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Biomedical subjects

A Funk

Publications and source records attributed to A Funk.

At least 37 records · Page 2Linked to original sources
PubMed1993

[The value of Doppler ultrasound studies within the scope of obstetric management in unexpected findings in the cardiotocograph].

In a study of 30 cases with moderate or serious foetal heart rate alterations, we examined the influence of Doppler ultrasound on our obstetrical management. Normal results of Doppler umbilical artery flow velocity waveform analysis would allow us in 22 of 24 cases, to continue the pregnancy under usual control. Only in two cases with moderate foetal heart rate alterations, absence of labour and a normal Doppler result, Caesarean section was necessary because of foetal distress. A pathological Doppler result was found in six cases with intrauterine growth retardation. These risks were not known prior to the patients hospitalisation. Surprisingly, we found only moderate foetal heart rate alterations in these cases. Without any further control of the foetal heart rate, we decided to perform Caesarean section immediately after the Doppler investigation. We are of the opinion, that Doppler ultrasound could be very useful in obstetrical management to decide, if the pregnancy must be ended or could possibly be continued in cases of premature birth.

Apgar Score↗
PubMed1993

[Doppler ultrasound studies of breast tumors with the continuous wave technique].

The aim of the study was to ascertain the reliability of continuous-wave Doppler signals in the diagnosis of breast cancer. CW-Doppler findings in a series of 63 cases of palpable breast tumors with histologic confirmation (24 malignancies and 39 benign tumors) are reported. Depending on the parameters used -20 -24 of 24 malignant nodes (83%-100%) and 20 -24 of 39 benign lesions (51%-62%) were correctly identified. Even benign tumors showed significant differences in systolic peak and diastolic frequencies compared to the contralateral breast. The Resistance-Index (RI) did not allow the differentiation of lesions when measured on one side only. Comparing the Resistance-Indices of both breasts helped improving the specificity of CW-Doppler-sonography to 89.7% and the positive predictive value to 73.3%. The CW-Doppler-sonography with the relevant parameters of diastolic and systolic peak frequency and the RI is considered a useful tool in the diagnosis of breast cancer.

Adolescent↗
PubMed1993

[Prognostic factors in primary gastric non-Hodgkin's lymphoma--results of uni- and multivariate analysis].

Retrospectively analyzed data of 41 patients with primary gastric non-Hodgkin lymphoma which were all treated by gastric resection are presented with regard to their histopathologic and clinical findings. 87% of the patients were distributed on stage EI and EII (51% high-grade and 49% low-grade lymphoma). R0 resection was achieved in 80% of our cases and in 27% of the cases gastric resection was part of a multimodal therapy. The median follow up of the living patients was 42 months, the overall 5-year survival rate 74%. Tumor stage, extent of surgical resection, histologic grade, tumor site, R0-resection and tumor size showed a significant prognostic influence on survival. The question whether R0 resectable cases benefit from an adjuvant therapy must be answered by further randomized studies.

Adult↗
PubMed1993

Immunoreactivity and expression of amylin in gastroenteropancreatic endocrine tumors.

Amylin was isolated from human insulinomas, but there has been only preliminary data regarding whether this peptide can also be detected in other types of gastroenteropancreatic endocrine tumors. In the present study, immunohistochemical staining of 87 gastroenteropancreatic endocrine tumors demonstrated amylin immunoreactivity in 21.8% of the neoplasmas. Thirteen of 15 insulinomas, three of 21 gastrinomas, two of 29 nonfunctioning tumors, and one of 18 carcinoids were amylin-immunoreactive. Seventeen of the 19 amylin-immunoreactive tumors were primarily located in the pancreas, but two tumors were found in the intestine. Measurements of amylin messenger RNA expression in a few tumors revealed amylin synthesis in these tumors. Amylin immunoreactivity did not correlate with invasion and metastasis. However, the rate of curative resections was significantly higher in amylin-immunoreactive tumors. These results demonstrate for the first time that amylin immunoreactivity is not restricted to insulinomas and can also occur rarely in endocrine tumors of the intestine.

Amyloid↗
PubMed1992

[Telemetric cardiotocography--clinical value and limits of the method in routine monitoring].

Cardiotocography by external telemetry and maternal ambulation has been compared to the usual recording in recumbent position. The visual interpretation extended to several items, such as technical quality, CTG scoring, contractions and foetal activity, which were interpreted for single groups of gestational age and diagnosis. A questionnaire of the patients joined with this study, referring to the acceptance of cardiotocography, definitely voted for the telemetrical method. As to the valuation of the cardiotocograms (CTGs), it was necessary to consider a slight restriction of the undulation of the foetal heart rate by telemetry. Referring to the technical quality of the CTGs, the telemetrical method was inferior in all points while recording in recumbent position. Problems appeared to occur especially with adipose gravidas. In patients with toxaemia, we noticed a tendency to increasing systolic blood pressure combined with growing restriction of foetal undulation by telemetrical recording. The use of external telemetry with maternal ambulation at other diagnostical situations should depend only on technical quality and maternal acceptance of telemetry, since there are no differences with respect to information.

Adolescent↗
PubMed1992

[Initial studies of the possibility of selective ablation of arteriosclerotic vascular changes using laser-induced shock waves].

We studied the effect of laser-induced shock waves in 94 arterial segments from freshly obtained autopsy material. In analogy to the well-established method of shock-wave based lithotripsy, the new principle of our treatment depends on an indirect interaction of the laser energy with the arterial wall via laser-induced mechanical shock waves (angiotripsy). We used a Nd:YAG laser, 1064 nm, 8-20 ns pulse-length to create shock waves that effected smooth craters in arteriosclerotically affected arteries. The histological examination found no thermal damage. Shock waves applied to the healthy and normal arterial wall only resulted in focal intimal ablation and in a minor loosening of the medial structures. The examination of the irrigation solution by means of a laser-guided, high-resolution analysis of the particles revealed that, in 97%, the particles created by our shock wave angiotripsy showed a diameter of less than 5 mm and an area of less than 25 mm2. Based on these first in vitro results, it seems possible to ablate arteriosclerotically affected tissue without significant damage to normal wall segments. Further in vitro and in vivo studies are required to evaluate the clinical implications of this new therapeutic approach.

Angioplasty, Laser↗
PubMed1990

Norepinephrine-induced cholestasis in the isolated perfused rat liver is secondary to its hemodynamic effects.

In this study we examined the effect of pharmacological doses of various alpha-adrenergic agents on hepatic portal perfusion, organic anion uptake and bile secretion using the isolated perfused rat liver. Addition of norepinephrine at portal perfusate concentrations ranging from 0.01 to 100 mumol/L induced a dose-related increase in portal pressure with a twofold increment at the highest concentration. This was accompanied by an inhibition of hepatocellular uptake of taurocholate by 16.8% +/- 1.8% and of sulfobromophthalein (BSP) by 32.9% +/- 3.0% compared with controls. Moreover, a 22.5% +/- 3% decrease in bile flow rate and a 22.8% +/- 4% inhibition of biliary excretion of taurocholate were observed. Addition of other alpha-adrenergic agonist (epinephrine, dopamine and phenylephrine) at similar concentrations produced the same hepatic effects as observed with norepinephrine. During infusion of these alpha-adrenergic agents, trypan blue infusion revealed a patchy perfusion pattern of the liver surface compared with the homogeneously stained organs in controls. The hemodynamic alterations could be confirmed by electron microscopy examination that demonstrated that increased portal pressure produced by norepinephrine was associated with sinusoidal shunting. All hemodynamic, metabolic and biliary changes induced by norepinephrine could be entirely prevented by concomitant infusion of the alpha-antagonist phentolamine, thus indicating that norepinephrine-induced hepatic effects were mediated by alpha-receptors. In contrast, simultaneous addition of papaverine, an unspecific vasodilator, prevented the hemodynamic and the biliary changes of norepinephrine, but failed to modify the metabolic effects of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Endosonographic Doppler flow measurement of the embryonic and fetal umbilical cord].

The blood flow in the umbilical cord was examined via endovaginal Doppler sonography in 30 cases of early pregnancy. For the first time it was possible to examine by Doppler sonography the arterial blood flow in the completed 6th week of pregnancy p.m. With increased duration of gestation there was a continuous increase in arterial blood flow until establishment of a constant flow over the entire cardiac cycle with a constant presence of a diastole in the 14th pregnancy week. Venous blood flow also showed from the 7th pregnancy week p.m. onwards a constant development until attainment of a continuous Doppler flow profile in the 10th pregnancy week. Since the doppler curves of the same gestation period agree with one another, the Doppler profiles obtained in each case can be considered to be both typical and representative. The course of the Doppler flow curves shows the improving performance of the heart of the embryo in the direction of an increasing metabolic exchange between embryo and mature placenta via the increasingly efficient vascular systems.

Blood Flow Velocity↗
PubMed1989

The use of a vaginal probe in the diagnosis of ectopic pregnancy.

75 patients with suspected ectopic pregnancy, referred to the department of Gynaecology and Obstetrics of the RWTH-Aachen between July 1987 and May 1988, were examined by means of transvaginal sonography. The sonographic findings were subsequently vaudated by clinical and/or surgical means. An ultrasound diagnosis of an ectopic pregnancy could not be confirmed in only 3 out of 25 such cases.

Adult↗
PubMed1989

Magnetic resonance imaging studies of the brains of anesthetized rats treated with manganese chloride.

An understanding of the distribution of manganese ions in the brain is of interest in connection with the development of an understanding of the neurotoxicity of this element. Information about the time dependent biodistribution of manganese ions in the brains of intact rats subsequent to single IP injections of MnCl2 has been obtained from magnetic resonance imaging (MRI) studies. The enhanced MRI contrast is based on the reduction in the spin lattice relaxation time (T1) of water protons which exchange into the coordination sphere of the manganese ions. These studies indicate rapid and significant accumulations of water accessible manganese in the ventricles, the pineal gland, and the pituitary gland. The rapid appearance of high levels of manganese in the ventricular cerebrospinal fluid indicates that manganese readily crosses the filtration barrier of the choroid plexus and is thereafter apparently absorbed by the ependymal surfaces of the ventricles and transported to the subarachnoid space.

Anesthesia↗
PubMed1988

[Three-dimensional imaging in ultrasonic diagnosis. Initial results].

A new method of three-dimensional (3-D) reconstruction of 2-D ultrasound images of the kidney is described. It is based on a coordinated spatial reconstruction of sequential cross-sectional images. The ultrasound head is moved longitudinally between two rails (parallel sections) and rotated. With a suitable computer program and contouring of each cross-section (so that the organ limits are defined for the computer) these cross-sectional pictures can be reconstructed into 3-D organ images. The kidney can then be presented spatially either as a binary picture or with closed surface. Ultrasound investigators are still unaccustomed to colour reproduction of 3-D reconstructed organs. It remains to be seen whether the method is valuable in routine clinical use.

Color↗
PubMed1988

NMR observability of ATP: preferential depletion of cytosolic ATP during ischemia in perfused rat liver.

The extent to which cellular metabolites are NMR observable is of fundamental importance in the interpretation of in vivo NMR studies. Analysis of ischemic rat liver shows that ATP resonances measured by 31P NMR decrease considerably faster than total tissue ATP measured in extracts. This discrepancy demonstrates that, in liver, ATP is not 100% observable. Furthermore, the data are consistent with the supposition that in situ mitochondrial ATP resonances are not normally observable by in vivo NMR techniques. The specificity of the NMR measurement for cytosolic ATP indicates that 31P NMR can be a valuable tool for the specific measurement of ATP in this compartment.

Adenosine Triphosphate↗
PubMed1987

Metabolism of excess methionine in the liver of intact rat: an in vivo 2H NMR study.

L-Methionine is the most toxic amino acid if supplied in excess, and the metabolic basis for this toxicity has been extensively studied, with varying conclusions. It is demonstrated here that in vivo 2H NMR spectroscopy provides a useful approach to the study of the hepatic metabolism of methionine in the anesthetized rat. Resonances corresponding to administered L-[methyl-2H3]methionine, and to the transmethylation product sarcosine, are observed during the first 10-min period after an intravenous injection of the labeled methionine, and the time dependence has been followed for a period of 5 h. A third resonance, assigned to the N-trimethyl groups of carnitine, phosphorylcholine, and other metabolites, becomes observable several hours after administration of the deuteriated methionine. In addition, there is a small increase in the intensity of the HDO resonance over the period of the study, which is interpreted to reflect the ultimate oxidation of the labeled sarcosine methyl group via mitochondrial sarcosine dehydrogenase. Additional small 2H resonances assigned to N1-methylhistidine and creatine could be observed in perchloric acid extracts of the livers of rats treated with the deuteriated methionine. Inhibition of the flux through the transmethylation pathway is observed in the rat pretreated with the S-ethyl analogue of methionine, ethionine. These data provide strong support for the importance of glycine transmethylation in the catabolism of excess methionine.

Animals↗
PubMed1985

Use of gene transfer and a novel cosmid rescue strategy to isolate transforming sequences.

Mouse Lewis Lung tumor DNA was ligated to a cosmid containing a geneticin (G418)/kanamycin resistance gene and transferred into NIH3T3 cells. Recipient cells were first selected for geneticin resistance and subsequently for their ability to grow as a tumour when injected into nude mice. By repeating this transfection procedure with DNA from resultant tumours, geneticin-resistant NIH3T3 cells were obtained which were tumorigenic and contained approximately 1-5 copies of the transferred cosmid. The functional oncogene was cloned by preparing cosmid libraries of third round tumour DNAs, using a cosmid which does not contain a kanamycin resistance gene. Due to the original linkage of the oncogene with the cosmid containing the kanamycin resistance gene, a series of kanamycin-resistant cosmids were isolated, five of which contained an active oncogene. Subsequent analysis showed that the oncogene present was highly related to the human N-ras gene. Using a DNA probe from the MLL N-ras gene, a non-transforming counterpart was isolated from mouse liver DNA. A comparison between the two N-ras genes showed that a mutation at the amino acid position corresponding to 61 in the human gene is responsible for transforming activity of the rescued gene.

Animals↗
PubMed1981

Systemic immunity in herpetic keratitis.

The importance of specific immunity, especially cell-mediated, in resistance to herpes simplex disease is well documented, and animal experiments show that immune responses to previous herpetic infection can give considerable protection against reinfection in epithelial keratitis. Since susceptibility to stromal herpetic keratitis is probably determined in part by the extent of virus proliferation in the epithelium, immune responses to herpes simplex virus were studied in patients with epithelial or stromal keratitis, a group of patients with keratitis who were also severely atopic, and controls. The parameters measured were lymphocyte transformation, production of macrophage migration inhibition factor, and levels of serum antibody and immunoglobulin. No group differences were found except for a slight decrease in the whole blood culture assessment of lymphocyte transformation in stromal keratitis patients compared with seropositive controls and patients with epithelial disease. It is considered that in a small group of patients a deficiency in the specific cell-mediated immune response plays a role in determining the spread of virus into the corneal stroma.

Adolescent↗
PubMed1980

Two different species of murein transglycosylase in Escherichia coli.

We demonstrated that Escherichia coli murein transglycosylase exists in two forms. After mechanical disruption of the cells, one form was found in the soluble fraction and the other, in the cell envelope. The two enzymes differed with respect to molecular weight, isoelectric point, solubility in aqueous buffers, and to some extent in their requirements for maximal catalytic activity. The molecular weight of the membrane-bound transglycosylase (35,000) was half that of the soluble enzyme. Whether the high-molecular-weight soluble protein is a precursor of the membrane-bound enzyme species remains to be elucidated.

Cell Membrane↗