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Riboflavin or vitamin B 2 is an essential component of the coenzymes flavin mononucleotide and flavin adenine dinucleotide and is contained in numerous foods in free and mainly in conjugated forms. The physicochemical characteristics of riboflavin and its content in relevant foods are discussed as well as its reactive behavior in food under different conditions. Riboflavin is an effective trigger of reactive oxygen species and may induce photosensitized damage of food constituents, such as amino acids, proteins, vitamins, and antioxidants (polyphenols and flavonoids). Quantitative assessment of riboflavin in foods is most frequently performed by fluorimetric methods after high-performance liquid chromatography separation or by microbiological assay. An actual European standard method is described.

Bioverfugbarkeit und Biokinetik von Polyphenolen aus Rotwein (Lemberger) gegenuber rotem Traubensaft wurden in einem gemischten Kollektiv mit 9 gesunden Probanden im crossover Vergleich untersucht. Nach Verabreichung einer Einzeldosis entweder von 400 ml Rotwein oder 400 ml rotem Traubensaft mit abgestimmtem Gesamtanthozyangehalt (27,6 mg bzw. 283,5 mg) wurde der Plasmaspiegel von Anthozyaninglukosiden ebenso wie deren Harnausscheidungsrate in regelmassigen Intervallen HPLC analytisch ermittelt. Aus den Plasmawerten wurden biokinetische Parameter wie AUC, Maximalkonzentration cmax , deren Zeitpunkt tmax und die Halbwertszeit t1/2 abgeleitet. In der Harnausscheidung konnten Rmax (max. gemessene Ausscheidungsrate).deren Zeitpunkt tmax,R , Ae (Gesamtmenge ausgeschiedener Anthozyane) sowie der prozentuale Anteil der Aufnahmedosis Xe erfasst werden. In der Biokinetik der plasmatischen Anthozyane waren keine Unterschiede zwischen Rotwein und rotem Traubensaft zu erkennen, dagegen ubertraf die Anthozyanausscheidungsrate nach Traubensaftzufuhr mit 0,23% der Aufnahmedosis signifikant diejenige nach Rotweinzufuhr mit 0,18% der Aufnahmedosis. Signifikant erhoht war auch das antioxidative Potential im Plasma (TRAP-test) nach Traubensafteinnahme gegenuber Rotwein. Es zeigte sich, dass Anthozyane aus roten Trauben zu geringem Anteil als intakte Glukoside resorbiert und als solche im Harn ausgeschieden werden. Roter Traubensaft scheint wenigstens gleich- oder sogar hoherwertig gegenuber dem getesteten Rotwein zu sein im Vergleich der nachweisbaren, bioaktiven Inhaltsbestandteile.

The aim of the present pilot study was to characterise the renal elimination of betalains after consumption of red beet juice (RBJ). Six healthy, non-smoking female volunteers were given a single oral dose of either 500 mL of a commercial RBJ containing 362.7 mg of betalains and 500 mL of tap water, respectively, in a sequential manner. Urine was collected in intervals up to 24 h post-dose. Renal excretion of betalains was determined spectrophotometrically and quantified as betanin-equivalents. In addition, the identity of individual compounds was confirmed by HPLC coupled with diode-array detection and positive ion electrospray mass spectrometry, respectively. The amount (mean+/-S.D.) of intact betalains (betanin and isobetanin) recovered in urine was 1001+/-273 microg corresponding to 0.28+/-0.08% of the administered dose. Maximum excretion rates were observed after a median tmax,R of 3.0 h (range 2.5-8.0 h) amounting to 91.7+/-30.1 microg/h. The terminal elimination rate constant (lambdaz) and the corresponding half-life were 0.097+/-0.021 h(-1) and 7.43+/-1.47 h, respectively. Using the lambdaz estimates obtained the expected total betalain amount excreted in urine was 1228+/-291 microg. Based on the results obtained it is assumed that either the bioavailability of the betalains is low or that renal clearance is a minor route of systemic elimination for these compounds. The urinary excretion rates of unmetabolised betalains were fast and appeared to be monoexponential suggesting a one-compartment model. In order to get a more complete picture of the pharmacokinetics and health-promoting properties of red beet betalains, quantitative data on betalain bioavailability should include measurements of unchanged compounds and their corresponding metabolites in plasma, urine and bile.

The aim of the present study was to assess the renal excretion of red beet juice (RBJ) antioxidants in six healthy humans. After a single oral dose of RBJ. The pharmacokinetic parameters obtained from urine were compared to those obtained after ingestion of water on an intra-individual basis. Urine was collected in intervals up to 24 h post-intake. After RBJ ingestion, the betacyanins betanin and isobetanin were excreted in the volunteers' urine (0.28% of the administered dose) and unambiguously identified by HPLC-ESI-MS/MS. Compared to the ingestion of water, RBJ consumption resulted in a significantly increased urinary excretion of total phenolics (51.1% of the administered phenolics) and other antioxidant compounds (43.9% of the administered compounds) within 24 h.

The influence of either orally administered S-benzoylthiamine-O-monophosphate (benfotiamine) or thiamine nitrate on the thiamine status was tested in a randomised, two-group comparison study in 20 end-stage renal disease (ESRD) patients. Main outcome measures were the pharmacokinetics of thiamine diphosphate (TDP) in blood, the in vitro erythrocyte transketolase activity, its activation coefficient (alpha-ETK) and the TDP concentration in erythrocytes.After ingestion of a single dose of either 100 mg thiamine nitrate (corresponding to 305 micromol thiamine) or 100 mg benfotiamine (corresponding to 214 micromol thiamine), the blood levels of thiamine phosphate esters were analysed by means of high-performance liquid chromatography for a 24-h period. The TDP concentration in erythrocytes was calculated using the haematocrit and TDP concentration in blood. Erythrocyte transketolase activity and alpha-ETK were measured before and 10 h after administration. The pharmacokinetics of TDP in blood were compared with healthy subjects of other studies retrieved from database query.Regarding the blood concentrations of TDP, the patients with ESRD had a 4.3 times higher area under the concentration time curve after benfotiamine administration than after thiamine nitrate. After benfotiamine administration, the peak plasma concentration of TDP exceeded that in healthy subjects by 51%. In the ESRD patients, after 24 h, the mean TDP concentration in erythrocytes increased from 158.7+/-30.9 ng/ml initially to 325.8+/-50.9 ng/ml after administration of benfotiamine and from 166.2+/-51.9 ng/ml to 200.5+/-50.0 ng/ml after thiamine nitrate administration. The ratio between the maximum erythrocyte TDP concentration and basal concentration was 2.66+/-0.6 in the benfotiamine group and 1.44+/-0.2 in the group receiving thiamine nitrate (P0.001). After 24 h, it was 2.11+/-0.4 and 1.23+/-0.2, respectively. The transketolase activity increased from 3.54+/-0.7 microkat/l initially to 3.84+/-0.6 microkat/l after benfotiamine intake (P = 0.02) and from 3.71+/-0.8 microkat/l to 4.02+/-0.7 microkat/l after thiamine nitrate intake (P = 0.08). Likewise, alpha-ETK decreased from initially 1.10+/-0.07 to 1.04+/-0.04 (P = 0.04) and from 1.12+/-0.05 to 1.08+/-0.06 (P = 0.09). After 24 h, the phosphorylation ratio in whole blood decreased from 12.9+/-6.9 initially to 5.6+/-3.2 after benfotiamine administration (P = 0.02) and from 13.5+/-7.3 to 9.0+/-4.8 (P = 0.03) after administration of thiamine nitrate. No correlation between erythrocyte TDP concentration and transketolase activity and/or alpha-ETK was observed in ESRD patients, either before or 10 h after administration.Compared with thiamine nitrate, the oral administration of benfotiamine leads to higher TDP concentrations in erythrocytes accompanied with a significant improvement of the erythrocyte transketolase activity in ESRD patients.

A three-armed, randomized, multicentre, placebo-controlled double-blind study was used to examine the efficacy of benfotiamine vs a combination containing benfotiamine and vitamins B6 and B,2 in out-patients with severe symptoms of alcoholic polyneuropathy (Benfotiamine in treatment of Alcoholic Polyneuropathy. BAP I). The study period was 8 weeks and 84 patients fulfilled all the prerequisite criteria and completed the study as planned. Benfotiamine led to significant improvement of alcoholic polyneuropathy. Vibration perception (measured at the tip of the great toe) significantly improved in the course of the study, as did motor function, and the overall score reflecting the entire range of symptoms of alcoholic polyneuropathy. A tendency toward improvement was evident for pain and co-ordination, no therapy-speci fic adverse effects were seen.

After muscular or periostal bleedings hemophilic pseudo tumors can occur as a complication of inadequate replacement therapy in hemophiliacs. They are incomplete reabsorbed and encapsulated hematomas that show recurrent bleeding inside a pseudocyst together with progressive growth and that mimic malign tumors. The disease was first described by Starker in 1918 [1]; Fernandez de Valderrama [2] demonstrated the detailed pathomechanism and recognized the importance of vascularization of hemophilic pseudo tumors [3]. Due to their progredient growth and depending on their anatomical location hemophilic pseudo tumors produce clinical symptoms as a result of soft tissue destruction, bone erosion or neurovascular compression.

We investigated the urinary pharmacokinetics of monomeric anthocyanins in seven healthy volunteers. The volunteers were administered a single oral dose of 3.57 g total anthocyanins contained in 150 ml of a concentrated elderberry juice under fasting conditions. Within 24 h the urinary excretion of unchanged cyanidin-3,5-diglucoside (cyanidin-3-sambubioside-5-glucoside and cyanidin-3,5-diglucoside were calculated as cyanidin-3,5-diglucoside equivalents), cyanidin-3-glucoside, cyanidin-3-sambubioside and total anthocyanins (i.e., the sum of all quantifiable anthocyanidin glycosides) was 0.16, 0.06, 0.05 and 0.06% of the administered doses, respectively. Maximum excretion rates were determined within 1.0 h after intake. The estimates (arithmetic mean +/- SD) of t1/2 were 1.25 +/- 0.25, 1.53 +/- 0.36, 1.38 +/- 0.20 and 1.35 +/- 0.18 h for cyanidin-3,5-diglucoside, cyanidin-3-glucoside, cyanidin-3-sambubioside and total anthocyanins, respectively. The urinary excretion of intact anthocyanins was fast and the decline of excretion rates appeared to be monophasic, suggesting a one-compartment pharmacokinetic model. The low urinary excretion of dietary anthocyanidin glycosides with values below 1% indicates that a large proportion of these plant pigments consumed are metabolized before entry into the circulation.

In a comparative study with 20 end-stage renal disease (ESRD) patients the pharmacokinetics of two therapeutically used thiamine (vitamin B1) preparations were assessed.After a single oral dose of either 100 mg benfotiamin (S-benzoylthiamine-o-monophosphate, BTMP) or 100 mg thiamine mononitrate (TN), blood levels of thiamine phosphate esters were analyzed by HPLC after precolumn derivatization to thiochrome phosphate esters for a 24-hour period.The pharmacokinetic parameters AUC0-24h, Cmax and tmax of the benfotiamin group in whole blood and plasma exceeded significantly those in the TN group. Only 1.0 vs. 0.6% of the administered dose were excreted in urine in the BTMP group and TN group, respectively. A high cellular efficacy, as was concluded from the short-term stimulation of the thiamine-dependent transketolase activity in erythrocytes (ETKA), was assessed for BTMP as well as TN. The activation coefficient (ETK-AC) decreased significantly from 1.10 to 1.04 vs. 1.12 to 1.07 in both the BTMP as well as TN groups, respectively. In addition, a high transfer rate to thiamine diphosphate (TDP) was observed in the patients after ingestion of BTMP. The TDP concentration in whole blood increased by 2.6 and 1.4 times from baseline levels to Cmax in the BTMP and TN groups, respectively. The AUC0-24h of TDP in whole blood after BTMP ingestion exceeded those after TN ingestion by 420%.These findings justify the therapeutic application of BTMP in ESRD, because a high intracellular concentration of TDP may protect against numerous adverse effects of uremia in the long run.

In 23 patients with chronic renal failure (CRF), 23 patients on chronic intermittent hemodialysis treatment (DP), 22 patients after renal transplantation (RT) and 40 normal persons (NP), Biotin plasma levels and the urinary excretion were analysed and compared to the dietary Biotin intake. Unsupplemented DP had lower intake of Biotin than the CRF, RT, NP and DP with supplementation. DP excreted only 1.6-6.3% of the daily intake as compared to 39.7% in NP, 27.6% in CRF and 24.3% in RT. In unsupplemented DP patients, Biotin plasma levels were elevated by 4 times and in supplemented patients by 6 times compared to NP. During hemodialysis treatment, the Biotin plasma level dropped by about 30% in DP with and by 33% in DP without vitamine supplementation. However, after 44 hours, the initial concentration was reached again in those receiving vitamine supplementation (99% of basal level) and in DP without substitution (97% of basal level). Only in male DP significantly higher Biotin plasma levels before HD were detected irrespective of the supplementation dose as compared to female patients (30 micrograms and 300 micrograms Biotin after each dialysis session). Biotin plasma concentration did not vary with respect to the underlying renal disease, the serum creatinine concentration and the length and frequency of dialysis treatment, including the type of dialyzer (low- vs high flux) used and the blood flow rate (QB 180-260 vs 270-280 vs 300 ml/min). There were no major effects of the age of the patients (60 years vs60 years), the BMI, nicotine abuse, or alcohol intake on Biotin blood concentration. Our results showed normal Biotin plasma levels which reflect a normal functional status and exclude a functional deficit, therefore there is no reason for a regular Biotin supplementation in patients with chronic renal failure.

In a multiple change-over study the bioequivalence of 3 thiamine preparations, used therapeutically as neurotropic agents for the treatment of polyneuropathies, was tested in a collective of 7 volunteers. After ingestion of a single dose of either 100 mg benfotiamin CS-benzoylthiamine-o-monophosphate), fursultiamin (thiamintetrahydrofurfuryldisulfide) or thiaminedisulfide, thiamine blood levels were analyzed for a 10-hour period. Thiamine was measured by HPLC after precolumn derivatization to thiochrome. The maximal thiamine concentration Cmax and its time (tmax) in plasma and hemolysate, the area under concentration time curve (AUC), and thiamine excretion in 24-hour urine were assessed as criteria of bioavailability. Additionally the erythrocytic transketolase activity (ETK) and alphaETK were determined as indicators of the cellular thiamine availability. After benfotiamin ingestion a more rapid and earlier increase of thiamine in plasma and hemolysate was observed in contrast to fursultiamin and the disulfide. All biokinetic data demonstrated a significantly improved thiamine bioavailability from benfotiamin compared with the other preparations. The lowest bioavailability was detected with thiamindisulfide. From our results it can be concluded that oral administration of benfotiamin is best suitable for therapeutical purposes owing to its excellent absorption characteristics.

The contents of the vitamins B1 (27 ng/ml), B2 (57 ng/ml), A (1.3 micrograms/ml), and E (9.7 micrograms/ml) as well as beta-carotene (0.2 microgram/ml) in transitional human milk were determined for up to 35 women aged between 19 and 31 years. Additionally, the vitamin content in maternal and cord plasma as well as the erythrocytic transketolase- and glutathione-reductase activities of the water soluble vitamins were measured. Dietary recalls were evaluated for the nutritional intake of vitamins. Concerning the fat soluble vitamins, the breast fed newborns received the recommended amounts of the German Society of Nutrition (DGE) for this group. In contrast to this, the supply of the water soluble vitamins (B1: 13.5 micrograms/500 ml; B2: 28.5 micrograms/500 ml) attained only 5 to 10% of the recommendations for newborns during the first two weeks after parturition with breast feeding. Vitamin content of maternal plasma (B1: 6.1 +/- 2.8 ng/ml) and erythrocytic enzyme activities (alpha ETK: 0.86-1.62; alpha EGR: 1.08-1.75) indicated a low or sufficient intake, while the values in cord blood (B1: 19.8 +/- 6.5 ng/ml; alpha ETK: 0.62-1.62; alpha EGR: 1.01-1.47) were in accordance with a satisfactory supply.

The vitamin C status of patients with chronic renal failure (CRF), dialysis patients (DP) and patients after renal transplantation (RT) was the object of this investigation. Levels of vitamin C intake from dietary records were estimated at mean values of 93.5 mg/d (CRF), 65.5 mg/d (DP) and 163.9 mg/d (RT). Compared to the recommendation of the German Society of Nutrition (75 mg/d), this indicated a normal range of supply for all groups except the group of DP. The corresponding mean plasma concentrations were 62.2 mumol/l (CRF), 80.3 mumol/l (DP) and 68.8 mumol/l (RT). Supplements of 60 or 100 mg vitamin C given to patients of the DP-group after each dialysis session showed slightly, but not significantly higher concentrations of vitamin C in plasma. During dialysis treatment, plasma vitamin C concentrations dropped to approximately 50% of the basal value, but almost reached initial levels again 44 hours later, both with and without supplementation. During one treatment period, vitamin C loss in the dialysate of three patients ranged between 92.5 and 333.6 mg. The amount of vitamin C in plasma, however, dropped to approximately 50% of the basal value for these patients, too.

A questionnaire containing 56 questions on educational activities and occupational preferences was sent to postgraduate trainees at all Departments of Diagnostic Radiology in Denmark. Answers were received from 154 individuals or 63% of the trainees. Trainees at University departments assessed the daily educational activities as less satisfactory than did trainees at other departments. Financial support for educational courses was less often given to trainees from the eastern region including the capital than to trainees from the rest of the country. Evaluation interviews, made in order to assess the trainee's progress, had been attended by 22%. Fifty-nine % of these interviews resulted in alteration of the trainee's working programme. If appropriate for their career, 82% would apply for an appointment requiring changing their address.

The Manual for Nutrition Surveys of the Interdepartmental Committee on Nutrition for National Defense [1, 2] can be considered to be the first attempt to provide a description and standardization of methods for vitamin nutriture assessment.

Es wurden Lagerungsversuche mit den Kartoffelsorten Hansa (mittelfruh) und Hela (sehr fruh) in unterschiedlichen Verpackungsmaterialien bei Tages- und bei Dammerlicht durchgefuhrt. Ausgewahlt wurden: PE-folie, perforier-farblos, -schwach getont, -stark gefarbt; PE-folie, nicht perforiert -farblos; Papiertute, perforiert und nicht perforiert und Kunststoffnetze. Zwei Gebindegrosen wurden miteinander verglichen: 2,5-kg-Haushaltspackung und 25-kg-Gebinde. Die Lagerdauer betrug 3 Monate. Sortenspezifische Unterschiede waren in der Veranderung der auseren Beschaffenheit und im Gehalt an Trockensubstanz erkennbar. Kartoffeln der Sorte Hela keimten fruher als die Kartoffelsorte Hansa. Proben, die im Dammerlicht gelagert waren, zeigten eine ausgepragtere Keimungstendenz als Tageslichtproben. Grosere Gebinde waren besser lagerfahig als Kleinpackungen, Kunststoffnetze und Papierverpackungen erwiesen sich gunstiger als Kunststofffolien. Das Auftreten von Faulnis und Schimmelbildung ging prinzipiell parallel mit der Keimbildung und war am starksten bei den Proben ausgepragt, die in PE-folien gelagert waren, ursachlich bedingt durch erhohte Schwitzwasserbildung und gehemmte Ventilation in diesen Proben. Die sehr fruhe Sorte Hela war anfalliger gegen Schimmel- und Faulnisbildung, auch die Keimung setzte fruher ein. Der hochste Gehalt an Trockensubstanz wurde in Proben aus Papierverpackungen und Kunststoffnetzen gefunden. Tageslichtproben hatten im allgemeinen einen hoheren Gehalt an Trokkensubstanz als Dammerlichtproben. Diese Unterschiede waren jedoch insgesamt nicht sehr bedeutsam.

Bei Lagerungsversuchen von 2 Kartoffelsorten (Hansa, mittelfruh; Hela, sehr fruh) in verschiedenen Verpackungsmaterialien (PE-folie, perforiert-farblos; -schwach getont; -stark gefarbt; PE-folie, nicht perforiert-farblos; Papiertute, perforiert und nicht perforiert, Kunststoffnetze) und bei unterschiedlichen Beleuchtungsverhaltnissen (Tages- und Dammerlicht) zeigte sich, das der Solaningehalt innerhalb einer Lagerdauer von 3 Monaten auf mehr als das Doppelte seines Ausgangswertes ansteigen kann. Bei den meisten Proben war die Solaninzuwachsrate im Tageslicht hoher als im Dammerlicht. Der Einflus der Verpackung war entgegen der Erwartung weniger deutlich ausgepragt. Die partielle Lichtdurchlassigkeit von PE-folien begunstigte jedoch offenbar eine Erhohung des Solaningehalts. Der Alkaloidgehalt der Proben in den lichtdurchlassigen farblosen Folien ubertraf sogar den von gleichfalls lichtdurchlassigen Kunststoffnetzen. Zwischen perforierten und nicht perforierten Folien waren ins Gewicht fallende Unterschiede nicht festzustellen. Fur eine langere Lagerung von Kartoffeln geeignet erscheinen anhand unserer Versuche lichtundurchlassige Papiertuten bzw. -sacke und Kunststoffnetze. Der Verpackungseinflus auf die lichtinduzierte Solaninbildung der Kartoffeln wurde bei den vorliegenden Untersuchungen wahrscheinlich uberdeckt von einer initialen Solaninbiosynthese, hervorgerufen durch einen „Lichtstos”, dem die Kartoffeln vor dem Verpacken bzw. auf dem Transport ausgesetzt waren. Der „Lichtstos” erfolgte bei Sorte Hela offenbar zu einem fruheren Zeitpunkt als bei Sorte Hansa. Signifikante Unterschiede bezuglich des Alkaloidgehalts waren im vorliegenden Fall nicht nachweisbar. Der mittlere Solaningehalt der beiden Kartoffelsorten im gesamten Untersuchungszeitraum lag bei 20,6 mg/100 g Trockensubstanz. Die durchschnittliche Schwankungsbreite (Zu- oder Abnahme) betrug 50%. Parallel zu den verpackten Kartoffeln eingelagerte unverpackte Kartoffeln hatten trotz ziemlich gunstiger Lagerbedingungen am 2. und 3. Untersuchungstermin grostenteils einen hoheren Alkaloidgehalt als die verpackten Proben. Dieser Befund wird mit einer verminderten Stoffwechselrate bei den verpackten Kartoffeln erklart.

Chinin kann dunnschichtchromatographisch von seinen Nebenalkaloiden quantitativ abgetrennt werden, wenn man zunachst mit einem vorwiegend polaren Laufmittelgemisch bis zur gleichmasigen Durchfeuchtung entwickelt, dann die Platte trocknet und anschliesend in entgegengesetzter Richtung mit einem vorwiegend unpolaren Fliesmittel ebenfalls bis zum Plattenrand entwickelt (Umkehrentwicklung). — Eine auf diesem Befund basierende dc Methode zur Bestimmung von Chinin in Chinarinden, bei der die quantitative Ermittlung photometrisch erfolgt, wird beschrieben, und die Ergebnisse mit nach der Internationalen Standardmethode erhaltenen verglichen. Determination of Quinine in Cinchona Barks by Thin-layer-chromatography Quinine can be separated quantitatively from its byalkaloids by using the following TLC-procedure. At first the plates are completely developed with a mainly polar solvent and dried. Then they are developed in the reverse direction with a mainly unpolar solvent also to the edge of the plates (reverse development) — A new TLC-method based on this procedure is described in order to determine quinine in Cinchona barks. The quantitative evaluation proceeds by the photometric method and the results are compared with the International Standard procedure.

Die Trennung von Chinin, Chinidin, Cinchonin, Cinchonidin, Hydrochinin und Hydrochinidin gelang mittels zweidimensionaler Dunnschichtchromatographie unter Verwendung vorwiegend polarer Laufmittelgemische in der einen und vorwiegend unpolarer in der anderen Richtung. — Chinin, Chinidin, Hydrochinin und Hydrochinidin wurden mittels praparativer Schichtchromatographie gereinigt. Schmelzpunkte und Spezifische Drehungen der reinen Basen und daraus dargestellter Salze wurden zur Uberprufung der DAB-7-Angaben bestimmt. Separation and Purification of Cinchona Alkaloids by Thin-layer-chromatography The alkaloids quinine, quinidine, cinchonine, cinchonidine, dihydroquinine and dihydroquinidine could be separated by means of two-dimensional thin-layer-chromatography (TLC) using mainly polar solvent-systems in the first and mainly unpolar solvent systems in the other direction. — Quinine, quinidine, dihydroquinine and dihydroquinidine were purified by preparative TLC. Melting points and specific rotatory powers of the pure bases and their salts were determined in order to control the data of the German Pharmacopeia DAB 7.

In order to test the effect of a long term alcohol administration on the thiamin metabolism in blood, heart and liver under suboptimal supply, an experiment with rats was carried out over a period of 16 weeks. The suboptimal thiamin supply became visible mainly in the liver stores which were lowered during the whole test period. The unphosphorylated thiamin (T) of liver and heart was not detectable after 4 weeks up to the end of experiment. On the other hand the total thiamin concentration in the erythrocytes increased from the beginning due to an enhanced thiamin-diphosphate (TDP) and thiamintriphosphate (TTP) pool and T was lowered to undetectable amounts only after 16 weeks. In contrast, the alpha-TK in blood and liver was enhanced only after 2 and 4 weeks and tended to become normal by the end of the test period indicating an apoenzyme degeneration. Alcohol ingestion resulted in a general diminution of the total thiamin and the thiamin phosphates in blood, heart and liver and a reduced thiamin excretion in urine. An alcohol induced shift of the phosphorylation status could be observed only in the liver, but not in the heart and the erythrocytes, leading to a lowered concentration of T and TMP. The results demonstrate that the level of thiamin and thiamin phosphates in blood and organs under suboptimal thiamin supply seems to be more sensitive to chronic alcohol administration than the transketolase activity and the alpha-TK value.

A method is described for determining riboflavin excretion in urine by thin-Layer chromatography. The sample will be preliminarily purified on Permutit T with subsequent separation of riboflavin by thin-layer chromatography on Kieselgel HR with pyridine--acetic acid--water as an eluant. Substances interfering with the fluorescence of riboflavin can be eliminated through the procedure. Riboflavin remission is measured by a chromatogram-spectralphotometer with fluorescence equipment. Between 0.02 to 0.5 mug riboflavin intensity of fluorescence is proportional to the concentration of riboflavin.

The biotin content of plant and animal food samples as well as of human plasma and urine specimens was assessed by a modified protein binding assay (PBA). Protein bound biotin in samples was released by digestion with papain, food samples were in addition treated previously with liquid nitrogen. Comparing analyses by use of the conventional microbiological test with L. plantarum resulted in slightly enhanced biotin values, in case of plasma by 9.2% and in case of urine by 10.3%, but the results obtained by both methods correlated well (r = 0.926 for plasma and 0.934 for urine). Regarding food analysis the additional comparison of different disintegration procedures led to best reproducible results by using the PBA with preceding papain digestion.

Adjuvante Therapiemasnahmen, wie die zeitweise, zusatzliche orale oder parenterale Ernahrung, die Schmerzbekampfung und die psychische Betreuung der Krebskranken haben in der Tumortherapie grose Bedeutung erlangt. Um eine adjuvante Ernahrung zum richtigen Zeitpunkt den spezifischen Bedurfnissen des Patienten angepast einsetzen zu konnen, sind genaue Kenntnisse des Ernahrungszustandes sowie des Stoffwechsels in verschiedenen Krankheitsstadien bei unterschiedlichen Tumoren erforderlich. Als Beitrag hierzu wurde deshalb der Vitaminversorgungszustand bei Patientinnen mit Mammakarzinomen untersucht.

Assaying the activation of pyruvate carboxylase in erythrocytes by measuring the enzyme activity before and after addition of biotin and ATP to the reaction mixture enables to estimate the biotin supply in vitro. According to this method in biotin deficient rats the pyruvate carboxylase-activity increased to 70%, while the increase of activity in supplemented animals amounted to 16%.

Intake of bulk vegetable material has diminished in the western countries considerably since the beginning of industrialisation. Lack of bulk substances is being held responsible lately for the increase of diseases of the gastrointestinal tract. It has been shown, that bulk materials increased stool weight and decreased gastrointestinal passage time; it is assumed, that they do have beneficial effects in the treatment of diverticulosis of the colon. It is still controversial, how bulk materials influence mineral metabolism, especially intestinal resorption of iron, calcium and other bivalent cations. Hypocholesterinemic effects of lignin and pectin, which form part of vegetable bulk food, are as yet not well defined. The question is still open, if bulk foods do have prophylactic effects in regard to carcinoma of the colon.

Die Riboflavinausscheidung im Harn last sich mit Hilfe der Dunnschichtchtomategraphie quantitativ erfassen. Nach Vorreinigung der Harnprobe uber Permutit T wird Riboflavin anschliesend auf Kieselgel HR mit dem Fliesmittel Pyridin-Eisessig-Wasser von storenden Nebenfluoreszenzen abgetrennt und die Remission des Riboflavins am Chromatogramm-Spektralphotometer mit Fluoreszenzansatz gemessen. Im Bereich von 0,02–0,5 µg ist die gemessene Fluoreszenz direkt proportional der Riboflavinkonzentration.

Die Bestimmung der Pyruvatcarboxylase-Aktivierung im Erythrozytenhamolysat durch Messung der Enzymaktivitat vor und nach Zusatz von Biotin und ATP zum Reaktionsansatz eroffnet eine Moglichkeit, den Biotinstatus in vitro zu objektivieren. Bei Biotinmangelratten ergab sich nach diesem Verfahren ein Anstieg der Pyruvat-Carboxylaseaktivitat um 70%, wahrend bei vollernahrten Tieren der Aktivitatsanstieg bei 16% lag.