Effects of Farm Management Practices and Transport Time on Post-Mortem Changes of Longissimus lumborum Muscle Proteins in Suckling Goat Kids

The combined effect of farm management practices, transport time, and ageing time on the electrophoretic changes of sarcoplasmic (SPP) and myofibrillar (MFP) protein fractions of goat kids was studied. A total of 64 suckling goat kids were withdrawn from two farms with "high" (GW) and "low" (DW) welfare-friendly management practices, and they were transported for 2 or 6 h immediately before slaughtering. Longissimus lumborum samples were obtained at 3, 8, and 21 days post-mortem, and muscle proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis SDS-PAGE. Both protein extracts displayed significant changes attributable to meat maturation. Managing conditions of kids in DW farms increased the post-mortem susceptibility of muscle proteins. Some MFP of Longissimus lumborum muscle, such as troponin T, as well as 26-30 and 35-37 kDa fractions were influenced significantly by deficient on-farm management, and therefore, these protein fragments might be considered as indicators of low-welfare on-farm management in goat kids.

Calprotectin protects against experimental colonic inflammation in mice

BACKGROUND AND PURPOSE

Calprotectin is a heterodimer composed of two myeloid-related proteins, S100A8 and S100A9, that is abundant in neutrophils and monocytes/macrophages. Faecal levels of calprotectin are used routinely to monitor inflammatory bowel disease activity.

EXPERIMENTAL APPROACH

We aimed to assess the role of calprotectin in intestinal inflammation, using the dextran sulfate sodium model of colitis in mice. Calprotectin was administered (50 or 100 μg·day-1 ) by the intrarectal or by i.p. injection (50 μg·day-1 only). The condition of the mice was characterized by morphological and biochemical methods.

KEY RESULTS

Intrarectal calprotectin protected significantly against colitis, as shown by lower levels of macroscopic and microscopic damage, colonic myeloperoxidase activity and decreased expression of TNFα and toll-like receptor 4. IL-17 production by spleen and mesenteric lymph node cells was reduced. Calprotectin had no effect on body weight loss or colonic thickening. There were no effects of calprotectin after i.p. injection. Calprotectin had virtually no effects in control, non-colitic mice. Calprotectin had almost no effect on the colonic microbiota but enhanced barrier function. Treatment of rat IEC18 intestinal epithelial cells in vitro with calprotectin induced output of the chemokines CXL1 and CCL2, involving the receptor for advanced glycation end products- and NFκB.

CONCLUSION AND IMPLICATIONS

Calprotectin exerted protective effects in experimental colitis when given by the intrarectal route, by actions that appear to involve effects on the epithelium.

A synbiotic composed of Lactobacillus fermentum CECT5716 and FOS prevents the development of fatty acid liver and glycemic alterations in rats fed a high fructose diet associated with changes in the microbiota

We investigated the effect of a high fructose diet (HFD) on Sprague Dawley rats and the impact of a synbiotic composed of Lactobacillus fermentum CECT5716 and fructooligosaccharides. Feeding the HFD for 5 weeks resulted in liver steatosis and insulin resistance but not obesity. These changes were associated with increased production of short-chain fatty acids and increased Bacteroidetes in feces, with an augmented Bacteroidetes/Firmicutes ratio, among other changes in the microbiota. In addition, barrier function was weakened, with increased LPS plasma levels. These data are consistent with increased fructose availability in the distal gut due to saturation of absorptive mechanisms, leading to dysbiosis, endotoxemia, hepatic steatosis, and insulin resistance. Treatment with the synbiotic prevented some of the pathological effects, so that treated rats did not develop steatosis or systemic inflammation, while dysbiosis and barrier function were greatly ameliorated. In addition, the synbiotic had hypolipidemic effects. The synbiotic composed by L. fermentum CECT5716 and fructooligosaccharides has beneficial effects in a model of metabolic syndrome induced by a HFD, suggesting it might be clinically useful in this type of condition, particularly considering that high fructose intake has been related to metabolic syndrome in humans.

Germ-free and Antibiotic-treated Mice are Highly Susceptible to Epithelial Injury in DSS Colitis

BACKGROUND AND AIMS

Intestinal microbiota is required to maintain immune homeostasis and intestinal barrier function. At the same time, intraluminal bacteria are considered to be involved in inflammatory bowel disease and are required for colitis induction in animal models, with the possible exception of dextran sulphate sodium [DSS] colitis. This study was carried out to ascertain the mechanism underlying the induction of colitis by DSS in the absence of bacteria.

METHODS

Conventional and germ-free [GF] Naval Medical Research Institute [NMRI] mice were used, plus conventional mice treated with an antibiotic cocktail to deplete the intestinal microbiota ['pseudo-GF' or PGF mice]. The differential response to DSS was assessed.

RESULTS

Conventional mice developed DSS-induced colitis normally, whereas GF mice showed only minimal inflammation [no colonic thickening, lower myeloperoxidase activity, IL-6, IL-17, TNF-α, and IFN-γ secretion by splenocytes and mesenteric cell cultures, etc.]. However, these mice suffered enhanced haemorrhage, epithelial injury and mortality as a consequence of a weakened intestinal barrier, as shown by lower occludin, claudin 4, TFF3, MUC3, and IL-22. In contrast, PGF mice had a relatively normal, albeit attenuated, inflammatory response, but were less prone to haemorrhage and epithelial injury than GF mice. This was correlated with an increased expression of IL-10 and Foxp3 and preservation barrier-related markers.

CONCLUSIONS

We conclude that enteric bacteria are essential for the development of normal DSS-induced colitis. The absence of microbiota reduces DSS colonic inflammation dramatically but it also impairs barrier function, whereas subtotal microbiota depletion has intermediate effects at both levels.

Fructooligosaccharides exert intestinal anti-inflammatory activity in the CD4+ CD62L+ T cell transfer model of colitis in C57BL/6J mice

PURPOSE

Fructooligosaccharides (FOS) are used as functional foods due to their prebiotic effects. Intestinal anti-inflammatory activity has been established in most, but not all, studies in animal models of colitis, using mainly chemically induced inflammation. Our goal was to test the effect of FOS (degree of polymerization 2-8) in the chronic, lymphocyte-driven CD4+ CD62L+ T cell transfer model of colitis.

METHODS

Colitis was induced by transfer of CD4+ CD62L+ T cells to C57BL/6J Rag1(-/-) mice. FOS (75 mg day(-1)) was administered by gavage as a post-treatment. Three groups were established: non-colitic (NC), colitic control (C, CD4+ CD62L+ transferred mice treated with vehicle) and colitic+FOS (C+FOS, similar but treated with FOS). Mice were killed after 13 days.

RESULTS

Treatment of mice with FOS ameliorated colitis, as evidenced by an increase in body weight, a lesser myeloperoxidase and alkaline phosphatase activities, a lower secretion of proinflammatory cytokines by mesenteric lymph node cells ex vivo (IFN-γ, IL-17, and TNF-α), and a higher colonic expression of occludin (C+FOS vs. C, p < 0.05). Increased relative abundance of lactic acid bacteria was observed in FOS-treated mice (p < 0.05).

CONCLUSIONS

FOS exert intestinal anti-inflammatory activity in T lymphocyte-dependent colitis, suggesting it may be useful in the management of inflammatory bowel disease in appropriate conditions.

Rutin has intestinal antiinflammatory effects in the CD4+ CD62L+ T cell transfer model of colitis

Rutin, one of the most abundant flavonoids in nature, has been shown to exert intestinal antiinflammatory effects in experimental models of colitis. Our aim was to study the antiinflamatory effect of rutin in the CD4+ CD62L+ T cell transfer model of colitis, one of the closest to the human disease. Colitis was induced by transfer of CD4+ CD62L+ T cells to Rag1(-/-) mice. Rutin was administered by gavage as a postreatment. Treatment with rutin improved colitis at the dose of 57mg/kg/day, while no effect was noted with 28.5mg/kg/day. Therapeutic benefit was evidenced by a reduced disease activity index, weight loss and damage score, plus a 36% lower colonic myeloperoxidase and a 54% lower alkaline phosphatase activity. In addition, a decreased secretion of proinflammatory cytokines (IFNγ and TNFα) by mesenteric lymph node cells was observed ex vivo. The colonic expression of proinflammatory genes, including IFNγ, TNFα, CXCL1, S100A8 and IL-1β, was significantly reduced by more than 80% with rutin as assessed by RT-qPCR. Flavonoid treated mice exhibited decreased activation of splenic CD4+ cells (STAT4 phosphorylation and IFNγ expression) and reduced plasma cytokine levels. This effect was also apparent in mucosal lymphocytes based on reduced STAT4 phosphorylation. The protective effect was comparable to that of 3mg/kg/day budesonide. Rutin had no effect on splenocytes or murine T cells in vitro, while its aglycone, quercetin, exhibited a concentration dependent inhibition of proinflammatory cytokines, including IFNγ. Rutin but not quercetin showed vectorial basolateral to apical transport in IEC18 cells, associated with reduced biotransformation. We conclude that rutin exerts intestinal antiinflammatory activity in chronic, T lymphocyte dependent colitis via quercetin release and actions involving mucosal and lymph node T cells. Our results suggest that rutin may be useful in the management of inflammatory bowel disease in appropriate dosage conditions.

Active hexose correlated compound exerts therapeutic effects in lymphocyte driven colitis

Active hexose correlated compound (AHCC) is a commercial extract of Basidiomycetes fungi enriched in oligosaccharides that is used as a human nutritional supplement for various purposes in humans. Our aim was to study the anti-inflammatory effect of AHCC in the CD4+ CD62L(+) T cell transfer model of colitis, considered one of the closest to the human disease. Colitis was induced by transfer of CD4(+) CD62L(+) T cells to recombination activating gene 1(-/-) mice. AHCC (75 mg/d) was administered by gavage as a post-treatment. Three groups were established: noncolitic, colitic (CD4(+) CD62L(+) transferred mice treated with vehicle), and AHCC (colitic treated with AHCC). AHCC improved colitis, as evidenced by a 24% lower colonic myeloperoxidase and a 21% lower alkaline phosphatase activity. In addition, a decreased secretion of proinflammatory genes assessed by RT-qPCR was observed, particularly TNF-α and IL-1β. Ex vivo mesenteric lymph node cells obtained from AHCC treated mice exhibited a fully normalized production of IL-6, IL-17, and IL-10 (p < 0.05). Also, AHCC treated mice exhibited decreased STAT4 and IκB-α phosphorylation in splenic CD4(+) cells. Our data provide validation of AHCC colonic anti-inflammatory activity in a chronic, T cell driven model of inflammatory bowel disease.

Prebiotic oligosaccharides directly modulate proinflammatory cytokine production in monocytes via activation of TLR4

SCOPE

Prebiotic oligosaccharides are currently used in a variety of clinical settings for their effects on intestinal microbiota. Here, we have examined the direct, microbiota independent, effects of prebiotics on monocytes and T lymphocytes in vitro.

METHODS AND RESULTS

Prebiotics generally evoked cytokine secretion (TNF-α, IL-6, and IL-10) by mouse splenocytes but inhibited LPS -induced IFN-γ and IL-17 release. Inulin was found to enhance LPS-induced IL-10 secretion. Splenocytes from TLR4(-/-) (where TLR is Toll-like receptor) mice showed a markedly depressed response. Conversely, in both basal and LPS-stimulated conditions, prebiotic inhibition of IFN-γ levels was preserved. These results suggested a predominant effect on monocytes via TLR4 ligation and possible inhibition of T cells. Hence, we studied the modulation of primary rat monocytes and T lymphocytes, focusing on fructooligosaccharides (FOS) and inulin. In monocytes, FOS and inulin induced TNF-α, growth-regulated oncogene α, and IL-10, but not IL-1β release. The NF-κB inhibitor Bay 11-7082 fully prevented these effects. Pharmacological evidence also indicated a significant involvement of mitogen-activated protein kinase and phosphatidylinositol-3-kinase. There was little effect on T cells. FOS and inulin also generally increased TNF-α, IL-1β, and IL-10, but not IL-8, in human peripheral blood monocytes.

CONCLUSION

We conclude that prebiotics may act as TLR4 ligands or as indirect TLR4 modulators to upregulate cytokine secretion in monocytes.

Effect of sublethal concentrations of waterborne copper on lipid peroxidation and enzymatic antioxidant response in Gambusia holbrooki

The aim of the current research was to assess the possible influence of copper sulphate contamination on the antioxidant enzymatic defenses and lipid peroxidation (LPO) in the mosquitofish (Gambusia holbrooki). Quadruplicated lots of this fish were exposed to three increasing sub-lethal concentrations of Cu (0.10; 0.17 and 0.25mgCu/L) and a control without Cu for 20 days. Previous to laboratory acclimation, 8 fish were taken to define the initial population. At the end of the trials, 12 fish/sex/treatment were sampled for the determination of levels of copper in gills, metallothioneins (MTs) content, total lipids, fatty acids profiles and antioxidant enzymatic activity, as well as lipid peroxidation. Most of the antioxidant enzymatic defenses assayed were not activated and lipid peroxidation decreased significantly in fish exposed to any concentration of copper applied. This leads us to presume the existence of a protective mechanism against peroxidation other than the enzymatic antioxidant defense, which could be related to the observed increase of copper content in the gills.

Exogenous alkaline phosphatase treatment complements endogenous enzyme protection in colonic inflammation and reduces bacterial translocation in rats

Alkaline phosphatase (AP) inactivates bacterial lipopolysaccharide and may therefore be protective. The small intestine and colon express intestinal (IAP) and tissue nonspecific enzyme (TNAP), respectively. The aim of this study was to assess the therapeutic potential of exogenous AP and its complementarity with endogenous enzyme protection in the intestine, as evidenced recently. IAP was given to rats by the oral or intrarectal route (700U/kgday). Oral budesonide (1mg/kgday) was used as a reference treatment. Treatment with intrarectal AP resulted in a 54.5% and 38.0% lower colonic weight and damage score, respectively, and an almost complete normalization of the expression of S100A8, LCN2 and IL-1β (p<0.05). Oral AP was less efficacious, while budesonide had a more pronounced effect on most parameters. Both oral and intrarectal AP counteracted bacterial translocation effectively (78 and 100%, respectively, p<0.05 for the latter), while budesonide failed to exert a positive effect. AP activity was increased in the feces of TNBS colitic animals, associated with augmented sensitivity to the inhibitor levamisole, suggesting enhanced luminal release of this enzyme. This was also observed in the mouse lymphocyte transfer model of chronic colitis. In a separate time course study, TNAP was shown to increase 2-3 days after colitis induction, while dextran sulfate sodium was a much weaker inducer of this isoform. We conclude that exogenous AP exerts beneficial effects on experimental colitis, which includes protection against bacterial translocation. AP of the tissue-nonspecific isoform is shed in higher amounts to the intestinal lumen in experimental colitis, possibly aiding in intestinal protection.

Effects of flavonoids and other polyphenols on inflammation

Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

Tissue-nonspecific alkaline phosphatase is activated in enterocytes by oxidative stress via changes in glycosylation

BACKGROUND

Intestinal inflammation produces an induction of alkaline phosphatase (AP) activity that is attributable in part to augmented expression, accompanied by a change in isoform, in epithelial cells.

METHODS

This study focuses on induction of AP in intestinal epithelial cells in vitro.

RESULTS

Treatment with the oxidants H2O2, monochloramine, or tButOOH increases AP activity in vitro in Caco-2, HT29, and IEC18 cells. We selected IEC18 cells for further testing. Basal AP activity in IEC18 cells is of the tissue-nonspecific (bone-liver-kidney) type, as indicated by Northern and Western blot analysis. Oxidative stress augments AP activity and the sensitivity of the enzyme to levamisole, homoarginine, and heat in IEC18 cells. Increased immunoreactivity to tissue-nonspecific AP antibodies suggests an isoform shift from liver to either kidney or bone type. This effect occurs without changes at the mRNA level and is sensitive to tunicamycin, an inhibitor of N-glycosylation, and neuraminidase digestion. Saponin and deoxycholate produce similar effects to oxidants. Butyrate but not proinflammatory cytokines or LPS can induce a similar effect but without toxicity. The AP increase is not prevented by modulators of the MAPK, NF-κB, calcium, and cyclic adenosine monophosphate (cAMP) pathways, and is actually enhanced by actinomycin D via higher cell stress.

CONCLUSIONS

Oxidative stress causes a distinct increase in enterocyte AP activity together with cell toxicity via changes in the glycosylation of the enzyme that correspond to a shift in isotype within the tissue-nonspecific paradigm. We speculate that this may have physiological implication for gut defense.

Flavonoids exert distinct modulatory actions on cyclooxygenase 2 and NF-kappaB in an intestinal epithelial cell line (IEC18)

BACKGROUND AND PURPOSE

Cyclooxygenase 2 (COX-2) is involved in inflammatory bowel disease, but the effect of flavonoids at the intestinal epithelial level is unknown. We aimed to characterize the effect and structure-activity relationship of nine selected flavonoids on COX-2 expression in intestinal epithelial cell (IEC)18 cells. We also investigated the signal transduction pathway(s) responsible for the effects observed.

EXPERIMENTAL APPROACH

Intestinal epithelial cell 18, a non-tumour cell line with intestinal epithelial phenotype, was used. COX-2 was measured by Western blot and the involvement of the NF-kappaB pathway assessed by Western blot, pharmacological inhibition, luciferase reporter assays and nuclear translocation experiments.

KEY RESULTS

The effect of flavonoids on COX-2 expression depended on the experimental conditions tested [non-stimulated and lipopolysaccharide (LPS)-stimulated]. Flavonoids caused an increase in COX-2 expression and NF-kappaB-dependent gene transcription under basal conditions. Conversely, under LPS stimulation flavonoids increased, decreased or did not affect COX-2 levels depending on the specific type. Variable effects were observed on extracellular signal regulated kinase/p38/c-Jun N-terminal kinase phosphorylation and p50/65 nuclear translocation.

CONCLUSION AND IMPLICATIONS

The effect of flavonoids on COX-2 expression depended on the balance of the interference with IkappaB-alpha phosphorylation and other signalling targets, and therefore depends on the experimental conditions and on the type of flavonoids. This is expected to result in different effects in inflammatory conditions. In general, flavonoids may limit epithelial COX-2 expression in inflammatory conditions while favouring it when inflammation is not present.

Bovine glycomacropeptide has intestinal antiinflammatory effects in rats with dextran sulfate-induced colitis

Milk κ-casein-derived bovine glycomacropeptide (GMP) has immunomodulatory and bacterial toxin-binding effects, and it has been shown to exert intestinal antiinflammatory activity in the trinitrobenzenesulfonic acid-induced model of colitis. However, its mechanism of action is not well characterized, and it is not known whether GMP is effective in other experimental models. The intestinal antiinflammatory activity of GMP was assessed in the dextran sulfate sodium (DSS)-induced model of rat colitis. DSS was applied at a starting concentration of 5% (wt:v) in drinking water and adjusted when the disease activity index (DAI) increased substantially for 10 d. There were 3 experimental groups: control (no inflammation), DSS, and GMP (GMP-treated rats with DSS-induced colitis). GMP pretreatment (500 mg · kg(-1) · d(-1), starting 2 d before DSS treatment) reduced the DAI by 60% and lowered the colonic damage score by 44% (P < 0.05). GMP fully normalized the colonic expression of interleukin (IL) 1β, IL17, IL23, IL6, transforming growth factor β, IL10, and Foxp3 as assessed by quantitative RT-PCR. The production of interferon-γ by mesenteric lymph node cells ex vivo was also normalized by GMP treatment. In contrast, GMP did not change colonic thickening, myeloperoxidase, cyclooxygenase 2, or alkaline phosphatase. Histology analysis showed better preservation of the epithelium and attenuated infiltration and submucosal thickening in rats treated with GMP. We conclude that GMP exerts intestinal antiinflammatory activity in this model, which may be primarily related to actions on Th1 and Th17 lymphocytes and perhaps macrophages.

The intestinal antiinflammatory agent glycomacropeptide has immunomodulatory actions on rat splenocytes

Bovine glycomacropeptide (GMP) is an immunologically active milk peptide that is a part of the normal human diet. GMP has therapeutic value in preclinical models of intestinal inflammation, and its mechanism may be related to effects on lymphocytes. This study focuses on the actions of GMP on rat splenocytes in vitro and in vivo. Bovine serum albumin and lactoferrin were used for comparative purposes. GMP (0.01-0.1mgmL(-1)) enhanced Concanavalin A (ConA) evoked but not basal splenocyte proliferation. At 1mgmL(-1) GMP lost this effect but augmented basal TNF-alpha secretion and also iNOS and COX2 expression. IFN-gamma, IL-2 and IL-17 were not affected by GMP in quiescent splenocytes, but IL-10 was augmented at all concentrations tested. On the other hand, GMP produced a marked inhibitory effect (70%) on IFN-gamma secretion and to a lower extent (50%) also on TNF-alpha. GMP was shown to block STAT4 but not IkappaB-alpha phosphorylation. The Treg marker Foxp3 was markedly upregulated by GMP. Bovine serum albumin had some effects on splenocyte function which were of lower magnitude and not entirely coincidental, while lactoferrin had a strong antiproliferative effect, as expected, indicating a specific effect of GMP. When administered for 3 days to normal Wistar rats, GMP reproduced the Foxp3 induction effect observed previously in vitro. This was observed in splenocytes but not in thymocytes, and only when administered by the oral rather than the intraperitoneal route. Thus our results support the hypothesis that GMP may limit intestinal inflammation acting at least in part on lymphocytes.

Bovine glycomacropeptide induces cytokine production in human monocytes through the stimulation of the MAPK and the NF-kappaB signal transduction pathways

BACKGROUND AND PURPOSE

Bovine glycomacropeptide (BGMP) is a natural milk peptide that is produced naturally in the gastrointestinal tract during digestion. Glycomacropepide has intestinal anti-inflammatory activity, but the mechanism of action is unknown. Here we have characterized the effects of BGMP on monocytes.

EXPERIMENTAL APPROACH

We have used human THP-1 cells as an in vitro monocyte model. The effect of BGMP on the secretion of tumour necrosis factor (TNF), interleukin (IL)-1beta and IL-8 was assessed, as well as the involvement of the NF-kappaB and MAP kinase signalling pathways. The stimulatory effect of BGMP was also tested in human peripheral blood monocytes.

KEY RESULTS

BGMP up-regulated the secretion of TNF, IL-1beta and IL-8 in a concentration-dependent fashion. The biological activity was exerted by the intact peptide, because cytokine secretion was not affected by protease inhibitors. The secretion of IL-8 and specially TNF and IL-1beta was blocked by PD98059, SP600125, SB203580 and Bay11-7082, suggesting the involvement of the MAP kinases p38, c-Jun N-terminal kinase and ERK and particularly the NF-kappaB pathway, although IL-8 secretion was independent of p38. BGMP was shown to elicit the phosphorylation of IkappaB-alpha and the nuclear translocation of the NF-kappaB subunits p50 and p65. The effect of BGMP on cytokine secretion was validated in human primary blood monocytes.

CONCLUSIONS AND IMPLICATIONS

BGMP stimulates human monocytes, operating via MAP kinase and NF-kappaB pathways. BGMP may exert an indirect intestinal anti-inflammatory effect by potentiating host defences against invading microorganisms.

Molecular bases of impaired water and ion movements in inflammatory bowel diseases

The intestine is dedicated to the absorption of water and nutrients. Fine tuning of this process is necessary to maintain an adequate balance and inflammation disrupts the equilibrium. This review summarizes the current evidence in this field. Classical mechanisms proposed include alteration of epithelial integrity, augmented secretion, and reduced absorption. In addition, intestinal inflammation is associated with defects in epithelial barrier function. However, our understanding of the phenomenon has been complicated by the fact that ionic secretion is in fact diminished in vivo, even after inflammation has subsided. Inhibited ionic secretion can be reversed partially or totally in vitro by maneuvers such as blockade of inducible nitric oxide synthase or removal of the submucosal layer. Disturbances in ionic absorption are less well characterized but clearly involve both electroneutral and electrogenic Na(+) absorption. Altered ionic transport is associated with changes in the expression and function of the transporters, including the Na(+)/K(+) ATPase, the sodium/potassium/chloride cotransporter 1 (NKCC1), the sodium/hydrogen exchanger 3 (NHE3), and the epithelial sodium channel (ENaC), as well as to the modulation of intracellular signaling. Further investigation is needed in this area in order to provide an integrated paradigm of ionic transport in the inflamed intestine. In particular, we do not know exactly how diarrhea ensues in inflammation and, consequently, we do not have specific pharmacological tools to combat this condition effectively and without side effects. Moreover, whether transport disturbances are reversible independently of inflammatory control is unknown.

Disturbances in metabolic, transport and structural genes in experimental colonic inflammation in the rat: a longitudinal genomic analysis

Background

Trinitrobenzenesulphonic acid (TNBS) induced rat colitis is one of the most widely used models of inflammatory bowel disease (IBD), a condition whose aetiology and pathophysiology are incompletely understood. We have characterized this model at the genomic level using a longitudinal approach. Six control rats were compared with colitic animals at 2, 5, 7 and 14 days after TNBS administration (n = 3). The Affymetrix Rat Expression Array 230 2.0 system was used.

Results

TNBS-induced colitis had a profound impact on the gene expression profile, which was maximal 5 and 7 days post-induction. Most genes were affected at more than one time point. They were related to a number of biological functions, not only inflammation/immunity but also transport, metabolism, signal transduction, tissue remodeling and angiogenesis. Gene changes generally correlated with the severity of colitis. The results were successfully validated in a subset of genes by real-time PCR.

Conclusion

The TNBS model of rat colitis has been described in detail at the transcriptome level. The changes observed correlate with pathophysiological disturbances such as tissue remodelling and alterations in ion transport, which are characteristic of both this model and IBD.

Bovine glycomacropeptide ameliorates experimental rat ileitis by mechanisms involving downregulation of interleukin 17

BACKGROUND AND PURPOSE

Bovine glycomacropeptide (BGMP) is an inexpensive, non-toxic milk peptide with anti-inflammatory effects in rat experimental colitis but its mechanism of action is unclear. It is also unknown whether BGMP can ameliorate inflammation in proximal regions of the intestine. Our aim was therefore two-fold: first, to determine the anti-inflammatory activity of BGMP in the ileum; second, to characterise its mechanism of action.

EXPERIMENTAL APPROACH

We used a model of ileitis induced by trinitrobenzenesulphonic acid in rats. Rats were treated orally with BGMP and its efficacy compared with that of oral 5-aminosalicylic acid or vehicle, starting 2 days before ileitis induction.

KEY RESULTS

BGMP pretreatment (500 mg kg(-1) day(-1)) resulted in marked reduction of inflammatory injury, as assessed by lower extension of necrosis and damage score, myeloperoxidase, alkaline phosphatase, inducible nitric oxide synthase, interleukin 1beta, tumour necrosis factor and interleukin 17. These effects were generally comparable to those of 5-aminosalicylic acid (200 mg kg(-1) day(-1)). Neither compound affected the production of interferon gamma, tumour necrosis factor and interleukin 2 by mesenteric lymph node cells isolated from animals with ileitis. The expression of Foxp3 was increased in ileitis and not reduced significantly by BGMP or aminosalicylate treatment.

CONCLUSIONS AND IMPLICATIONS

These results demonstrate that BGMP has anti-inflammatory activity in the ileum with similar efficacy to 5-aminosalicylic acid. The mechanism of action may involve Th17 and regulatory T cells and perhaps macrophages but probably not Th1 lymphocytes. Patients with Crohn's ileitis may benefit from treatment with BGMP.

Contribution of polyunsaturated fatty acids to intestinal repair in protein-energy malnutrition

The aim of this study was to assess the effect of polyunsaturated fatty acids supplied in the diet on intestinal mucosa repair in a rat model of protein-energy malnutrition. Rats were fed either a standard semipurified diet or the same diet containing lactose as the only source of carbohydrate to cause protein-energy malnutrition. Diarrhea was induced within 24 h and was maintained for 2 weeks, after which both groups of rats were fed for 1 week either the standard diet or the standard diet supplemented with different sources of fatty acids, such as olive oil (OO), fish oil (FO), and purified phospholipids from pig brain (BPL). The lactose-enriched diet caused loss of enterocyte microvilli, lymphocyte infiltration, supranuclear cytoplasmic vesiculation, decreased number of goblet cells, low-density enlarged mitochondria, and less cristae. The FO diet improved the pathology score according to the histological and ultrastructural analysis, with an increased number of goblet cells, ratio of microvilli length to crypt depth, and percentage of intraepithelial lymphocytes compared to those found in rats with protein-energy malnutrition. We previously reported that chronic diarrhea depletes the antioxidant defense in rat intestine; we now show that both, the FO and the BPL diets, increase GSH levels in colon and that some antioxidant enzyme activities vary according to the source of fatty acids, with higher catalase and superoxide dismutase by the FO diet in jejunum, increased catalase by the BPL diet in jejunum, and elevated glutathione peroxidase by the OO diet in colon. The fatty acid profile of intestinal mucosa reflects the source of fat in the diet, with the lowest ratio of n-6/n-3 for rats fed the FO diet. These results suggest that dietary polyunsaturated fatty acids, particularly those in the n-3 series, may play an important role in intestinal repair in chronic diarrhea due to protein-energy malnutrition.

Active hexose correlated compound acts as a prebiotic and is antiinflammatory in rats with hapten-induced colitis

Active hexose correlated compound (AHCC) is a product prepared from the mycelium of edible Basidiomycete fungi that contains oligosaccharides. Here we have studied the antiinflammatory effect of AHCC in the trinitrobenzenesulfonic acid (TNBS) model of colitis in rats. Rats received AHCC (100 or 500 mg/kg) daily starting 2 d before (pretreatment) colitis induction and were killed 6 d after the TNBS challenge. The status of the rats was assessed by morphological and biochemical methods. The effect of AHCC on the colonic microflora was also assessed by studying the bacteria profile in feces by standard culture techniques. AHCC administration attenuated colonic inflammation, improving rat weight, food intake, damage score, extension of necrosis, colonic weight, colonic weight-to-length ratio, myeloperoxidase and alkaline phosphatase activities, glutathione concentration, and the expression of proinflammatory cytokines and chemokines (IL-1beta, IL-1 receptor antagonist, TNF, and monocyte chemoattractant protein-1) and of mucins 2-4 and trefoil factor 3. The magnitude of the antiinflammatory effect of AHCC was similar to that of sulfasalazine (200 mg/kg). The study of colonic microflora indicated that rats treated with AHCC had higher aerobic and lactic acid bacteria counts as well as higher bifidobacteria counts, whereas clostridia were reduced when compared with the TNBS group. Therefore, our results indicate that AHCC is antiinflammatory and could be useful as a prebiotic to design functional foods for inflammatory bowel disease patients.

The bisphosphonate alendronate improves the damage associated with trinitrobenzenesulfonic acid-induced colitis in rats

BACKGROUND AND PURPOSE

The nitrogen-containing bisphosphonates are drugs used successfully in the treatment of osteoporosis. They act inhibiting farnesyl diphosphate synthase. This mechanism may also produce anti-inflammatory effects. The therapeutic activity of alendronate was tested in vivo using a model of inflammatory bowel disease.

EXPERIMENTAL APPROACH

The trinitrobenzenesulfonic acid model of colitis in the rat was used. Rats were treated orally with alendronate and its efficacy compared with that of oral sulphasalazine or vehicle, starting 2 h after colitis induction. The status of the animals was assessed 5 days later.

KEY RESULTS

Alendronate treatment (25 or 75 mg kg(-1) day(-1)) resulted in a decrease in the colonic damage score and loss of body weight (at 25 mg kg(-1) day(-1) only). This was associated to a dramatic reduction in the mRNA levels of interleukin 1 beta (IL-1 beta), monocyte chemoattractant protein 1 (MCP-1) and interleukin 1 receptor antagonist (IL-1 ra). The magnitude of the beneficial effect was comparable to that of sulphasalazine (at a 6-20 fold higher dose). Thus sulphasalazine post-treatment reduced the mRNA levels of IL-1 beta/IL-1 ra and MCP-1 to the same extent as alendronate and additionally lowered colonic alkaline phosphatase activity, but failed to affect body weight loss or colonic damage score. Alendronate failed to exert beneficial effects when administered intraperitoneally.

CONCLUSIONS AND IMPLICATIONS

Oral but not intraperitoneal alendronate significantly protected the colon in experimental rat colitis. Inflammatory bowel disease patients might benefit from exposure to oral alendronate.

Goat milk oligosaccharides are anti-inflammatory in rats with hapten-induced colitis

Oligosaccharides are included among the anti-inflammatory components of milk because of their prebiotic properties and their capacity to act as receptors of microorganisms. Here the intestinal anti-inflammatory effect of goat milk oligosaccharides (O) was assessed in trinitrobenzenesulfonic (T) acid-induced colitis in rats. Rats were randomly assigned to three different groups. Two groups (T and OS) of colitic rats and a control group (C) were studied. Group OS received 500 mg/(kg.d) of goat milk oligosaccharides orally, starting 2 d before the colitis induction until d 6, and groups T and C received the vehicle. When compared with the T group, the OS group showed decreased anorexia and body weight loss; reduced bowel wall thickening and longitudinal extension of necrotic lesions; downregulated colonic expression of interleukin 1beta, inducible nitric oxide synthase, cyclooxygenase 2, and mucin 3; and increased trefoil factor 3. Thus, goat milk oligosaccharides have anti-inflammatory effects in rats with experimental colitis and may be useful in the management of inflammatory bowel disease.

AU-rich elements in the mRNA 3′-untranslated region of the rat receptor for advanced glycation end products and their relevance to mRNA stability

Several putative polyadenylation sequences and an adenylate plus timidylate rich element (ARE) are present at the 3' end of the rat advanced glycation end products receptor (RAGE) gene. Two transcripts are generated by the use of alternative polyadenylation sequences, one containing the ARE sequence in its 3'-untranslated region (3'-UTR). Transfections of CHO-k1 or NRK cells with constructs expressing the 3'-UTRs of the transcripts fused to a green fluorescence protein mRNA show that the ARE sequence has a negative effect on protein expression correlating with a decrease in the amount of mRNA, as shown in CHO-k1 transfected cells. When transfected cells were incubated in the presence of Actinomycin D the amount of fluorescence decreased in cells transfected with the ARE sequence, indicating that this sequence induces lower mRNA stability. Thus, alternative polyadenylation signals and an ARE sequence provide a novel mechanism for the regulation of the rat RAGE gene expression.

Modulation of glucose transporters in rat diaphragm by sodium tungstate

Oral administration of sodium tungstate is an effective treatment for diabetes in animal models. We examined the effects of 6 weeks of oral administration of tungstate on glucose transporters (GLUT) in streptozotocin-induced diabetic rat diaphragm. Diabetes decreased GLUT4 expression while tungstate treatment normalized not only GLUT4 protein but also GLUT4 mRNA in the diabetic rats. Furthermore, treatment increased GLUT4 protein in plasma and internal membranes, suggesting a stimulation of its translocation to the plasma membrane. Tungstate had no effect on healthy animals. There were no differences in the total amount of GLUT1 transporter in any group. We conclude that the normoglycemic effect of tungstate may be partly due to a normalization of the levels and subcellular localization of GLUT4, which should result in an increase in muscle glucose uptake.

Chronic diarrhea impairs intestinal antioxidant defense system in rats at weaning

The aim of the present study was to evaluate the influence of severe protein-energy malnutrition on the antioxidant defense system in the small and large intestine in rats at weaning. Chronic diarrhea and the subsequent malnutrition were induced by oral intake of a lactose-enriched diet. Twenty rats were weaned at 21 days of age, and the control group was fed a semipurified synthetic diet for two weeks. The malnourished group was fed the same diet but carbohydrates were replaced by lactose, and they developed diarrhea one day after. Rats were killed, and macroscopic and histological features were analyzed, DNA content was measured, and alkaline phosphatase, myeloperoxidase, and gamma-glutamyltranspeptidase activities were determined to assess the degree of intestinal injury. Glutathione levels as well as the activities of intestinal glutathione transferase, glutathione reductase, total glutathione peroxidase, selenium-dependent glutathione peroxidase, superoxide dismutase, and catalase were measured to study the antioxidant defense system. Malnourished rats showed loss of body weight and an increase in length and weight in jejunum and ileum, while no significant changes were observed in colon. Epithelial cells showed fewer and shorter microvilli, larger mitochondria with low inner density and loss of cristae, dilated endoplasmic reticulum, and Golgi apparatus. The protein-to-DNA ratio was higher in the jejunum, ileum, and colon of malnourished rats. Glutathione levels decreased 40% in jejunum and 50% in colon of malnourished rats. A 40-50% decrease in the activity of all the enzymes of the antioxidant defense system was observed in the jejunum and ileum of malnourished rats, while only catalase and glutathione transferase activities decreased 50% in colon. These results suggest that early chronic diarrhea and severe protein-energy malnutrition impair the antioxidant defense system in both the small and large intestine, which may have a role in the pathogenesis and maintenance of the vicious circle of malabsorption-diarrhea-malnutrition in infancy.

Experimental ulcerative colitis impairs antioxidant defense system in rat intestine

Increasing attention has been given recently to the role of free radicals in the pathogenesis of ulcerative colitis, since the inflamed intestine is exposed to oxidative stress generated by infiltrating macrophages and neutrophils within the lamina propia. The overall goal of this study was to evaluate whether experimental ulcerative colitis induces significant changes in the antioxidant defense system in an experimental model induced by the intrarectal administration of 2,4,6-trinitrobenzenesulfonic acid. Twenty rats were treated with 80 mg/kg body weight of trinitrobenzenesulfonic acid and 20 with the same volume of 0.9% NaCl. Rats were killed at one and two weeks after treatment to evaluate colon damage by light and electron transmission microscopy. The degree of tissue injury and inflammation was determined by measuring alkaline phosphatase, gamma-glutamyltranspeptidase, and myeloperoxidase activities and prostaglandin E2 and leukotriene B4. Glutathione levels and the activity of the enzymes of the antioxidant defense system were determined. Enzymatic markers of colon injury showed higher activities in rats with ulcerative colitis. Concentrations of prostaglandin E2 and leukotriene B4 were higher in the groups treated for one week with trinitrobenzenesulfonic acid and markers decreased after two weeks of treatment. All antioxidant enzyme activities were higher at one and two weeks after treatment; however, a significant decrease in total glutathione content was also observed. In conclusion, ulcerative colitis induced by trinitrobenzenesulfonic acid damages the intestinal mucosa and is accompanied by a shift in the antioxidant enzyme activities, and low levels of glutathione. This deficiency in glutathione could be a target for new therapies to treat ulcerative colitis.

Dietary trans fatty acids affect docosahexaenoic acid concentrations in plasma and liver but not brain of pregnant and fetal rats

The aim of the present study was to investigate the maternal-fetal transport, incorporation, and effects on liver delta-6 fatty-acid desaturase activity of dietary trans fatty acids in pregnant rats. Three groups of six rats each were fed three experimental diets containing approximately 0%, 15%, and 30% of trans fatty acids but containing the same proportion of linoleic (18:2 n-6) and a-linolenic (18:3 n-3) acids for 10 wk. On d 20 of pregnancy, the animals from each group were killed. We determined the fatty acid profiles in plasma, brain, and liver microsomes of pregnant rats, as well as in placenta and fetal liver and brain. No changes were found in the number of fetuses of the pregnant rats. Trans fatty acids were incorporated in high concentrations in placenta and in maternal and fetal tissues, except brain, strongly elevating the linoleic acid proportion and lowering that of docosahexaenoic acid. The delta-6 fatty-acid desaturase activity in the liver microsomes of the pregnant rats was inhibited by trans isomers. In conclusion, high intakes of trans fatty acids partially inhibit liver delta-6 fatty-acid desaturase in pregnant rats, which may explain, in part, the low concentrations of docosahexaenoic acid in pregnant and fetal tissues. However, the fatty acid composition of both fetal and pregnant rat brain remains mostly unaffected regardless of the dietary trans fatty acid content.

Increased diaphragm expression of GLUT4 in control and streptozotocin-diabetic rats by fish oil-supplemented diets

Dietary fat intake influences plasma glucose concentration through modifying glucose uptake and utilization by adipose and skeletal muscle tissues. In this paper, we studied the effects of a low-fat diet on diaphragm GLUT4 expression and fatty acid composition in control and streptozotocin-induced diabetic rats. Control as well as diabetic rats were divided into three different dietary groups each. Either 5% olive oil, 5% sunflower oil, or 5% fish oil was the only fat supplied by the diet. Feeding these low-fat diets for 5 wk induced major changes in fatty acid composition, both in control and in diabetic rats. Arachidonic acid was higher in diabetic olive and sunflower oil-fed rats with respect to fish oil-fed, opposite to docosahexaenoic acid which was higher in diabetic fish oil-fed rats with respect to the other two groups. Animals receiving a fish oil diet had the lowest plasma glucose concentration. GLUT4 expression in diaphragm, as indicated by GLUT4 protein and mRNA, is modulated both by diabetes and by diet fatty acid composition. Diabetes induced a decrease in expression in all dietary groups. Plasma glucose levels correlated well with the increased amount of GLUT4 protein and mRNA found in fish oil-fed groups. Results are discussed in terms of the influence that arachidonic and n-3 polyunsaturated fatty acids may exert on the transcriptional and translational control of the GLUT4 gene.

Modulation of hepatic and intestinal glutathione S-transferases and other antioxidant enzymes by dietary lipids in streptozotocin diabetic rats

Antioxidant enzymes in liver and small intestine were investigated using control and streptozotocin diabetic rats fed diets with 5% olive, sunflower or fish oil for five weeks. In liver, Glutathione Peroxidase and Superoxide Dismutase decreased and in intestine Glutathione-S-transferase (GST) increased by diabetes. In isolated jejunum and ileum, this increase in GST activity was due to an increase in GST-alpha and -mu isoenzymes in jejunum and GST-alpha, mu and -pi in ileum. Since GST plays an important role in protecting tissues from oxidative damage, our results highlight the role of the intestine against free radicals in physiological or pathological situations.

Sequencing of two alternatively spliced mRNAs corresponding to the extracellular domain of the rat receptor for advanced glycosylation end products (RAGE)

The receptor for advanced glycosylation end products (RAGE) is an integral membrane protein responsible for the recognition and internalization of those extensively modified proteins. The receptor has an extracellular domain that binds to the advanced glycosylation end products. By reverse-transcription and polymerase chain reaction amplification, we have identified in rat liver and kidney two amplified products that correspond to cDNA coding for a part of the extracellular domain of the receptor. Sequencing of these products showed that these amplified molecules were similar except for a 27-bp fragment that was absent in the smaller product. This spliced region is located close to the transmembrane region of the receptor. We have confirmed the possibility of the alternative splicing in the generation of these mRNA isoforms by cloning a fragment of the rat gene for RAGE. This fragment has a distribution of introns and exons fully compatible with the proposed alternative splicing.

Effect of dietary (n-9), (n-6) and (n-3) fatty acids on membrane lipid composition and morphology of rat erythrocytes

Studies focused on the intake of different dietary fats have shown changes in membrane lipid composition and, as a result, alterations in membrane physical properties. These changes affect erythrocyte morphology, receptor activity and oxygen transport, among others. Here, we compare the effects of diets exclusively differing in the type of fat (olive oil rich in monounsaturates, sunflower oil rich in n-6 polyunsaturates and fish oil rich in n-3 polyunsaturates) on fatty acid composition of plasma and erythrocyte membranes and erythrocyte morphology under scanning electron microscopy in rats. Monounsaturates are highest in animals fed olive oil diets; as are linoleic and arachidonic acids in sunflower oil-fed animals and n-3 PUFAs in fish oil-fed animals. The lowest levels of arachidonic acid are found in fish oil-fed animals and so are n-3 PUFAs in sunflower oil-fed animals. Our results show that sunflower oil-fed animals present lower discocyte, the major cell shape related to tissue oxygen supply, and higher codocyte percentages than olive oil- and fish oil-fed groups. Echinocyte percentage is higher in fish oil-fed animals with respect to the other two groups. The collective data indicate that olive oil elevates monounsaturates and the number of discocytes, pointing out a possible beneficial aspect of this dietary fat.

Short-term effects of dietary fats on the lipid composition and desaturase activities of rat liver microsomes

Diets supplemented with 10% coconut, olive or sunflower oil were given to rats at weaning. After two, four and six days, the lipid composition and desaturase activities of liver microsomes were measured. The percentage of oleic acid and delta 9-desaturase activity were increased in animals fed an olive oil diet while animals given sunflower oil showed the highest content of linoleic and polyunsaturated n-6 fatty acids. On day 6, olive oil-fed rats had the highest levels of 22:6 n-3 in the phosphatidylethanolamine fraction. Saturated fatty acids were similar among dietary groups, despite the marked differences in the saturated fatty acid content of the three oils. Polyunsaturated n-6 and n-3 fatty acids decreased during the six days of feeding with coconut oil. Our results show that liver microsome membranes respond to different dietary fatty acids sources by changes in enzyme activities and relative content of some fatty acids after a period of dietary manipulation as brief as 6 days.

Dietary restriction induces biochemical and morphometric changes in the small intestine of nursing piglets

The purpose of this study was to evaluate the biochemical and morphometric changes in the small intestine of nursing piglets caused by 60% dietary restriction, and to ascertain whether this model reproduces the intestinal alterations caused by malnutrition in human infants. Piglets subjected to dietary restriction had significantly lower levels of mucosal DNA and protein, and significantly reduced segmental disaccharidase and leucine aminopeptidase activities compared with age-matched, freely fed controls. However, greater disaccharidase-specific activities were observed in duodenum and jejunum of diet restricted piglets compared with controls. Other findings included significantly lower thickness of the mucose, villous height and width, and villous surface area, a significantly lower number of goblet cells, and significantly greater mucosal crypt depth, intraepithelial leucocyte number, and infiltrated cells per area of lamina propria. The model reproduces most of the biochemical and morphometric changes observed in the small intestine of young human infants with chronic diarrhea and malnutrition, and may be useful in further investigations of the biochemical and molecular mechanisms of intestinal alterations caused by primary malnutrition in early infancy.

Effects of native and hydrolyzed whey protein on intestinal repair of severely starved rats at weaning

The aim of this study was to evaluate the effect of two sources of dietary nitrogen (isolated whey protein and hydrolyzed whey protein) on the intestinal repair of malnourished rats at weaning. The malnutrition was achieved by a 3 days' starvation period. Normally fed male Wistar rats were used as controls. Intestinal repair was studied after a refeeding period of 4 days. The parameters studied included nitrogen balance, lactase, sucrase, isomaltase, and maltase activities of the jejunum; liver acetylcholinesterase and glutamate dehydrogenase activities; and the serum amino acid profile. In addition, tests of intestinal permeability to macromolecules were performed by measurement of ovalbumin and beta-lactoglobulin in serum. Both diets of led to the recovery of the severely starved rats, in terms of the values of all the parameters evaluated. The serum beta-lactoglobulin was the only exception, because its concentration was significantly lower in the normally fed animals. This study suggests that the intestinal mucosal barrier is not completely repaired, even after a 4-day refeeding period, to the point of being suitable to accept an increase in the uptake of antigens.

Age-related response of the small intestine to severe starvation and refeeding in rats

The impact of severe starvation and refeeding on the intestinal mucosa of rats of different ages has been studied in a diet-controlled model. Structural and functional alterations of the small intestinal mucosa were assessed by standard parameters including mucosal protein, DNA content as well as maltase, sucrase and leucine aminopeptidase enzymatic activities. Decreases in mucosal mass, DNA, protein and leucine aminopeptidase activity in both the jejunum and ileum caused by starvation, diminished with age. The depression of disaccharidase activities increased with age in the jejunum but not in the ileum. Except for jejunal protein and leucine aminopeptidase activity, the recovery from starvation, after refeeding, was complete for the other parameters studied, regardless of age.

Newborn universal immunisation against hepatitis B: immunogenicity and reactogenicity of simultaneous administration of diphtheria/tetanus/pertussis (DTP) and oral polio vaccines with hepatitis B vaccine at 0, 2 and 6 months of age

The reactogenicity and immunogenicity of the administration of recombinant vaccine against hepatitis B simultaneously (but at separate sites) with diphtheria/tetanus/pertussis (DTP) and oral polio vaccines were examined. Six hundred and twenty-six children (group I) were given hepatitis B vaccine at 0, 2 and 6 months of age; the other vaccines were administered at 2, 4 and 6 months of age. A control group of 731 children (group II) received only DTP and oral polio vaccines. The results showed that 93% of the infants in group I had anti-HBs titres above the protective level ( > or = 10 mIU ml-1) after vaccination. There were no differences in the immune responses for DTP and polio between the two study groups. The vaccine efficacy against poliomyelitis was 96% for serotype I, 100% for serotype II and 97-98% for serotype III. Of the infants in both groups, 97% had antibodies against B. pertussis; all children were positive for tetanus and diphtheria. There were no differences in the incidences of general reactions between groups. Local swelling and redness were reported following 4.2 and 4.4%, respectively, of all injections of hepatitis B vaccine. These reactions were reported following 31 and 33%, respectively, of all doses of DTP vaccine. It can be concluded that the simultaneous administration of hepatitis B vaccine with the DTP and polio vaccines is well-tolerated; hepatitis B vaccine remained highly immunogenic and did not interfere with the immune response to the other antigens.

Changes in the fatty acid pattern of plasma fractions of rats fed coconut, olive or sunflower oil

The fatty acid composition of plasma phospholipids, triacylglycerols and cholesteryl esters from rats fed diets supplemented (10% w/v) with coconut, olive or sunflower oil during six days has been studied. Rats fed the olive oil diet showed an increased amount of oleic acid whereas the animals fed the sunflower oil diet showed a higher content of linoleic acid than that of the other two groups. n-6 polyunsaturated fatty acids were mainly carried in phospholipid and cholesteryl-ester fractions. There were no differences in the amount of n-6 and n-3 polyunsaturated fatty acids. The effect of diet supplementation was shown after only six days of treatment and the results were similar to those reported in longer treatments.

The short-term effect of dietary fats on the brain fatty acid composition in rats

The effects of dietary fats on brain fatty acid composition were studied in weanling rats. Three groups of rats were fed for six days a basal diet supplemented with a 10% (w/w) of fat as coconut, olive or sunflower oil. There were no differences in the saturated and monounsaturated fatty acid content among the different groups. The more abundant polyunsaturated fatty acids were arachidonic (20:4 n-6) and docosahexaenoic (22:6 n-3) acids. No effect of the diet on their amount in brain membranes has been found. We can conclude that the brain does not modify its fatty acid composition after a short-time administration of these lipids.

Nutritional value and antigenicity of two milk protein hydrolysates in rats and guinea pigs

Two milk protein (whey protein and casein) hydrolysates were obtained by enzymatic hydrolysis. In the casein hydrolysate, an ultrafiltration stage was performed to remove all the peptides with molecular weights > 2500. A nutritional value study of both hydrolysates was undertaken. No differences were found between the native proteins and their enzymatic hydrolysates. Neither the enzymatic hydrolysis nor the heat treatments used affected the nutritional value of the protein sources. The two hydrolysates were studied for antigenic properties. The enzymatic hydrolysis of the whey protein concentrate followed by a thermal treatment at 90 degrees C for 10 min reduced significantly its antigenicity. However, the in vivo allergenicity tests showed some positive reactions in both systemic anaphylaxis and passive cutaneous anaphylaxis. The casein hydrolysate, after being ultrafiltered, was devoid of sensitizing capacity by the oral route and was also ineffective in producing local or systemic anaphylaxis in previously sensitized animals, as shown by in vivo assays.

Effect of dietary nucleotides on the fatty acid composition of rat liver microsomes

The present study was designed to evaluate the influence of dietary nucleotides on the lipid composition of liver microsomes in weanling rats. Rats at weaning were fed, one group with a semipurified nucleotide-free diet and three groups with the same diet supplemented with three different levels of each of the nucleotides AMP, GMP, IMP, UMP and CMP, during 4 weeks. Long chain polyunsaturated fatty acids of the n-6 and n-3 series were increased in phospholipids of liver microsomes for rats fed the nucleotide supplemented diets; however, the cholesterol/phospholipid phosphorus ratio was maintained fairly constant. The results obtained suggest that dietary nucleotides modify the polyunsaturated fatty acid metabolism through a lower rat liver delta-9 desaturase activity and through increased activities of delta-5 and delta-4 desaturases.

[Utilization of an emergency service by patients with HIV infection]

BACKGROUND AND METHODS

To know the impact of HIV infection in a hospital emergency department the health care episodes of seropositive individuals are reviewed in a retrospective study from the January 1 to March 31, 1992. Cases have been identified comparing the list of those infected by HIV with the users of the department during the period studied.

RESULTS

430 episodes in 288 patients (1.5 episodes/patient) have been included constituting 2.3% of the total. 76.4% were males, with a mean age of 29.2 years (range, 18-59) and 60.2% were evaluated the medical area. Hospital admission was indicated on 147 occasions (34.2% versus 19% of seronegatives; p < 0.001). The most frequent diagnoses were infections which were or were not associated to alteration of cellular immunity (32.8%) and complications related with the abuse of opioid substances (23.7%).

CONCLUSIONS

The pathology associated to HIV infection and to the abuse of intravenous drugs constitutes a frequent problem in the emergency departments. The infectious diseases which are or are not associated to alteration in cellular immunity, complications related with the consumption of opioids and the high index of admissions are of note. Professionals carrying out health care work in this medium must be familiarized with the diagnosis and treatment of these processes.

Changes in fatty acid profiles of red blood cell membranes mediated by dietary nucleotides in weanling rats

Dietary nucleotides have been described to play multiple physiological roles. We examined the effect of feeding, for 4 weeks, nucleotide-supplemented diets (N-50 and N-250) on red blood cell (RBC) membrane fatty acid composition in weanling rats. Long-chain polyunsaturated fatty acids (LC-PUFA) of the n-6 series, especially arachidonic acid, increased in total RBC phospholipids in N-50 and N-250 groups. Concentrations of LC-PUFA of the n-3 series were preserved or slightly decreased. Saturates and monoenates also decreased. Phosphatidylethanolamine and sphingomyelin followed the variations observed for total phospholipids. Phosphatidylcholine showed a different response; saturated fatty acids increased while n-6 LC-PUFA decreased. Dietary nucleotides seem to affect the conversion of essential fatty acids to their long-chain derivatives in weanling rats in a similar way to that occurring in newborn infants during early life. These results show that the rat may be a valid model with which to study the biochemical mechanisms by which dietary nucleotides affect fatty acid desaturation.

Changes in lipid composition and desaturase activities of duodenal mucosa induced by dietary fat

In the present work we have studied the effects of feeding either olive or sunflower oil on lipid composition and desaturase activities of duodenal mucosa microsomes. Duodenal microsomes prepared from dogs fed the sunflower oil diet showed higher percentages of saturated, of linoleic and of n - 3 polyunsaturated fatty acids as well as lower levels of oleic, dihomo-gamma-linolenic and arachidonic acids in phosphatidylcholine and phosphatidylethanolamine than those prepared from animals fed the olive oil diet. In sphingomyelin, the dietary supplementation did not produce significant differences between the two groups. The cholesterol/phospholipid molar ratio was higher in the sunflower oil group than in the olive oil group. The in vitro delta 9-desaturase activity was higher in microsomes from the olive oil dogs. The delta 6-desaturase activity was similar in microsomes from the two groups and lower than that found for delta 9-desaturase activity. Desaturase activities were higher in duodenal microsomes than those previously found for liver microsomes.