Biomedical subjects
Publications and source records attributed to W Schmidt.
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The cellular localization and regional distribution of peptides of the gastrin/cholecystokinin family was investigated in human fetal, neonatal and adult brains by use of immunohistochemical techniques. It could be revealed that a cholecystokinin-like immunoreactivity is already present in human brain at the 11/12th gestational weeks. With the 19th week a strong increase in number of CCK reactive cells and the reaction intensity is obvious. The data are compared with the distribution pattern of the adult brain. Our data permit to conclude that gastrin/CCK-related material might play roles independent of neurotransmitter functions during early human brain development.
The in vitro developmental potential of mouse blastocyst-derived embryonic stem cell lines has been investigated. From 3 to 8 days of suspension culture the cells form complex embryoid bodies with endoderm, basal lamina, mesoderm and ectoderm. Many are morphologically similar to embryos of the 6- to 8-day egg-cylinder stage. From 8 to 10 days of culture about half of the embryoid bodies expand into large cystic structures containing alphafoetoprotein and transferrin, thus being analagous to the visceral yolk sac of the postimplantation embryo. Approximately one third of the cystic embryoid bodies develop myocardium and when cultured in the presence of human cord serum, 30% develop blood islands, thereby exhibiting a high level of organized development at a very high frequency. Furthermore, most embryonic stem cell lines observed exhibit similar characteristics. The in vitro developmental potential of embryonic stem cell lines and the consistency with which the cells express this potential are presented as aspects which open up new approaches to the investigation of embryogenesis.
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From plasma of essential hypertensives and normotensives several fractions were obtained after: (1) removing proteins with a relative molecular mass greater than 6,000-8,000, and (2) chromatography on a Biogel P4 or Biogel P2 column. The eluate was separated into 3-4 fractions. These fractions were concentrated to a small volume of 0.5 ml and were injected intravenously in normotensive rats, the mean arterial pressure of which was monitored. One of the fractions from normotensive plasma increased blood pressure in the rat in some but not in all cases. Using the fractions from hypertensive plasma there was an increase in blood pressure in the fraction corresponding to that of normotensive plasma increasing blood pressure and in another fraction of lower molecular weight. Angiotensin II is unlikely to be responsible, since it could be identified in another fraction than that containing the hypertensive factor. It can be concluded that in the blood of essential hypertensives a hypertensive factor is present, which increases blood pressure even in normotensive animals. Its secretion may represent the critical step in the pathogenesis of essential hypertension.
A simple and reproducible method for cultivation of fetal chicken small intestine is presented. The culture was performed in a defined medium without serum. Duodena were excised from embryos at the 14th day of fetal development and cut in small segments that were maintained in culture until day 16. It could be shown that the morphology of cultured intestine resembles that of noncultured gut of corresponding age as judged by light microscopy. The increase in activity of sucrase and maltase in cultured explants is comparable with that of intestine in ovo, whereas that of alkaline phosphatase is lower than under in vivo conditions. Hormones (thyroxine, dexamethasone) influence the enzymic pattern of fetal intestine in a known manner. Therefore, the method permits maintenance of fetal intestine in tissue culture for 2 days, a period sufficient for investigation of maturation processes of intestinal mucosa.
Myocardial biopsy specimens were taken from 10 patients undergoing aortic valve replacement using extracorporeal circulation and continuous perfusion blood cardioplegia at extremely low myocardial temperature (10 degrees C). They were analyzed for adenosine triphosphate, creatine phosphate, creatine, and lactate before, after 10 minutes, and after 60 minutes of cardioplegia. Patient inclusion criteria were heart volume less than 700 ml/m2 body surface area and no significant coronary atherosclerosis as judged from preoperative angiograms. The profound hypothermic cardioplegia resulted in a smaller intramyocardial lactate accumulation but a greater decrease in adenosine triphosphate and creatine phosphate than a moderate reduction of myocardial temperature (15 degrees C) as previously reported in a similar patient group. This suggests that at the lower temperature energy-generating processes are thwarted more than energy consumption. In addition, the profound hypothermic cardioplegia led to a reduction of the myocardial pool of total creatine, which may delay restitution of myocardial high-energy phosphate and function after cardioplegia.
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Deep vein thrombosis in the leg and pelvis was seen in a 26-year old woman during the seventh month of pregnancy. 20 days after initial administration of heparin sodium, a local, markedly progressing erythema and induration was observed at the subcutaneous injection sites. The same cutaneous reactions occurred after application of heparin calcium. Following oral anticoagulation treatment with phenprocoumon, the patient was treated towards the end of pregnancy and directly post partum with a low-molecular semisynthetic heparin analogue without any side effects. The skin test again showed good tolerance of another heparin analogue and a low-molecular heparin.
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This paper continues our studies of physico-chemical properties of vesicle-bound flavins. Based on previous results, an advanced model system was designed in order to study the mechanisms underlying bluelight-induced redox transport across artificial membranes. The lumen of single-shelled vesicles was charged with cytochrome c, and amphiphilic flavin (AF1 3, AF1 10) was bound to the membrane. Upon bluelight irradiation redox equivalents are translocated from exogeneous 1e-(EDTA)-and 2e-(BH3CN-) donors across the membrane finally reducing the trapped cytochrome c both under aerobic and anaerobic conditions. The mechanisms involved are explored and evidence for the involvement of various redox states of oxygen, dihydroflavin and flavosemiquinone is presented.
"Total" fetal motor activity was determined in 111 healthy patients between 25 weeks of pregnancy and term using two real-time ultrasound devices simultaneously. Furthermore tocographic findings and also maternal perception of fetal movements of the same patients were stored synchronously on magnetic tape. A comparison was drawn between these three methods, i.e. real-time ultrasonography, maternal perception and tocographic tracings ("spikes" indicating fetal movements). Of all fetal movements, as assessed by real-time ultrasonography, the mothers perceived a total of 38% whereas "spikes" in tocographic tracings corresponded with fetal motor activity (excluding "breathing") in only 25% of the cases (P less than 0.001). Also major statistically significant differences could be found between maternal perception of fetal body movements with or without fetal limb movements in 56% and routine- tocography in 37% (P less than 0.001). Also isolated limb movements were most often detected by mothers (23%) than were revealed by tocographic findings (14%; P less than 0.001). Maternal signals were truly positive in 74% compared to tocography in only 56% of the cases (P less than 0.001). It is concluded that maternal perception of fetal movements is a more reliable method of monitoring fetal motor activity than analysis of tocographic tracings.
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.
The authors report on results of examinations of 18 women between the 38th and 42nd weeks of pregnancy in respect of the observation of foetal sleep/waking cycles. The following parameters were noted simultaneously, i.e. with time synchronicity: foetal heart rate, foetal eye movements, foetal thorax movements, and movements of the body and extremities. On the basis of the criteria published by Prechtl (1974) and by Nijhuis et al. (1982) it is possible to define with relative accuracy foetal sleep/waking cycles just before the term of birth; 4 independent researchers achieved agreement in the allocation of the various cycles in 86% of the cases investigated by them. In view of the fact that monitoring is complicated and exacting, recording cannot be continuous all the time and certain dropout periods must be taken into account. This applies, for example, to the foetal heart rate, foetal eye movements and movements of the thorax. The average dropout time during recording of foetal heart rate is 16%, during recording of foetal eye movements 22%, and of foetal thorax movements 3%. 11% of the recordings could not be evaluated because of poor recording quality and faulty monitoring. In the study under reference the shortest period of a cycle was three minutes, whereas the longest phase recorded so far was 39 minutes. In 55% of all monitored pregnancies between the 38th and 42nd weeks of pregnancy the foetus was awake, whereas in 45% the foetus was found to be asleep.
Clinically important ovarial cysts are extremely rare in the female foetus and newborn. About 70 cases only have been published so far. There are only four reports on antepartally diagnosed ovarial tumours. The article reports on the prenatal ultrasonographic diagnosis of a foetal ovarial tumour in the 34th week of pregnancy. Diagnosis "on suspicion" was substantiated by the identification of an intact and properly functioning foetal urogenital system and no abnormal findings in the intestinal organs, as well as by the identification of the sex of the foetus. Differential diagnosis in all cases of cystic foetal space-occupying tumours should consider, in the first place, malformations of the urogenital system, cysts of the liver, pancreas and mesenterium, as well as disturbances of function or malformations of the foetal digestive tract.
The complex problem of a coccygeal teratoma diagnosed prenatally is described, using a case report as basis. The possibility of a coccygeal teratoma should always be considered in solid and/or cystic processes in the caudal range of the foetus when performing differential diagnosis in which possible disturbances of neural tube occlusion and rare neurogenic tumours should be included. After having confirmed the diagnosis of a coccygeal teratoma via supplementary examinations and after having excluded other concomitant foetal malformations, the physician should communicate with the parents while considering the duration of pregnancy and the extent of the tumour. Whether abortion should be performed or whether the pregnancy should continue, is a decision which can only be arrived at, first of all, after full clarification of the expected malformation and, secondly, after ensuring closest possible interdisciplinary cooperation between obstetrician, neonatologist, paediatric surgeon and genetic engineer; as a matter of fact, such cooperation is absolutely imperative. In case of small coccygeal teratomas, it will be necessary to plan the time and mode of delivery as early as possible and to make sure that the newborn receives immediate surgical attention post partum by the paediatric surgeon.
If, in twin pregnancy, one twin shows severe malformation, the question arises as to how the other twin can remain unaffected. For the purpose of ensuring the diagnosis in case of suspected neural tube defect, the main diagnostic tools are sonography, biochemical methods of alpha-fetoprotein determination and acetyl cholinesterase activity, as well as cell-morphological identification of so-called "rapidly adhering cells". Parents and obstetricians face a difficult decision when confronted by the possibilities of maintaining pregnancy or of induced abortion after diagnosis of a malformed and a healthy twin. The case of a severe discordant cranial malformation is described on the basis of a case report. The diagnostic and therapeutic problems are discussed.