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Biomedical subjects

G Mielke

Publications and source records attributed to G Mielke.

At least 19 recordsLinked to original sources
PubMed2004

Double-chamber right ventricle associated with severe fetal cardiac failure.

Fetal cardiac defects leading to intrauterine cardiac failure and subsequent fetal hydrops are rare. We report an unusual case of a double-chamber right ventricle leading to progressive fetal cardiac insufficiency and hydrops. The patient was first managed conservatively. Delivery by Cesarean section was performed for a pathological fetal heart-rate tracing at 28 weeks of gestation. The newborn died 4 h postpartum due to generalized cardiac insufficiency.

Adult↗
PubMed2002

Large-core needle biopsy for diagnosis and treatment of breast lesions.

PURPOSE: Large-core needle biopsy (LCNB) has become a more widely used technique in the evaluation of breast lesions. This study was undertaken to access the accuracy of percutaneous LCNB on breast lesions and the impact on further proceeding. METHODS: A retrospective review of imaging-guided LCNB of 159 breast lesions was done. 143 LCNB were taken with ultrasound guided automated spring gun biopsy and 16 stereotactic-guided with vacuum-assisted biopsy device. Histology and morphobiological parameters were compared with subsequent material from surgery. RESULTS: In 113 core biopsies (71%), an infiltrating breast cancer was diagnosed, 5 biopsies (3%) yielded in-situ/atypical lesions and a benign lesion was shown in 38 cases (24%). In 3 cases, insufficient/necrotic material was obtained. 108 patients underwent subsequent surgery. In 100/108 cases (93%), histology on LCNB and surgery was identical. LCNB was false negative in 5 core biopsies (5%). Immunhistochemical stains of hormone receptors, bcl-2, c-erbB-2, p53 and MIB-1 was comparable on LCNB and on surgical material. Based on the results of LCNB, 17/113 patients (15%) with infiltrating carcinoma were primarily treated with hormones or with neoadjuvant therapy. 32/38 patients (84%) with benign lesions were followed up by imaging control. CONCLUSIONS: In patients with benign lesions on imaging, open biopsies can be avoided by LCNB. In patients with biopsy proven carcinoma, therapy planning is improved. The addition of morphobiological parameters allows early individual treatment.

Adenocarcinoma, Mucinous↗
PubMed2002

Prenatal diagnosis and perinatal management of left coronary artery to right atrium fistula.

Serious complications due to coronary artery fistulae have been described. Most authors recommend early intervention at the time of diagnosis. We present a case of a fistula originating from a dilated left coronary artery and draining into the right atrium, which was diagnosed prenatally by color Doppler echocardiography. During pregnancy, the echocardiographic findings remained unchanged, and there were no signs of heart failure. After birth, the fistula was confirmed by angiography. Additionally, a persistent left superior vena cava draining into the coronary sinus and a very small ventricular septal defect were detected. The fistula was closed successfully by transcatheter coil embolization. At 17 months old the child was in good clinical condition. Prenatal diagnosis of coronary artery fistulae may be possible and may improve perinatal management and outcome.

Adult↗
PubMed2002

Clinically significant persistence and enlargement of an antenatally diagnosed isolated choroid plexus cyst.

Isolated choroid plexus cysts are usually diagnosed at the time of screening ultrasonography during the second trimester. While they raise the question of underlying chromosomal abnormalities, their clinical course is almost invariably benign with complete resolution often by the third trimester. We report the highly unusual case of a choroid plexus cyst diagnosed at 14 weeks of gestational age with subsequent further enlargement of the cyst, necessitating postpartum neurosurgical intervention.

Adult↗
PubMed2001

Cardiac output and central distribution of blood flow in the human fetus.

BACKGROUND: The objectives of this study were to establish reference ranges for left and right cardiac output and to investigate blood flow distribution through the foramen ovale, ductus arteriosus, and pulmonary bed in human fetuses. METHODS AND RESULTS: A prospective study was performed in 222 normal fetuses from 13 to 41 weeks of gestation with high-resolution color Doppler ultrasound. Cardiac output and ductal flow were calculated by use of vessel diameter and the time-velocity integral. Pulmonary blood flow was expressed as the difference between right cardiac output and ductal flow. Foramen ovale flow was estimated as the difference between pulmonary flow and left cardiac output. Gestational age-specific reference ranges are given for left, right, and biventricular output and volume of ductal blood flow, showing an exponential increase with gestational age. Median ratio of right to left cardiac output was 1.42 and was not associated with gestational age. Right cardiac output was 59% and left cardiac output was 41% of biventricular cardiac output. Median biventricular cardiac output was estimated to be 425 mL. min(-1). kg(-1) fetal weight. Ductal blood flow was 46%, estimated pulmonary flow was 11%, and estimated foramen ovale flow was 33% of biventricular output. CONCLUSIONS: The study establishes reference ranges for fetal cardiac output and offers insights into the central blood flow distribution in human fetuses from 13 weeks to term. There is a clear right heart dominance. The estimated ratio of pulmonary blood flow to cardiac output is higher than in fetal lamb studies.

Blood Flow Velocity↗
PubMed2001

[Clinical experience with large-core needle biopsies of the breast and evaluation of histopathology].

OBJECTIVE: Interventional techniques allow a microinvasive diagnostic of breast lesions. We examined the reliability of large core needle biopsies for histologic diagnosis on breast lesions. MATERIAL AND METHODS: 143 ultrasound guided automated spring gun biopsies and 16 stereotactic guided vacuum-assisted device biopsies were analyzed. Indications included confirmation of malign or benign lesions and diagnosis of suspicious lesions. RESULTS: In 113 biopsies (71%) an invasive breast carcinoma was diagnosed, in 5 biopsies (3%) in situ/atypical lesions were seen and 38 cases (24%) showed benign lesions. Based on the bioptic results, 108 patients underwent subsequent surgery. An identical histology was seen in 100/108 patients (93%), 5 biopsies were false negative (5%) and 3 specimens yielded necrotic/insufficient material. The immunohistochemical results of percutaneous biopsies and surgical specimens were comparable. 17 out of 113 patients (15%) with biopsy proven carcinoma were treated with neoadjuvant therapy. 32/38 patients with benign lesions were follow-up clinically. CONCLUSION: Ultrasound- or stereotactic guided percutaneous biopsies are methods to confirm histological diagnosis. Based on the biopsy results the, number of surgical excisions can be reduced and treatment of biopsy proven carcinoma can be improved by individual presurgical planing.

Biomarkers, Tumor↗
PubMed2000

Reference ranges for two-dimensional echocardiographic examination of the fetal ductus arteriosus.

OBJECTIVES: To establish reference ranges for 2D-echocardiographic examination of the fetal ductus arteriosus and its relationship to the main pulmonary artery and the aorta. METHODS: A prospective cross-sectional echocardiographic study was performed in 222 normal fetuses from 13 to 41 weeks of gestation using high resolution/color Doppler ultrasound equipment. RESULTS: Gestational age-specific reference ranges are given for the diameter of the pulmonary valve anulus, diameter of the ductus arteriosus at its beginning, middle, and end, ductal length, ductal diameter-to-pulmonary valve anulus diameter ratio, and the spatial relationship of the ductus arteriosus to the main pulmonary artery and to the aorta. CONCLUSIONS: The presented data derived from a study group of 222 normal fetuses provide in-vivo insights into the morphology of the ductus arteriosus and its relationship to the adjacent vessels. The reference ranges may be helpful in prenatal diagnosis of cardiac malformations and abnormalities of the ductus arteriosus, such as obstruction or aneurysm from 13 to 41 weeks of gestation.

Aorta, Thoracic↗
PubMed2000

Blood flow velocity waveforms of the fetal pulmonary artery and the ductus arteriosus: reference ranges from 13 weeks to term.

OBJECTIVE: To establish reference ranges for blood flow velocity waveforms of the fetal main pulmonary artery and the ductus arteriosus during the second and third trimesters of pregnancy. METHODS: A prospective cross-sectional echocardiographic study was performed in 222 normal fetuses from 13 to 41 weeks of gestation using high resolution/color Doppler ultrasound equipment. RESULTS: Gestational age-specific reference ranges are given for peak velocity across the pulmonary valve, velocities in the ductus arteriosus, peak systolic velocity in the ductus arteriosus-to-peak velocity across the pulmonary valve ratio, ductal systolic velocity-to-diastolic velocity ratio, ductal resistance index and ductal pulsatility index. In the ductus arteriosus, increasing fetal heart rate was significantly associated with increasing end-diastolic velocity and decreasing systolic-to-diastolic ratio, decreasing resistance index, and decreasing pulsatility index. CONCLUSIONS: Based on a prospective study in more than 200 normal fetuses, the data provide gestational age specific reference ranges for blood flow velocity waveforms of the fetal pulmonary artery and the ductus arteriosus. The reference ranges may be helpful in prenatal diagnosis of cardiac malformations and ductal obstruction from 13 to 41 weeks of gestation.

Blood Flow Velocity↗
PubMed1998

Circulatory changes following intrauterine closure of the ductus arteriosus in the human fetus and newborn.

Prenatal detection of intrauterine closure of the ductus arteriosus unrelated to maternal administration of non-steroidal anti-inflammatory drugs or glucocorticoids made it possible to study the circulation in this condition in the human fetus and newborn by pre- and postnatal echocardiography and neonatal cardiac catheterization. At 38 weeks, the fetus presented intrauterine ductal closure associated with right ventricular dilatation and marked hypertrophy of the right ventricle and the interventricular septum, as well as severely diminished right ventricular fractional shortening and diminished pulmonary blood flow. Blood flow redistribution was characterized by reduced blood flow through the right heart and increased right-to-left shunting across the dilated foramen ovale. Pathological Doppler waveforms of the inferior vena cava and the ductus venosus were found, although the cardiotocogram was normal. Following unsuccessful induction of labour a Caesarean section was performed. Postnatal echocardiography confirmed the prenatal findings. Cardiac catheterization, performed because of persistent dependence on additional oxygen administration, revealed increased pulmonary vascular resistance, reduced pulmonary blood flow, and prolonged right-to-left shunt across the foramen ovale. Reduced peripheral pulmonary artery diameters were shown angiographically. Follow-up examinations revealed regression of right ventricular hypertrophy and recovery of right ventricular and pulmonary function. The findings confirm results from haemodynamic studies in animal experiments.

Adult↗
PubMed1998

Fetal sex determination by high resolution ultrasound in early pregnancy.

OBJECTIVE: Fetal sex determination by ultrasound, and its medical and ethical implications, has been predominantly discussed in mid and late gestation. The development of high resolution ultrasound equipment has provided the possibility of detailed visualization of the fetus in early pregnancy. The present prospective study investigates the feasibility and accuracy of fetal sex determination by transabdominal ultrasound in early pregnancy. METHODS: Sonographic determination of fetal sex was attempted prospectively prior to genetic amniocentesis in 173 fetuses from 11 to 16 weeks of gestation. The result of ultrasound examination was compared with the karyotype obtained from amniotic fluid cells. RESULTS: Sonographic sex determination was feasible in 80.3% of cases, and all these determinations proved to be correct. There was no difference in the identification rate between male (n=87) and female (n=86) sex. Fetal sex determination was also feasible and correct in all four sets of twins and in the one set of quadruplets. CONCLUSION: Fetal sex assignment in the late first and early second trimester can be useful in pregnancies at risk for severe sex-linked diseases, in fetal disorders involving the genitalia, and in the individual identification of multiple fetuses. Prenatal sex assignment in early pregnancy implicates also far-reaching ethical problems because of the potential risk of sex-selected abortion.

Ethics, Medical↗
PubMed1997

The predominant protein in peroxisomal cores of sunflower cotyledons is a catalase that differs in primary structure from the catalase in the peroxisomal matrix.

This paper describes a biochemical study on the protein composition of crystalline inclusions (cores) from plant peroxisomes. By SDS/PAGE and immunoblotting, a catalase of 59 kDa was identified as the predominant protein component in purified cores from sunflower (Helianthus annuus L.) cotyledons. A 55-kDa catalase was the only additional peptide detected. In contrast to in cores, the 55-kDa catalase was the major catalase protein in matrix fractions obtained from lysed peroxisomes. These findings suggested two peroxisomal populations of catalase differing in molecular structure and subperoxisomal compartmentation in sunflower cotyledons. Evidence for different amino acid sequences of the two catalases was found by peptide mapping with endoproteinase Glu-C, by expressing a cDNA encoding matrix catalase in Escherichia coli, and by partial amino acid sequencing of peptide fragments from 59-kDa core catalase. These results contradict the previous view that the formation of cores occurred via condensation of matrix catalase, and indicate that new concepts on the biogenesis and physiological function of plant peroxisomal cores need to be developed.

Amino Acid Sequence↗
PubMed1997

Ductus arteriosus-dependent pulmonary circulation secondary to cardiac malformations in fetal life.

The objective of this study was to describe the characteristic prenatal findings of a ductus arteriosus-dependent pulmonary circulation secondary to cardiac malformations. B-mode, color and pulsed wave Doppler echocardiography were performed in seven fetuses with severe pulmonary stenosis or atresia. All findings were confirmed postnatally by echocardiography and cardiac catheterization or autopsy. Severe fetal pulmonary stenosis or atresia was characterized by decreased pulmonary valve diameters, frequently with reduced pulmonary artery diameters, increased flow velocities or absent flow across the stenotic pulmonary valve, increased ascending aorta diameters, slightly increased aortic velocities and normal umbilical and middle cerebral artery Doppler wave forms. In all cases, prenatal assessment of neonatal ductus dependence was possible by demonstrating reverse flow across the fetal ductus with peak systolic velocities ranging from 0.9-2.0 m/s and absent diastolic flow. Ductal diameters were slightly decreased, ranging from 2-4 mm. Prenatal detection of a ductus-dependent pulmonary circulation is a strong indication of the presence of severe pulmonary stenosis or atresia. Its diagnosis allows avoidance of maternal administration of drugs with constrictive effects upon the ductus, interdisciplinary planning of perinatal management, early postnatal confirmation of the diagnosis, and early postnatal intervention, in particular administration of prostaglandins to prevent life-threatening ductal closure.

Blood Flow Velocity↗
PubMed1997

Prenatal detection of double aneuploidy trisomy 10/monosomy X in a liveborn twin with exclusively monosomy X in blood.

Both double aneuploidy and trisomy 10 are rare chromosome findings. All five published cases of trisomy 10 in liveborns were found to be mosaic with an euploid cell line. In a liveborn female twin, double aneuploidy mosaicism 47,XX, + 10/45,X was detected prenatally by amniocentesis performed because of severe intrauterine growth retardation and malformations. Chromosome analysis from neonatal lymphocyte cultures revealed exclusively the 45,X cell line. Double aneuploidy mosaicism trisomy 10/monosomy X was confirmed from skin fibroblasts. The child died at the age of 7 weeks. This is the first reported case of double aneuploidy involving trisomy 10, and the first case of trisomy 10 without a normal cell line in a liveborn. Prenatal diagnosis of trisomy 10 in a liveborn has not been published so far. The case illustrates that in specific cases amniotic fluid cells may reflect the karyotype of the fetus better than blood.

Diseases in Twins↗
PubMed1997

An accurate method for sonographic estimation of the weight of very preterm fetuses.

This study was undertaken to test the accuracy of formulas we recently developed for the sonographic estimation of the weight of very preterm fetuses. The formulas were used to determine estimated weights from prenatal sonographic data for 62 premature infants born at 23-29 weeks of gestation, weight < or = 1,400 g. The mean absolute deviation of the actual birth weight from the estimated weight was 75.8 +/- (SD) 68.5 g, the mean percent deviation +0.60% and the absolute mean percent deviation 8.1 +/- (SD) 5.6%; 90.3% of the birth weights lay within 15% of the estimated weight. The model described represents an accurate method for prenatal estimation of the weight of very preterm fetuses.

Birth Weight↗