Determine effect of pressure heating on carbohydrate related molecular structures in association with carbohydrate metabolic profiles of cool-climate chickpeas using Globar spectroscopy

Grain has been heat-processed to alter rumen degradation characteristics and improve nutrient availabilities for ruminants. However, limited study was found on internal structure changes induced by processing on a molecular basis. The objectives of this study were to use advanced vibrational molecular spectroscopy to: (1) determine the processing induced carbohydrate (CHO) structure changes on a molecular basis, (2) investigate the effect of pressure heating on changes of CHO chemical profiles, CHO subfractions in cool-climate CDC Chickpea varieties, and (3) to reveal the association between carbohydrates related molecular spectra with carbohydrate metabolic profiles. The cool-climate CDC chickpea varieties with multisource were pressure heated in an autoclave at 120 °C for 60 min; and FTIR vibrational spectroscopy was used to detect the molecular spectra. Molecular spectroscopic results showed that compared to raw chickpea varieties, autoclave heating induced changes in both total CHO (region and baseline ca. 1186-946 cm^-1) and structural CHO (STCHO, region and baseline ca. 1482-1186 cm^-1), except for cellulosic compounds (CELC, region and baseline ca. 1374-1212 cm^-1). The CHO chemical profile and rumen degradation results showed that autoclave heating decreased rumen degradable, undegradable and intestinal digestible sugar (CA4) content, but increased available fiber (CB3) content, without affecting available energy of chickpeas. The changes of CHO molecular spectra in chickpea varieties were strongly correlated with CHO chemical profiles, CHO subfractions, and CHO rumen degradation characteristics. Moreover, the regression analysis showed that STCHO peak 1 height could be used to predict sugar content, its rumen degradability and digestibility of chickpeas. Our results suggest that autoclave heating markedly changes sugar and fiber degradation characteristics. The carbohydrate molecular spectral profiles are associated with carbohydrate metabolic profiles in raw and pressure heated cool-climate chickpeas.

Ultrasound assisted extraction of carbohydrates from microalgae as feedstock for yeast fermentation

Recently, carbohydrates biomass from microalgae is considered as a promising and inexpensive feedstock for biofeuls production by microorganism fermentation. The main obstacle of the process is microalgae pretreatment and carbohydrates extraction from algal cell. In this study, comparison of three pretreatment methods was performed and the results showed that ultrasonic assisted extraction (UAE) was very effective. The effects of four parameters (ultrasonic power, extraction time, flow rate and algal cell concentration, respectively) on extraction efficiency were also investigated. Additionally, in order to identify significant factors for glucose yield, combination of these four parameters was examined by using fractional factorial design (FFD) and the regression model was obtained. Meanwhile, the refined model was confirmed as a good fitting model via analysis of variance (ANOVA). After extraction, glucose obtained from microalgae was used as substrate for Rhodosporidium toruloides fermentation and yeast biomass was much higher than that of control culture.

Microwave modification of sugar cane to enhance juice extraction during milling

Sugar extraction from cane requires shredding and crushing, both of which are energy intensive activities. Cane shredders account for almost 30% of the total power requirements for the juice extraction train in a sugar mill with four mills. Shredder hammers also wear quickly during the crushing season and need to be regularly maintained or replaced. Microwave pre-treatment of other plant based materials has resulted in significant reductions in total processing energy. This paper briefly reviews the underlying structure of sugar cane and how microwave pre-treatment may interact with sugar cane. Microwave treatment reduced the strength of sugar cane samples to 20% of its untreated value. This strength reduction makes it easier to crush the cane and leads to a 320% increase in juice yield compared with untreated cane when cane samples were crushed in a press. There was also a 68% increase in Brix %, a 58% increase in total dissolved solids, a 58% reduction in diffusion time, a 39% increase in Pol%, and a 7% increase in juice purity compared with the control samples after 60 minutes of diffusion in distilled water.

Ultrasonic pretreatment of corn slurry for saccharification: a comparison of batch and continuous systems

The effects of ultrasound on corn slurry saccharification yield and particle size distribution was studied in both batch and continuous-flow ultrasonic systems operating at a frequency of 20 kHz. Ground corn slurry (28%w/v) was prepared and sonicated in batches at various amplitudes (192-320 microm(peak-to-peak (p-p))) for 20 or 40s using a catenoidal horn. Continuous flow experiments were conducted by pumping corn slurry at various flow rates (10-28 l/min) through an ultrasonic reactor at constant amplitude of 12 microm(p-p). The reactor was equipped with a donut shaped horn. After ultrasonic treatment, commercial alpha- and gluco-amylases (STARGEN 001) were added to the samples, and liquefaction and saccharification proceeded for 3h. The sonicated samples were found to yield 2-3 times more reducing sugars than unsonicated controls. Although the continuous flow treatments released less reducing sugar compared to the batch systems, the continuous flow process was more energy efficient. The reduction of particle size due to sonication was approximately proportional to the dissipated ultrasonic energy regardless of the type of system used. Scanning electron microscopy (SEM) images were also used to observe the disruption of corn particles after sonication. Overall, the study suggests that both batch and continuous ultrasonication enhanced saccharification yields and reduced the particle size of corn slurry. However, due to the large volume involve in full scale processes, an ultrasonic continuous system is recommended.

Sonochemistry: a powerful way of enhancing the efficiency of carbohydrate synthesis

Using sonication as a means of facilitating organic reactions in carbohydrate chemistry was explored under the conditions used for traditional organic synthesis. An array of representative reactions, including hydroxy group manipulation (acylation, protection/deprotection, acyl group migration), thioglycoside synthesis, azidoglycoside synthesis, 1,3-dipolar cycloaddition and reductive cleavage of benzylidene, commonly used in the synthesis of carbohydrate derivatives was examined. A series of glycosylation reactions that employ thioglycosides, glycosyl trichloroacetimidate, glycosyl bromide and glycosyl acetate as the glycosyl donors was also examined. Our results demonstrate that sonication can significantly shorten the reaction time, enhance the reactivity of reactant and lead to superior yield and excellent stereoselectivity. More importantly, a general protocol of glycosylation may finally be developed. Sonication is compatible to the conditions used for traditional organic synthesis. We believe that sonication can also be applied to other areas of synthetic processes.

Microwave energy: a versatile tool for the biosciences

As the range of techniques for microwave heating has expanded, so have the areas in which it can have a profound impact. Two emerging areas are the application of microwave heating for the synthesis of peptides, peptoids, oligopeptides and carbohydrates and in the field of proteomics.

Photo-induced hole transfer from base to sugar in DNA: relationship to primary radiation damage

This work presents the hypothesis that photo-excitation of G.+ in DNA and model systems results in the same electronic states expected from direct ionization of the sugar phosphate backbone and that these states lead to specific sugar radicals on the DNA sugar phosphate backbone. As evidence we show that visible photo-excitation of guanine cation radicals (G.+) in the dinucleoside phosphate TpdG results in high yields (about 85%) of deoxyribose sugar radicals at the C1' and C3' sites. Further, we have calculated transition energies of hole transfer from G.+ in TpdG using time-dependent density functional theory (TD-DFT) at the B3LYP/6-31G(d) level in gas phase as well as in a solvated environment. These calculations clearly predict that visible excitation of G.+ in TpdG causes transitions from only inner-shell filled molecular orbitals (MOs) to the singly occupied molecular orbital (SOMO) that effectively result in hole transfer from guanine either to the sugar phosphate backbone or to the adjacent base, thymine. The hole transfer is followed by rapid deprotonation from the sugar to form C1' and C3' radicals. These experimental and theoretical results are in agreement with our previously published experimental and theoretical results that photo-excitation of G.+ results in high yields of deoxyribose sugar radicals in DNA, guanine deoxyribonucleosides and deoxyribonucleotides. Photo-excitation of G.+ therefore provides a convenient method to produce and study sugar radicals that are expected to be formed in gamma-irradiated DNA systems unencumbered by the many other pathways involved in direct ionization.

High-light–induced Changes on Photosynthesis, Pigments, Sugars, Lipids and Antioxidant Enzymes in Freshwater (Nostoc spongiaeforme) and Marine (Phormidium corium) Cyanobacteria

We studied the effects of high-light exposure (500 micromol m(-2) s(-1) of photosynthetic active radiation) on the cyanobacteria Nostoc spongiaeforme Agardh, a fresh-water alga, and Phormidium corium Agardh (Gomont), a marine alga, with respect to photosynthesis, pigments, sugar content, lipid peroxidation, fatty acids composition, antioxidant enzymes activity and DNA. It was seen that the ratio of variable fluorescence (Fv) to maximum fluorescence (Fm), which is indicative of photosynthetic efficiency, decreased because of the light treatment. The damage to photosynthesis occurred in the antenna system and the photosynthetic II reaction center. Photobleaching of photosynthetic pigments was also observed. High-light treatment also resulted in decreased sugar content, which was probably due to the effect on photosynthesis. Peroxidation of membrane lipids, indicating oxidative damage to lipids and a high level of unsaturation in the cell membrane, was also observed. The activity of antioxidant enzyme superoxide dismutase and ascorbate peroxidase was increased, probably as a result of oxidative damage observed in the form of lipid peroxidation. Quantitative decreases in phospholipid and glycolipid levels were also observed. The level of unsaturated fatty acids in total lipids and glycolipids remained unchanged in both species; however, the level of saturated fatty acids decreased, which slightly changed the ratio in favor of unsaturated fatty acids. Degradation of DNA was also observed in both species. There was a transient plateau 2-4 h after exposure to high-light treatment in the Fv/Fm ratio and in levels of phycobilisome pigments, sugars and antioxidant enzymes after an initial decrease 1 h after the treatment. These findings may indicate a period of partial adaptation to high light that is due to the efficiency of protective processes operational in the two species, which subsequently failed after a longer exposure duration of 4-6 h.

Study of materials for mixed field dosimetry by EPR spectroscopy

EPR dose reconstruction after accidental photon exposure based on materials irradiated in the vicinity of the victim (sucrose, medicine tablets, etc.) was used successfully in several cases referenced in the literature. However, accidental exposure may also occur with a neutron component such as in the Tokai-Mura criticality accident. The aim of this work is to investigate the potentiality of EPR dosimetry for mixed photon and neutron field exposure with different organic materials already used for photon exposure (sucrose) or with potential dosimetric properties (ascorbic acid, sorbitol, glucose, galactose, fructose, lactose and mannose). To assess the neutron sensitivity, the materials were exposed to a mixed radiation field of an experimental reactor with different neutron to photon ratios. The relative neutron sensitivity was found to range from 12 to 43% according to the materials. The potentiality of these materials for mixed field EPR dosimetry is discussed.

Homolytic cleavage of the O-glycoside bond in carbohydrates: a steady-state radiolysis study

The formation of products resulting from the O-glycoside bond cleavage following radiolysis of aqueous solutions of methyl-alpha-D-glucopyranoside (I), 3-O-methyl-alpha-D-glucopyranose (II), maltose, lactose, gentiobiose and cellobiose were studied. Radiation-induced destruction yields were also determined for dextran, laminarin and trimethylcelulose upon irradiation of their aqueous solutions. Oxygen, quinones and compounds capable of forming quinoid structures were found to inhibit radiation-induced homolytic destruction processes taking place in glycosides, di- and polysaccharides. The data obtained in this study enabled the authors to demonstrate an important role played by the fragmentation reaction of C-2 radicals which were generated from the starting substances in the formation of final radiolysis products.

Sugar radicals in DNA: isolation of neutral radicals in gamma-irradiated DNA by hole and electron scavenging

In this investigation of the radical formation and the reaction of radicals in gamma-irradiated DNA, we report the isolation of putative neutral radicals by the scavenging of holes by Fe(CN)6(4-) and of electrons by Fe(CN)6(3-). Experiments are performed under conditions that emphasize direct and quasi-direct effects (collectively called direct-type effects.) Samples containing Fe(CN)6(4-) show effective scavenging of holes and the ESR spectra obtained arise principally from DNA anion radicals and neutral radicals. On the other hand, for samples containing Fe(CN)6(3-), electron scavenging is highly efficient, and the resulting spectra arise principally from guanine cation radicals and neutral radicals. When both Fe(CN)6(4-) and Fe(CN)6(3-) are present, a near complete scavenging of cation radicals and anion radicals is observed at 77 K, and the ESR spectra that result originate predominantly with neutral radicals which are assigned predominantly to radicals on the sugar phosphate backbone. A notable finding is the presence of spectral components that indicate the formation, through the rupture of the C3'-O bond, of a neutral deoxyribose radical; a concurrent strand break must accompany formation of this radical. This radical was previously reported in argon-ion-irradiated DNA and now, for the first time, is reported in DNA irradiated with low-LET radiation.

EPR and UV spectral study of gamma-irradiated white and burned sugar, fructose and glucose

The EPR and UV spectral properties of gamma-irradiated white and burned sugar, fructose and glucose are studied with the accent on their suitability as dosimetric materials. It is shown that gamma-irradiation of solid samples of white sugar and fructose yields stable EPR spectra whereas glucose signal remains time-dependent even 11 months later. Sugar and glucose exhibit linear EPR dose response in the region 0.44-21 kGy and fructose only up to ca. 10 kGy. The relative radiation sensitivity obtained for sugar and fructose is up to 10 kGy and slightly lower for glucose. Burned saccharides provide 2-3 orders of magnitude lower EPR radiation sensitivity making them not suitable for the proposed designation. According to the UV spectra water solutions of gamma-irradiated solid white saccharides show well pronounced absorption bands at 267 and 286 nm for sugar and fructose with time-dependent intensities reaching steady values ca. 11 days after dissolution. The intensities of these absorption bands are in linear relation with the absorbed dose of gamma-radiation. Glucose shows low sensitively because irradiation with 5.5 kGy yields only a shoulder at about 260-280 nm with decreasing to ca. 40% intensity in the first few days after dissolution. Excellent correlation between the intensities of the EPR- and UV-absorbed dose response is found for sugar and fructose in the region 0.44-10 kGy. This opens new possibilities for independent calibration the EPR dose response. Finally, the comparison suggests sugar as the best, universal material for EPR- and/or UV-dosimetry in the region 0.44-160 kGy.

[Characteristics of indices of biological oxidation under the therapeutic influence of electromagnetic radiation of millimeter range in a human organism]

The results of studying the process of biological oxidation of carbohydrates and Krebs cycle enzymes under the therapeutical influence of electromagnetic radiation of mm-range as a response of patient with gastroduodenal pathology are presented. Positive clinical effect was accompanied by multidirectional changes of biochemical parameters and activation of main mechanism of sanogenesis. Correcting action of EMR of m-range on the homeostasis system and process of biological oxidation of carbohydrates and Krebs and the functional state of a human's systems and organs were ascertained.

Effect of saccharide additives on response of ferrous-agarose-xylenol orange radiotherapy gel dosimeters

Glucose, sucrose, starch, and locust bean gum have been used as additives to the ferrous-agarose-xylenol orange (FAX) gel dosimeter. The saccharide enhanced dosimeters were found to have a higher dose sensitivity over a standard FAX gel as measured by both optical density change and magnetic resonance imaging (MRI). With optical density measurement, OD-dose sensitivity increases were up to 55% for glucose, 122% for sucrose and 43% for starch, while locust bean gum did not give a consistent response. With MRI, R1-dose sensitivity increases were up to 178% with sucrose addition. The FAX gel with sucrose was studied in greatest detail. The OD-dose sensitivity dependence on cooling rate was reduced for the sucrose FAX gel over the standard FAX gel, which has significant implications for uniform dose sensitivity in large gel phantoms. The thermal oxidation rate in the sucrose FAX gel was up to 2.3 times higher than in the standard gel. The OD-dose sensitivity of oxygenated sucrose FAX gels was 4.3 times greater than standard FAX gels, while continued enhancement in OD-dose sensitivity with increased sucrose concentrations beyond 2.0 g/l was found only for the oxygenated sucrose FAX gels. Both the molar absorption coefficient of the ferric ion-xylenol orange complex at 543 nm and gel pH were not affected by the presence of sucrose, with the implication that the higher OD-dose sensitivity of gels with saccharides is due to increased chain reaction production of ferric ions.

Electron paramagnetic resonance evidence for a C3' sugar radical in crystalline d(CTCTCGAGAG) X-irradiated at 4 K

Debije, M. G. and Bernhard, W. A. Electron Paramagnetic Resonance Evidence for a C3' Sugar Radical in Crystalline d(CTCTCGAGAG) X-Irradiated at 4 K. Radiat. Res. 155, 687-692 (2001). A neutral sugar radical formed by the net loss of hydrogen from C3' has been identified in crystalline DNA X-irradiated at 4 K. Crystals of duplex d(CTCTCGAGAG), known to be of B conformation, were studied using electron paramagnetic resonance (EPR) spectroscopy. The C3' radical was identified by using information from dose saturation, power saturation, thermal annealing, and spectrum simulation. The yield of the C3' radical, G(C3'), is 0.03 +/- 0.01 micromol/J, and its concentration does not appear to saturate up to at least 100 kGy. In the region in which total radical concentration increases linearly with dose, the C3' radical makes up about 4.5% of the total radical population trapped in the oligodeoxynucleotide crystal at 4 K. Based on free base release measured in other oligodeoxynucleotides, we suggest that in d(CTCTCGAGAG) the C3' radical is responsible for about one-third of the strand breakage events.

Reactivity of cartilage and selected carbohydrates with hydroxyl radicals: an NMR study to detect degradation products

It was investigated to what extent isolated, monomeric and polymeric carbohydrates as well as cartilage specimens are affected by hydroxyl radicals generated by gamma-irradiation or Fenton reaction and what products can be detected by means of NMR spectroscopy. Resonances of all protons in glucose and other monosaccharides as well as carbon resonances in 13C-enriched glucose were continuously diminished upon gamma-irradiation. Formate and malondialdehyde were found as NMR detectable products in irradiated glucose solutions under physiologically relevant (aerated) conditions. In polysaccharide solutions (e.g. hyaluronic acid) gamma-irradiation and also treatment with the Fenton reagent caused first an enhancement of resonances according to mobile N-acetyl groups at 2.02 ppm. This indicates a breakdown of glycosidic bonds in polysaccharides. Using higher radiation doses or higher concentrations of the Fenton reagent formate was also detected. The same sequence of events was observed upon treatment of bovine nasal cartilage with the Fenton reagent. First, glycosidic linkages in cartilage polysaccharides were cleaved and subsequently formate was formed. In contrast, collagen of cartilage was affected only to a very low extent. Thus, HO-radicals caused the same action on cartilage as on isolated polymer solutions, inducing a fragmentation of polysaccharides and the formation of formate.

Where are the sugar radicals in irradiated DNA?

Numerous sugar radicals have been observed by EPR and ENDOR spectroscopy in X-irradiated nucleosides and nucleotides. However, no sugar radicals have been observed in irradiated DNA. One possibility exists that sugar radicals may be present in relatively small abundance and therefore have so far escaped detection. Another possibility is that each of the five carbon-centered H-abstraction sugar radicals may exist in a wide range of conformations. Adding together various groups of radicals with different hyperfine couplings and anisotropic g factors may result in very broad EPR lines which would be difficult to detect. Using the crystal structure of a B-DNA dodecamer, the conformations of the five H-abstraction sugar radicals have been computed at all sites. The X-band EPR spectra for each radical were then simulated using typical alpha-proton and beta-proton couplings computed from the various radical conformations. The results suggest considerable broadenings of the EPR lines for the C2', C3' H-abstraction radicals. Composite EPR spectra were simulated by adding 15% of an H-abstraction radical to the DNA spectrum. The results indicate that the outer lines of the C1' radical are visible and should be easy to identify. The broad spectra of the C2' and C3' radicals are barely visible. The simulated spectra of the C4' and C5' radicals are basically doublets and are obscured by the DNA signal.

Assessment of microwave sterilization of foods using intrinsic chemical markers

The uniformity of microwave processing was investigated by measuring the formation of intrinsic chemical markers in disc-shaped and cylindrically-shaped whey protein gel model systems. These markers are formed as a result of thermally induced reactions of sugar and protein precursors. They were measured in samples placed in a pressurizable Teflon vessel and microwave heated to different peak temperatures using different power levels. Heating uniformity was mapped by sectioning the sample and analyzing for markers. The destruction of B. stearothermophilus spores in alginate beads was correlated with marker formation. The results show that the markers can be used to assess sterility and spatial time-temperature distributions in solid food samples.

[The hormonal status and carbohydrate-energy metabolism of rats after the long-term action of low doses of ionizing radiation and heat]

Hormonal status (blood content of triiodothyronine, thyroxin, insulin, 11-hydroxycorticosteroids), dehydration in the Krebs cycle, and activity of the first enzyme in the pentose-phosphate cycle, glucose-6-phosphate dehydrogenase, in the brain and myocardium of white rats were studied at different time periods after separate and combined prolonged exposure to radiation in relatively small doses and heat. It was found that combination of ionizing radiation and heat led to hypofunction of the endocrine glands and inhibition of dehydration processes in the Krebs Cycle.

[The effect of radon on the hormonal regulation of carbohydrate metabolism]

Wistar rat experiments provided evidence for marked inhibition of early insulin secretion after a single dose of radon water (radon concentration 200 nCi/1). Hepatocytes and activity of transaminase remained unchanged. Miners in long contact with radon in mines (radon concentration in the air of mines 1.5 nCi/1) develop long-term adaptation of the hormonal systems associated with hyperadaptosis in the system of hormonal regulation of glycohomeostasis.

[The application of microwave energy in preparation of herbal drugs. 2]

On the basis of various plant organs the relation between the used microwave energy and the drying processes, temperatures of the surface and the interior of the drying materials as well as the remaining moisture in the drugs was investigated. Leaf, flower and herb drugs showed a similar drying behaviour. Plant material of high humidity, e.g. meaty fruits or roots, should be dried by means of pulsed microwave application to avoid too high temperatures. In almost all investigated drugs microwave drying resulted in a lower remaining moisture than air drying. The effect of microwave irradiation on carbohydrates, fats and proteins in plant materials was preliminarily investigated.

Radiation dosimetry with an electron spin resonance spectrometer

Radiation dosimetry was undertaken using an electron spin resonance (ESR) spectrometer in students' laboratory work. Sugar was used as a dosimeter element and irradiated with both an X-ray generator (34 kVp, 8 mA) and a 60Co sealed source (3.7 MBq). The ESR system detects unpaired electrons created by the ionizing radiation. The lowest detection limit of the absorption dose was 20 Gy.

Effects of irradiation on surface carbohydrates of larvae of Schistosoma mansoni

Ultra-violet irradiated larvae of Schistosoma mansoni stimulate high levels of resistance to challenge infection in experimental animals. In the experiments presented here, the binding patterns of antisera specific for the cercarial glycocalyx, and of various lectins, demonstrate that u.v. irradiation causes a pronounced modification of the carbohydrate antigens expressed at the surface of cercariae and newly transformed schistosomula. These alterations were dependent on the irradiation dose, and on the batch of cercariae used in each experiment. Our results strongly suggest that the changes in carbohydrate antigens consequent upon u.v. irradiation may be important in generating the enhanced immunogenicity of irradiated cercariae.

[The hormonal functions regulating carbohydrate metabolism in participants in the cleanup of the sequelae of the accident at the Chernobyl Atomic Electric Power Station with a neurocirculatory dystonia syndrome]

Radioimmunoassay revealed in participants of Chernobyl disaster sequelae preclinical changes of some hormonal functions: moderate increase of the basal concentration of blood insulin, somatotropin, C-peptide against the background of persistent hypercortisolemia. Increase of the level of "hyperglycemic" hormones (cortisol, somatotropin, C-peptide) is explained by adaptative and compensatory reactions of the body in response to lesioning effects of ionizing radiation and other negative factors of the Chernobyl accident. Relative hyperinsulinemia is, apparently, compensating the total hyperglycemic effect of these hormones leading to stabilization of the blood sugar level.

[The radiation modification of the sugar fragment in DNA: the formation of breaks, a change in polymer conformation and the transfer of the damage to the base]

Comparative analysis of the author's own data and data reported in the literature on the nature of the intermediate and end molecular products of radiolysis of DNA, its precursors and substances stimulating certain DNA fragments, allows to attribute the formation of breaks and alkaline-labile sites in DNA strands and changes in the polymer conformation, to the formation and transformations of some types of primary radicals of the sugar fragment. In order to explain certain effects induced by irradiation of DNA and its precursors (a balance of basic products of radiation destruction of DNA and ESR data concerning low temperature radiolysis of bases, nucleotides and nucleosides) the author proposes a model of the transfer of a damage (free valence) from 2-deoxyribosyl to a base within one nucleotide.

[Metabolic reactions in sensory and motor neurons after exposure to various physical factors]

A course of radiation of biologically active points of the guinea pig lumbosacral area has been performed by means of focused frequency-modulated and a continuous beam of the helium-neon laser, having various power density, as well as by means of an impulsive magnetic field. A comparative histoenzymatic analysis of sensitive neurons of the lumbar spinal nodes and of the caudal-mesenteric motor neurons has been carried out. The response of the metabolic processes in the sensitive neurons depends not so much on the type of action, as on adequacy of the parameters applied. The power density, frequency of impulse generation and time of application are important for characterization of the adequacy of the laser radiation. Peculiarities of the metabolic reactions in the sensitive and sympathetic neurons in response to the actions studied are discussed.

Effects of irradiation and tunicamycin on the surface glycoproteins of Schistosoma mansoni

The cercarial glycocalyx and schistosomulum surface contains a number of glycoproteins which are expressed in very variable amounts within a parasite population. Tunicamycin inhibits glycoprotein synthesis of schistosomula if the parasites are incubated for 24 hr with the drug (10 micrograms ml-1). An unexpected increase in lectin binding to the parasite surface was observed but no other changes were detected. Schistosomula treated in this way did not develop in the host past the lung stage. Ultraviolet irradiation (400 microW min cm-2) also inhibited glycoprotein synthesis. Synthesis of other proteins, and in particular heat shock proteins, were also inhibited. Sera from mice (NIH strain) infected with irradiated cercariae contained antibodies which bound to normal schistosomula with lower affinity than to irradiated parasites. This is evidence that irradiation modifies the surface and secreted glycoproteins of schistosomula, so they are processed in a different way to normal glycoproteins by the host's immune system. The effects of irradiation on heat shock protein synthesis may allow the parasite to release a variety of proteins and glycoproteins in abnormal conformations. This may explain the enhanced immunogenicity of irradiated cercariae.

Radiation target analysis of glycoproteins

The radiation sensitivity of glycoproteins is shown to depend only on the protein portion of the molecule. An artificially created glycoprotein containing glucose-6-phosphate dehydrogenase observes this rule as well as natural enzymes and receptors containing from 2 to 50% carbohydrate. No exceptions have been found. Radiation damage to carbohydrates occurs close to the site of the primary ionization, with little spread of damage into attached polypeptides.

Lyoluminescence response of irradiated saccharides to radiation quality effects

Lyoluminescence sensitivity of five different saccharide powders to electron irradiation has been determined using luminol solution as a solvent. Effect of electron energy variation in the range of 5-20 MeV on the lyoluminescence yield has been measured. The light conversion efficiencies of different saccharides irradiated with x-rays, beta-particles, gamma-rays, fast electrons, 170-MeV/c pi(-)-mesons and 8-MeV neutrons have been calculated. Factors affecting light conversion efficiency, sensitivity and accuracy of measurements are discussed.

[Effect of branched-chain amino acids on the irradiated body]

The administration to rats of amino acids (valine, leucine, and isoleucine) for 10 days after whole-body X-irradiation with a dose of 7 Gy increased the survival rate and average life of animals and normalized some carbohydrate and nitrogen metabolism indexes. The insulin-like effect of these amino acids on glucose absorption by phrenic muscles of the exposed rats was detected.

Radiation inactivation of the glycoprotein, invertase

The radiation target size for invertase activity has been determined for the Saccharomyces cerevisiae glycoprotein which contains 50% carbohydrate. Identical inactivation curves were observed for the native enzyme as well as samples depleted of carbohydrate by incubation with Endo-beta-N-acetylglucosaminidase H. The functional unit of 120,000 daltons was unaltered by the per cent of oligosaccharide cleaved by the enzyme, or by the presence or absence of the released sugars. The irradiated samples showed no change in hexose content even after radiation exposures which grossly destroyed enzymatic activity. Reducing sugars appeared in the irradiated samples, indicating radiation damage to the oligosaccharides. These results unequivocally identify the enzymatically functional portion of the invertase molecule as the polypeptide homodimer, independent of the covalently-bound carbohydrates, and indicate that transfer of radiation energy from protein to oligosaccharide or vice versa is inefficient.

Role of red and far-red light in frost resistance of yarovized winter wheat after thaw

The short day in the thawing of hardened winter wheat, yarovized to a different degree, increased its frost resistance in comparison with uninterrupted illumination. Interruption of darkness of the short-day cycle by red light reduced frost resistance, far-red light had the opposite effect, but to a different degree, on the length of yarovization. Maximal resistance developed toward the end of the yarovization period. There were observed changes connected with the stabilization of the photoacceptor of the phytochrome system in the process of yarovization. The phytochrome complex participated in regulation of the movement and utilization of metabolites. There was revealed the variety specificity of winter wheat in relation to the investigated characters.

Mass spectrometry of some ultraviolet absorbing derivatives of sugars and related alditols: identification in biologic fluids after separation by high performance liquid chromatography

The 70 eV electron impact mass spectra of the acyclic perbenzoyl 0-benzyloximes of several mono- and disaccharides of clinical interest and the perbenzoates of certain related alditols have been obtained and compared with those of other similar derivatives studied previously. In general, the spectra of the benzyloximes contain molecular ions and characteristic fragments due to [C6H5]+,[C7H7]+,[C6H5CO]+ and [C6H5CooH]+., losses of HCHO, C6H5COO. and C6H5COOH, and cleavages along the carbon chain. The most unique ions in these spectra arise from the combined loss of C7H7. and C6H5COO.from the molecular ion: m/z 191 (C3), m/z 339 (deoxy-C5), m/z 459 (C5), m/z 473 (deoxy-C6), and m/z 593 (C6). The alditol benzoates fragment similarly, but they do not yield molecular ions. These data are being used to help confirm the identities of carbohydrates in biologic fluids fractionation by high performance liquid chromatography, prior to the establishment of routine quantitative assays for several of these compounds.

Mutagenicity and cytotoxicity of irradiated foods and food components

The preservation of foods by treatment with ionizing radiation can significantly increase the world's food resources by reducing spoilage and waste. However, irradiation can bring about chemical transformations in food and food components resulting in the formation of potential mutagens, particularly hydrogen peroxide and various organic peroxides. In order to evaluate the safety of irradiated foods for general consumption by the public, and, indeed, the safety of all foods subjected to environmental factors such as food additives, pesticides, drugs, air and water pollutants, etc., it is necessary to supplement the usual feeding tests with procedures designed to detect all classes of genetic damage. This article includes a comprehensive critical review of (1) the experimental evidence relating to the presence of mutagenic and cytotoxic agents in irradiated media, as detected by their effects on mammalian and non-mammalian cells; (2) the chemical changes produced in irradiated media, especially those which produce known mutagenic substances; and (3) new and convenient in vivo methods for the detection and evaluation of genetic damage in mammals.

Radiation-induced glyoxal formation in sugar solutions

Aqueous solutions (4 %) of glucose, fructose, and sucrose were exposed to gamma irradiation in the dose range of 2.2 to 24.0 megarads. The Gglyoxa1 values at 2.2 megarads were 0.35, 0.18, and 0.06 for glucose, fructose, and sucrose, respectively. These values decreased at higher dose levels. The glyoxal concentration of the irradiated solutions did not appreciably change during a 2-week postirradiation storage at room temperature.