The influence of extrusion on loss and racemization of amino acids.

The influence of the operation conditions (temperature and residence time) of a thermic treatment on the total amount (free and protein-bound) of amino acid enantiomers of dry fullfat soya was investigated. Total amino acid content was determined using conventional ion-exchange amino acid analysis of total hydrolysates and chiral amino acid analysis was performed by HPLC after precolumn derivatization with o-phthaldialdehyde and 1-thio-beta-D-glucose tetraacetate. Contrary to corn that was investigated previously, notable racemization was detected even at lower temperatures. At 140 degrees C the ratio of the D-enantiomer was 0.87% for glutamic acid, 2.81% for serine, and 1.92% for phenylalanine; at 220 degrees C the ratios of the D-enantiomer of the above amino acids were 1.43, 4.61, and 4.68%, respectively. The concentration of several L-amino acids decreased. At 220 degrees C there was 10% less L-glutamic acid, 17% less L-serine, 5% less L-phenylalanine, 6.6% less L-aspartic, acid and 21% less L-lysine than in the control; their loss can be assigned to different degrees of L - D conversion. While nearly complete transformation of L-phenylalanine can be attributed to racemization, the main cause of the loss of L-lysine is not racemization. The treatments in the same order of magnitude resulted in the formation of more D-amino acids and greater extent of racemization of amino acids in fullfat soya than that of maize.

The influence of manufacture on the free D-amino acid content of Cheddar cheese.

The changes in the concentration and those of composition of alanine, aspartic acid and glutamic acid enantiomers were investigated during manufacture of Cheddar cheese. The amount of D-alanine increased continuously during ripening following the liberation of L-alanine originated from the proteolysis of milk proteins. There was slightly more D-aspartic and D-glutamic acid in the dry matter of curd after pressing than before pressurization. The D-amino acid content and the ratio of the D-enantiomers related to the total amount of free amino acids differed significantly among cheeses produced with different single-strain starters. The D-amino acid composition changed during manufacture, but the influence of the strain selection was not significant on the D-amino acid pattern.

[Improvement in surgical treatment of rectal cancer in the surgical department of County Hospital, Szekszard]. / Chirurgische Therapie des Rektumkarzinoms: Verbesserung der Behandlungsergebnisse im Bezirkskrankenhaus Szekszard.

247 elective rectal operations were performed between 1st of Jan., 1996 till 31st of Dec., 2001 in our surgical department. The observation period was divided into one 4-year and one 2-year period. 148 operations were performed in the first and 99 in the second period. In the second period some personal, methodical and technical changes occurred. Age and sex distributions were similar, and the groups were comparable. The early postoperative mortality rate decreased from 9% to 4%. Due to the double stapling technique the rate of anterior rectal resections increased from 40% to 69% and the rate of abdomino-perineal rectal extirpation decreased from 43% to 23% in the same time. Large differences were found in the rate of palliative stoma performing operations, the rate decreased from 16% to 8% in the second period, so the quality of life of the patients improved. The operative time, the length of hospital stay and the rate of blood transfusions decreased as did the rate of postoperative infections. The new quality program improved the results significantly.

Lack of acid-resistant trypsin inhibitor in mare's colostrum: short communication.

Mare's colostrum was collected and examined for the presence of trypsin inhibitors. It was found to contain a low level of trypsin inhibitor which could be denatured by 2.5% trichloroacetic acid and, therefore, it clearly differs from the acid-resistant colostral inhibitor of Artiodactyla and Carnivora. This finding is exceptional for a species that concentrates IgG in the colostrum and whose newborn absorbs colostral proteins non-selectively by the gut. It appears that the presence of colostral trypsin inhibitor is not essential for the transmission of maternal immunity via the colostrum and the gut.

Influence of mastitis on D-amino acid content of milk.

The California Mastitis Test was used as an indicator of mastitis in this study. Five cows were chosen for each of the five test scores (from 0 = healthy to 4 = severe mastitis). Milk samples were analyzed for free AA and free D-AA. The contents of free AA, free D-AA, and the ratio of free D-AA to free AA increased significantly as the California Mastitis Test score increased. The free D-AA content of foremilk (first milk jets) from healthy cows (test score = 0) was approximately five times that in samples drawn later from the same udders. Contents of free AA and free D-AA were highly associated with test score and udder inflammation. Very low concentrations of free D-AA are normal for raw milk. Higher concentrations of free D-AA could be attributed to inclusion of foremilk and milk from cows having subclinical mastitis in the bulk tank milk.

Age determination based on amino acid racemization: A new possibility.

A method has been developed to determine the age of fossil bone samples based on amino acid racemization (AAR). Approximately one hundred fossil bone samples of known age from Hungary were collected and analysed for D- and L-amino acids. As the racemization of amino acids is affected by temperature, pH, metal content of the soil, and time passed since death, these factors were eliminated by comparing the estimated age to age determined by the radiocarbon method. Determining the D- and L-amino acid contents in samples of known age, determining the half life of racemization and plotting the D/L ratio as a function of time, calibration curves were obtained. These curves can be used for the age estimation of samples after determining their D- and L-amino acid content. The D/L ratio for 2 to 3 amino acids was determined for each sample and the mean value of estimated ages based on calibration curves was considered to estimate age of the fossil samples.

Separation of D- and L-amino acids by ion exchange column chromatography in the form of alanyl dipeptides.

A method of ion exchange column chromatography was developed for the determination of D- and L-amino acids in the form of diastereomeric dipeptide. First the protein containing samples were hydrolyzed with 6 molar hydrochloric acid, then the single amino acids were separated in an LKB automated amino acid analyzer with the LKB fraction collector. Following lyophilization, the single amino acids were transformed into alanyl dipeptides with tertiary-butyloxycarbonil-L-alanine-N-hydroxy-succinimide (t-BOC-L-Ala-ONSu) active ester. The alanyl dipeptides were easily separated from one another and the initial amino acids. Determination of the D- and L-amino acids in this form is relatively accurate and reproducible but takes some time (33-38 min). Accuracy of the determination is satisfactory. The coefficient of variation amounts to 3-5%. The use of the method is suggested to laboratories having an amino acid analyzer and wish to determine D-and L-amino acids in synthetic-amino acids complements, peptides or natural materials.

Effect of heat treatment and subsequent urea supplementation of sunflower meal on the in vitro ruminal degradability of crude protein content and its postruminal digestibility.

A three-phase laboratory procedure was used for predicting the degradability of the protein of extracted sunflower meal before (SFM) and after heat treatment (HSFM). The rumen fluid degraded 69.1% and 67.1% of the SFM and HSFM protein, respectively. The digestibility values of rumen undegraded protein (UDP) were 57.3% (SFM) and 57.0% (HSFM) with pepsin and 17.6% (SFM) and 15.9% (HSFM) with pancreatin. Urea supplementation practically did not alter the rumen degradability of HSFM protein, while the pepsin digestibility of UDP decreased to 47.2%. Four fractions (NH3, dissolved amino acids, oligopeptides and proteins) of rumen degradable crude protein (RDP) were also determined in vitro: 81 to 92% of the degraded crude protein was found in the fractions tested. Heat treatment reduced free NH3 content but did not alter the other three fractions. Urea supplementation decreased the quantity of NH3, peptides and proteins as well.

An assay for selecting high risk population for gastric cancer by studying environmental factors.

Gastric cancer mortality incidence data registered in two different areas of Eastern Transylvania (Roumania) were reported related to 325,000 inhabitants from the period of 1951-1972. The findings were compared to some geographical environmental factors deriving from an area of 13,300 km with 905,700 inhabitants. A 2-3.5 times larger incidence of gastric cancer (75-140 per 100,000/year) was found in some selected geographical areas of the intermontane depressions of Gheorgheni and Ciuc in comparison to hilly area of Transylvanian Tableland. The difference might be explained by some unknown environmental gastric cancer risk factors. Of the natural factors, the presence of magmatic substrata shows a significant degree of correlation. The main pedological factor seems to be badly drained pseudoglyied podzolic and peaty soils of low pH and high content of organic matter. Sofs drinking waters also may be involved as risk factor. High altitude, cold climate determining a restricted assortiment of cultivated plants, the successive production of vegetal and animal food on the same soil for livelong periods and several generations, especially in isolated rural areas, seem to represent gastric cancer risk factors. According to authors' opinion a survey of the high-risk population selected on the basis of the environmental factors, especially of the persons suffering from gastric disorders considered today possible precursors of gastric cancer, may offer some progress in detecting early gastric malignancy in the future.