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Biomedical subjects

A Löffler

Publications and source records attributed to A Löffler.

At least 37 records · Page 2Linked to original sources
PubMed1995

Absorption and bioavailability of pentaerithrityl-tetranitrate (PETN, Dilcoran 80).

The effects of 80 mg pentaerithrityl-tetranitrate (PETN) as suspension or formulated as tablets were compared to placebo in a single blind, randomized, crossover study in 18 healthy subjects (study A), and the bioequivalence of two tablet formulations (marketed Dilcoran 80 vs a new formulation) was studied in 24 healthy subjects after administration of single oral doses of 80 mg PETN according to a placebo controlled, randomized, double blind, two-way crossover study design (study B). The perfusion of the right middle finger was measured by rheography (altitude A of the changes of resistance and of the incisure D) before and 24 h post-dose, and blood pressure and heart rate were measured in supine position at the same time. The values of area under curve (AUC) of the ratio A/D were calculated by the trapezoidal rule. In study A the mean A/D-values were reduced from about 2.0 to about 1.3 after intake of PETN (solution or tablet) with a minimum 60 to 90 min postdose (solution) and 2 h postdose (tablet). A significant reduction in this ratio was seen up to 8 (solution) or 12 h (tablet) post dose. Changes in blood pressure were not observed while the heart rate decreased in the subjects of all three groups 1 to 2 h postdose followed by an increase by 6 to 10 beats per min. After subtraction of the AUC values of placebo from the PETN-derived AUC values, mean values of 6.61 (SD 1.52, solution) and 7.25 (SD 1.48, A/D*h, tablet) were calculated (p > 0.1, study A).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

New type of linkage between a carbohydrate and a protein: C-glycosylation of a specific tryptophan residue in human RNase Us.

We report a new type of linkage between a carbohydrate and a protein, involving the rarely modified side chain of a tryptophan residue. An aldohexopyranosyl residue was found to be linked via a C-C bond to the indole ring of the tryptophan residue at position 7 of human RNase Us. Mass spectrometric analysis of peptides containing this residue showed a molecular mass 162 Da higher than that expected for tryptophan. The fragmentation pattern of the modified amino acid side chain was reminiscent of that of aromatic C-glycosides, suggesting a direct attachment of a hexose residue to a C-position of the tryptophan indole moiety. 1H and 13C NMR spectroscopic data confirmed this inference and unequivocally demonstrated the substituent to be an aldohexopyranosyl residue, C-glycosidically linked to the C2 atom of the indole. This mode of attachment differs from the ones known so far, in which carbohydrates are linked to an amino acid side chain by N- or O-glycosidic bonds.

Amino Acid Sequence↗
PubMed1993

[Data on the epidemiology of Crohn disease in the city of Cologne].

In the period between 1.7.1985 and 30.6. 1986 283 patients with Crohn's disease were recorded prospectively in the city of Cologne, which has a total of 922,552 inhabitants. This corresponds to a prevalence of 30.67 per 100,000 inhabitants (women 35.97, men 24.90). During this one-year survey period, 47 new cases of the disease occurred, i.e. the incidence is 5.1 per 100,000 (women 5.8, men 4.3). The highest total incidence is in the age group of 20 to 24 years (17.3) and the highest total prevalence is in the group of 25 to 29 years of age (90.0). There is a substantial sex difference with a female/male ratio of 173:110. Only data of patients residing primarily in Cologne were evaluated. Figures are given on the diagnostic latency, the locations, operations, complications and misdiagnoses of Crohn's disease.

Adolescent↗
PubMed1993

Amino acid sequence of an intracellular, phosphate-starvation-induced ribonuclease from cultured tomato (Lycopersicon esculentum) cells.

The primary structure of an intracellular ribonuclease (RNase LX) from cultured tomato (Lycopersicon esculentum) cells has been determined. Previous studies have shown that the protein is located inside the tomato cells but outside the vacuoles and that its synthesis is induced after depleting the cells for phosphate [Löffler, A., Abel, S., Jost, W., Beintema, J. J., Glund, K. (1992) Plant Physiol. 98, 1472-1478]. Sequence analysis was carried out by analysis of peptides isolated after enzymatic and chemical cleavage of the protein. RNase LX consists of 213 amino acids and has a molecular mass of 24300 Da and an isoelectric point of 5.33. The enzyme contains 10 half-cystines and there are no potential N-glycosylation sites detectable in the sequence. RNase LX, as compared to an extracellular tomato RNase (RNase LE), which is also phosphate regulated and the amino acid sequence of which was recently established [Jost, W., Bak, H., Glund, K., Terpstra, P. & Beintema, J. J. (1991) Eur. J. Biochem. 198, 1-6] has 60% of all amino acids identical and in identical positions, revealing a high degree of similarity between both proteins. In contrast to RNase LE, RNase LX has a C-terminal extension of nine amino acids. The C-terminal tetrapeptide HDEF may be a retention signal of the protein in the endoplasmic reticulum.

Amino Acid Sequence↗
PubMed1992

Phosphate-Regulated Induction of Intracellular Ribonucleases in Cultured Tomato (Lycopersicon esculentum) Cells.

Four intracellular RNases were found to be induced in cultured tomato (Lycopersicon esculentum) cells upon phosphate starvation. Localization studies revealed three (RNases LV 1-3) in the vacuoles and one (RNase LX) outside these organelles. All of these RNases were purified to homogeneity and were shown to be type I RNases on the basis of type of splitting, substrate, and base specificity at the cleavage site, molecular weight, isoelectric point, and pH optimum. Moreover, RNase LV 3 was shown by fingerprinting of tryptic digests on reversed-phase high-performance liquid chromatography and sequencing the N terminus and two tryptic peptides to be structurally very similar to a recently characterized extracellular RNase LE which is also phosphate regulated (Nürnberger et al. [1990] Plant Physiol 92: 970-976; Jost et al. [1991] Eur J Biochem 198: 1-6). Expression of the four intracellular RNases is induced by depleting the cells of phosphate and repressed by adding phosphate. Our studies indicate that higher plants, in addition to secreting enzymes for scavanging phosphate under starvation conditions, also induce intracellularly emergency rescue systems.

Journal Article↗
PubMed1986

Characterization of a parasporal inclusion body from sporulating, enterotoxin-positive Clostridium perfringens type A.

Inclusion bodies (IB) synthesized during sporulation and enterotoxin formation by Clostridium perfringens NCTC 8239 and 8798 were isolated and characterized. IB were isolated by disruption of sporangia by sonication in the presence of tetrasodium EDTA and phenylmethylsulfonyl fluoride. Fractionation was carried out in a linear gradient of sodium bromide, sucrose, or diatrizoate sodium. Denaturing and reducing agents were necessary to solubilize the IB. An alkylating agent was required to prevent reaggregation of the subunits. Molecular weight, compositional, and serological analyses and peptide mapping revealed strong similarities between the IB subunits and the enterotoxin synthesized during sporulation by C. perfringens. IB appear to represent the structural component where overproduced enterotoxin accumulates intracellularly. Enterotoxin-like subunits in the IB appeared to be held together by noncovalent and disulfide bonds, which were generally resistant to the action of intracellular proteases of C. perfringens, trypsin, or trypsin plus bile salts.

Amino Acids↗
PubMed1985

[Granular-cell tumor of the esophagus].

A granular-cell oesophageal tumour was demonstrated in a 47-year-old man. With rare exception this type of tumour is benign. As it grows dysphagia develops. Surgical resection is the treatment of choice. It should be a wide excision, because the non-encapsulated tumour is microscopically more extensive than macroscopically. If too little is excised it may recur. But the high operative risk justifies expectant waiting, perhaps combined with local partial endoscopic removal of the tumour. Only in the rare instance of a small or pedicled tumour is total endoscopic excision possible.

Epithelium↗
PubMed1984

[Intragastric balloon in the treatment of excessive obesity. Preliminary report].

Implantation of a commercially available silicone balloon permits continuous weight reduction without metabolic derangement in patients with excessive overweight. Dangers of surgical treatment of obesity can thus be avoided. In addition, balloon-induced weight reduction is suitable for preparation of severely obese patients with abdominal wall hernias requiring surgery for this intervention.

Adolescent↗
PubMed1983

[Resorption of hydrocyanic acid from linseed].

Resorption of hydrocyanic acid after ingestion of linseed was investigated in 20 healthy volunteers and 5 patients. The persons investigated took a single dose of 30 g or of 100 g of linseed or they received throughout several weeks 15 g. t.i.d. One volunteer also took for purposes of comparison bitter almonds or potassium cyanide. Before, during and after the periods of ingestion plasma levels of hydrocyanic acid and of thiocyanate were normal. During long-term trials urinary excretion of thiocyanate was monitored regularly. Intake of linseed even in extremely high dosages never caused significant rises of plasma thiocyanate levels; this, however, was the case after intake of bitter almonds or potassium cyanide. Thus, it can be excluded, that intoxication by hydrocyanic acid can be caused by linseed. Long-term intake of linseed however, raised plasma levels of thiocyanate significantly; at the same time urinary excretion of thiocyanate increased.

Adult↗