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Biomedical subjects

G Mielke

Publications and source records attributed to G Mielke.

At least 37 records · Page 2Linked to original sources
PubMed1997

Sonographic assessment of the fetal palpebral fissure slant--an additional tool in the prenatal diagnosis of syndromes.

Several syndromes and aneuploidies are associated with ocular abnormalities including up- and down-slanting palpebral fissures. We describes a technique for the sonographic assessment of the fetal palpebral fissure slant which was used in 70 normal pregnancies from 14 to 36 weeks of gestation. In a frontal view of the fetal face, the inferior angle between the palpebral fissure and the midline of the skull was determined. The median angle was 89 degrees, with a range from 87 degrees to 90 degrees. In selected cases, sonographic assessment of the fetal palpebral fissure slant may be a helpful additional tool in the prenatal diagnosis of syndromes, as demonstrated in a fetus with Seckel syndrome associated with downslanting palpebral fissures and in a fetus with Down's syndrome associated with upslanting palpebral fissures.

Craniofacial Abnormalities↗
PubMed1996

[Placental location and incidence of pre-eclampsia].

AIM: In pregnancies with unilateral placental location, the uteroplacental Doppler flow measurements show significant side-to-side differences. Highly divergent findings seem to be associated with an unfavourable outcome, particularly with preeclampsia. Therefore, we studied the relationship between placental location and subsequent development of preeclampsia prospectively. METHOD: 184 patients between 24 and 36 weeks of gestation were studied prospectively. Placental location was classified as central or lateral by ultrasound. Preeclampsia was defined by blood pressure > or = 140/90 mmHg and proteinuria > or = 500 mg/24 h. RESULTS: After consideration of exclusion criteria, 148 pregnancies could be evaluated: 115 had a laterally and 33 a centrally located placenta. The incidence of preeclampsia in these groups was 32/115 (28%) and 3/33 (9%) respectively. CONCLUSION: These data suggest that a laterally located placenta is associated with a significantly increased incidence of preeclampsia, with a risk ratio of 3.1 when compared to pregnancies with centrally located placentas.

Adult↗
PubMed1996

De novo direct tandem duplication of a small segment of the short arm of chromosome 7 (p21.22-->22.1).

We report a boy with duplication of a small segment of the short arm of chromosome 7 (46,XY, dir dup (7) (p21.2-->22.1). The boy presented with supravalvular pulmonary stenosis, atrial septum defect and mental retardation. The origin of the additional material from chromosome 7 was confirmed by fluorescence in situ hybridization. This technique in combination with the use of single-copy DNA probes may in future help to delineate the phenotype/karyotype correlation.

Abnormalities, Multiple↗
PubMed1995

Fetal and transient neonatal right heart dilatation with severe tricuspid valve insufficiency in association with abnormally S-shaped kinking of the ductus arteriosus.

Alterations of the ductus arteriosus, e.g. occlusion, constriction or aneurysm, can influence the fetal and neonatal circulation. A case of fetal right atrial and ventricular dilatation, severe tricuspid valve insufficiency and transient pulmonary valve regurgitation at 32 weeks of gestation is reported. Structural heart defects and extracardiac diseases (e.g. high output cardiac failure in arteriovenous shunts and anemia) were excluded by Doppler echocardiography and fetal blood sampling. An abnormally S-shaped kinking of the ductus arteriosus with increased systolic and diastolic flow velocities in the distal part was demonstrated. At 35 weeks' gestation, Cesarean section was performed, because of increased tricuspid valve insufficiency, and a healthy boy was born. After birth, right heart dilatation and tricuspid valve insufficiency decreased. The cardiac changes in relation to the anatomical abnormality of the ductus arteriosus are discussed.

Adult↗
PubMed1995

[Doppler sonography of the ductus venosus in high risk pregnancies at 23 and 26 weeks].

Ductus venosus blood flow was assessed in 3 high-risk pregnancies, which were terminated at 23 to 26 weeks' gestation because of HELLP-syndrome. The fetuses were extremely growth-retarded and showed diastolic reverse flow in the umbilical artery. In all cases the ductus venosus flow pattern was abnormal and finally showed loss of blood flow during atrial contraction. This finding suggests that the fetal central venous pressure is pathologically increased and may be interpreted as a sign of threatening cardiovascular decompensation.

Abortion, Eugenic↗
PubMed1995

A new formula for prenatal ultrasonographic weight estimation in extremely preterm fetuses.

A new formula for the prenatal estimation of the weight of extremely preterm fetuses was derived using ultrasound measurements and birth weights of 73 premature infants delivered before 30 completed weeks of pregnancy and weighing between 400 and 1,680 g at birth. The actual birth weight lay within +/- 15% of the estimated weight calculated with this formula in 92% of the cases. Preliminary testing of the reliability of the formula was performed on a further test group of 19 nonselected cases. The formula developed in this study offers a reliable and simple method of prenatal estimation of fetal weight between 23 and 30 weeks of gestation.

Body Weight↗
PubMed1993

[3H-leucine incorporation into the secretory cells of the murine mammary gland under the action of adrenomimetics].

Although there is some evidence suggesting the involvement of the sympathoadrenal system in the mammary gland function, the precise mechanism by which adrenergic agents may influence galactopoietic processes is largely unknown. The aim of this study was to investigate whether the reported decrease in milk and organic substance content after catecholamine administration might be due to the inhibition of protein synthesis. For that purpose, the incorporation of 3H-leucine into the secretory cells of the mammary gland of lactating mice under the influence of the alpha-adrenoceptor agonist phenylephrine and the beta-adrenoceptor agonist isoproterenol, respectively, was studied by light microscopic autoradiography. Tissue radioactivity as a whole was measured by liquid scintillation counting. It was shown that neither the alpha- nor the beta-agonist simultaneously given with the labeled amino acid were able to change the amount of radioactivity taken up by the mammary gland. From this result it is concluded that a transitory increase in catecholamine concentration in the blood has no effect on mammary gland protein synthesis.

Animals↗
PubMed1993

Transperitoneal calcium mass transfer using dialysate with a low calcium concentration (1.0 mM).

Lower dialysate calcium concentrations were recently proposed to overcome the risk of hypercalcemia in continuous ambulatory peritoneal dialysis (CAPD) patients on calcium-containing phosphate binders and/or vitamin D metabolites using the standard dialysate calcium concentration (SCa) of 1.75 mM. To assess transperitoneal calcium mass transfer (CaMT) in CAPD patients using a dialysate with a low calcium concentration (LCa, 1.00 mM), 18 stable patients were randomly allocated to receive either LCa or SCa. CaMT was assessed over 4 hours using 2L dialysate bags with three different dialysate glucose concentrations (1.5%, 2.3%, 4.25%). Total serum calcium (tCa), ionized calcium (iCa), and the exact dialysate volume were measured before and after the 4-hour dwell. A sample of the drained dialysate was obtained to measure the dialysate calcium concentration. The tCa and iCa levels were not significantly different in both groups prior to and did not change throughout the test. CaMT (median/range) was -0.64 mmol/exchange (-0.35(-)-1.29 mmol/exchange) using LCa with 1.5% glucose compared to 0.23 mmol (-0.18-0.87 mmol) with SCa (p < 0.0001). CaMT was negatively correlated to iCa and ultrafiltration volume [4.25%: LCa-1.22 (-0.84(-)-1.9); SCa -0.43 (-1.35-0.13); p < 0.001]. In summary, LCa results in a loss of calcium into the dialysate even at low ultrafiltration volumes and serum iCa levels. This might facilitate the prevention and therapy of renal osteodystrophy with calcium-containing phosphate binders and calcitriol. However, patients using LCa must be carefully monitored for calcium homeostasis and bone turnover.

Aged↗
PubMed1990

[Ultrasound of the knee joint: normal values and changes in rheumatoid arthritis].

The bursa suprapatellaris, infrapatellaris, the patella tendon, condylar cartilage, menisci and fossa poplitea were examined sonographically in 56 healthy persons in defined sections. References for normal findings are given. The examination of 22 patients with rheumatoid arthritis revealed joint effusions, Baker cysts, synovial hypertrophy, intraarticular septae and changes in the echogenicity of the synovial fluid.

Adult↗
PubMed1990

Calcium ionophores injure alveolar epithelial cells: relation to phospholipase activity.

Phospholipases and certain of their hydrolytic products are toxic to alveolar epithelial cells. Since many intracellular phospholipases are Ca2+ dependent, we postulated that elevating cytosolic Ca2+ with ionophores might cause epithelial injury via phospholipase activation. Isolated perfused hamster lungs exposed to an Ca2+ ionophore A23187 develop functional evidence of severe epithelial injury. Ultrastructural studies show widespread lysis of type I epithelial cells, with only minimal abnormalities in other lung cells, including the microvascular endothelium. Analysis of whole lung lipid extracts reveals a modest elevation in free arachidonic acid but no changes in other putative products of phospholipase activity. Parallel studies were performed in cultured cells of pulmonary origin. As measured by 51Cr release, A23187 causes substantial cytotoxicity in 3-day-old cultures of rat type II alveolar epithelial cells (RAEC) but not in cultured bovine pulmonary artery endothelial cells (BPAEC). RAEC prelabeled with [14C]stearic acid [( 14C]SA) and [3H]arachidonic acid [( 3H]AA) release radiolabeled free fatty acids (FFA) in response to A23187 in a dose- and time-dependent manner that parallels the cytotoxicity index. Analyses of putative phospholipase products in cells radiolabeled with [14C]SA and [3H]AA, with [14C]choline, or with [14C]ethanolamine suggest that liberation of radiolabeled FFA may be due to several phospholipases but with principal activity being exhibited by a phospholipase C having specificity toward phosphatidylcholine and phosphatidylethanolamine. Prelabeled BPAEC release only minimal quantities of FFA in response to A23187 under the same conditions. These studies demonstrate that elevations of intracytoplasmic Ca2+ are capable of severely and selectively damaging alveolar epithelial cells and that the injury is associated with activation of intracellular phospholipases. These findings may have implications in regard to the pathogenesis of acute lung injury in humans.

Animals↗
PubMed1981

[Olfactory stimulation and contingent negative variation (CNV) (author's transl)].

In addition to olfactory evoked responses (Fig. 1a) the vertex-negative voltage shift was registered in 20 normal adults. Fig. 2 shows this potential for an olfactory indicative stimulus followed by a tone burst or flash sequence, which are stopped by the test person's manual reaction. In Fig. 3 two alternating odorous stimuli are presented, one of which is followed by the tone. The selective expectancy wave is followed by the tone. The selective expectancy wave is only built up by the marked olfactory stimulus. For the first time CNV can be used as a clinical investigation tool to confirm central perception of odorous stimuli and furthermore to objectivate impaired central odour discrimination (parosmia).

Adult↗
PubMedDate not supplied

Late onset of hydrops fetalis following intrauterine parvovirus B19 infection.

We present a case of intrauterine parvovirus B19 infection, diagnosed by detection of B19 DNA in the amniotic fluid obtained at 15 weeks of gestation for chromosome analysis in an asymptomatic pregnancy, causing hydrops fetalis 7 weeks later. Following intrauterine transfusion, rapid resolution of hydrops could be observed and a healthy boy was born at 38 weeks of gestation. The respective laboratory data obtained from the examination of the amniotic fluid and maternal, fetal, and neonatal blood offer interesting insights into the dynamics of maternal-fetal parvovirus B19 infection.

Adult↗
PubMedDate not supplied

Prenatal diagnosis of idiopathic stenosis of the ductus arteriosus associated with fetal atrial flutter.

Antenatal stenosis or closure of the ductus arteriosus unrelated to either congenital heart defects or prostaglandin inhibitors is considered to be uncommon, but may result in congestive heart failure, hydrops fetalis, and perinatal death. We report a case of idiopathic ductal stenosis detected prenatally by two-dimensional and Doppler echocardiography in a fetus presenting atrial flutter and right atrial dilatation at 31 weeks of gestation. Prenatal treatment with digoxin and verapamil resulted in conversion to sinus rhythm. The fetus was closely monitored. Congestive heart failure did not develop, and the fetus was delivered spontaneously in good condition at 39 weeks of gestation. In case of ductal stenosis, the potential risk of congestive heart failure must be considered, and maternal administration of drugs with constrictive effects on the ductus arteriosus, as indomethacin or betamethasone, should be avoided.

Adult↗