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Biomedical subjects

R Göbel

Publications and source records attributed to R Göbel.

At least 19 recordsLinked to original sources
PubMed2000

New ultradeformable drug carriers for potential transdermal application of interleukin-2 and interferon-alpha: theoretic and practical aspects.

Transfersomes (TFs) are highly deformable hydrophilic lipid vesicles that are able to penetrate the skin barrier spontaneously because of their characteristics. Transfersomes are able to transport noninvasively low- and high-molecular-weight molecules into the body. We describe the formulation and several biologic characteristics of interleukin-2 (IL-2)- and interferon-alpha (IFNalpha )-containing TFs. TFs contain natural phosphatidylcholine and sodium cholate. Recombinant human IL-2 and human hybrid IFNalpha were added to TFs and incubated for 24 hours at 4 degrees C. Immunotransfersomes were isolated from free IL-2 and IFNalpha by filtration (Centrisart, Sartorius). The biologic activity of immunotransfersomes was measured by a cytotoxic lymphoid line assay for IL-2 and by an A549-encephalomyocarditis virus assay for IFN; concentrations of proteins were determined by the enzyme-linked immunosorbent assay (ELISA). It was possible to incorporate a large amount of IL-2 and IFN in TFs (75-80%), and the incorporated IL-2, and IFN were biologically active. The increased lipid/protein ratio (90.9/1.0) led to a growing probability of association. We were thus able to show that IL-2 and IFN are trapped by transfersomes in a biologically active form and in sufficient concentrations for immunotherapy. In upcoming experiments these IL-2- and IFN-containing TFs will be used for a transdermal approach in the murine RENCA cell line model.

Administration, Cutaneous↗
PubMed1999

[Encephalopathies caused by valproate].

Valproic acid (VPA)-induced encephalopathy is a rarely considered side effect, with somnolence, reduced motor activity and severe deterioration of cognitive and behavioural abilities. In accordance with the increasing clinical importance of valproate clinical symptoms, causes and possibilities of treatment are reviewed by reporting on two cases of valproate-induced encephalopathy. In comparison to VPA intoxication, which is associated to increased VPA blood levels, the mechanisms of encephalopathy may include interactions of the hepatic enzymes, a direct toxic effect on the cerebral receptors, as well as drug interactions, a paradoxical epileptogenic effect and metabolic interactions. In most cases withdrawal of VPA produces regression of the symptoms within a few days; the role of L-carnitin or citrullin supplementation in clinical treatment remains unclear.

Adult↗
PubMed1994

[The contamination of feed, fruits and vegetables with benzo(a)pyrene in Land Brandenburg].

Benzo(a)pyren (BaP) was analysed in 218 samples of grass, hay, straw, grains, lettuce, curly kale and apples by means of thin-layer chromatography und analysing other polycyclic aromatic hydrocarbons (PAH) by capillary gas chromatography and mass-spectrometry. Despite the fact that normally BaP concentrations were relatively low, up to 13.5 micrograms BaP per kg hay (dry matter) and 19.3 micrograms BaP per kg lettuce (dry matter) could be detected at some places.

Animal Feed↗
PubMed1992

[Experimental studies of electroplating-resin bonding systems].

Optimized conditioning of galvanically produced gold frameworks (Auro-Galva-Crown-System) by means of Silicoater, Silicoater MD and Rocatec techniques gives rise to a reliable bond to veneering resins. After experimental stress (thermocycling) the strength of the compound could be found between 17 and 26 MPa and SEM investigations of the contact zone showed no crevices.

Composite Resins↗
PubMed1992

[Taurine requirement of premature infants in parenteral nutrition].

The aim of our studies was to clarify, which dose of taurine should be added to amino acid solutions, in order to achieve plasma levels in premature infants as they are found during nutrition with mother's milk. In 22 premature infants born in the 30th-35th week of gestation plasma taurine levels during parenteral nutrition were measured on the 5th-9th day of life before and after infusing an amino acid solution supplemented with taurine. For analysis the principle of chromatographical ion exchange was applied. The requirement of taurine was calculated by means of a linear regression between supply and blood level. The mean plasma taurine levels before substitution were 88.7 mumol (95%-range of tolerance: 32.8-240 mumol/l). In premature infants with cerebral haemorrhages significantly higher plasma taurine levels were observed. Continuous parenteral taurine supply of approximately 0.05 g/kg/day was able to raise the taurine level by about 70 mumol/l, which caused a plasma taurine level of above 100 mumol/l in any case. During parenteral nutrition it is possible to achieve taurine levels as high as in breastfed neonates by substituting taurine at an amount of 0.05 g taurine per kg body weight.

Birth Weight↗
PubMed1990

[The effect of energy-rich and energy-reduced rations with n-alkane yeast portions on the fatty acid composition of fat stores of swine].

In 3 test groups (11 pigs in each group), rations with an identical fatty acid pattern of the fat in the fodder (except C 17 acids) with a high energy level (energy concentrations = 131%), medium energy level (energy concentrations = 100%) and low energy level (energy concentrations 90 or 82%, resp.) were used. In the course of the investigation the fatty acid spectrum was studied by analyzing spinal fat biopsy specimen. An interrelation was found to exist between the energy supply and the fatty acid spectrum in the depot fat. When identical quantities of heptadecenoic and heptadecanoic acids were added to the fodder, a high energy level resulted in a reduced C17 acid content in the spinal fat, whereas a low energy level led to an increased C17 acid content in the spinal fat. Different energy concentrations caused a change in the contents of oleic acid, linoleic acid and linolenic acid in the spinal fat. With changed energy concentrations, the C16 and C18 acid content showed variations compared with the group given standard fodder. The myristin acid content showed almost no change.

Adipose Tissue↗
PubMed1990

[The effect of energy-rich and energy-reduced rations with n-alkane yeast portions on the fatty acid composition of selected organ lipids in swine].

In 3 test groups (11 pigs in each group) rations with identical fatty acid patterns (except C 17 acids) at high, medium and low-energy levels of the rations were fed. The fatty acid composition of the lipids of liver, heart and brain was analyzed at the end of the experiments. A correlation was found to exist between energy and fatty acid intake and the fatty acid spectrum of the organ lipids. With identical intake of odd-numbered fatty acids, an energy-rich diet leads to a reduction of odd-numbered fatty acids in the heart and liver lipids. A reduced energy concentration causes an increase of odd-numbered fatty acids in liver and heart. Under energy-rich and energy-reduced feeding, C 15 and C 19 acids can be traced in the hepatic lipids. In liver, heart and brain, an energy-rich diet results in increased contents of eicosapentaene and eicosahexaene acid. Under low-energy diet, a reduction of these fatty acids can be found in the brain.

Animal Feed↗
PubMed1990

[Transvaginal contrast hysterosalpingo-sonography with the B-image procedure and color-coded duplex sonography for the assessment of fallopian tube patency].

Transvaginal hysterosalpingo-contrast-sonography (HYCOSY), a new method for the direct assessment of tubal patency by means of ultrasonography, was employed in 68 women with infertility problems. In 67 cases, the findings were compared with hysterosal-pinography or chromolaparoscopy, performed either subsequently while the patient was still under the anaesthetic or later. The contrast demonstration of the Fallopian tubes was performed with the B mode procedure in 54 cases (Group 1) and by means of colour-coded duplex sonography in 14 (Group 2). In Group 1, the findings agreed completely in 39 cases, partially in 14 and not at all in one. In Group 2, in which 13 of the 14 cases were compared, the findings were identical in 9 cases and partially in 4. From the point of view of image documentation, the more vivid demonstration of free tubal passage in colour Doppler sonography compared to the simple B mode appears to be an advantage. Further studies are needed to determine whether contrast-perfused but dislocated tubes can be detected more easily and quickly with colour Doppler than in B mode.

Adolescent↗
PubMed1989

[The effect of microbial protein from a hydrocarbon base (fermosin) with a defined fatty acid composition on fat metabolism and fat composition in slaughter animals. 2. The effect of "fermosin" on the composition of back fat in hogs].

Two tests have been undertaken to investigate the influence of feeding microbial biomasses to pigs. No alterations of the fat parameters characterizing the fat stability were observed. All the values obtained are in a normal range. Increases in heptadecenic acid were detected dependent on the content of microbial biomasses in the feed and its fat content. The alterations are mainly in a normal range or slightly beyond it. In nature odd-numbered fatty acids are ubiquitous. Uptake and storage suggest that the organism reacts to an increased offer of C17-fatty acids with an accelerated decomposition of these fatty acids or/and with inhibition of their endogenous synthesis. The results are discussed in comparison with those of literature.

Adipose Tissue↗
PubMed1988

[The effect of microbial protein, obtained on a hydrocarbon base (fermosin), with a defined fatty acid composition on fat metabolism and fat composition in slaughter animals. 1. The effect of fermosin on the composition of broiler depot fat].

A study has been undertaken to investigate the influence of fermosin on the depot-fat composition of broilers and the oxidative stability of these fats in parallel with test animals fed yeast conventional produced on carbohydrate base. The data obtained are discussed with reference to literature.

Adipose Tissue↗
PubMed1987

Hepatic vs. gastrointestinal presystemic extraction of oral midazolam and flurazepam.

An experimental model was developed to elucidate the site of presystemic extraction of drugs with incomplete bioavailability due to high extraction after p.o. dosage. Domestic pigs received single i.v. or p.o. doses of midazolam (1 mg/kg) or flurazepam (2 mg/kg), two benzodiazepine derivatives with high presystemic extraction after p.o. dosage. Multiple blood samples were simultaneously drawn from the portal vein and from a systemic vein during 8 hr after dosage. After i.v. administration, both drugs had high systemic serum clearance, averaging 24 ml/min/kg. Area under the serum concentration curve (AUC) for systemic vs. portal sites was nearly identical for midazolam (769 vs. 737 ng/ml x hr); for flurazepam, systemic AUC exceeded portal AUC (1035 vs. 778 ng/ml x hr, P less than .01). After p.o. dosage, the systemic/portal AUC ratio averaged 0.15 for midazolam and 0.11 for flurazepam; for both drugs, portal AUC after p.o. dosage did not differ significantly from systemic AUC after i.v. administration. Thus, the extensive presystemic extraction of orally administered midazolam and flurazepam are mainly attributable to hepatic biotransformation rather than metabolism either within the gastrointestinal tract or during absorption into the portal circulation.

Administration, Oral↗