls should be used in both areal and volumetric BMD measurements in states of growth failure.

Absorptiometry, Photon↗
PubMed2000

Developmental changes in erythrocyte Na(+),K(+)-ATPase subunit abundance and enzyme activity in neonates.

AIM: To study the relation between erythrocyte Na(+),K(+)-ATPase subunit isoform composition, Na(+),K(+)-ATPase activity, and cation pump function in preterm and term neonates. DESIGN: Erythrocyte Na(+),K(+)-ATPase subunit isoform abundance, Na(+),K(+)-ATPase activity, and cation pump function were studied in blood samples obtained from 56 preterm neonates of 28-32 weeks gestation (group 1), 58 preterm neonates of 33-36 weeks gestation (group 2), and 122 term neonates (group 3) during the first two postnatal days. RESULTS: alpha(1) isoform abundance was higher and beta(2) isoform abundance was lower in group 1 than in group 3 (p = 0.0002). alpha(2) and beta(1) isoform abundance did not change with maturation and there was no evidence for the presence of the alpha(3) isoform. Gestational age was inversely related to Na(+), K(+)-ATPase activity (p = 0.0001) and directly related to intracellular Na(+) concentration (p = 0.0025). CONCLUSIONS: Expression of the alpha(1) and beta(2) Na(+),K(+)-ATPase subunit isoforms is developmentally regulated. The increased abundance of alpha(1) isoforms of immature neonates translates to increased ATPase activity. The lower intracellular Na(+) concentration of immature neonates suggests that their erythrocyte Na(+),K(+)-ATPase cation pump function may also be increased.

Blotting, Western↗
PubMed2000

Determination of H+/K+-ATPase activity in human gastric biopsy specimens.

The aim of our work was to develop a method to determine the the H+/K+-ATPase activity of human gastric biopsy samples. Our method is based on the phosphatase activity and the K+-inducible property of the enzyme. K+-inducible pNPPase activity was determined from homogenated corpus and antrum biopsy samples. H+/K+-ase activity was calculated as the difference between the corpus and antrum K+-inducible pNPPase activities. Quality control measurements were done during 20 successive days from pooled homogenates. The total, between-day and between-run, within-day and within-run coefficients of variations were between 10 and 16%. The healthy mean and reference range of K+-inducible pNPPase activity in the corpus was 95.8 (95% CI: 83.4-108.2 mU/mg protein); in the antrum it was 28.3 (21.6-35.0) mU/mg protein. The calculated H+/K+-ATPase activity was 67.2 (56.9-77.5) mU/mg protein. The measured activities were independent of the age and gender. Summarizing our results we have concluded, that our novel method might be a potential tool to gather data about the functional acid producing capability of human gastric mucosa.

Adolescent↗
PubMed1999

[Hepatitis G virus infection in hemodialyzed children and adults following kidney transplantation].

Recently, a new human virus hepatitis G virus was identified. The aim of the present study was to use a combination of the reverse transcription-polymerase chain reaction and a new test for antibodies to the viral envelope protein E2 to assess the prevalence of hepatitis G virus infection in sera of children and adults treated with hemodialysis or peritoneal dialysis as well as in sera of those who underwent renal transplantation. Hepatitis G virus RNA prevalence was higher in the shole group of patients with renal failure than in control group. The difference between hepatitis RNA prevalence in transplanted group and in control group was found to be significant. Anti-E2, which are is considered as an indicator of a past hepatitis G virus infection, were detected in the similar rate in the treated and control subjects. Time on hemodialysis was significantly longer in hepatitis G virus infected patients as compared to uninfected patients and all patients with hepatitis G virus RNA have a history of blood transfusions. Patients with renal failure treated with dialysis or subjected to renal transplantation are at increased risk of acquiring the hepatitis G virus infection. Higher rates of the hepatitis G virus RNA and similar prevalence of anti-E2 in patients with renal failure as compared to controls suggest that the rate of hepatitis G virus infection resolution in immunosuppressed patients with renal failure might be lower than in immunocompetent subjects.

Adolescent↗
PubMed1999

Sodium-lithium countertransport in children with nephrotic syndrome.

The mechanisms of sodium retention in edema-forming minimal change nephrotic syndrome (MCNS) have not been completely evaluated. The aim of this study was to characterize the transmembrane sodium transport in nephrotic syndrome by measuring the erythrocyte sodium-lithium countertransport (SLC) in vitro. Eighteen children with MCNS were studied in the edema-forming state, and subsequently at the beginning of remission. Nephrotic children with edema retained sodium (10+/-12 micromol/day) and had a higher SLC [426+/-118 vs. 281+/-60 micromol/l red blood cells (RBC) per hour, P=0.003). The intracellular sodium concentration of nephrotics was 6.1+/-2.1 mmol/l RBC, which did not differ from that of controls (6.42+/-2.24, n=13). In remission sodium balance became negative (-30+/-21 mmol/day), and the SLC decreased but still differed significantly from control values (P=0.009). The intracellular sodium content decreased to 4.4+/-0.9 mmol/l RBC (P=0.002). There was a negative correlation between erythrocyte SLC and plasma albumin concentration (r=0.48, P=0.003), and urinary sodium excretion rate (r=0.66, P=0.001). In conclusion, erythrocyte SLC is high in the edema-forming state of childhood nephrotic syndrome and decreases with the onset of remission. A role for the SLC in the altered sodium homeostasis of nephrotic syndrome is suggested.

Antiporters↗
PubMed1998

[The in vitro effect of recombinant human growth hormone on lymphocyte and granulocyte function in healthy and uremic children].

The aim of the study was to establish the effect of GH on immune functions in 22 healthy and in 11 uremic children, in vitro. Oxydative burst of granulocyte in the presence of GH measured by chemiluminescence and lymphoblast proliferation to GH and lectin stimuli were studied. Gene expression of GH receptor was analyzed with reverse transcriptase polymerase chain reaction (RT-PCR) method. The metabolic burst of granulocytes individually differed, specially in the chronic renal failure (CRF) group (60%) showed rather dose and time-dependent increase, the GH had only a priming effect. In 59% of the healthy children the GH stimulated the lympho-proliferative response itself or interaction with the lectin (ANOVA-test) and increased the spontaneous lymphoproliferation in 45% of the uremic patients. The GH receptor mRNA expression differed in the childrens lymphocytes, showing no correlation with the effect of GH on lymphoproliferation. The GH has a cytokine-like role in the regulation of the human immune system, and the GH treatment in uremic children is rather stimulating on immune functions.

Adolescent↗
PubMed1998

Sodium transport and bone mineral density in hypercalciuria with thiazide treatment.

Erythrocyte sodium-potassium (Na+/K+)-ATPase and sodium-lithium (Na+/Li+) countertransport activities were measured in 18 children (aged 9.6 years, range 6-16 years) with idiopathic hypercalciuria (IHU) to evaluate cellular Na handling. The effect of chronic thiazide administration on these parameters and on bone mineral density was also evaluated. Patients with IHU had significantly lower erythrocyte Na+/K+-ATPase activity than 23 age-matched healthy controls (mean +/- SEM 2,156 +/- 110 micromol P/l erythrocyte per hour vs. 3,165 +/- 175, P < 0.01). Thiazide treatment significantly lowered urinary calcium excretion; this was followed by a slight suppression of intact parathyroid hormone (iPTH). The urinary calcium/creatinine ratio before and during treatment was 0.90 +/- 0.07 mmol/mmol versus 0.51 +/- 0.06 respectively, P < 0.01. The corresponding iPTH levels were 5.9 +/- 0.6 pmol/l and 5.1 +/- 0.7, P < 0.05. The Na+/K+-ATPase activity increased significantly (2,769 +/- 169 micromol P/l erythrocyte per hour vs. 2,156 +/- 110 in the control period, P < 0.01) and the Na+/Li+ countertransport decreased (268 +/- 28 micromol Li/l erythrocyte per hour vs. 328+26 in the control period, P < 0.03). The bone mineral density Z score rose from -1.3 +/- 0.26 to -0.8 +/- 0.22 (P < 0.03). We conclude that IHU is accompanied by abnormalities of erythrocyte Na+/K+-ATPase and Na+/Li+ countertransport which are corrected by chronic hydrochlorothiazide administration. These changes could model alterations in renal tubular transport mechanisms still to be elucidated. Chronic thiazide treatment also has a positive effect on bone mineral density.

Adolescent↗
PubMed1998

Hepatitis G virus infection in children on dialysis and after renal transplantation.

The aim of the present study was to use a combination of the reverse transcription-polymerase chain reaction and a new diagnostic test for antibodies against the viral envelope protein E2 to assess the prevalence of hepatitis G virus (GBV-C/HGV) infection in sera of Hungarian children on hemodialysis (HD) or peritoneal dialysis (CAPD), as well as in sera of renal transplant patients (RTx). The GBV-C/HGV RNA prevalence was significantly higher in the whole group of children with renal failure (18.5%) than in the control group (children with urinary tract infection, 2.5%). The difference between the GBV-C/HGV RNA prevalence in the RTx group (33.3%) and in the control group (2.5%) was significant (P = 0.007). Anti-E2, which is considered an indicator of a past GBV-C/ HGV infection, was detected in 10% (1/10) of HD patients, in 33.3% (4/12) of RTx patients, but in none of the children on CAPD. These differences were not significant. Children receiving a renal graft are at an increased risk of developing GBV-C/HGV infection, which may be attributed to the immunosuppressive drugs necessary to maintain the grafts.

Adolescent↗
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↗
PubMed1998

In vitro effect of human recombinant growth hormone on lymphocyte and granulocyte function of healthy and uremic children.

The recombinant human growth hormone (rhGH), currently used in supraphysiological doses to promote growth acceleration in chronic renal failure children (CRF), also has the ability to influence their impaired immune functions. The effect of human growth hormone on the lymphoproliferative response in vitro was analyzed in the peripheral blood lymphocytes of 25 healthy and 11 uremic children. In 72% of the uremic cases and in 60% of the healthy individual children the hormone increased the lymphoproliferation alone, and/or when used in combination with phytohaemagglutinine. The range of the effective hormone concentrations differed individually. Using semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) a great variation in the gene expression of growth hormone- (GH)-receptor in peripheral lymphocytes was detected. The respiratory burst activity of peripheral polymorphonuclear leukocytes (PMN) in vitro, in response to GH alone and when combined with suboptimal dose of phorbolester (PMA), was assessed by measuring luminol enhanced chemiluminescence in ten uremic and 18 healthy children. In six out of the ten of the CRF patients and in eight out of 18 of the healthy children the GH enhanced the oxidative burst activity of granulocytes provoked by a suboptimal dose of PMA. However, the effective doses (10, 50 and 300 ng/ml) and incubation times (0, 45 and 90 min) showed individual variations. Our data suggest that rhGH treatment in uremic children could be advantageous considering this population's enhanced susceptibility to bacterial, viral and fungal infections.

Adolescent↗
PubMed1998

Functional and structural properties of Na+/K(+)-ATPase enzyme in neonatal erythrocytes.

BACKGROUND: The Na+/K(+)-pump is the main regulator enzyme of intracellular monovalent cation concentration. There are only limited data available concerning its structure and function in healthy neonates, in comparison with data available regarding its structure and function in children. PATIENTS AND METHODS: Samples of 100 microL of anticoagulated blood were taken from 53 healthy neonates (age under 6th postnatal day, median age 3.5 days) and 61 healthy children (median age 12.4 months, range 6-36 months,). The Na+/K(+)-ATPase activity, its sensitivity to ouabain (a digoxin-analogue substance) and the expression of Na+/K(+) ATPase subunit isoforms were determined. RESULTS: The enzyme activity (429.2 +/- 17.2 versus 295.5 +/- 10.2 U, P < 0 x 0.001) and I50 value for ouabain inhibition (1.50 +/- 0.10 versus 0.96 +/- 0.10 mumol L-1, P < 0.05) was higher in neonates. More alpha 1 subunits (relative density: 1.16 +/- 0.10 versus 0.75 +/- 0.03, P < 0.001) and higher alpha 1/ alpha 2 ratio (4.14 +/- 0.21 versus 2.02 +/- 0.16, P < 0.01) were detected. CONCLUSION: This is the first study demonstrating changes of Na+/K(+) -ATPase molecules not only in enzyme activity, but also on protein level. Our results might contribute to the understanding of the resistance of neonatal cell membranes toward the pharmacodynamic actions of cardiac glycosides.

Aging↗
PubMed1998

Developmental regulation of the inhibitory effect of dopamine on prolactin release in the preterm neonate.

The secretion and release of prolactin from the anterior pituitary is under the tonic inhibitory control of endogenous dopamine produced in the central nervous system. Exogenous dopamine inhibits prolactin secretion by reaching the pituitary via the portal circulation, and the hypolactotropic effect of dopamine infusion has been documented in all age groups in humans. However, the maturation of lactotroph sensitivity to dopaminergic inhibition has not been studied. Therefore, we followed the changes in serum prolactin concentrations before, during, and after dopamine infusion in 19 sick preterm infants with a mean gestational age of 30.6+/-0.6 weeks during the first 3 days of life, and examined the relationship of the hypolactotropic effect of dopamine to gestational age and birth weight in this patient population. As expected, dopamine therapy resulted in a decrease in mean serum prolactin from 89.4+/-9.5 to 58.6+/-9.1 microg/l (p < 0.05) with a return of the serum prolactin concentration to the pretreatment level 2-6 h after discontinuation of drug administration (98.3+/-11.7 microg/l, p < 0.05). However, simple regression analysis of the individual data revealed that the magnitude of the dopamine-induced decrease in serum prolactin was significantly influenced by gestational age (p = 0.006) and birthweight (p = 0.037). Thus, our findings provide evidence for the maturation of pituitary lactotroph sensitivity to dopaminergic inhibition in the preterm human neonate.

Dopamine↗