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Biomedical subjects

R Boos

Publications and source records attributed to R Boos.

At least 37 records · Page 2Linked to original sources

[Value of high-resolution real-time sonography in breast cancer].

1015 women were examined via scanning echo sonography in the course of a prospective study. Histological results are available from 370 patients following sample excisions or breast amputations. 122 histologically established malignant findings were compared with the preoperatively effected tumour status prognosis obtained via echo mammography and x-ray mammography. In 60 of 122 cases (50%) we found that the patients had carcinomas of stage T1. The sonographic accuracy rate was high (49 out of 60 carcinomas = 81%), whereas x-ray mammography yielded an accuracy of only 77%, since 46 out of 60 cases only had been classified as malignant. The smallest carcinomas visualised by sonography had diameters of 4 mm, 5 mm and 6 mm. In accordance with the fine structure of the tissue, solid carcinomas were recognised most frequently, compared with all other carcinomas, the rate of detection being 96% (26 out of 27). In 64% of all carcinomas, a retrotumourous sonographic shadow was seen. In cases with solid carcinomas, this "sonographic shadow phenomenon", however, was actually present in 34.6% of the cases only, although the rate of identification was highest of all. The results show that echo mammography is the most important additive investigation method in diagnosis of diseases of the breast, besides x-ray mammography, which is of course also an important method. Echo mammography offers a high degree of accuracy in preoperative differential diagnostic assessment of tumour status in malignant processes of the breast.

Adenocarcinoma, Scirrhous

In vivo performance of the pH tissue electrode during acute acid-base changes in the dog.

The ROCHE tissue pH-electrode was tested in acute animal experiments under various metabolic conditions. In anesthetized dogs an electrode was placed in the subcutaneous tissue of the scalp, neck, and axilla. Simultaneous with the continuous measurement of tissue pH, the overall acid-base balance of the animal was measured discontinuously at 5-min intervals by means of indwelling arterial and venous catheters. Various forms of acidosis and hypoxia were produced in the experimental animal and the sensitivity of the electrodes in relation to their site was tested. A high correlation between the continuously measured tissue pH values and the corresponding arterial and venous actual blood pH values were found in the physiologic pH range. With acute changes of acid-base balance no correlation could be found in the acidotic range.

Acid-Base Imbalance

Continuous measurement of tissue pH in the human fetus.

The ROCHE pH electrode was tested clinically in 20 fetuses and one nonviable newborn with severe malformations. The proper fixation of the electrode in the fetal scalp is difficult. In the physiologic pH range a good correlation between capillary blood pH and tissue pH exists. The situation is less clear for the acidotic range.

Capillaries

Actions of GABAergic ligands on brisk ganglion cells in the cat retina.

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian retina. We tested the actions of iontophoretically applied GABAergic ligands on the spontaneous and stimulus-evoked activity of retinal ganglion cells recorded extracellularly in the in vivo cat eye. GABA as well as GABAA receptor agonists inhibited all brisk ganglion cell types. This action was antagonized by bicuculline. Bicuculline on its own increased the activity of ON-ganglion cells but suppressed OFF-ganglion cells. This suppression effect was abolished during the blockade of glycinergic transmission by strychnine. The GABAB receptor agonist baclofen inhibited OFF-ganglion cells whereas the activity of ON-ganglion cells was either increased or decreased depending on the stimulus contrast. The antagonists, phaclofen and 2-hydroxy saclofen, produced opposite effects to baclofen and antagonized its action. The present study demonstrates that both GABAA and GABAB receptors modulate the activity of ON- and OFF-ganglion cells in the cat retina.

Animals

[Mediastinal cystic lymphangioma as a cause of hydrops fetalis].

This report is upon a case with fetal hydrops on the base of a paracardiac cystic lymphangioma in the mediastinum. The newborn which had hypoplastic lungs and multiple pneumatothoraces died because of a pulmonary insufficiency. An overview is given about the most common causes of the nonimmune fetal hydrops, and the pathomechanisms are discussed.

Female

[Doppler sonography--effect of fetal position, site of the placenta and measurement site of the fetal aorta].

The influence of fetal position, the site of placenta and the site of measurement in the fetal aorta on doppler-flow parameters was investigated in patients with uncomplicated pregnancies. In 20 cases the S/D-ratio was obtained in three different regions of the descending aorta. Measurements superior the renal vessels showed comparable values (4.1-4.3). No differences were found between signals obtained cranial or caudal of the diaphragma. Measurements at the aortal bifurcation showed significantly increased median values (6.6, p less than 0.05). No differences could be obtained concerning the influence of fetal position or site of placenta on S/D-ratio. All median values of a total of 197 patients were in the range of 4.8. Therefore it may be concluded that the above mentioned parameters do not have significant influence on doppler flow parameters in fetal vessels. However, a proximal site of measurement in the descending aorta fetalis should be reassured.

Aorta

[Twin pregnancies with fetofetal transfusion syndrome].

During an observation period of 10 years 30 cases (11%) of twin transfusion syndrome were observed in a collective of 286 twin pregnancies at the University Women's Clinic Heidelberg. Typical symptoms of a twin transfusion syndrome as polyhydramnios, hydrops fetalis, polyserositis, disparity in fetal growth of the twins and pathological CTGs were examined for their diagnostic and prognostic values. A difference in birth weight of more than 25% was noted in only 28% of cases (range 2-58). A polyhydramnios was diagnosed in 63% of cases, an acute form in 30%. Eight of the nine pregnancies with an acute hydramnios ended in an abortion or intrauterine death up to 28 weeks of gestation. Amniocentesis for reduction of the excessive amount of amniotic fluid had no positive therapeutic effect. Eight of the pregnancies, in which a hydramnios had been detected, were further complicated by a hydrops fetalis (23%). Typical sinusoidal CTGs were registered in only 3 cases. Intrauterine fetal mortality respectively abortion up to 28 weeks of gestation was noted in 6 patients (12/60; 20%). Fetal mortality after 28 weeks of gestation occurred in 9/60 cases (15%). Four infants died more than 7 days post partum (7%). The fetal malformation rate was determined in our collective with 7% (4/60 fetuses). No chromosomal abnormalities were observed. The data collected show the prognostic relevance of the parameters analysed and reveal the cases in which a therapy might be effective. Ultrasonographic scanning of fetal activity or doppler flow measurements are further diagnostic procedures that can be employed in surveillance of risk pregnancies with twin transfusion syndrome. Also umbilical cord puncturing under direct ultrasonographic monitoring is of certain diagnostic and therapeutic value.

Cardiotocography

[Prune belly syndrome. Prenatal diagnosis and obstetric procedure].

With an incidence of between 1 in 30,000 and 1 in 50,000 births, prune-belly syndrome (PBS) is a rare malformation syndrome. The phenotypical and pathoanatomic changes range from discrete expression to very severe malformation complexes with extremely poor prognosis. Malformations of the kidneys and the efferent urinary tract are common. In such cases, oligohydramnios often develops early in such fetuses, followed by Potter's sequence. This syndrome can generally be diagnosed by timely ultrasound investigations, i.e., before the end of the first half of pregnancy. Striking features in the fetus are often oligohydramnios and a greatly dilated urinary bladder, more rarely multicystic-dysplastic kidneys and other malformations of the urogenital tract. Diagnostic possibilities and obstetric procedure are described on the basis of ten cases seen between January 1984 and July 1987 at Heidelberg University Gynecological Clinic.

Abdominal Muscles

[Prenatal diagnosis of thanatophoric dwarfism with cloverleaf skull].

Thanatophoric dwarfism is a rare condition occurring in 1 in 100,000 births. To date, only 2 cases have been reported on in which this condition was diagnosed prenatally before the 24th week of pregnancy post menstruationem. The majority of cases reported so far were born by cesarean section. This condition can be diagnosed early by measurement of the fetal diaphyseal bones and accompanying specific diagnostic measures to establish the possible presence of malformations. The pregnancy can then be terminated if need be, and unnecessary interventions thus avoided.

Abortion, Eugenic

[Fetofetal transfusion syndrome in twin pregnancy with prune belly syndrome].

The authors report on a twin pregnancy with one phenotypically normal twin and one with Prune-Belly-syndrome. Since a severe urethral obstruction-malformation complex was apparent, a premature vaginal delivery was aimed for. A pathologic CTG of the healthy twin, with silent and sinusoidal graph pattern, rendered a primary cesarean section necessary in the 36th + 0 week of pregnancy. The cause was established as a fetofetal transfusion syndrome with severe anemia of the phenotypically normal newborn. Following appropriate blood transfusion the subsequent development of this child was free of complications. The child with Prune-Belly-syndrome died on the second day of life.

Adult

[Controlled acoustic and photic stimulation of the fetus in the last pregnancy trimester].

The aim of the study communicated here was to check any fetal reactions occurring after external stimulation (light-optic and acoustic stimuli), depending on fetal behavioral status. The group studied (acoustic/light stimulation) comprised 85 patients with normal course of pregnancy at term (37th to 42nd week of gestation). They were compared with a control group of nonstimulated patients (n = 26), also with normal course of pregnancy and corresponding gestational age. Fetal heart frequencies and an external tokogram were recorded synchronously with the fetal respiration, body, limb and eye movements registered simultaneously by two independent observers and the fetal behavioral statuses were defined (Nijhuis, Prechtl et al. 1982; Boos and Schmidt 1984; van Vliet et al. 1985). The stimulation methods used were as follows: 1. Single-frequency pure tone (2 kHz, 120 dB, 5 sec) 2. Sawtooth-modulated pure tone (0.5-2.0 kHz, modulation frequency 10 Hz, 120 dB, 5 sec) 3. Low-frequency, sawtooth-modulated pure tone (with vibration effect), (0.1-0.3 kHz, modulation frequency 10 Hz, 120 dB, 5 sec) 4. Light stimulation: electronic photographic flash, luminous intensity 25 X 10(6) Lux/10(-3) sec, 8 flash sequences in 10 sec, distance from maternal abdomen 20 cm. In order to rule out purely coincidental changes in fetal attitude, both genuine and "sham" stimulations were performed in randomized sequence, in the latter case without any acoustic or light-optic signals. No differences in fetal reactions were found with the three different acoustic stimulation methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation