Biomedical subjects

W Rascher

Publications and source records attributed to W Rascher.

At least 55 records · Page 3Linked to original sources

PubMed2001

Decreased gene expression of 11beta-hydroxysteroid dehydrogenase type 2 and 15-hydroxyprostaglandin dehydrogenase in human placenta of patients with preeclampsia.

Cortisol reduces the activity of the PG-inactivating enzyme 15-hydroxyprostaglandin dehydrogenase (PGDH) in human placental cells. The objective was to investigate a possible relation between 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), converting cortisol to cortisone, and PGDH gene expression in the placenta of patients with preeclampsia. In placental tissue taken from 20 healthy women with normal pregnancy, 20 premature babies born after labor before term, and 18 neonates after preeclamptic pregnancy, 11beta-HSD2 and PGDH messenger RNA (mRNA) expression was determined using quantitative TaqMan real-time PCR and quantitative competitive PCR. When comparing matched pairs, there were 3-fold lower 11beta-HSD2/glyceraldehyde-3-phosphate dehydrogenase (11beta-HSD2/GAPDH) mRNA levels in placentas of patients with preeclampsia than in controls [0.18 +/- 0.04 relative units (RU) and 0.61 +/- 0.10 RU, P = 0.0003]. We also found a 2-fold reduction in placental PGDH/GAPDH mRNA concentrations (0.28 +/- 0.15 RU and 0.50 +/- 0.18 RU, P = 0.0003). PGDH and 11beta-HSD2 mRNA levels correlated significantly (r = 0.66, P < 0.0001). In term placenta, 11beta-HSD2/GAPDH, but not PGDH, showed a significant correlation to birth weight (r = 0.43, P = 0.01) and to placental weight (r = 0.47, P = 0.01). Results could be confirmed by competitive PCR. We conclude that, in preeclampsia, 11beta-HSD2 mRNA expression is reduced, leading to the known decrease of 11beta-HSD2 activity. By means of an autocrine or paracrine mechanism, the diminished conversion of placental cortisol may lead to reduced PGDH mRNA expression as found in the present study.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed2001

Course of placental 11beta-hydroxysteroid dehydrogenase type 2 and 15-hydroxyprostaglandin dehydrogenase mRNA expression during human gestation.

BACKGROUND: During human pregnancy, 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) plays an important role in protecting the fetus from high maternal glucocorticoid concentrations by converting cortisol to inactive cortisone. Furthermore, 11beta-HSD2 is indirectly involved in the regulation of the prostaglandin inactivating enzyme 15-hydroxyprostaglandin dehydrogenase (PGDH), because cortisol reduces the gene expression and enzyme activity of PGDH in human placental cells. OBJECTIVE: To examine developmental changes in placental 11beta-HSD2 and PGDH gene expression during the 2nd and 3rd trimesters of human pregnancies. METHODS: In placental tissue taken from 20 healthy women with normal pregnancy and 20 placentas of 17 mothers giving birth to premature babies, 11beta-HSD2 and PGDH mRNA expression was determined using quantitative real-time PCR. RESULTS: Placental mRNA expression of 11beta-HSD2 and PGDH increased significantly with gestational age (r=0.55, P=0.0002 and r=0.42, P=0.007). In addition, there was a significant correlation between the two enzymes (r=0.58, P<0.0001). CONCLUSIONS: In the course of pregnancy there is an increase in 11beta-HSD2 and PGDH mRNA expression in human placental tissue. This adaptation of 11beta-HSD2 prevents increasing maternal cortisol concentrations from transplacental passage and is exerted at the gene level. 11beta-HSD2 up-regulation may also lead to an increase in PGDH mRNA concentrations that, until term, possibly delays myometrial contractions induced by prostaglandins.

11-beta-Hydroxysteroid Dehydrogenase Type 2↗

PubMed2001

Renal loss of leptin in patients with nephrotic syndrome.

OBJECTIVE: In humans, short term changes of serum leptin lead to alterations in food intake and energy expenditure. The objective of the present study was to relate urine leptin concentrations with the extent of proteinuria in patients with nephrotic syndrome (NS). A second goal was to investigate the impact of potential urinary leptin losses on serum leptin concentrations and body composition. DESIGN AND METHODS: Seventeen patients with proteinuria were compared with twenty patients with remission of NS and ten healthy children. Leptin was measured by radioimmunoassay. RESULTS: Urinary leptin excretion in proteinuric patients was significantly higher than in non-proteinuric patients with and without NS and in healthy controls (2.64+/-0.034 microg/g creatinine, 0.026+/-0.05 microg/g creatinine, and 0.073+/-0.11 microg/g creatinine respectively; P<0.001 and P<0.01 respectively compared with controls). Urine leptin positively correlated with urine IgG concentration (P=0.013, r2=0.36) in the proteinuric group. No difference in serum leptin values could be demonstrated between the three groups. CONCLUSIONS: In summary, our data demonstrate a significant leptin excretion in children with severe proteinuria. Proteinuria, however, does not lead to changes in serum leptin, suggesting that the significant loss of leptin is compensated for by sustained up-regulation of leptin production.

Adolescent↗

PubMed2001

Unmasking of childhood hypothyroidism by disseminated xanthomas.

Secondary hyperlipidemia is a common laboratory finding in children with nephrotic syndrome, diabetes mellitus, and hypothyroidism. However, clinical signs of hyperlipidemia are extremely rare in childhood. We report on an 11-year-old girl who presented with a disseminated yellow papulomatous rash on the lower limbs and yellow skin creases on the palms of her hands. Blood tests yielded an opaque serum with a triglyceride concentration of 820 mg/dL and cholesterol of 1050 mg/dL. Skin biopsy of one of the papules confirmed the diagnosis of xanthomas. Additional examinations revealed clinical (weight gain, diminished growth rate) and biochemical primary hypothyroidism (free T4: 0.4 ng/L [normal 8-22 ng/L]; thyroid-stimulating hormone: >200 mU/L) as a consequence of Hashimoto thyroiditis (thyroid peroxidase and thyroglobulin: 4400 U/mL and >2000 U/mL, respectively; normal <60 U/mL). The patient was started on L-thyroxine, which led to a gradual decline of cholesterol and triglycerides to normal concentrations and a complete remission from the xanthomatous rash. For the first time, this case depicts disseminated xanthomas of the skin as the presenting complaint of severe hypothyroidism. hyperlipidemia, hypothyroidism, xanthoma.

Child↗

PubMed2001

Diagnostic and scientific applications of TaqMan real-time PCR in neuroblastomas.

This review summarizes the present data on the diagnostic and scientific applications of TaqMan real-time PCR in neuroblastomas, a novel fluorescence-based method for quantitation of gene expression and gene copy number variations as gene amplification and locus haploinsufficiencies. Particular emphasis is spent on precision and accuracy and the comparison of TaqMan real-time PCR with more traditional methods for quantitative PCR. Provided a proper assessment for each new marker, this method has been shown to be an easy, fast and reliable alternative to the more traditional methods for the determination of MYCN amplification and neuropeptide Y gene expression. The combination with single cell picking in the neuroblastoma tissue may be a future target of the application of real-time PCR.

Biomarkers, Tumor↗

PubMed2001

AT1 receptor antagonist telmisartan administered peripherally inhibits central responses to angiotensin II in conscious rats.

The effects of systemic treatment with the AT1 receptor antagonist telmisartan on central effects of angiotensin II (Ang II), namely, increase in blood pressure, vasopressin release into the circulation, and drinking response, were investigated in conscious, normotensive rats. The central responses to i.c.v. Ang II (30 ng/kg) were measured at 0.5, 2, 4, and 24 h following acute i.v. or acute and chronic oral telmisartan application. At a dose of 10 mg/kg i.v., the drinking response to i.c.v. Ang II was completely blocked over 4 h, while the pressor response and the release of vasopressin in response to i.c.v. Ang II were blocked by 60 to 80%. The inhibition of the centrally mediated pressor and drinking response to Ang II was sustained over 24 h. The lower doses of telmisartan (0.3 and 1 mg/kg) significantly inhibited the Ang II-induced actions over 4 h. A consistent 24-h inhibition of the central responses to i.c.v. Ang II was obtained after acute and chronic oral treatment with 30 mg/kg telmisartan. Oral treatment with 1 and 3 mg/kg telmisartan produced a slight but inconsistent inhibition of the central actions of Ang II. Telmisartan concentrations measured in the cerebrospinal fluid following 8 days of consecutive daily oral treatment (1-30 mg/kg) ranged from 0.87 +/- 0.27 ng/ml (1 mg/kg/day) to 46.5 +/- 11.6 ng/ml (30 mg/kg/day). Our results demonstrate that, following peripheral administration, the AT1 receptor antagonist telmisartan can penetrate the blood-brain barrier in a dose- and time-dependent manner to inhibit centrally mediated effects of Ang II.

Angiotensin II↗

PubMed2000

Gene expression of neuronal nitric oxide synthase and adrenomedullin in human neuroblastoma using real-time PCR.

The objective of our study was to assess the gene expression of the antiproliferative systems neuronal nitric oxide synthase (nNOS) and adrenomedullin (AM) in human neuroblastoma. A novel real-time PCR method was evaluated using neuropeptide Y (NPY) for validation. Glyceraldehyd-3-phospate dehydrogenase (GAPDH) and NPY gene expression in neuroblastomas of 50 patients were measured in parallel by competitive quantitative and TaqMan real-time RT-PCR. AM and nNOS mRNA were determined by real-time PCR. Our results showed a linear relationship between competitive quantitative and real-time RT-PCR measurements of NPY and GAPDH (r = 0.87 and r = 0.92, respectively). AM and nNOS mRNA was found in all tumor samples. AM/GAPDH mRNA increased with higher differentiation according to Shimada (p = 0.013). There was no relation between MYCN amplification nor with the tumor stage (p = 0.78 and p = 0.30, respectively). AM/GAPDH did not relate to recurrence or death in a 5-year follow-up period. Neuronal NOS/GAPDH expression did not relate to any biological or clinical parameter of prognosis or differentiation. Similar results were obtained when the neuronal marker protein gene product 9.5 (PGP9.5) was used to normalize mRNA concentration. In conclusion, TaqMan real-time PCR appears to be a reliable method to quantify gene expression in neuroblastomas. Adrenomedullin mRNA in neuroblastoma is linked to tumor differentiation but not to prognostic markers.

Adolescent↗

PubMed2000

Nuclear gene targeting using negatively charged liposomes.

Oligonucleotides are a very useful tool to control gene activity. Oligos work by complementary base-pairing with target sequences either in the nucleus or in the cytosol (Zelphati, O., Szoka, F.C., Jr., 1996. Liposomes as a carrier for intracellular delivery of antisense oligonucleotides: a real or magic bullet? J. Contr. Rel. 41, 99-119). In a new approach using chimeric oligonucleotides (Yoon, K., Cole Strauss, A., Kmiec, E.B., 1996. Targeted gene correction of episomal DNA in mammalian cells mediated by a chimeric RNA-DNA oligonucleotide. Proc. Natl. Acad. Sci. USA 93, 2071-2076) conversion of single base mutations with help of intranuclear repair mechanisms maybe an advantageous method to cure genetic diseases which are based on single point mutations. These chimeric oligonucleotides are constructed in a way that they form an intramolecular double strand of DNA and modified RNA-bases. We used a fluorescent labelled pure 68-mer DNA-analogue of a chimeric oligonucleotides to follow the intracellular fate of these kind of genetic material. The oligos were complexed with protamine sulfate and coated with three different liposomal formulations. The AVE-3 formulation shows enhanced properties compared to a classical neutral and negatively charged formulation. Nuclear localisation of oligos could only be observed with the AVE-3 formulation. Furthermore only the negatively charged liposome formulations interact with the protamine-complexed oligonucleotides.

Biological Transport↗

PubMed2000

Recovery from withdrawal of inhaled nitric oxide and kinetics of nitric oxide-induced inhibition of nitric oxide synthase activity in vitro.

OBJECTIVE: To examine the kinetics of successful nitric oxide (NO) withdrawal in vivo and in vitro. DESIGN AND SETTING: Prospective study in a university pediatric intensive care ward and research laboratory. PATIENTS AND MATERIALS: Nineteen patients with acute respiratory distress syndrome (ARDS) or persistent pulmonary hypertension of the newborn (PPHN). Primary porcine pulmonary artery cells in vitro. INTERVENTIONS: NO inhalation and withdrawal in patients; exposure to NO donor sodium nitroprusside (SNP) and gaseous NO in vitro. MEASUREMENTS AND RESULTS: In patients: a slight, but significant, increase of oxygenation index (OI) from 4.57 +/- 0.24 cmH2O/torr (mean +/- SEM) to 4.90 +/- 0.26 cmH2O/torr after withdrawal of NO (p < 0.001). Recovery of OI (4.43 +/- 0.23 cmH2O/torr) 30 min after weaning, a significant drop after 4 h (3.72 +/- 0.17 cmH2O/ torr;p < 0.001), values restored after 12 h. In vitro: NO synthase (NOS) activity was significantly lower in SNP-incubated cells (20.0 +/- 4.0 microM/min) than in control cells (37.6 +/- 7.0 microM/ min; p < 0.05). Thirty minutes after SNP withdrawal there was NOS activity of 35.8 +/- 10.0 microM/min with a significant increase by 4 h (p < 0.05). No alteration of endothelial NOS (ENOS) mRNA expression by NO (Northern Blot). CONCLUSION: In patients there is a slight, but significant, reversible increase of OI after successful weaning from NO. In vitro, NO leads to a reversible decrease of ENOS activity on a post mRNA level, resembling clinical observations.

Administration, Inhalation↗

PubMed2000

Role of hypotension in brain-death associated impairment of liver microcirculation and viability.

Hypotension in brain-dead organ donors is considered a determinant factor of graft viability. The aim of this study was to elucidate the role of hypotension in brain-death associated impairment of hepatic microcirculation and function. Male Sprague-Dawley rats with an intracranial balloon were used. Group I (n = 7) served as sham controls. In group II (n = 7) brain death was induced through inflation of an intracranial balloon. In group III (n = 7) hypotension without brain death was induced by means of pentobarbital. In group II, a steep rise of arterial pressure was followed by a fall to a lower level (P < 0.01, vs. group I). Also in group III arterial pressure was lower (P < 0.01, vs. group I). In group II, bile production was diminished (P < 0.05). Impaired sinusoidal perfusion (P < 0.01) and enhanced leukocyte endothelium interaction (P < 0.05) were documented in hepatic microvasculature. Electron microscopic analysis revealed vacuolization of hepatocytes; these changes were not observed in group III. Brain death induces specific changes of liver microcirculation, function and histomorphology. Independent of associated hypotension, brain death per se impairs donor liver graft quality.

Alanine Transaminase↗

PubMed2000

Nuclear transport of oligonucleotides in HepG2-cells mediated by protamine sulfate and negatively charged liposomes.

PURPOSE: The aim of this study was to characterize the intracellular fate and nuclear uptake kinetics of oligonucleotides (ON) that were complexed with protamine sulfate (PS) and negatively charged liposomes at different ratios of ON to PS. METHODS: Double-fluorescence labelling of ON and liposomal lipid was applied to simultaneously monitor the interaction as well as the individual fate of active agent and carrier upon intracellular delivery using confocal laser scanning microscopy (CLSM). A DNA-analogue of a 68-mer intramolecular double-stranded RNA:DNA-hybridoligonucleotide (chimeraplasts) with unmodified phosphate backbone was employed. This construct was condensed with PS and coated with a liposomal formulation (AVE-3 = artificial viral envelope). RESULTS: PS-ON complexes and AVE -3-coated complexes with a defined composition were very effective in nuclear transport of ON for a ON:PS charge ratio of 1:3. Nucleus:cytosol fluorescence ratios peaked at about 10 hrs and started to decrease again at 21 hrs. CONCLUSIONS: AVE associates with PS-condensed ON, and this complex is able to be taken up by cells and to deliver ON to the nucleus. PS-ON complexes are released from the liposomal formulation, mainly as an extranuclear enzymatic degradation of the liposomal phospholipids. The results of the kinetic analysis can be used to optimize transfection protocols with ON in HepG2 cells.

Anions↗

PubMed2000

Sedation and monitoring of paediatric patients undergoing open low-field MRI.

UNLABELLED: The purpose of this study was to determine the need, effectiveness and safety of sedation and monitoring in infants and children in a paediatric open low-field MRI system. Of 274 patients (median age 9 y) examined, only 74 children (median age 25 mo) needed sedation. Sedation was achieved by intravenous administration of midazolam (0.2 mg/kg) and etomidate (0.2 mg/kg). Mean total doses required were 0.28 and 0.27 mgl/kg, respectively. With the exception of eight primarily ventilated patients, all children breathed spontaneously. O2 saturation, arterial blood pressure and ECG were monitored. The low resonance frequency of the MRI system required a specially designed high frequency (HF) shielding of the monitor system to avoid HF artifacts. The overall sedation rate was markedly lower (74/274 = 27%) compared to a control group previously examined in a closed high-field MRI system (52/111 = 47%). This was due to a significant lower need for sedation in patients aged up to 10 y (p < or = 0.0001) in the open MRI unit. General anaesthesia could be avoided in all patients. No significant movement artifacts occurred in any of the MRI examinations and no serious side effects were observed. CONCLUSIONS: MRI of children is easier in an open MRI system and with fewer sedations, as in closed high-field systems. Sedation by a combination of midazolam and etomidate is highly effective and safe. Monitoring devices for high-field systems may have to be modified for low-field systems. An in-house paediatric MRI unit with an open and special paediatric design is of major advantage for imaging paediatric patients.

Child↗

PubMed2000

Comparison of methylene blue, riboflavin, and N-acetylcysteine for the reduction of nitric oxide-induced methemoglobinemia.

OBJECTIVE: To investigate the treatment of nitric oxide (NO)-induced methemoglobinemia by methylene blue (MB), riboflavin, and N-acetylcysteine (NAC) in vitro. DESIGN: Prospective, controlled in vitro study. SETTING: Research laboratory in a university hospital. PARTICIPANTS: Five healthy volunteers. INTERVENTIONS: Generation of 16% to 18% of methemoglobin in red blood cells by NO and subsequent addition of MB, riboflavin, or NAC. Simultaneous NO (32 ppm) and MB or riboflavin exposure of red blood cells. Induction of 14% to 18% of methemoglobin in red blood cells by NO, subsequent addition of MB or riboflavin, and further incubation with NO (80 ppm). MEASUREMENTS AND MAIN RESULTS: After discontinuation of NO, mean half-life for methemoglobin was significantly reduced by MB from 356 mins (controls) to 5 mins (10 microM) in a dose-dependent manner (p < .001). NAC did not alter the half-life for methemoglobin, and a reduction from 356 to 168 mins was seen for 120 microM riboflavin (p < .001). Methemoglobin formation after 3 hrs of NO exposure was 4.3%+/-0.7% in controls and 0.3%+/-0.1% with 10 microM MB (p < .001); 1 microM MB attenuated methemoglobin formation to 1.9%+/-0.1% (p < .01). With riboflavin (120 microM), methemoglobin was 2.2%+/-0.5% vs. 3.2%+/-0.6% in controls (p < .001). In the presence of high methemoglobin concentrations, further methemoglobin formation was inhibited by 1 and 10 microM MB (p < .001) and attenuated by 0.1 microM MB (p < .001) but not by riboflavin. CONCLUSIONS: In vitro, NO-induced methemoglobin formation is significantly decreased by medium (1 microM) and high (10 microM) concentrations of MB and partially by high riboflavin concentrations (120 microM). NAC and low concentrations of riboflavin do not alter methemoglobin formation.

Acetylcysteine↗

PubMed2000

Case of XXXXY syndrome. Development throughout adolescence and endocrine aspects.

49,XXXXY syndrome is a very rare condition that is associated with a considerable more severe phenotype than classic 47,XXY Klinefelter syndrome. We present a patient with 49,XXXXY syndrome, who was first presented to an endocrinological unit at the age of 12.5 years with prepubertal genitalia. He was then lost from follow-up and showed clear clinical and biochemical signs of hypergonadotropic hypogonadism when presenting again at the age of 16 years. The patient was started on testosterone replacement therapy. This case is reported to underline the need for thorough endocrinological follow-up examinations in males with X polysomies.

Adolescent↗

PubMed2000

Variability of leptin values measured from different sample matrices.

Leptin concentrations are usually determined in serum or EDTA-treated plasma. Our aim was to evaluate the precision and accuracy of leptin measurement from serum and various kinds of plasma. Blood samples were collected from healthy volunteers and divided into aliquots of serum and plasma with administration of K(2)-EDTA, citrate, fluoride and lithium-heparinate, respectively. Leptin concentrations were measured by a specific radioimmunoassay. There were clear differences between the leptin values from the different matrices. The coefficient of variation (CV) was highest in serum samples (CV: 11.9 %) and very low in K(2)-EDTA-treated plasma samples (CV: 5.3%). Leptin measurements from serum yielded significantly lower results than the respective K(2)-EDTA-treated plasma samples (p < 0.05). The measurement in Li-heparinate-treated plasma revealed similar results to that in K(2)-EDTA-treated plasma. The lowest CV was determined in fluoride-treated plasma (5.2%). A higher CV was determined in citrate-treated plasma (5.8%) and the values were about 25% lower than in the respective K(2)-EDTA-treated plasma samples (p < 0.0001). Lower leptin measurements in citrate-treated plasma may partially, but not in total, be a consequence of dilution by anticoagulating additives. Because of the low CV K(2)-EDTA- and Li-heparinate-treated plasma samples appear most reliable for the measurement of leptin. The usage of these sample matrices is therefore recommended.

Adult↗

PubMed1999

Blood pressure reduction and diabetes insipidus in transgenic rats deficient in brain angiotensinogen.

Angiotensin produced systemically or locally in tissues such as the brain plays an important role in the regulation of blood pressure and in the development of hypertension. We have established transgenic rats [TGR(ASrAOGEN)] expressing an antisense RNA against angiotensinogen mRNA specifically in the brain. In these animals, the brain angiotensinogen level is reduced by more than 90% and the drinking response to intracerebroventricular renin infusions is decreased markedly compared with control rats. Blood pressure of transgenic rats is lowered by 8 mmHg (1 mmHg = 133 Pa) compared with control rats. Crossbreeding of TGR(ASrAOGEN) with a hypertensive transgenic rat strain exhibiting elevated angiotensin II levels in tissues results in a marked attenuation of the hypertensive phenotype. Moreover, TGR(ASrAOGEN) exhibit a diabetes insipidus-like syndrome producing an increased amount of urine with decreased osmolarity. The observed reduction in plasma vasopressin by 35% may mediate these phenotypes of TGR(ASrAOGEN). This new animal model presenting long-term and tissue-specific down-regulation of angiotensinogen corroborates the functional significance of local angiotensin production in the brain for the central regulation of blood pressure and for the pathogenesis of hypertension.

Angiotensin II↗

PubMed1999

Effects of systemic treatment with irbesartan and losartan on central responses to angiotensin II in conscious, normotensive rats.

Angiotensin AT1 receptor antagonists represent a novel class of cardiovascular drugs. In conscious, normotensive rats, irbesartan ((2-n-butyl-3-[(2'-(1H-tetrazol-5-yl)-biphenyl-4-yl) methyl]-1,3-diaza-spiro[4,4]non) and losartan ((2 n-butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl)biphenyl -4-yl) methyl] imidazol), two specific, high- affinity angiotensin AT1 receptor antagonists administered intravenously (i.v.) at doses of 0.3, 1, 3 and 10 mg/kg body weight, or orally (p.o.) at doses of 1, 3, 10 and 30 mg/kg body weight, antagonized the pressor responses to i.v. angiotensin II (50 ng/kg body weight) in a dose-related manner and with similar potency. In the following sets of experiments, we tested the hypothesis that these angiotensin AT1 receptor antagonists, when applied systemically, can inhibit the effects of angiotensin AT1 receptor stimulation in the brain. Irbesartan and losartan were administered i.v. or p.o. at doses of 3, 10, 30 and 100 mg/kg body weight. The responses to 100 ng angiotensin II injected into the lateral brain ventricle (i.c.v.), namely blood pressure increase, vasopressin release into the circulation and drinking, were recorded for up to 3 h. While both angiotensin AT1 receptor antagonists dose-dependently attenuated the pressor responses to central angiotensin AT1 receptor stimulation to a similar degree (maximal inhibition, irbesartan: 62% i.v., 39% p.o.; losartan: 62% i.v., 46% p.o.; respectively), irbesartan was more effective with respect to the inhibition of vasopressin release (76% i.v., 65% p.o.) and drinking (63% i.v., 79% p.o.) than losartan (58% i.v., 33% p.o and 22% i.v., 56% p.o., respectively). We conclude that systemically administered angiotensin AT1 receptor antagonists have access to central angiotensin receptors. The degree of central angiotensin AT1 receptor blockade following peripheral application may vary between different representatives of this class of drugs.

Administration, Oral↗

PubMed1999

The value of renal scintigraphy during controlled diuresis in children with hydronephrosis.

Dynamic renal scintigraphy (DRS) during controlled diuresis is the method of choice to diagnose the functional relevance of urinary tract obstruction in children with sonographically demonstrated hydronephrosis. However, there are no commonly accepted scintigraphic criteria for surgical intervention. On the basis of our findings, we propose four stages of washout (WO) of tracer following diuresis: in stage I, WO>50%, neither further diagnosis nor intervention is necessary; in stage II, 50%>/=WO>/=12%, repetition of DRS is advised within 3-4 months; and in stage III, 12%>WO>/=5%, DRS should be repeated within 1-2 months. Only in stage IV, WO<5%, should surgery be done immediately. This procedure reduces surgical interventions by 50% without increasing the risk of residual renal damage.

Diuresis↗