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[Hemorheologic and circulatory effects of hemodilution with medium molecular weight hydroxyethyl starch in two concentrations (HAES 200/0.62 10% and 6%)].

This study was designed to investigate whether the positive effect occurring after infusion of a 10% hydroxyethyl starch solution 200.000/0.62 on cutaneous capillary blood flow could still be increased by using a 6% solution having a lower initial viscosity (HES 6% 200.000/0.62). A single blind study of 10 female volunteers was carried out to study the influence of a hypervolemic hemodilution using 500 ml of a 10% solution hydroxyethyl starch solution at first and that of 6% hydroxyethyl starch solution on macro- and microcirculation, transcutaneous oxygen partial pressure and blood fluidity. After hydroxyethyl starch infusion blood flow in the macro- and microvessels increased significantly. This increase occurred considerably earlier after administration of 6% solution than after infusion of 10% solution. Thus blood flow had already increased after 1 hour and continued to show a tendency of increase over about three hours. 6 hours after end of infusion blood flow had almost dropped to its initial value. The volume effect of the 6% solution immediately after infusion was less pronounced than that after infusion of the 10% solution, but it reached the value of the 10% solution at a later point in time. The course of the haematocrit reflected this process. Average decrease in haematocrit value compared to that following the 10% solution was not as pronounced at hour 3. After 6 hours the decreases were comparable. Similar observations were made of plasma viscosity and platelet aggregation. One hour after infusion plasma viscosity and erythrocyte aggregation had hardly changed but haematocrit had clearly dropped. Thus, blood viscosity at this point in time was essentially lowered.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Synthesis of sorbent from cross-linked starch for affinity purification of glucose(mannose)-specific lectins].

Cross-linked starch gel for the affinity chromatography of D-glucose (D-mannose)-specific lectins is suggested. In order to optimize hydrodynamic properties of gel 30% starch has been hydrolysed by HCI at 70 degrees C during 60 min and then cross-linked by epichlorohydrin under alkaline conditions. Every 100 g of starch require 18 ml of epichlorohydrin and 36 ml of 8 N KOH. The gel obtained has been successfully used for the purification of lectins from Pisum sativum L., Lens culinaris L., Vicia sativa L., and Vicia faba L. seeds. These lectins, purified on starch gel do not differ from sephadex-purified samples.

Chromatography, Affinity↗

Starch gel electrophoresis of lactate dehydrogenase and glucose phosphate isomerase of poultry coccidia using the LKB multiphor.

A modification of thin-layer starch gel horizontal electrophoresis is described. The original method of Wraxall and Culliford (1986) is improved so that the preparation of starch gel is as simple as preparing the agarose gel. Thus the commercially supplied kits and instruments for the agarose gel electrophoresis can be also used for the starch gel electrophoresis. Furthermore, a method of preparing the permanent dry enzymograms from the starch gels with visualized enzymes is presented. The described procedure was used in the LDH and GPI analyses of poultry coccidia.

Animals↗

Quantitative selection of denitrifying bacteria in continuous cultures and requirement for organic carbon. I. Starch.

A mixed population of bacteria from bottom sludge of nitrogen wastewater reservoir was incubated in continuous culture in medium containing 1000 mg nitrate nitrogen/l and starch. Maximal efficiency of denitrification was 5 mg N/l/h. Marked changes in participation of denitrifying bacteria (16-76%) among total number of bacteria was observed, this being dependent on the ratio of starch concentration (CS) to nitrogen concentration (CN) in the medium. The optimal CS/CN ratio ensuring highest participation of denitrifying bacteria was 3.2. The amount of starch required for the denitrification of a defined quantity of nitrogen is negatively correlated (r = -0.98) with the frequency of the occurrence of denitrifying bacteria (XD) and is: CS = (5.53-0.028XD) CN. The denitrifying bacteria in continuous culture were dominated, depending on CS/CN ratio and flow rate of medium, by Alcaligenes faecalis, Paracoccus denitrificans or Pseudomonas mendocina, that is species unable to hydrolyse starch.

Bacteria↗

[Ultrathin-layer starch gel electrophoresis--a method qualified to solve specific problems in enzyme analysis].

Particular separation problems of enzymatic analysis led to optimization investigation on starch gel electrophoresis. Investigations on the optimum gel concentration range a well as on the duration of the hydrolysis of starch for a suitable gel network gave rise to a starch level with good molecular sieve effect. Optimization of the electrophoretic buffer system and the development of an optimum technique for manufacturing handy transparent ultra thin-layer starch gels with high selectivity results for a broad spectrum of diagnostically enzymatic systems has turned out to be of advantage for enzymatic electrophoresis.

Buffers↗

[Intestinal malabsorption of starch and gas production in the colon].

The amount of dietary starch released in the colon, its excretion in the stools, the hydrogen and methane resulting from its fermentation, were measured in six healthy volunteers, ingesting two diets, rich and low in starch (100 and 300 grams). Regardless of the diet, approximately 5% of the ingested starch was malabsorbed in the small bowel and completely metabolized in the colon. While the amount of malabsorbed starch was 2.5 times higher with 300 g than with 100 g, the volumes of hydrogen exhaled were not different. This suggests that the responsibility of alimentary substrates in the production of colic gas is overestimated.

Adult↗

Light and electron microscopic investigation of in vitro starch synthesis in chromoplasts.

Chromoplasts having a globular inner structure in the petals of Forsythia suspensa can form starch grains in their stroma when incubated with glucose solution. The same result was obtained with chromoplasts, similar in structure, from Laburnum anagyroides and Ranunculus acer. Fibrillar chromoplasts in tepals of Lilium croceum are able to synthesize starch in vitro, not, however, from glucose but from glucose-1-phosphate. This starch differs from the above mentioned both in respect of electron microscopic structure and digestibility with alpha-amylase, a feature presumably caused by the relatively high activity of the branching (Q) enzyme. The substrate specificity of Lilium-starch synthesis can be explained by blocking of the phosphorylation of glucose in the cytoplasm, rather than by the selective permeability of the plasmalemma.

Microscopy, Electron↗

[Production of yeast biomasses from starch].

The well known fodder yeasts do not accumulate extracellular amylolytic enzymes and are therefore unable to utilize starches for the production of microbial biomasses. Some of the Endomycopsis yeasts produce glucoamylase but their specific growth rate is so small that continuous cultivation in starch containing media results in low productivites. In the "Symba-process" this drawback is overcome by a twostage fermentation process. In the first stage only Endomycopsis fibuliger yeasts are continuously cultivated and in the second stage the main part of the starch containing medium is converted to microbial biomasses by a mixed culture consisting of fodder yeasts (p.a. Candida utilis) and Endomycopsis fibuliger transferred continously from the first stage. In this work methods for evaluating conditions of cultivation of such a process are presented and a two stage continuous fermentation of a starch containing medium is performed. In the second stage with a dilution rate of D Y 0,174 h-1 a productivity of 1,7 g dry biomasses/1-h was attained Methods for improving the productivity are discussed.

Amylases↗

Effects of tendamistate (an alpha-amylase inactivator), guar and placebo on starch metabolism.

Nine volunteers participated in a double-blind, cross-over study to compare the effects of tendamistate (HOE 467), guar and placebo on starch metabolism. In each phase of the trial they received a maize-meal porridge breakfast. They either received 5 g guar granules before the porridge or 100 mg tendamistate mixed with the porridge, or porridge alone. Sequential plasma glucose concentrations served as a criterion of starch digestion. The area under the plasma glucose curve and maximal glucose concentrations after administration of tendamistate with the starch were significantly lower (P less than 0,05) than after guar and placebo. No significant differences were found between placebo and guar. We concluded that tendamistate effectively attenuates starch digestion and is superior to guar in reducing postprandial glycaemia.

Adult↗

The starch digestion test in the horse.

Variable results were obtained when the starch digestion test was carried out on a suspected case of malassimilation in a horse. In order to re-evaluate this test, 15 starch digestion tests were carried out using 4 horses. Results showed a marked variation in the increase in plasma glucose levels between individual horses and especially between poor and good condition horses when the dose of starch was based on body mass. Results also suggest that a fixed dose of starch may give more consistent results.

Animals↗

[Effect of starch-induced structural and functional modification in a population of free phagocytes on antibody formation induction by ram erythrocytes in mice].

The influence of the starch-induced modification of the population of free phagocytes on the induction of antibody formation by sheep red blood cells (SRBC) in mice has been studied. The intraperitoneal injection of starch has been shown to render a pronounced modulating effect on immune response stimulated by the intramuscular injection of the antigen. The injection of a small dose of SRBC into the abdominal cavity enriched with starch-stimulated monocytes is accompanied by an increase in immune response; this phenomenon is not observed after immunization with a large dose of the antigen. Starch-stimulated macrophages, when introduced with SRBC into syngeneic recipients, show stimulating influence on immune response.

Animals↗

[The effect of molecular structure of hydroxyethyl starch on the elimination kinetics and fluidity of blood in human volunteers].

Influence of the Molecular Structure of Hydroxyethyl Starch on Elimination Kinetics and Blood Fluidity in Voluntary Subjects In a cross-over study 6 volunteers received an infusion of 500 ml hydroxyethyl starch of a batch with a high C2/C6-substitution ratio (10.8), or after a washout period of 3 months they received a batch with a low C2/C6-substitution ratio (5.8). The infusion solution was administered at random. The batches were identical as regards their physicochemical characteristics (HES 200/0.5 10%). The concentration and molecular weight distribution of the intravascular hydroxyethyl starch molecules were determined after infusion up to 24 h, the blood fluidity before and after infusion. The substitution ratio of the C2- or C6-atoms in the glucose ring has an effect on the degradation of the hydroxyethyl starch molecule: the molecules with a high C2/C6-substitution ratio appear to be degraded within the same period of time, the resulting degradation products, however, have a higher molecular weight. This influences the blood fluidity. While the haematocrit decrease occurring 1 h after end of infusion is comparable, it keeps up for a longer time in case of a higher C2/C6-substitution ratio. The increase of plasma viscosity is more pronounced in case of a high C2/C6-substitution ratio. Clinical consequences are discussed.

Adult↗

Photosynthetic carbon reduction cycle metabolites and enzymes of sucrose and starch biosynthesis in developing Brassica pods.

Rate of net CO2 exchange and activities of the key enzymes of fru-2,6-P2, sucrose and starch synthesis and levels of certain intermediates of Calvin cycle were determined in Brassica pods at different stages of their development. The rate of net CO2 exchange, activities of FBPase, UDPG-pyrophosphorylase and SPS, and the contents of 3-PGA, DHAP, RuBP and UDPG increased up to day 21 after anthesis followed by a continuous decrease thereafter. However the content of fru-6-P started decreasing only after 28 days of anthesis. Changes in the levels of fru-2,6-P2 were closely associated with the changes in F6P 2-kinase activity rather than with F2,6-P2ase activity. Similarly, activities of ADPG-pyrophosphorylase and ADPG-starch synthetase closely followed the pattern of starch accumulation in pod tissues. These observations suggest that during the early phase of pod development (up to 21 days after anthesis), which is also the active phase for pod photosynthesis, carbon is mainly utilised for sucrose synthesis and that during the later phase of pod development (from day 21 to 42 after anthesis), there is shift in metabolic path of carbon from sucrose to starch.

Brassica↗

[Phase I study on infusion of PJ-203 (degradable starch microspheres) into hepatic. PJ-203 Clinical Study Group].

Degradable Starch Microspheres (DSM) are spherical starch microspheres prepared from partially hydrolysed potato starch and then cross-linked by epichlorohydrin. PJ-203 is a transient intra-arterial embolic material and suspended in physiological saline at a concentration of 60 mg/ml starch microspheres. In the present multi-center cooperative Phase I clinical study, we examined the embolic effect and safety in patients with primary liver cancer (14 cases) and those with metastatic liver cancer (18 cases). The dose of DSM per patient was 300 mg in one minute. DSM was infused in increments of 300 mg, with a wash-out period of one minute between the increments, until the dose reached 1,200 mg. In addition to these four dose groups, one group consisting of patients with metastatic liver cancer received 900 mg in three minutes without interruption. DSM was infused via a catheter which had been inserted into the hepatic artery by means of the Seldinger method or laparotomy. In either primary liver cancer or metastatic liver cancer patients, a satisfactory embolization could be obtained with 900 mg or more DSM. Also, it was confirmed that the embolic period was one hour before and after. Pain was noted in all the groups. Other frequently observed adverse reaction were nausea.vomiting, anorexia and fever (38-39 degrees C). However, these symptoms improved within several hours or days. There was no dose-related incidence in these symptoms. Reduced blood pressure.weak pulse, pressure.heavy sensation in the right hypochondriac region, discomfort in the abdominal.chest region, or perspiration.cold sweat, were observed in 2 to 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Embolization, Therapeutic↗

HES 200/0.5 is not HES 200/0.5. Influence of the C2/C6 hydroxyethylation ratio of hydroxyethyl starch (HES) on hemorheology, coagulation and elimination kinetics.

The plasma clearance of hydroxyethyl starch (HES) depends on the initial molecular weight and the degree of substitution. So far, little attention has been paid to the clinical relevance of the C2/C6 substitution ratio of hydroxyethyl starch. 10 patients with cerebrovascular circulatory disturbance received hemodilution therapy for 10 days, consisting of 10% HES 200/0.5 (mean molecular weight 200 kD, degree of substitution 0.5) with a C2/C6 ratio of 13.4. A second group of 10 patients received a starch solution with identical initial molecular weight and degree of substitution but with a C2/C6 ratio of 5.7. After the administration of a single dose, no significant differences between the two groups were observed. After repeated administration, significant differences could be detected in hemorheology, coagulation and elimination (p < 0.01). The larger C2/C6 ratio led to a higher intravascular mean molecular weight (95 vs. 84 kD), which in turn led to a higher increase in serum concentration during the therapy (14.7 vs. 8.6 mg/ml). Hematocrit was lowered more (-30.5 vs. -23.5%) and plasma viscosity was increased more. There was also a more pronounced increase in partial thromboplastin time (+30% vs. +13%) and a factor of 2 larger decrease of factor VIII/von Willebrand factor-complex (p < 0.01), which exceeded the dilution effect. The higher C2/C6 ratio of HES 200/0.5/13.4 slows down enzymatic degradation. After repeated administration of this starch, large molecules accumulate which are inefficiently degraded. The same effect has been observed after therapy with highly-substituted HES. This accumulation of large molecules leads to a beneficial longer lasting volume effect. The disadvantages include an increase in plasma viscosity and coagulation disturbances, which cannot be explained with the respective dilution effect alone. For these reasons, the C2/C6 ratio is of clinical relevance and should be included in the product labeling in the future.

Alkylation↗

Production and properties of a raw-starch-degrading amylase from the thermophilic and alkaliphilic Bacillus sp. TS-23.

The optimum temperature and initial medium pH for amylase production by Bacillus sp. TS-23 were 55 degrees C and 8.5 respectively. Maximum amylase activity was obtained in a medium containing peptone and soluble starch as nitrogen and carbon sources. Activity staining revealed that two amylases with molecular masses of 150 and 42 kDa were produced when maltose, soluble starch or amylose was used as carbon source for growth, whereas only the 150 kDa protein was detected in the medium containing water-insoluble carbon sources. A raw-starch-degrading amylase was purified from culture supernatant of Bacillus sp. TS-23. The molecular mass of the purified amylase was estimated at 42 kDa by electrophoresis. The enzyme had a pI of 4. 2. The optimal pH and temperature for activity were 9.0 and 70 degrees C respectively. The thermoactivity of the purified enzyme was enhanced in the presence of 5 mM Ca2+; under this condition, enzyme activity could be measured at a temperature of 90 degrees C. The enzyme was strongly inhibited by Hg2+, Pb2+, Zn2+, Cu2+ and EDTA, but less affected by Ni2+ and Cd2+. The enzyme preferentially hydrolysed high-molecular-mass substrates with an alpha-1, 4-glucosidic bond except glycogen. The raw starches were partly degraded by the purified amylase to yield predominantly oligosaccharides with degrees of polymerization 3, 4 and 5.

Bacillus↗

Effect of molecular structure variation on the disintegrant action of sodium starch glycolate.

The effect of variation in the degree of cross-linkage and extent of carboxymethylation on the disintegration and dissolution properties of sodium starch glycolate has been examined. Samples of sodium starch glycolate were evaluated for particle size distributions and bulk and tapped densities. The bulk powders were also tested for sedimentation volumes, water uptake, and bulk swelling. Direct compression formulations containing aspirin and hydrochlorothiazide and varying concentrations of the modified starches were tableted on a rotary tablet press and evaluated for weight variation, hardness, disintegration, and dissolution. The results indicate that relatively small changes in molecular structure can cause substantial modification of disintegrant properties and suggest that the specifications for one commercially available sodium starch glycolate are within optimal specifications for both cross-linkage and degree of substitution.

Aspirin↗

Infant dumping syndrome: reversal of symptoms by feeding uncooked starch.

Two infants with dumping syndrome after Nissen's fundoplication were bolus-fed with regular cows' milk formula and with test meals containing either cooked or uncooked starch. Cows' milk formula and test meals made with cooked starch provoked dumping symptoms, hyperglycaemia and hyperinsulinaemia. Dumping symptoms vanished and normoglycaemia was established when meals contained uncooked starch as the sole carbohydrate. The findings suggest that uncooked starch has a place in the dietary control of dumping syndrome in infants and possibly in adults.

Dietary Carbohydrates↗