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Biomedical subjects

Peter Fürst

Publications and source records attributed to Peter Fürst.

At least 19 recordsLinked to original sources
PubMed2007

PCDD/F and dioxin-like PCB in human blood and milk from German mothers.

Blood samples of pregnant women aged between 19 and 42 years at the time they gave birth and milk samples from the same women following delivery were collected between September 2000 and January 2003 from 169 participants living in an industrialized area of Germany (Duisburg birth cohort study). All samples were analyzed for their content of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) as well as dioxin-like and indicator polychlorinated biphenyls (PCB). Levels of WHO-TEq were in the range of 4.34-97.3 pg/g(lipid base) (median: 26.37, arithmetic mean: 28.36) for blood, or 3.01-78.7 pg/g(lipid base) (median: 26.40, arithmetic mean: 27.27) for milk, respectively. The four congeners 12378-PeCDD, 23478-PeCDF, 33'44'5-PeCB (# 126) and 233'44'5-HxCB (# 156) contribute the main share to total WHO-TEq. The contribution of PCDD/F in relation to PCB to total WHO-TEq was 60:40% in blood and 52:48% in milk. Good correlations of the contaminant levels in lipid base between both matrices were found. The distribution between blood and milk depends on the molecular weight of the substances. Higher chlorinated PCDD/F- and PCB-congeners were found in 2-4-fold higher concentrations in blood in relation to milk and the concentrations of lower chlorinated PCB-congeners were up to 2-fold higher in milk in relation to blood. The body burden of PCDD/F and PCB increases with age and decreases over the total nursing period. Women who had lived outside highly industrialized countries showed lower concentrations of PCDD/F and PCB. In some cases, elevated levels of PCB were observed when the women had previously lived in Eastern Europe for a long time. In comparison with recent data, the decline in human PCDD/F and PCB levels observed during the nineties seems to have stopped. The individual exposures of the infants due to breastfeeding within the first 18 months were calculated to be from 4.4 to 318 ng WHO-TEq (median: 106, arithmetic mean: 118). The actual mean daily exposure of a breastfed infant can be estimated to 131 pg WHO-TEq/kg(body weight).

Adult↗
PubMed2006

Safety and efficacy of a new parenteral lipid emulsion (SMOFlipid) in surgical patients: a randomized, double-blind, multicenter study.

BACKGROUND/AIMS: A new lipid emulsion based on soybean oil, medium chain triglycerides, olive oil and fish oil (SMOFlipid) was tested for safety, tolerance, metabolic and clinical efficacy in surgical patients. METHODS: In a prospective, double-blind European multicenter study, postoperative patients (elective abdominal or thoracic surgery) were randomized to receive isonitrogenous, isoenergetic (30-35 kcal/kg) total parenteral nutrition over 5 postoperative days including either SMOFlipid 20% or standard soybean oil emulsion (Lipovenoes 20%) as lipid source (1.5 g kg(-1) day(-1)). Metabolic efficacy measurements included serum levels of triglycerides (AUC), phospholipids, and total cholesterol. Safety/tolerance parameters were: hematology; clinical chemistry; coagulation profile; clinical course (arterial blood pressure, heart rate, body temperature), and documentation of adverse events. Clinical efficacy was monitored by length of hospital stay and mortality. RESULTS: The 2 groups (per-protocol population: SMOFlipid n = 99, and Lipovenoes n = 100) were similar with respect to demographic characteristics and types of surgical intervention. Concentrations of serum triglycerides, phospholipids, and total cholesterol were comparable in both groups and within the expected ranges. Laboratory and clinical parameters were not different. A trend towards a reduced length of hospital stay was observed with SMOFlipid (15.7 +/- 6.3 vs. 17.8 +/- 13.2 days). CONCLUSIONS: SMOFlipid is clinically safe and well tolerated in postoperative patients. There are indications that SMOFlipid may be associated with a better liver tolerance and a shorter length of hospitalization.

Double-Blind Method↗
PubMed2006

Dioxins, polychlorinated biphenyls and other organohalogen compounds in human milk. Levels, correlations, trends and exposure through breastfeeding.

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF), together simplified termed "dioxins", polychlorinated biphenyls (PCB), polybrominated diphenylethers (PBDE) and organochlorine pesticides constitute lipophilic, persistent organic pollutants that bioaccumulate in the food chain and consequently can be found in humans at considerable concentrations. During the past 30 years our institute analyzed far more than 2,000 individual human milk samples for organochlorine pesticides and PCB and over 1,000 specimens for PCDD/PCDF. The results of these analyses provide an overview and reliable basis as to contamination of human milk with these compounds, their correlations among each other, the temporal trend of exposure through breastfeeding and the predominant parameters that influence the maternal body burden. It was found that the levels of most persistent organohalogen compounds in human milk decreased significantly over the past three decades and equally did their exposure through breastfeeding. Exceptions are PBDE, which are still extensively used as flame-retardants. PBDE levels in milk samples collected in the early 2,000s are approximately 60% higher compared to specimens sampled 10 years before. Moreover, in contrast to PCB, PBDE show no significant correlation with PCDD/PCDF in human milk, which might be interpreted as an indication for another mode of human exposure.

Breast Feeding↗
PubMed2005

Methodologic considerations for improving and facilitating human milk research.

Over the past several decades, interest in using human milk as a biomonitoring matrix has increased. However, it is not always an easy matter for a new mother to provide a milk sample. In this article, guidance on facilitating collection of human milk is provided. This includes addressing the mother's ease in expressing a milk sample, and engaging with many audiences to reduce the likelihood of negatively impacting the already low breastfeeding rates in the United States. In addition, this article covers concepts regarding long-term storage and integrity of human milk samples to maximize the utility of those samples, and proposed methods for improving public access to the full spectrum of human milk biomonitoring data, with context to understand the information presented. The environmental chemicals and chemical classes for which robust analytical methods exist are enumerated, and a process for prioritizing the development of analytical methods for additional environmental chemicals is described.

Adult↗
PubMed2005

Improved fatty acid and leukotriene pattern with a novel lipid emulsion in surgical patients.

OBJECTIVE: We assessed the effects of a novel lipid emulsion with reduced content of n-6 fatty acids (FA), increased share of MUFA and n-3 FA and supplemental vitamin E on fatty acid and leukotriene pattern in surgical patients. METHODS: In a double-blind, randomized study 33 patients received isonitrogenous, isocaloric TPN over 5 postoperative days following major abdominal surgery. 19 patients received the new SMOFlipid 20% and 14 patients a standard soybean oil emulsion (Lipovenoes 20%, both Fresenius Kabi), each 1.5 g fat/kg body weight (BW)/d. Routine lipid biochemistry, plasma tocopherol, fatty acid pattern in plasma phospholipids, as well as leukotriene (LT) release in leukocytes were assessed. Additionally, fatty acid pattern in leukocyte and platelet phospholipids were analysed, but results are not presented. RESULTS: On day 6, plasma alpha-tocopherol (34.2 +/- 10.3 vs. 17.6 +/- 2.9 micromol/L) and, in plasma PL, total n-3 FA were higher (11.1 +/- 1.9 vs. 4.9 +/- 0.9 mol%; p < 0.05) and total n-6 FA lower (23.8 +/- 2.2 vs. 31.8 +/- 1.7 mol%; P < 0.05); the ratio n-3/n-6 FA being elevated (0.5 +/- 0.1 vs. 0.2 +/- 0.0 p < 0.05) with SMOFlipid compared to the soybean oil emulsion. The shares of EPA (3.3+/-1.0 vs. 0.4+/-0.2 mol%; p<0.05) and DHA (6.9 +/- 1.8 vs. 3.7 +/- 0.8 mol%; p < 0.05) were highly increased but that of arachidonic acid (AA) was unchanged with SMOFlipid while the ratio EPA/AA was increased (0.7 +/- 0.2 vs. 0.1 +/- 0.0 p < 0.05). LTB(5) release was enhanced on day 6 (8.1 +/- 5.3 vs. 1.8 +/- 3.8 pmol/10(7) PMN, p < 0.05) and liberation of LTB(4) was lowered, yet not significantly with SMOFlipid (124.0 +/- 51.2 vs. 152.1 +/- 68.8 pmol/10(7) PMN). Length of hospital stay was significantly shorter with SMOFlipid (13.4 +/- 2.0 vs. 20.4 +/- 10.0 days, p < 0.05). CONCLUSION: Treatment with the new emulsion SMOFlipid is well tolerated and modulates FA and leukotriene pattern suggesting favourable anti-inflammatory effects and further clinical benefits.

Abdomen↗
PubMed2004

Phloridzin improves absorption of genistin in isolated rat small intestine.

BACKGROUND & AIMS: Cancer-protective effects of isoflavones like genistin or genistein are well known. High intakes and an adequate absorption rate of isoflavones are necessary for efficient chemoprevention, though other dietary agents might increase absorption efficacy. The aim of this study was to investigate the effect of phloridzin, an inhibitor of the sodium-dependent glucose transporter (SGLT1), on genistin absorption and metabolism. METHODS: Phloridzin and genistin were luminally administered in an isolated preparation of luminally and vascularly perfused rat small intestine. A synthetic perfusate free from blood components was used as vascular medium, with a perfluorocarbon as oxygen carrier. Luminal media consisted of a bicarbonate buffered sodium chloride solution spiked with genistin (24.5 micromol/l) and phloridzin (1 mmol/l). RESULTS: In previous experiments, genistin absorption rate of 17.2% has been observed. In the present study, phloridzin administered simultaneously with genistin, increased genistin uptake 2.5 fold (44.5%). CONCLUSION: The naturally occurring substance phloridzin, present in apples, thus considerably amplify genistin absorption. These effects might offer a promising novel method in designing functional foods for cancer prevention by combining genistin- and phloridzin-containing foods.

Animals↗
PubMed2004

Classic dengue fever affects levels of circulating antioxidants.

OBJECTIVE: We studied alterations of circulating antioxidant nutrients in patients with classic dengue fever in the tropical lowlands of Guatemala. METHODS: In nine patients with dengue fever and 12 healthy Guatemalan control subjects, we assessed plasma concentrations of retinol, alpha-tocopherol, beta-carotene, glutathione, taurine, thiobarbituric acid-reactive species, and total antioxidant status. Control subjects were assessed twice within 48 h to account for day-to-day variations. Febrile patients with dengue fever were examined on the day of admission to the hospital, at discharge after defervescence (approximately 5 d after admission), and 7 d thereafter. RESULTS: In patients with dengue fever, increases in plasma concentrations of retinol and beta-carotene were seen, whereas decreases were observed for glutathione and total antioxidant status. As compared with the reference group, patients with dengue fever had lower retinol concentrations in the acute phase of the disease and lower glutathione concentrations 7 d after discharge. Further, thiobarbituric acid-reactive species levels were higher in the dengue fever patients as analyzed by unpaired t test. CONCLUSION: Using dengue fever as a model for the metabolic response to an acute, self-limited tropical viral infection, the present findings suggest slight turbulence of the antioxidant system that may be a response to or a consequence of the viral inflammatory process.

Adult↗
PubMed2004

What are the essential elements needed for the determination of amino acid requirements in humans?

The aims of this introductory article are to survey and critically evaluate the concepts and approaches that have been used to assess amino acid adequacy and to hypothesize about possible future directions of research. The issue in question is extensive, consequently this article will be limited to: 1) definitions of amino acid requirements; 2) available techniques to assess amino acid requirements; 3) actual recommendations for healthy adults; 4) factors influencing requirements; and 5) requirements in acute and chronic wasting diseases. Recommendations for amino acid intakes for healthy adults were proposed by the FAO/WHO expert committee in 2001. They have not yet been published. The major factors affecting amino acid requirements are the stage of development, reproductive state, environmental factors, digestibility of dietary proteins, genotype of the individual, and pathological conditions. Remarkably, there are no conclusive data relative to changes in requirements induced by infection, injury, trauma, and renal or liver failure. Future research using modern methods to evaluate requirements must thus receive a high priority. Wasting diseases are associated with deficiencies and imbalances of particular amino acids causing specific changes in requirements. Consequently, a new approach has been used to categorize amino acids as conditionally indispensable according to their functional and physiological properties. Kinetic measurements of plasma amino acids might help to estimate qualitative requirements. Measurement of tissue intracellular free amino acid deficiencies or excesses is another method to estimate qualitative requirements. Based on these measurements tentative values for conditionally indispensable amino acids during disease are given in the article.

Acute Disease↗
PubMed2003

Absorption and metabolism of anthocyanin cyanidin-3-glucoside in the isolated rat small intestine is not influenced by ethanol.

Anthocyanins are receiving renewed attention for their positive health attributes. High intakes and an adequate absorption rate of anthocyanins are necessary for efficient protection, though other dietary agents might influence absorption efficacy. The aim of this study was to investigate intestinal handling of luminally administered cyanidin-3-glucoside in the absence and presence of ethanol in an isolated preparation of luminally and vascularly perfused rat small intestine. A synthetic perfusate free from blood components was used as vascular medium, with a perfluorocarbon as the oxygen carrier. Luminal media consisted of a bicarbonate buffered sodium chloride solution in water or in water/ethanol (95/5), spiked with cyanidin-3-glucoside. Absorption rate of cyanidin-3-glucoside was 4.3% +/- 3.2 (n=5). Ethanol (5 %) had no significant influence on absorption rate (2.9% +/- 1.8, n=5). Irrespective of the presence of ethanol, the majority of the absorbed cyanidin-3-glucoside appeared unchanged, besides some cyanidin-3-glucoside-conjugate.

Animals↗
PubMed2003

Influence of cooking process on phenolic marker compounds of vegetables.

Phenolic compounds are secondary plant metabolites which have long been associated with flavor and color characteristics of fruits and vegetables. These phenolic compounds attract great interest due to their postulated health protecting properties. However, adequate intakes and absorption rate of phenolic compounds are necessary for these beneficial effects. Until now, little is known about alterations of phenolic compounds content by the cooking process. In the present study, the influence of different volumes of cooking water on the amount of selected phenolic marker compounds resting in the vegetables was assessed. In zucchini, rutin was quantified as a marker for flavonoid glycosides. Chlorogenic acid, representative of phenolic acids was analyzed in carrots. In beans, rutin and quercitrin, both belonging to flavonoid glycosides, were investigated. In potatoes, chlorogenic and caffeic acid were determined. The cooking of zucchini, beans and carrots with smaller amounts of water resulted in significant higher content of phenolic phytochemicals in the vegetables compared to cooking with larger water volumes. For potatoes, which showed great variations in content of phenolic acids after cooking, no significant differences in phenolic acids was observed. It can be concluded from these observations, that real intakes of phenolic compounds from cooked vegetables are lower and that the amounts consumed are therefore overestimated.

Caffeic Acids↗
PubMed2003

The European view of hospital undernutrition.

Disease-related undernutrition is significant in European hospitals but is seldom treated or prevented. In 1999, the Council of Europe decided to collect information regarding nutrition programs in hospitals, and for this purpose, a network consisting of national experts from 12 of the Partial Agreement member states was established. The aim was to review the current practices in Europe regarding hospital food provision, to highlight deficiencies, and to issue recommendations to improve the nutritional care and support of hospitalized patients. Five major common problems were identified: 1) lack of clearly defined responsibilities, 2) lack of sufficient education, 3) lack of influence and knowledge of the patients, 4) lack of cooperation between different staff groups, and 5) lack of involvement from the hospital management. To solve the problems highlighted, a combined timely and concerted effort is required from national authorities and hospital staff, including managers, to ensure appropriate nutritional care and support.

Journal Article↗
PubMed2003

Assessment of dietary exposure to some persistent organic pollutants in the Republic of Karakalpakstan of Uzbekistan.

A 1999 study heightened long-standing concerns over persistent organic pollutant contamination in the Aral Sea area, detecting elevated levels in breast milk and cord blood of women in Karakalpakstan (western Uzbekistan). These findings prompted a collaborative research study aimed at linking such human findings with evidence of food chain contamination in the area. An international team carried out analyses of organochlorine and organophosphate pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) on samples of 12 foods commonly produced and consumed in Karakalpakstan. Analysis consistently detected long-lasting organochlorine pesticides and their metabolites in all foods of animal origin and in some vegetables such as onions and carrots--two low-cost components of many traditional dishes. Levels of PCBs were relatively low in all samples except fish. Analyses revealed high levels of PCDDs and PCDFs (together often termed "dioxins") in sheep fat, dairy cream, eggs, and edible cottonseed oil, among other foodstuffs. These findings indicate that food traditionally grown, sold, and consumed in Karakalpakstan is a major route of human exposure to several persistent toxic contaminants, including the most toxic of dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). Intake estimations demonstrate that consumption of even small amounts of locally grown food may expose consumers to dioxin levels that considerably exceed the monthly tolerable dioxin intake levels set by the World Health Organization. Data presented in this study allow a first assessment of the risk associated with the consumption of certain food products in Karakalpakstan and highlight a critical public health situation.

Dioxins↗
PubMed2002

Guidelines for analysis of human milk for environmental chemicals.

When analyzing human milk for environmental chemicals, in either a monitoring or research project, researchers must ensure that the technique used for measuring the target analytes complies with certain analytical criteria and that a quality control/quality assurance program is in place. In this report, these analytical criteria and the accompanying quality assurance program are elaborated in more detail. Examples of representative methods are also given for the determination of a number of classes of chemicals of environmental concern, such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, volatile organics, and halogenated flame retardants. Most of these techniques are physical/chemical in nature, but the possibility of the use of bioassays for screening of analytes in human milk is noted. The described methods are not exclusive, but any laboratory undertaking the analysis of human milk should demonstrate proficiency in their execution. This is usually accomplished by producing reliable data in interlaboratory studies. Human milk is an ideal matrix for estimating exposure to certain environmental chemicals, and researchers must ensure that the techniques used to determine these compounds adhere to known and accepted analytical requirements.

Environmental Monitoring↗
PubMed2002

Enantiomer ratios, patterns and levels of toxaphene congeners in human milk from Germany.

High resolution gas chromatography (HRGC) coupled to quadrupole negative ion chemical ionization (NICI) mass spectrometry (MS) was used to investigate congener patterns, levels and enantiomer distribution of selected toxaphene congeners (#26, #41, #44, #50, #63, B7-1453) in human milk from Germany. #50 and #26 were the most abundant congeners. Furthermore, the identification of B7-1453, B8-1412, #41, #42, #44 and #63 was possible. Levels for the sum of #26, #41, #44 and #50 ranged from 7 to 24 microg kg(-1) milk fat and contributed between 2 and 9% to the total burden of investigated organochlorines such as selected compounds of the chlordane group, HCH, DDT and polychlorinated biphenyls (PCB). Capillaries coated with heptakis-(2,3,6-O-tert-butyldimethylsilyl)-beta-cyclodextrin (TBDMS-CD) or octakis-(2,3,6-tri-O-ethyl)-gamma-cyclodextrin (TEG-CD) were used for the enantioselective separations. Enantiomer ratios (ER) and enantiomer fractions (EF) of the abundant toxaphene congeners #26 and #50 as well as of B7-1453, #41 and #63 were determined. Greatest deviations from a racemic composition in individual human milk samples were found for #41 (1.54-2.37), #50 (1.37-1.72) and #63 (0.53-0.71) whereas ERs for #26 were close to 1. Compared to wildlife biota such as fish and raptors ER changes were more pronounced in human milk but comparable to human adipose tissue.

Adult↗