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Biomedical subjects

U Hofmann

Publications and source records attributed to U Hofmann.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Nuclear magnetic resonance tomography of children's thorax].

Magnetic Resonance Imaging of the pediatric chest was performed in 53 patients. All examinations were performed using a 1.0 and 1.5 Tesla superconducting MR imager. 80% of the children were examined using anesthesia with a ventilation of 20% inspiration and 80% expiration. After performing the MR examination in 55% of the cases an operation was performed. In 29 patients anomalies of the brachiocephalic trunc were found. In four patients MR detected a doubled aortic arch, in four patients we found a dilated arch. In eight children a dilated pulmonary artery was diagnosed. In combination with eight tracheobronchoscopy, MR imaging proved to be the diagnostic method of choice for the evaluation of anomalies of the mediastinum. New developments like fast imaging techniques and 3D acquisition promise a further diagnostic improvement in the mediastinum.

Aorta, Thoracic↗
PubMed1991

[Stratum corneum and nail lipids in patients with atopic dermatitis. Decrease in ceramides--a pathogenetic factor in atopic xerosis?].

Dry skin is seen in many patients with atopic dermatitis and correlates with a disturbed epidermal barrier function demonstrated by such features as increased transepidermal water loss and diminished stratum corneum hydration. With regard to the importance of stratum corneum lipids for the permeability barrier, we have analysed plantar (n = 8) and lumbar (n = 20) stratum corneum and nail lipids (n = 15) of atopic subjects by high-performance thin-layer chromatography (HPTLC). Compared with controls our investigations show a decrease in the ceramide fraction as a percentage of total lipid and a diminished ratio of ceramides and free sterols in atopic subjects. This implies that impaired ceramide synthesis may be a factor in the pathogenesis of atopic xerosis.

Dermatitis, Atopic↗
PubMed1990

Syntheses of metabolites of S-carboxymethyl-L-cysteine and S-methyl-L-cysteine and of some isotopically labelled (2H, 13C) analogues.

The chemical syntheses of human metabolites of S-carboxymethyl-L-cysteine (3) and S-methyl-L-cysteine (12) are described. The additional preparation of some 2H- and 13C-labelled isotopomers enabled the direct evaluation of the stabilities of 3 and 12 under physiological conditions and also facilitated the unambiguous assignments of the signals in the 13C-NMR spectra of all compounds mentioned.

Carbocysteine↗
PubMed1990

Measurement of 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid and its metabolite 12-oxo-5Z,8E,10E-heptadecatrienoic acid in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry.

Thromboxane A2, the predominant product of arachidonic acid metabolism in the blood platelet, is a potent vasoconstrictor and platelet agonist. During its biosynthesis from cyclic endoperoxide, 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) is formed in equal amounts. The further metabolism of HHT, catalyzed by 15-hydroxyprostaglandin dehydrogenase, leads to 12-oxo-5Z,8E,10E-heptadecatrienoic acid (Oxo-HT). Sample workup procedures are described which allow for the sensitive and reproducible determination of these two arachidonic acid metabolites in human plasma by gas chromatography-mass spectrometry in the presence of deuterated analogues as internal standards. HHT is derivatized to the pentafluorobenzyl ester tert-butyldimethylsilyl ether. In order to enable quantification of low concentrations of about 10 pg/ml in nonstimulated human plasma, the samples have to be purified by HPLC. Oxo-HT is derivatized to the pentafluorobenzyl ester, which is purified by HPLC, and then derivatized to the trimethylsilyloxime. The method allows quantification of Oxo-HT in concentrations down to 10 pg/ml plasma. The reported methods have been used to measure HHT and Oxo-HT in stimulated platelet rich plasma and to quantify HHT in nonstimulated plasma. Determination of endogenous levels of these two arachidonic acid metabolites may give new insights into the overall biosynthesis of thromboxane A2 in man.

Blood Platelets↗
PubMed1990

[Magnetic resonance tomography as a new diagnostic criterium in vascular-induced stenoses of the upper airways in childhood].

Magnetic resonance (MR) imaging of the trachea was performed in twenty-one children with congenital or acquired narrowing of the trachea or main bronchi. The demonstration of the trachea and the surrounding tissue and vessels on MR images permitted the evaluation of the cause of trachea, compression and the degree and location of collapse. MRI is a well-suited modality for characterizing tracheal narrowing without employing ionizing irradiation or intravenous contrast medium. In the cases presented MRI should be the diagnostic step of choice after tracheo-bronchoscopy. It is an enrichment of the diagnostic possibilities for extrinsic tracheal or bronchial stenosis in pediatric patients.

Airway Obstruction↗
PubMed1990

[The content of Hb in blood and the protein, Fe, Fe-binding capacity, Cu and Zn in blood plasma of low parity sows before and after oral iron administration].

In investigations of 51 pregnant sows, blood Hb levels above 7.45 mmol/l (mean value of 8.94 +/- 0.88) were recorded from 43 animals (Group A), while levels below that margin were recorded from eight (Group B) (mean value of 6.73 +/- 0.31). Iron levels in blood plasma of Group A were 36.9 +/- 8.07 and were thus higher (p less than 0.01) than those in Group B (28.9 +/- 5.19 mumol/l). No difference was found to exist between the two groups with regard to iron fixation capacity as well as copper and zinc in blood plasma. Oral uptake of 50, 500 or 2,000 mg of iron in the form of FeSO4.7H2O with cereal shred as morning ration by 17 or 15 sows failed to cause any increase in blood plasma iron levels, within 360 minutes from uptake. Literature data as well as the results of these analyses have supported the recommendation that Hb variations between 4.96 and 9.93 mmol/l (8-16 g/dl) should be rated as physiological in the blood of pregnant sows. The GDR Standard TGL 35,423 on "Monitoring of Metabolism on Pig Breeding and Fattening Units" should be accordingly amended.

Animals↗
PubMed1990

[Effects of a conservative stomatological treatment on central and peripheral stress parameters and the influence of a beta-adrenergic blocking agent].

Under conservative stomatological treatment the behaviour of peripheral stress parameters is investigated in connection with an estimation of the subjective state of health as well as for the first time in the ambulatory stomatology the STH secretion as an expression of a central stress reaction. The possibility of the central nervous as well as cardiovascular influence by an unusual premedication form of the beta-adrenergic blocking agent "Obsidan" is estimated in various stages of treatment in comparison to a placebo application.

Dental Cavity Preparation↗
PubMed1989

The use of long-term bone marrow cultures (LTBMC) to detect hematotoxic side effects of purging methods.

With a view to the establishment of purging methods it is necessary to investigate complete-remission bone marrow as the real target of purging, rather than bone marrow from healthy donors. The results of LTBMC are superior to those of GM-CFC where the hematopoietic recovery of bone marrow is concerned. One-stage LTBMC after bone marrow manipulations may reflect mixed hematopoietic/stromal effects. The use of two-stage LTBMC allows the evaluation of the stem cell recovery without the possible influence of a damaged microenvironment.

Bone Marrow↗
PubMed1989

[Infection following surgery of the gastrointestinal tract in newborn infants].

In a retrospective study we examined the postoperative course of 642 children who had been operated on during the newborn period. 247 of them had been operated on for disorders of the gastrointestinal tract. 27.5% of these developed septicaemia: We showed that the frequency of sepsis could be reduced by perioperative antibiotic cover in all diseases with the exception of necrotising enterocolitis where antibiotic treatment was performed. Septicaemic courses were most frequent in premature infants and in those with necrotising enterocolitis. These results will be examined further in a subsequent prospective study.

Enterocolitis, Pseudomembranous↗
PubMed1989

[The value of MRT of the thorax in congenital tracheal stenoses].

MRI of the thorax was performed in 24 children aged between six weeks and five years, in whom a tracheal stenosis had been demonstrated by bronchoscopy. Since bronchoscopy can only demonstrate the interior of the trachea, various imaging methods, such as CT and angiography, were used to demonstrate the topography and cause of the tracheal stenosis. MRI has shown that the most common cause of a stenosis in the central section of the trachea is focal compression by an aberrant brachiocephalic trunk (10 cases). Stenosis of the distal trachea could be due to anomalies of the aortic arch (5 cases), a dilated pulmonary artery (4 cases) or a soft tissue mass (3 cases). In all these patients, MRI was greatly superior to the conventional methods. By using a special technique, MRI made it possible to clarify the cause and localisation of a tracheal stenosis by a non-invasive examination.

Aorta, Thoracic↗
PubMed1989

Growth of hemopoietic cells after incubation with VP 16-213.

We examined the effect of various concentrations of VP 16-213 (25-125 microM/l, 2-h incubation on normal and complete remission bone marrow from patients with acute leukaemia and on leukaemic blasts. The maximal tolerated dose of the drug for normal bone marrow GM-CFC was between 75 and 100 microM/l whereas that for complete remission bone marrow was distinctly lower. More early stem cells measured by aid of LTBMC were more resistant in normal, but not in every remission bone marrow. We have to examine if these LTBMC results are influenced by a damaged microenvironment by using 2 stage LTBMC. Spontaneous leukaemic cells showed a different, sometimes lower sensitivity to VP 16-213 doses maximally tolerated by normal hemopoietic cells so that the VP 16-213 incubation must not be effective for every leukaemia.

Bone Marrow↗
PubMed1989

[Complications after surgical interventions in the neonatal period and their relevance for quality of life].

In a retrospective study the postoperative course was examined of 296 neonates who had a birthweight of more than 1500 g and a congenital malformations between 1981 and 1987. A questionnaire was sent to the parents of the 242 surviving children in which they were asked about their children's current quality of life (average age 5.3 years). Of the 151 parents responding, 42% were of the opinion that the quality of their children's life had been reduced. The main reason was the operated malformation or accompanying illnesses. Only in 5% of the cases were postoperative complications considered responsible for the decline in quality of life.

Child↗
PubMed1989

Immunenzymometric assay for the heart specific glycogen phosphorylase BB in human serum using monoclonal antibodies.

An enzyme-linked immunosorbent assay for the determination of the human glycogen phosphorylase isoenzyme BB (GP BB) using two murine monoclonal antibodies was developed. A series of hybridoma clones producing monoclonal antibodies to GP BB were obtained by the standard lymphocyte hybridoma technique. Two of the selected clones synthesizing monoclonal antibodies, which recognize different epitopes, were employed for the immunenzymometric assay. The first monoclonal antibody was immobilized on microtiter plates and the bound glycogen phosphorylase BB was detected with the second monoclonal antibody conjugated with horse radish peroxidase. This assay enables a specific and sensitive measurement of GP BB in the range of 0.5-150 ng/ml phosphate-buffered saline containing 0.5% bovine serum albumin in less than 3 hours. The lower limit in human serum amounts about 3 ng/ml. Preliminary data obtained with human sera from patients after aorto-coronary artery bypass surgery are demonstrated.

Animals↗
PubMed1988

[Radiologic and scintigraphic diagnosis of primary chronic osteomyelitis in childhood].

Problems in the radiological and scintigraphic diagnosis of primary chronic osteomyelitis are discussed with reference to ten patients aged two to 13 years. Radiologically the lesions usually showed reduced bone density with surrounding sclerosis, most commonly in the distal femoral or proximal tibial metaphysis. In five children the lesions were multilocular. In four children the lesion had not healed after two years. One lesion resembling a tumour, which suffered a pathological fracture, is described. In three patients the initial bone scintigrams showed no abnormalities despite definite radiological lesions. A normal three-phase bone scintigram does not exclude osteomyelitis during childhood.

Adolescent↗