Metabolomics of faecal samples offers a non-invasive method to monitor gastrointestinal (GI) development and microbial activity in dairy heifers during key physiological transitions. In this longitudinal study, faecal metabolites from 10 Holstein heifers were analyzed from birth to first calving using targeted metabolomics. Faecal samples were collected at 12 h post-birth, week 6 (pre-weaning), week 14 (weaning), 8 months (post-weaning), and at first calving (26 ± 2.3 months). Calves were fed 3.8 L of colostrum within 2 h of birth, followed by 6 L of maternal transition milk for 5 days, then 6 L of milk replacer twice daily. Group housing began at 14 days. Partial least squares discriminant analysis (PLS-DA) showed distinct temporal clustering of faecal metabolites. Heatmap analysis revealed significant metabolite alterations, particularly between pre- and post-weaning stages. A linear mixed-effects model identified significant stage effects for all 17 amino acids. Of the 55 biogenic amines and amino acid-related metabolites, 48 significantly differed across stages. Elevated amino acids and polyamines early in life reflected colostrum intake and immature digestion, decreasing post-weaning, indicating improved nutrient absorption and rumen functionality. Increased microbiota-derived compounds, including β-alanine, serotonin, and indole derivatives, reflected microbial colonization and co-regulation with the host. Elevated dopamine, homocysteine, and phenylethylamine in late gestation indicated neuroactive and redox adaptations. Overall, faecal metabolite profiles provide insights into metabolic remodelling related to nutrition, GI maturation, and reproductive development, highlighting faecal metabolomics as a useful non-invasive tool for monitoring heifer development.

The aim of this research was to study the effect of 12-minute clinical death on innate and acquired behavior, biogenic amine concentration, and the composition and quantity of neural populations in specific brain regions of white rats. The study shows that in animals during the postresuscitation period with formal restoration of neurological status, there are changes in emotional reactivity, orientation-exploration reactions, impairment of learning and memory, decrease in exercise tolerance and pain sensitivity. These processes are accompanied by alterations in serotonin and norepinephrine levels in the frontal cerebral cortex, dopamine and serotonin levels in the striatum, certain biochemical indices in blood plasma and neural loss in the CA1 sector of the hippocampus and lateral portions of the cerebellum.

The inhibitor of monoaminooxydase isatin and the ligand of B-receptors cholecystokinin-4 play a significant role in the suppression and induction of depressive and anxiety states. We induced the formation of auto-antibodies to these compounds against their conjugates with antigen-carrier by immunization of white rats. The result was long-term (more than 2 months) stimulation of depressive and anxiety behavior after immunization to isatin and, in contrast, the suppression of such behavior after immunization to cholecystokinin. The perspective of immunochemical approach to long-term correction of behavior is discussed.

The purpose of this work was to analyse the influence of rennet from different Cynara cardunculus plants, selected for its clotting and proteolytic activity on caseins, on the characteristics of manufactured ‘Torta del Casar’ cheeses. After classifying the cardoon according to proteolytic activity into five groups of greater or lesser activity, 16 batches of cheeses were made with rennet derived from different wild cardoon plants. We observed a major development of the proteolysis during ripening leading to the generation of non-protein nitrogen compounds. Especially noteworthy was the relationship of amino acid nitrogen (AN) generation with rennet clotting activity after 24 h of maceration, and the fact that the production of biogenic amines was not related to the proteolytic activity of the rennet. The activities of the rennet observed ‘in vitro’ were also developed ‘in vivo’ in the cheeses, with the different rennets used affecting the final sensory characteristics of cheeses. The rennet with high clotting activity after 24 h of maceration was positively correlated with the creaminess, viscosity, and acceptability of the cheese. However, the high proteolytic activity rennet negatively influenced the acidity, bitterness, and creaminess parameters. Therefore the most appropriate cardoons for making this cheese are those with higher clotting activities and moderate proteolytic activities especially on β-casein. The use of controlled and characterised cardoons in the manufacturing process of Torta del Casar is fundamental to obtaining the homogeneous product demanded by the Torta del Casar Registry of the Protected Designation of Origin.

The effects of age on microbiota composition, gut fermentation end-product formation and peripheral lymphocyte numbers were compared between old and young adult Beagle dogs fed four kibble diets differing in yeast cell wall contents. The experiment had a double 4 × 4 Latin square design, one with four mature dogs (4 years old) and the other with four old dogs (10 years old), with four replicates (diets) per dog. In each period a 15 d adaptation period preceded a 5 d total collection of faeces for the digestibility trial. On day 21, fresh faecal samples were collected for the determination of bacterial enumeration, pH, biogenic amine and short-chain fatty acid. Flow cytometry was used for immunophenotypic evaluation. Dogs were fed four kibble diets with similar composition with 0, 0·15, 0·30 and 0·45 % of yeast cell wall (as-fed), respectively. Data were evaluated using general linear models of Statistical Analysis Systems statistical software (P < 0·05). No evidence of a difference in faecal bacteria counts between ages was found (total aerobes, total anaerobes, Bifidobacterium, Lactobacillus, Clostridium and Escherichia coli: P>0·15). Faecal concentrations of butyrate, histamine, agmatine and spermine were lower (P ≤ 0·05) and faecal pH was higher (P = 0·03) in older dogs than in mature adult dogs, suggesting an alteration in bacterial metabolic activity, or in the rate of intestinal absorption of these compounds. Concentrations of T-lymphocytes, T-cytotoxic lymphocytes and B-lymphocytes were also lower (P ≤ 0·01) in older dogs than in mature adult dogs. The study confirmed alterations in peripheral lymphocytes and revealed a reduced concentration of some fermentation end products in the colon of old dogs.

This article describes a neurobiological basis for the “first attachment” of the primate infant to its caretaker. The infant normally internalizes a neurobiological “image” of the behavioral and emotional characteristics of its caregiver that later regulates important features of its brain function. Current models of sensorimotor analysis and its relation to emotion suggest that sensorimotor systems are also habit and memory systems, their functional status and lability regulated in part by biogenic amine systems. The intertwined development of neural and social functions can sometimes go awry. If the attachment process fails or the caregiver is incompetent, the infant may become socially dysfunctional. This helps explain the developmental psychopathology and later vulnerability to adult psychopathology that result from disruptions of social attachment.

Adult early treated hyperphenylalaninaemic patients can show specific deficits of prefrontal cortical functions. The development of additional therapeutic strategies for these patients requires the understanding of the mechanisms involved in phenylalanine-dependent impairment of fronto-cortical functions. We tested the hypothesis of phenylalanine interference with aminergic neurotransmission in the prefrontal cortex by evaluating, in vivo, amine release in adult Pahenu2 mice, the genetic model of phenylketonuria. Mice of healthy background responded to a psychogenic stressor with the classic time-dependent increase of norepinephrine, dopamine and serotonin release from prefrontal cortical terminals. Neither the dopaminergic nor the serotoninergic responses were observable in the Pahenu2 mice. Temporary reduction of circulating phenylalanine, by phenylalanine-free diet without amino- acid supplement, promoted recovery of the serotonin response only, demonstrating direct interference with serotonin synthesis in the mature brain. Evaluation of different steps of serotonin synthesis in the prefrontal cortex of hyperphenylalaninaemic mice demonstrated inhibition of cortical tryptophan hydroxylase activity. Finally, systemic administration of 5-hydroxytryptophan, the product of tryptophan hydroxylase activity, allowed frontal cortical serotonin response to stress in hyperphenylalaninaemic mice. Collectively, these results demonstrate that hyperphenylalaninaemia interferes with the ability of the mature prefrontal cortex to respond to psychological challenges, point to serotonin synthesis as the target of phenylalanine interference, and support the use of 5-hydroxytryptophan in lifelong treatment of hyperphenylalaninaemic subjects.

Many medically important diseases of man are caused by blood-sucking arthropods which serve as vectors for a wide range of viral, bacterial, protozoal and nematode infections (Table 1). Furthermore, serious economic losses are caused by the numerous arthropod parasites which infect domesticated animals (for examples, see Table 2). Among these the ixodid hard ticks are particularly important and it has been estimated that the global cost of hard tick infections is $7000 million per annum (F.A.O., 1984). Not surprisingly, there have been strenuous efforts to control infections caused by arthropods.

The nematode nervous system employs many of the same neurotransmitters as are found in higher animals. The inactivation of neurotransmitters is absolutely essential for the correct functioning of the nervous system, In this article we discuss the various mechanisms used generally in animal nervous systems for synaptic inactivation of neurotransmitters and review the evidence for similar mechanisms operating in parasitic and free-living nematodes. The sequencing of the entire Caenorhabditis elegans genome means that the sequence of nematode genes can be accessed from the C. elegans database (ACeDB) and this wealth of information together with the increasing knowledge of the genetics of this free-living nematode will have great impact on all aspects of nematode neurobiology. The review will provide an insight into how this information may be exploited to identify and characterize target proteins for the development of novel anti-nematode drugs.

An experiment was conducted to determine whether adding oat hulls to weaner pig diets based on extruded rice or unprocessed wheat influenced post-weaning diarrhoea (PWD) and protein fermentation in the large intestine. Ninety-six male piglets (5·16 (sem 0·08) kg) were allocated to (i) extruded rice plus animal proteins (RAP); (ii) RAP with added oat hulls (20 g/kg); (iii) wheat plus animal proteins (WAP); (iv) WAP with added oat hulls (20 g/kg). Blood and faecal samples were collected on days 7 and 14 after weaning at about age 21 d. Pigs fed RAP had more PWD than pigs fed WAP (P < 0·05). Oat hull supplementation to diet RAP decreased the incidence of PWD (P < 0·05). The total-tract digestibility of DM, starch and energy was higher in rice-based diets than in wheat-based diets (P < 0·001); however, oat hulls decreased digestibility of DM and gross energy (P < 0·001). Pigs fed RAP had higher plasma creatinine concentrations (P < 0·01), which were positively correlated to cumulative β-haemolytic Escherichia coli scores after weaning (R2 0·928; P = 0·015). Addition of oat hulls decreased plasma urea concentrations only in pigs fed RAP (interaction; P < 0·05). Pigs fed RAP had lower faecal total biogenic amine concentrations than pigs fed WAP (P < 0·001). Oat hull supplementation tended to decrease total biogenic amine concentrations (P = 0·103). These data indirectly suggest that a mostly insoluble dietary fibre source such as oat hulls can decrease PWD in dietary situations where there may be a misbalance of carbohydrate to protein entering the hindgut.

The consumption of food and beverages containing high amounts of biogenic amines (BA) can have toxicological effects. BA found in foods and beverages are synthesized by the microbial decarboxylation of certain amino acids. This paper reports the concentrations of BAs in a number of commercial cheeses, as determined by HPLC. The cheeses studied were made from raw and pasteurized milk of different origin, and were subjected to different ripening periods. BA concentrations were lower in short ripening period than in long ripening period cheeses, and higher in cheeses made from raw milk than in those made from pasteurized milk. The highest BA concentrations were recorded in blue cheeses made from raw milk. Tyramine was the most commonly recorded and abundant BA. The presence of tyramine-producing bacteria was determined by PCR, and a good correlation obtained between the results of this method and tyramine detection by HPLC. These methods could be used to complement one another in the detection and quantification of tyramine in cheese prevention of tyramine accumulation in cheese.

Biogenic amines (BA) are toxic substances that appear in foods and beverages. Tyramine is the most abundant BA in cheeses. A PCR method was developed to detect the presence of tyramine-producing bacteria during cheese manufacture and ripening. Six different batches of a farmhouse blue cheese were analysed by PCR. Tyramine concentrations were also determined by HPLC. The PCR method was able to anticipate tyramine accumulation in the cheeses; the presence of tyramine-producing microorganisms in the early stages of manufacture correlated well with a high concentration of BA in mature cheese samples.

Changes in nitrogen compounds during ripening of 40 batches of Manchego cheese made from raw milk (24 batches) or pasteurized milk (16 batches) at five different dairies throughout the year were investigated. After ripening for six months, degradation of p-κ- and β-caseins was more intense in raw milk cheese and degradation of αs2-casein in pasteurized milk cheese. Milk pasteurization had no significant effect on breakdown of αs1-casein. Hydrophobic peptide content did not differ between raw and pasteurized milk cheese, whereas hydrophilic peptide content was higher in raw milk cheese. There were no significant differences between seasons for residual caseins, but hydrophobic peptides were at a higher level in cheese made in autumn and winter and hydrophilic peptides in cheese made in winter and spring. Raw milk cheese had a higher content of total free amino acids and of most individual free amino acids than pasteurized milk cheese. The relative percentages of the individual free amino acids were significantly different for raw milk and pasteurized milk cheeses. The relative percentages of Lys and Ile increased, while those of Val, Leu and Phe decreased during ripening. There were also seasonal variations within the relative percentages of free amino acids. In raw milk cheeses, Asp and Cys were relatively more abundant in those made in autumn, Glu and Arg in cheeses made in winter, and Lys and Ile in cheeses made in spring and summer. Biogenic amines were detected only in raw milk cheese, with the highest levels of histamine, tryptamine and tyramine in cheeses made in spring, winter and spring, respectively.

The effect of the hygienic quality of milk on changes in microbial counts and biogenic amine content was evaluated during ripening of goat cheeses manufactured from pasteurized and raw milks at 1, 14, 30, 60 and 90 d. The original milk, rennet, curd and whey were also included in the study. The pH, salt content and extent of proteolysis in the cheese were also evaluated. Spermidine and spermine were the main amines in raw milk, while they were minor amines in cheeses. Other amines increased markedly during ripening, tyramine being the main amine in cheese made from raw milk and cadaverine and putrescine in those produced from pasteurized milk. Enterobacteriaceae counts decreased during ripening whereas those of lactic acid bacteria increased, especially lactobacilli and enterococci. Cheese made from raw milk showed higher microbial counts during ripening than those made from pasteurized milk, especially for Enterobacteriaceae and enterococci, counts being 2 or 3 log units higher. Raw milk cheese showed remarkably higher biogenic amines compared with pasteurized milk cheeses. Therefore, pasteurization of milk causes a decrease in final biogenic amine content of cheese as a result of the reduction of its microbial counts.

Bacterial decarboxylases and aminotransferases may be involved in the production of flavour or off-flavour compounds from aromatic amino acids during cheese ripening. Transamination is one of the first steps in amino acid catabolism for both lactococci and lactobacilli (Gao et al. 1997; Klein et al. 2001). Biologically active amines, produced by decarboxylation, such as tyramine, phenylethylamine, tryptamine, histamine, cadaverine and putrescine, known as biogenic amines, have been found in cheese and can cause migraine and hypertension in susceptible consumers (McSweeney & Sousa, 2000).

Effects of biogenic amines on silage intake and rumen fermentation during dietary changes were studied in sheep. Two direct-cut grass silages were prepared from a single grass sward, one untreated (WAS) and one treated with 4·0 litres formic acid (850 ml/1) per tonne (FAS). Diets of FAS, and FAS supplemented with 7·2 g biogenic amined/kg DM (FAS +A), were offered ad libitum, once daily to four rumen-cannulated, and four intact wethers in a repeated crossover design experiment. During a pre-period before each crossover, the animals were offered either the silage low in biogenic amines (FAS), or that containing moderate concentrations (WAS). During the first 4 d of the FAS+A treatment, the added biogenic amins tended to lower daily DM intake (DMI) and lowered significantly the DMI during the principal meal after feeding. This acute effect on DMI tended to be reduced when the sheep were previously preconditioned to amines by feeding WAS, and the acute DMI depression during the principal meal was significantly reduced. At the end of the 14 d FAS+A feeding period daily DMI was similar to that of the FAS treatment, but the daily pattern of intake remained different, with lower intake of FAS+A during the first 5 h after feeding, this being compensated for by the end of the day. Rumen fermentation tended to be less during the first 4 d that FAS+A was offered, due to the lower DMI and not due to the acute effect of amines. However, in the sheep unadapted to FAS+A, amine content in the rumen was higher than when the sheep were adapted for 14 d to FAS+A or WAS. Adaptation to FAS+A and feeding WAS during the pre-periods, increased the amine-degrading capacity of rumen fluid. In conclusion, in sheep unadapted to dietary amines, feeding amines will acutely lower DMI through reduced palatibility and most probably by stressing intermediary metabolism. Being preconditioned to amines slightly reduces the acute effect on daily DMI. Although the sheep adapted within 14 d to biogenic amines in the diet and increased daily DMI, there was clear evidence that amines have a negative effect on palatability.