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Biomedical subjects

B Viell

Publications and source records attributed to B Viell.

At least 19 recordsLinked to original sources
PubMed1999

Formation of the comutagenic beta-carboline norharman in a simple tryptophan-containing model system at low temperature (40 degrees C-80 degrees C).

The formation of the comutagenic tryptophan derivate norharman in heat-processed food is a well known phenomenon. As a first step to investigate the possible formation of norharman during food storage particularly in regard to fortified food we developed a model system and studied the non-enzymatic formation of the comutagen at temperatures below 100 degrees C. With standard conditions (4 h, 80 degrees C) iron and copper (Fe2+/Cu2+) was required for the formation of norharman. Addition of glucose to the reaction mixture increased the norharman formation and a plateau was reached with 400 microM tryptophan. Decreasing the reaction temperature to 40 degrees C led to a significant formation of norharman after 72 hours of incubation indicating that the formation of norharman can take place at temperatures that are close to ranges occurring during food storage.

Carbolines↗
PubMed1996

[New caffeinated beverages. A pilot survey of familiarity and consumption by adolescents in North-Rhine Westphalia and Berlin and considerations of consumer protection].

It was the aim of the present study to evaluate how adolescents in Germany accept and consume the new caffeinated drinks (NCD), which can now be legally marketed in Germany. In summer and fall 1994, three surveys were carried out at different schools in Germany, (Aachen, Cologne, Wuppertal, Berlin-West and Berlin-Ost). 1,265 boys and girls were asked for acquaintance with NCD (module I) and 875 of them about consumption (module II). With 727 pupils a third question (module III) was applied by which consumption of Cola drinks compared to that of NCD could be quantified. In total, 93.6% of the young people indicated to know about the NCD, and 53.3% to have tasted these new drinks. Consumption was reported as sometimes (< 1 can/week) from 23% and as repeatedly (1-7 cans/week) from 3%. Acquaintance and consumption were clearly related to age and gender, but even the youngest group (10-13 years old) indicated to have tasted the NCD (30.7% in females and 50% in males) and to drink them sometimes (5.2% in females and 23.1% in males). In the series with question module III 9.5% reported not to drink cola, 36.6% to drink cola "sometimes", 30.9% "repeatedly", 8.6% "often" and 11.6% "frequently" (> 2 cans/day). The corresponding figures for the NCD were 69.9% (non-drinkers), 23.3% "sometimes", 3.3% "repeatedly", 0.3% ten nd 0.6% "frequently". The results suggest that all young people in Germany know about the NCD but actually consume these new drinks moderately. They prefer cola drinks. The observation, however, that a small group may consume extreme amounts and that even very young pupils consume the NCD regularly should give rise to have a close look at the consumption pattern in the near future.

Adolescent↗
PubMed1991

[The role of nutrition in the intensive care unit].

Clinical (artificial) nutrition in patients in a surgical intensive care unit (ICU) is a supportive, and not a therapeutic, measure. However, it is as necessary as medical or surgical treatment, because nutrition can prolong life, so that time is bought during which the clinician can start adequate treatment. Studies on the effectiveness of clinical nutrition are rare and difficult, but there is a huge amount of indirect evidence supporting the following basic concept. The caloric requirement of an ICU patient is clearly higher than that of a normal person. However, it seldom exceeds 2500 kcal (about 35 kcal kg-1 day-1) and can be satisfied with a standardized regimen. Fat and carbohydrates should be given, with fat amounting to 10% at least and 50% at most of total calories. Glucose administration should be limited to about 500 g day-1. As with calories, the demand for amino acids (100-150 g day-1) is increased in ICU patients due to catabolic illness and nitrogen loss, e.g., via drains, wound. The successful creation of different kinds of a stable and safe access to the gastrointestinal tract for enteral nutrition has opened a true alternative to the well-known practice of parenteral delivery of food to a critically ill patient. Today it is possible to nourish nearly all patients enterally via the stomach or small bowel with commercially available fluid diets. This kind of clinical nutrition obviates the need for concern about the optimal substrate composition. Moreover, enteral nutrition appears to be much simpler and more logical than parenteral nutrition. There is evidence suggesting that there are even clinical advantages of enteral nutrition.

Critical Care↗
PubMed1991

[Perioperative use of antibiotics for preventive indications].

The prevention of infections in surgical patients undergoing an operation is a major challenge. One of the several possibilities is the administration of appropriate antibiotics during the perioperative period. For this type of prophylactic use the agent selected should be given before contamination--a single dose is very often sufficient. Common indications for antibiotic prophylaxis are: operations involving a high chance of contamination and those that have hither to be clean but in which the implications of infections would be highly threatening.

Anti-Bacterial Agents↗
PubMed1991

[Dyspepsia and food intolerance in symptomatic gallstone disease. Does cholecystectomy help?].

60 patients with symptomatic gallstone disease were asked about their abdominal symptoms and food intolerance. Equally a healthy control group was investigated. Preoperatively, 72% of patients with gallstones suffered from right upper quadrant pain. Additionally all patients complained of associated dyspeptic symptoms (100% vs. 8% of the control group). 51% of patients with gallstone disease vs. 15% of the control group avoided flatulent and fatty food. 4 months after cholecystectomy, 90% were painfree, 82% were free of dyspeptic symptoms and 84% were not complaining of any food intolerance. 6% developed new food intolerances. Thus cholecystectomy seems to be an effective treatment, not only for typical gallstone related symptoms, but also for associated symptoms, such as dyspepsia and food intolerance. Different therapeutic regimens have to compete with these results.

Adult↗
PubMed1989

[Supraclavicular plexus blockade using prilocaine in patients with chronic anemia].

It has not yet been clarified whether prilocaine-induced methemoglobinemia is a problem in patients with chronic anemia. We therefore performed supraclavicular brachial blockade for upper limb surgery (6 mg/kg prilocaine 2% + 0.1 IU vasopressin/ml) in ten female patients with chronic renal failure (mean Hb 8.19%) requiring hemodialysis. Before the blockade, a catheter was inserted into the opposite internal jugular vein and blood samples were drawn before and 10, 15, 20, 30, 45, 60, 90, 120 and 180 min after injection. Plasma prilocaine concentrations and methemoglobin levels were within the ranges measured by other authors in healthy patients. There was no correlation between plasma prilocaine levels and methemoglobinemia. We therefore consider prilocaine to be a safe local anesthetic in patients with renal failure and chronic anemia.

Aged↗
PubMed1988

Analysis of tryptophan, tyrosine and related dipeptides in mouse brain by isocratic high-performance liquid chromatography with switchable wavelength fluorescence detection.

Tryptophan (Trp) and tyrosine (Tyr) are pharmacologically active compounds which, after administration of adequate doses, are increased in level in the brain, and stimulate neurotransmitter synthesis. Trp and Tyr containing dipeptides were tested as possible substitutes with regard to the effect on precursor level in the brain. Glycyltryptophan, alanyl-tryptophan and glycyl-tyrosine were intravenously applied to young female mice and the brain levels of dipeptides, Trp and Tyr measured 30 min after application. Neurotransmitter precursor levels in the brain increased similarly in all cases. The results suggest that the dipeptides are as effective as the single amino acids and may be superior because of their better solubility.

Journal Article↗
PubMed1988

Analysis of 5-OH-indoles in human gut biopsy tissues by reversed-phase high-performance liquid chromatography with fluorimetric detection.

A method was devised for the rapid simultaneous determination of major indoles in human gut tissues. Analysis with picomol detection limits was done by HPLC on a C(18) reversed-phase column with fluorimetric detection at 276/350 nm. This simple method for which there is no necessity of derivatization or purification was validated for routine analysis of small mucosa samples (less than 4 mg fresh weight) obtainable during endoscopy. A comprehensive list of 5-OH-indole compounds in human gut tissue is presented.

Journal Article↗
PubMed1988

[The action of bupivacaine-HCl following supraclavicular plexus block in patients with chronic kidney insufficiency].

A reduced duration of activity of local anesthetic drugs in patients with chronic renal failure has been described by several authors. Because surgical duration is not always predictable and these patients must be classified as high-risk patients (ASA physical status III-IV), reduced effectiveness may be a significant problem in clinical practice. Various reasons have been discussed as possible explanations for this phenomenon such as: (1) uremia-induced changes in acid-base status of blood and tissue, (2) alterations in protein-binding; and (3) changes in hemodynamic parameters. However, we have not been able to find any severe changes in electrolyte or acid-base status in patients with chronic renal failure after adequate hemodialysis. We wondered, therefore, whether changes in tissue pH might be one cause of the shorter duration of action of anesthetic drugs. We also examined some other pharmacokinetic parameters after administration of the anesthetic drug in order to find differences in comparison to healthy patients. Supraclavicular brachial blockade (3 mg/kg bupivacaine 0.5% + 0.1 IU vasopressin/ml) was performed in 11 patients with chronic renal failure requiring hemodialysis who were admitted to the hospital for a shunt operation in the forearm. The control group consisted of 11 healthy patients who were admitted for minor hand surgery. Preoperative blood samples were taken for measurement of blood urea nitrogen, serum creatinine, serum electrolytes, lactate, hemoglobin and hematocrit, and an arterial blood gas duration of action was defined as the time to full recovery of sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Polarimetric assay for the determination of the native collagen content of soluble collagen.

Two standardized assays for determining the amount of native collagen in a collagen solution are described which are based on polarimetric measurements. Native collagen content is calculated from the loss of optical rotation during transition from the original to the denatured conformation using constants which were obtained from standard collagen of highest available native collagen content. While Method I gives information on the content of helical collagen, Method II estimates collagen which is resistant to peptic degradation. Both methods are simple to perform and suitable for routine quality control.

Animals↗
PubMed1987

Effects of the hormone relaxin on the metabolism of the glycosaminoglycans in the mouse symphysis pubis.

The influence of the peptide hormone relaxin on the glycosaminoglycan (GAG) metabolism was investigated in the pubic ligament of the symphysis pubis and in serum of the virgin mouse. Fresh weight DNA and GAG content per 1 ligament is significantly increased, the level of water soluble protein is not affected. A shift in the electrophoretic GAG pattern by an increasing amount of hyaluronic acid and a decreasing amount of chondroitin sulfate and dermatan sulfate can be observed. Concerning GAG-splitting enzymes (N-acetylglucosaminidase, arylsulfatase, beta-glucuronidase) the N-acetylglucosaminidase reveals a significant increase of its activity in the interpubic ligament and in the serum. The data demonstrate that relaxin treatment induces some changes in the GAG metabolism.

Acetylglucosaminidase↗