Determination of biogenic amines by capillary electrophoresis.

A method for determining biogenic amines in food using micellar electrokinetic capillary chromatography has been developed. Derivatization of the amines was performed with AccQ (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate; Waters, Milford, MA, USA) reagent. The influence of buffer composition on the separation (including pH, SDS concentration and various additives) was investigated. The separation of seven biogenic amines (histamine, tyramine, tryptamine, spermine, spermidine, cadaverine and putrescine) could be achieved within 25-30 min with good repeatability. The biogenic amine profiles in three different food samples (wine, salami and chive) were determined and quantitated.

[Preoperative diagnosis of breast tumors in our clinic]. / Az emlötumorok preoperativ diagnosztikája klinikánkon.

Between 1983 and 1988 197 patients underwent mammography and fine needle aspiration cytology procedure beside physical examination before operation for breast tumor in our clinic. The sensitivity of mammography and fine needle aspiration cytology were 81.9 and 66.1%, their specificities were 91.2 and 95%, the specificity of physical examination was 97.7%. When all three examinations indicated malignancy, this was confirmed by histology without exception. When the examinations showed benign lesion in concert, four of the 26 diagnoses were false, histology proved breast cancer smaller than 2 centimetres in diameter without lymph node metastases in each case. Those aspirations which were considered unsatisfactory because of the lack of cells supported the diagnosis of a benign tumor raised by physical examination and mammography. Our data indicate that the diagnosis yielded by the combination of the three examinations may support therapy more than it does in the present.

Artificial tripartite symbiosis involving a green alga (Chlamydomonas), a bacterium (Azotobacter) and a fungus (Alternaria): morphological and physiological characterization.

A long-living artificial tripartite symbiosis involving a green alga (Chlamydomonas), a bacterium (Azotobacter) and a fungus (Alternaria) was established on carbon- and nitrogen-free medium. The basis of the interdependence is the complementation of photosynthetic CO2 assimilation and atmospheric nitrogen fixation. Green color of the colonies indicated that the algal cells had enough nitrogen to synthesize chlorophylls. The chlorophyll content was nearly 40% of the control cells. The relatively high rate of photosynthetic oxygen evolution proved that nitrogen was effectively used for building up a well functioning photosynthetic apparatus. This was supported by the analysis of photosystems and ultrastructural investigations. In comparison with degreened algae cultured on nitrogen-free medium, the chloroplasts in the symbiont algal cells contained a well-developed, stacked thylakoid membrane system without extreme starch or lipid accumulation. The occurrence of the fungus in the association greatly increased the chlorophyll content. Far fewer types of amino acids were excreted by the tripartite cultures than by pure cultures. Cystathionine, which is a common intermediate in the sulfur-containing amino acid metabolism, was produced in high quantities by the tripartite symbiosis. This can mostly be attributed to the activity of the fungus.

Biogenic amines and microbial quality of sprouts.

Changes in the biogenic amine content relative to microbial activities in mung bean, lentil and radish sprouts were investigated in prepacked and "home-grown" products. Biogenic amines were determined by ion-exchange chromatography. The major groups of micro-organisms were enumerated by aerobic plate count procedures, using universal and selective media. Putrescine, cadaverine, spermidine, agmatine and spermine were detected in different concentrations, depending on the type of sprouts. In prepacked retail products the total biogenic amine content was higher than in home-grown samples (mung bean 106 micrograms/g compared to 87 micrograms/g; lentil 316 micrograms/g compared to 181 micrograms/g; radish 1486 micrograms/g compared to 252 micrograms/g). It is concluded that sprouting time and storage conditions play a major part in the hygienic quality of legume sprouts.

Determination of biogenic amines in leafy vegetables by amino acid analyser.

An automated ion-exchange chromatographic method is described for determination of biogenic amines in leafy vegetables using a cation-exchange resin column in potassium form and a three-buffer system. The following amines were separated and quantified for Chinese cabbage, endive, iceberg lettuce and radiocchio: putrescine, histamine, cadaverine, spermidine, agmatine, spermine, tyramine. Amines from vegetable samples were extracted with 10% trichloroacetic acid. The total concentration of these amines ranged from 14 to 20 micrograms/g fresh weight. Spermidine was the major polyamine detected, present at concentrations of 7-15 micrograms/g fresh weight.

The functional damages of ischemic/reperfused skeletal muscle.

Skeletal muscle is frequently damaged by ischemia-reperfusion when exposed to direct injury or in the surgical practice. The purpose of the present experiments was to examine how the different types of skeletal muscles (fast & slow) react functionally to one and two hours of ischemia followed by two weeks of reperfusion. The fast-twitch (m. extensor digitorum longus/EDL) and the slow-twitch (m. soleus/SOL) muscle were prepared. They were stimulated, in vivo, either directly or indirectly at different reperfusion times following tourniquet ischemia, and the contraction force (CF) was recorded. CF of the EDL was reduced over 40% and 90% of the control value during the first 24 hours of reperfusion after 1 and 2 hours of ischemia, respectively. It was about 50% at the end of the 2nd week in the one-hour group. CF increased significantly during the second week if ischemia lasted for two hours. Reduction of CF in the SOL muscle was over 50% and 90% following one and two hours of ischemia, respectively. It further decreased in the 1-hour group, and it started to regenerate from the second week after 2 hours of ischemia. It is concluded that 1. two hours of ischemia causes significantly more severe damages in both types of skeletal muscles than one hour. 2. There is a reperfusion injury in both muscles during the first week of reperfusion. 3. The two types of muscles regenerate differently, i.e. the SOL starts to regenerate earlier than the EDL.

The functional and morphological damage of ischemic reperfused skeletal muscle.

Skeletal muscle is frequently damaged by ischemia-reperfusion both caused by direct injury and also by surgery. The purpose of the present experiments was to examine how the different types of skeletal muscles (fast and slow) react functionally and morphologically after 1 and 2 h of ischemia followed by different periods of reperfusion. The fast-twitch (musculus extensor digitorum longus, EDL) and the slow-twitch (musculus soleus, SOL) muscle of Wistar rats were prepared. They were stimulated in vivo, either directly or indirectly at different reperfusion times following tourniquet ischemia, and the contraction force of the muscles was recorded. The morphological changes were examined by light microscopy. At early reperfusion times, the contraction force of the EDL muscle was reduced by 40 and 90% after 1 and 2 h of ischemia, respectively. The contraction force was about 50% at the end of a 2-week reperfusion period in the 1-hour ischemia group and it increased significantly (from 5 to 38%) during the second week if the ischemia lasted for 2 h. Reduction of contraction force in the SOL muscle was over 50 and 90% following 1 and 2 h of ischemia, respectively, and it started to improve from the 2nd week. Morphological changes of the two types of muscle were identical. At early reperfusion times granulocytes were seen in the blood vessels adhering to the endothelium. 24 h later neutrophil granulocytes migrated into the endomysium and thereafter into the perimysium. One week after 1 h of ischemia both muscles showed normal histology. However, the structural regeneration process only started at the end of the 1st week of reperfusion after 2 h of the ischemic damage. The following conclusions can be drawn. (1) There is functional morphological evidence of ischemic and reperfusion injury in both muscles after 24 h and also after 1 week of reperfusion. (2) Functionally, the two types of muscles regenerate differently, i.e. the SOL starts to regenerate earlier than the EDL. (3) Morphologically the two types of muscle show the same reactions. An increase in the time of ischemia from 1 to 2 h delays the regeneration processes.

Possible chromosomal location of genes determining the osmoregulation of wheat.

Stress-induced free amino acid accumulation in the presence of 0.7 M mannitol has been compared in tissue cultures of moderately stress-tolerant 'Chinese Spring' and stress-sensitive 'Cappelle Desprez' cultivars and in disomic chromosome substitution lines of 'Cappelle Desprez' into 'Chinese Spring'. The profile of amino acid accumulation was different in the two parents. The amino acid concentration of the substitution lines belonging to the A, B and D genomes, respectively, altered characteristically under stress condition. The 'Cappelle Desprez' chromosomes associated with non-ionic osmotic stress-induced free amino acid accumulation were 5A and 5D.

Biochemical studies of some non-conventional sources of proteins. Part 7. Effect of detoxification treatments on the nutritional quality of apricot kernels.

Detoxification of apricot kernels by soaking in distilled water and ammonium hydroxide for 30 h at 47 degrees C decreased the total protein, non-protein nitrogen, total ash, glucose, sucrose, minerals, non-essential amino acids, polar amino acids, acidic amino acids, aromatic amino acids, antinutritional factors, hydrocyanic acid, tannins and phytic acid. On the other hand, removal of toxic and bitter compounds from apricot kernels increased the relative content of crude fibre, starch, total essential amino acids. Higher in-vitro protein digestibility and biological value was also observed. Generally, the detoxified apricot kernels were nutritionally well balanced. Utilization and incorporation of detoxified apricot kernel flours in food products is completely safe from the toxicity point of view.