L-Arginine supplementation prevents allodynia and hyperalgesia in painful diabetic neuropathic rats by normalizing plasma nitric oxide concentration and increasing plasma agmatine concentration.

PURPOSE: Neuropathic pain is a common diabetic complication. It is characterized by symptoms of spontaneous and stimulus-evoked pain including hyperalgesia and allodynia. L-Arginine is a common precursor of many metabolites of biological interest, in particular, nitric oxide (NO), ornithine, and hence polyamines. In central nervous system, NO, glutamate, and polyamines share an N-methyl-D-aspartate (NMDA) receptor-mediated effect. We hypothesized that a variation in arginine metabolism caused by diabetes may contribute to development and maintenance of neuropathic pain and to the worsening of clinical and biological signs of diabetes. METHODS: We examined whether oral L-arginine supplementation (2.58 ± 0.13 g/l in drinking water for 3 weeks) could improve the development of neuropathic pain and the clinical, biological, and metabolic complications of diabetes in streptozocin (STZ)-induced diabetic (D) rats. RESULTS: STZ administration induced classical symptoms of type 1 diabetes. Diabetic rats also displayed mechanical hypersensitivity, tactile, and thermal allodynia. Plasma citrulline and NO levels were increased in diabetic hyperalgesic/allodynic rats. L-Arginine supplementation failed to reduce hyperglycaemia, polyphagia, and weight loss. Moreover, it abolished hyperalgesia and allodynia by normalizing NO plasma concentration and increasing plasma agmatine concentration. CONCLUSIONS: L-Arginine supplementation prevented the development of mechanical hyperalgesia, tactile, and thermal allodynia in painful diabetic neuropathy with concomitant reduction of NO and increased agmatine production, offering new therapeutic opportunities for the management of diabetic neuropathic pain.

Prevalence, risk factors and clinical implications of malnutrition in French Comprehensive Cancer Centres.

BACKGROUND: This epidemiological observational study aimed at determining the prevalence of malnutrition in non-selected adults with cancer, to identify risk factors of malnutrition and correlate the results with length of stay and 2-month mortality. METHODS: This prospective multicentre 1-day study conducted in 17 French Comprehensive Cancer Centres included 1545 patients. Body mass index (BMI), weight loss (WL) in the past 6 months and age were routinely recorded according to the French national recommendations for hospitalised patients; malnutrition was rated as absent, moderate or severe according to the level of WL and BMI. Age, sex, tumour site, type of hospitalisation and treatment, disease stage, World Health Organisation performance status (PS) and antibiotic therapy were the potential malnutrition risk factors tested. Follow-up at 2 months allowed to determine the correlation with length of stay and mortality. RESULTS: Malnutrition was reported in 30.9% of patients, and was rated as severe in 12.2%. In multivariate analysis, only pre-existing obesity (BMI> or =30), PS > or =2 and head-and-neck or upper digestive cancers were associated with increased risk of malnutrition. Antibiotics use was significantly higher in malnourished patients (35.5 vs 22.8%; P<0.001). Severe malnutrition was independently associated with mortality. The median length of stay was 19.3+/-19.4 days for malnourished patients vs 13.3+/-19.4 days for others (P<0.0001). CONCLUSION: In French Comprehensive Cancer Centres, one out of three cancer patients are malnourished and this was associated with a longer length of stay. Pre-existing obesity could be identified as a new risk factor for malnutrition in our cancer patient population perhaps because of a misidentification or a delay in nutrition support in this category of patients.

Relationship between nutritional status and quality of life in patients with cancer.

Patients with cancer frequently suffer a deteriorated quality of life and this is an important factor in the therapeutic decision. The correlation between quality of life and malnutrition seems obvious and bidirectional. The aim of our study was to describe the global quality of life and its various dimensions in patients with cancer, as a function of the nutritional status. A transversal observational study was performed in wards in hospitals in Clermont-Ferrand and Saint Etienne on 907 patients. The EORTC questionnaire, QLQ-C30, was used to assess the quality of life. The mean global quality of life score was 48.8 for patients who had a weight loss of more than 10% since the beginning of their illness, compared with 62.8 for the other patients (p<0.001). A significant association with weight was observed for the main dimensions of the quality of life: physical, functional, cognitive, social, fatigue, nausea, pain, loss of appetite, constipation and diarrhoea. This strong relation between quality of life and weight loss shows the importance of dietary management in patients with cancer.

Age-related change in the retinoid X receptor beta gene expression in peripheral blood mononuclear cells of healthy volunteers: effect of 13-cis retinoic acid supplementation.

The regulation of cell growth and differentiation and also expression of a number of genes by retinoids are mediated by nuclear retinoid receptors (RARs and/or RXRs). In this study we investigated age-related alteration in both RAR and RXR receptor subtypes gene expression and tissue transglutaminase (tTG) activity before and after supplementation with 13-cis retinoic acid (13cRA) in human peripheral blood mononuclear cells (PBMCs). Healthy men (40) were divided in two groups according to their age (young group: 26.1+/-4.1 years and old group: 65.4+/-3.8 years). Each volunteer received 13cRA (Curacné), 0.5mg/(kgday)) during a period of 4 weeks. We have shown that RXRbeta expression was decreased significantly (p=0.0108) in PBMCs of elderly men when compared to that of young volunteers. Distribution of retinoic acid receptor subtype expression in PBMCs was found in the order: RXRbeta>RARgamma>RXRalpha>RARalpha. The tTG activity in PBMCs reflected a trend to be enhanced after 13-cis retinoic acid supplementation. In conclusion, we demonstrate a significant decrease in the expression of RXRbeta subtype of rexinoid receptors in PBMCs of healthy elderly men. Our data suggest that in healthy elderly men reduction of RXRbeta expression in PBMCs might be a common feature of physiological senescence.

In vivo evidences that insulin regulates human polymorphonuclear neutrophil functions.

Polymorphonuclear neutrophils (PMN) are able to destroy invasive mircoorganisms by a wide variety of functions. Whereas insulin does not stimulate hexose transport in PMN, previous reports have clearly shown that this hormone regulates glucose metabolism inside this cell, raising the question of insulin action on PMN functions in humans. It is interesting that in vitro studies established a strong relationship between specific binding of insulin to its PMN membrane receptor and the activation of the main PMN functions. Therefore, investigation in healthy subjects under strict euglycemia and physiological insulinemia was performed to understand the in vivo-specific action of insulin on PMN functions without hyperglycemia interferences. We determined numerous PMN functions before and after hyperinsulinemia (0.5 mU/kg/min) and euglycemia (0.9 g/l) clamp for 4 h in eight adult healthy volunteers (24+/-6 years). The total number of PMN and the number of PMN expressing CD11b, CD15, CD62L, and CD89 were significantly increased over baseline (P<0.001), whereas the density of these receptors was down-regulated (P<0.01) by insulin. PMN chemotaxis (+117%, P<0.05), phagocytosis (+29%, P<0.001), and bactericidal (+17-25%, P<0.001) capacities were increased during the insulin clamp (P<0.05). Therefore, insulin treatment may modulate PMN functions not only by attainment of a better metabolic control, as suggested by in vivo studies in diabetic patients, but also through a direct effect of insulin.

Involvement of glutamine, arginine, and polyamines in the action of ornithine alpha-ketoglutarate on macrophage functions in stressed rats.

The ability of ornithine alpha-ketoglutarate (OKG) to enhance macrophage cytotoxicity in stress situations has been described, but the mechanisms involved remain unclear. It is known that OKG administration generates glutamine (GLN), arginine (ARG), and polyamines. This study will (1) evaluate the effect of OKG on tumor necrosis factor alpha (TNF-alpha) secretion and nitric oxide (NO*) production in macrophages from glucocorticoid (DEX)-treated rats, and determine whether these effects can be reproduced by GLN or ARG supplementations, and (2) use in vivo metabolic inhibitors methionine sulfoximine (inhibitor of GLN synthetase), S-methylthiourea (inhibitor of inducible nitric oxide synthase), and difluoromethylornithine (inhibitor of ornithine decarboxylase) to assess the roles of GLN, ARG, and polyamines in OKG action. Controls received a mixture of nonessential amino acids (NEAA). GLN, ARG, and OKG all restored TNF-alpha secretion by macrophages of glucocorticoid-treated rats. The same results were obtained with GLN and ARG supplementation. However, the use of inhibitors clearly showed that OKG does not modulate TNF-alpha secretion by GLN, ARG, or polyamine pathways. We also observed that OKG enhanced NO* release by stimulated macrophages (DEX-OKG, 1.77 +/- 0.64 vs. DEX-NEAA, 0.29 +/- 0.29 nmol/ 10(6) cells, P < 0.05). Using inhibitors, it appears that this action of OKG is probably mediated via polyamine synthesis and GLN. However, an oral administration of an equimolar amount of GLN failed to reproduce the OKG-mediated effect, possibly because OKG generates more GLN in the systemic circulation than GLN itself when these substances are given orally. Our results underline the complexity of the mechanism of action of OKG, which can differ according to the functions of even a single cell type.

Leptin: a potential regulator of polymorphonuclear neutrophil bactericidal action?

It is well known that leptin, the ob gene product, is involved in the regulation of food intake and thermogenesis. Recent studies also demonstrate that leptin may be able to modulate functions of cells involved in nonspecific immune response such as phagocytosis and secretion of cytokines by macrophages. This and the prominent implication of polymorphonuclear neutrophils (PMNs) in infectious response suggested a possible role of leptin as a modulator of PMN functions. We detected a leptin receptor on the PMN membrane by immunocytochemistry with an anti-leptin receptor. Using chemiluminescence we then demonstrated that leptin enhances oxidative species production by stimulated PMNs. These results show for the first time that a functional leptin receptor is present on PMNs and that leptin may be able to influence their oxidative capacity.

Immunonutrition stimulates immune functions and antioxidant defense capacities of leukocytes in radiochemotherapy-treated head & neck and esophageal cancer patients: A double-blind randomized clinical trial.

BACKGROUND: Immunonutrition has been reported to improve the immune status of perioperative cancer patients, thereby reducing complications and length of hospital stay. AIM: This study aimed to assess whether immunonutrition enriched in arginine, EPA & DHA and nucleotides could impact the immune cells responses in head & neck and esophageal cancer patients treated by radiochemotherapy (RCT). METHODS: A double-blind clinical trial was carried out in 28 patients randomized into two groups, receiving either an immunomodulating enteral nutrition formula (IEN, n = 13, Impact(®), Nestlé) or an isoenergetic isonitrogenous standard enteral nutrition formula (SEN, n = 15) throughout RCT (5-7 weeks). After isolation from whole blood, immune cells metabolism and functions were assessed at the beginning (Db) and at the end (De) of RCT. RESULTS: Immunonutrition maintained CD4(+)/CD8(+) T-lymphocyte counts ratio and CD3 membrane expression between Db and De. Polymorphonuclear cells CD62L and CD15 densities and ROS production were increased in IEN patients. Peripheral blood mononuclear cells (PBMC) production of pro-inflammatory prostaglandin-E2 was stable in IEN patients and lower than in SEN patients at De. Genes coding for immune receptors, antioxidant enzymes and NADPH oxidase subunits were overexpressed in the PBMC of IEN vs SEN patients at De. CONCLUSION: Immunonutrition can enhance immune cell responses through the modulation of their phenotypes and functions. By modulating the gene expression of immune cells, immunonutrition could make it easier for the organism to adapt to the systemic inflammation and oxidative stress induced by RCT. CLINICAL TRIAL REGISTRATION: This clinical trial has been registered on ClinicalTrial.gov website: NCT00333099.

Methionine dependency and cancer treatment.

Conventional chemotherapies have showed their limits, notably for patients with advanced cancer. New therapeutic strategies must be identified, and the metabolic abnormalities of cancer cells offer such opportunities. Many human cancer cell lines and primary tumors have absolute requirements for methionine, an essential amino acid. In contrast, normal cells are relatively resistant to exogenous methionine restriction. The biochemical mechanism for methionine dependency has been studied extensively, but the fundamental mechanism remains unclear. A number of investigators have attempted to exploit the methionine dependence of tumors for therapeutic effects in vivo. To reduce in vivo methionine in plasma and tumours, dietary and pharmacological treatments have been used. Methionine-free diet or methionine-deprived total parenteral nutrition causes regression of a variety of animal tumours. Alternatively, methionine depletion was achieved by the use of methioninase. This enzyme specifically degrades methionine and inhibits tumour growth in preclinical models. Because of potential toxicity and quality of life problems, prolonged methionine restriction with diet or with methioninase is not suitable for clinical use. Methionine restriction may find greater application in association with various chemotherapeutic agents. Several preclinical studies have demonstrated synergy between methionine restriction and various cytotoxic chemotherapy drugs. The experimental results accumulated during the last three decades suggest that methionine restriction can become an additional cancer therapeutic strategy, notably in association with chemotherapy.

Aging: a barrier to renutrition? Nutritional and immunologic evidence in rats.

BACKGROUND: Previous reports suggest that correcting the malnourished state is more difficult in elderly people than in younger ones and that protein requirements may be higher in elderly than in younger adults. OBJECTIVE: The aim of this study was to establish whether malnourished old rats respond to protein-supplemented nutritional repletion as do young adult rats. DESIGN: Adult (3 mo old) and old (22 mo old) rats were submitted to dietary restriction programs that induced similar metabolic and nutritional alterations. Malnourished adult and old rats were then killed (R groups) or refed for 1 wk with a high-protein diet (HPD; 23% protein) or a very-high-protein diet (VHPD; 27% protein). Control groups at both ages were fed ad libitum throughout the experiment. Effects of food repletion were evaluated in terms of protein metabolism, intestinal histomorphometry, and nonspecific immune status. RESULTS: In adult rats, HPD sufficed to increase body weight and restore basal values of liver weight and protein content (P: < 0.01 compared with the R adult group), nitrogen balance (P: < 0.01 compared with the R adult group), and hydrogen peroxide production by polymorphonuclear neutrophils and monocytes (P: < 0.01 compared with the R group); VHPD had no supplementary effect except on nitrogen balance. In old rats, HPD was less effective and greater benefit was observed with VHPD in terms of body weight gain (10%; P: < 0.01 compared with the old group fed HPD), albuminemia, muscle weight and protein content, plasma arginine concentration, and hydrogen peroxide production by stimulated polymorphonuclear neutrophils and monocytes compared with the old R group (P: < 0.01). CONCLUSION: Aging is a significant variable affecting the response to nutritional support.

Specific and nonspecific immune responses to fasting and refeeding differ in healthy young adult and elderly persons.

BACKGROUND: Undernutrition is a main cause of immunodeficiency. Many confounding factors limit the interpretation of immune function in hospitalized elderly patients. OBJECTIVE: We compared the effects of short-term fasting and refeeding on lymphocyte subset distribution and neutrophil function in healthy subjects. DESIGN: Seven young adult (x +/- SE age: 24 +/- 2 y) and 8 elderly (71 +/- 3 y) subjects were fed standardized diets (1.6 x predicted resting energy expenditure; 16% protein) for 7 d. They then fasted for 36 h and were refed for 4 h (42 kJ/kg). Lymphocyte subsets were quantified by using fluorochrome-conjugated monoclonal antibodies. Neutrophil chemotactic migration was evaluated by using a 2-compartment chamber. Neutrophil reactive oxygen species production was measured by using a luminol-amplified chemiluminescence assay and oxidation of 2'7'-dichlorofluorescein diacetate. RESULTS: Baseline total and cytotoxic T lymphocyte subpopulations were lower in elderly than in adult subjects (P < 0.01). Nutritional state had a significant effect (P < 0.05) on total, helper, and cytotoxic T and B lymphocyte counts in all subjects, and the response of lymphocyte subpopulations to nutritional fluctuations was significantly affected by age. The chemotactic index was lowered by fasting in both groups (P < 0.05 compared with basal values). After refeeding, neutrophil migration was restored in adult but not elderly subjects. The superoxide anion production rate increased with fasting and reverted to prefasting values with refeeding in both groups (P < 0.05). Fasting induced a significant decrease in hydrogen peroxide production in stimulated neutrophils that was reversed by refeeding in adult but not elderly subjects. CONCLUSION: The lack of response of lymphocyte subpopulation counts and neutrophil function to nutritional changes may help to explain the proneness of elderly persons to infection.

Evidence for an alteration of plasma and liver proteins response to dexamethasone in aging rats.

The aim of this study was carried out to analyse the liver and plasma proteins response to dexamethasone in adult (6-8 months) and old (24 months) rats in order to ascertain the involvement of glucocorticoids in the aging process. The animals received dexamethasone (Dex) for 5 or 6 days. As Dex decreased food intake, all groups were pair fed to dexamethasone-treated old rats. The synthesis of mixed plasma and liver proteins (assessed by a flooding dose of [13C] valine) was similarly greatly improved in adult and old rats after Dex treatment. However, the level of mixed plasma proteins was only slightly increased. When specific plasma proteins were assessed, a similar increase in the concentration of albumin and alpha1 acid glycoprotein was observed in adult and old rats. By contrast, fibrinogen decreased to a greater extend in old rats and alpha2 macroglobulin became undetectable in old animals. It was concluded that the response of plasma and liver proteins to Dex was altered in old rats and may contribute to the pathogenesis of several diseases which occur during aging.

Ultrastructural localization of binding sites for PNA and VVA-B(4) lectins in human breast cancer cell lines detected by confocal fluorescence microscopy.

Three cancer cell lines (MCF-7, HBL-100, MDA-MB 231) and subnormal breast epithelial cell line MCF-10A were labeled with FITC-conjugated VVA-B4 lectin, specific for D-GalNAcalpha-O-ser/thr, matching the structure of Tn antigen sugar residues, and with RTIC-conjugated PNA lectin, specific for DGalbeta1-3GalNAc-O-ser/thr, corresponding to the structure of T antigen. Simultaneous expression of Tn and T antigens on the same cells (but in widely differing proportions) led to their large heterogeneity and occurrence of numerous cell subpopulations within each of the studied cell lines. This observation proved that the changes leading to the formation of Tn antigen are not caused by an irreversible genetic mutation of beta1-3-galactosyltransferase. Expression of Tn antigen on MCF-10A cells with normal (or subnormal) karyotype suggests that the process of malignant transformation of the cell begins with the changes in molecular structure of glycoconjugates.

An intracellular modulation of free radical production could contribute to the beneficial effects of metformin towards oxidative stress.

Metformin (dimethylbiguanide) is an antihyperglycemic agent used in type 2 diabetes. Beyond its action on glycemic control, metformin exhibits other intrinsic effects that could play a role in prevention against diabetes complications. Some studies thus reported an improvement in the antioxidant status in patients treated with metformin. This might be in part related to its property to limit formation of advanced glycation end products (AGEs) and to decrease the overproduction of free radicals in diabetic subjects. The aim of this study was to investigate the in vitro ability of metformin to modulate the action of reactive oxygen species (ROS) generated either by water gamma radiolysis or by stimulated human leukocytes. Our results showed that metformin at pharmacologically relevant concentrations was in vitro able to scavenge hydroxyl ((.)OH) but not superoxide (O(.-)(2)) free radicals and that hydrogen peroxide did not react with metformin. Nevertheless, when polymorphonuclear cells (PMN) are stimulated by phorbol myristate acetate (PMA), or above all by formyl methionine leucyl phenylalanine (fMLP), a systematic (although nonsignificant) decrease of the ROS-induced chimiluminescence (CL) was observed. These results suggest that metformin could directly scavenge ROS or indirectly act by modulating the intracellular production of superoxide anion, of which NADPH oxidase constitutes the major source. This could contribute to the additional benefits of metformin, especially those related to the improvement in the cardiovascular outcomes in diabetes.

Leptin regulates functional capacities of polymorphonuclear neutrophils.

Recent studies report that leptin may be able to modulate some functions of cells involved in non-specific immune response. We recently found that a functional leptin receptor is present on polymorphonuclear neutrophils (PMNs) and may be able to influence their oxidative capacities. We demonstrate here for the first time that leptin is also able to stimulate chemotaxis of PMNs and exerts by itself a chemoattractive effect comparable to that of well-known formyl-methionyl-leucyl-phenylalanine, and a stimulating effect on intracellular hydrogen peroxide production, without modification of phagocytosis.

Anti-inflammatory effects of Melaleuca alternifolia essential oil on human polymorphonuclear neutrophils and monocytes.

OBJECTIVE AND DESIGN: The fungicidal and bactericidal actions of the essential oil (EO) of Melaleuca alternifolia seem well established, but their anti-inflammatory and anti-oxidative effects remain unclear. In this study, we investigated in vitro the possible role of whole M. alternifolia EO as a modulator of the oxidative response, i.e. reactive oxygen species (ROS) production, of leukocytes (monocytes and polymorphonuclear neutrophils (PMNs)) in humans. METHODS: Whole blood leukocytes from healthy human volunteers (n = 7), isolated from erythrocytes by haemolytic shock, were incubated for 30 min with M. alternifolia EO (0-0.1%) to determine their ROS production by flow cytometry with or without stimulation of cells. We compared the effects of 3 different stimulating agents acting differently on transductional pathways to stimulate the ROS production: a phorbol ester (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP) and opsonised zymosan (OZ). RESULTS: As attested by the Krüskall-Wallis test, M. alternifolia EO at 0.1% directly stimulated ROS production by PMNs (x 8.7 vs. 0% EO, p < 0.05) and increased the intracellular ROS produced by monocytes. Whichever the stimulating agent used (PMA, fMLP or OZ), M. alternifolia EO decreased the intracellular ROS production at the dilution of 0.1% by PMNs and monocytes, more so with PMNs. CONCLUSION: M. alternifolia EO may be both a direct active mediator of the bactericidal action of the circulating leukocytes and may be efficient in protecting the organism from an excess of ROS, through an anti-oxidant and radical scavenging activity.

Can a glutamate-enriched diet counteract glutamine depletion in endotoxemic rats?

The study evaluated whether a glutamate-enriched diet would restore glutamine tissue pools and maintain tissue trophicity in endotoxemic rats. For this purpose, young male Sprague-Dawley rats received an intraperitoneal injection of lipopolysaccharide (LPS) from Escherichia coli at 3 mg/kg body weight. After 24 hours of food deprivation, the rats were enterally refed for 48 hours using Osmolite enriched with glutamate at 4 g/kg/d (LPS-Glu group, n = 7) or glycine isonitrogenous to glutamate (LPS-Gly group, n = 7). A control group (healthy group, n = 7) had free access to a standard rodent diet. Tissue weights and protein contents were significantly lower in both LPS-treated groups than in the healthy group. No plasma or tissue accumulation of glutamate was observed except in the liver. Glutamine concentrations were increased in the jejunum, liver, and plasma in the LPS-Glu group versus the other two groups (P < 0.05). Conversely, they were depleted in muscles of the endotoxemic groups versus the healthy group (P < 0.05). Villus height was significantly greater in the LPS-Glu group than in the LPS-Gly group in the jejunum (P < 0.05), but not in the ileum. In conclusion, a glutamate-enriched diet administered enterally to endotoxemic rats can counteract glutamine depletion in the splanchnic area but not in muscles. In addition, glutamate displayed a trophic effect restricted to the jejunum.

Characterization of lipoproteins during human cholestasis.

We have characterized changes in lipoproteins from cholestatic individuals and reproduced them by incubating lipoproteins from healthy individuals with cholic acid. The cholestatic patients showed an increase in low density lipoprotein (LDL) (>85%), with a smaller proportion of esterified cholesterol, and a fall in high density lipoprotein (HDL) (<10%), with a larger proportion of phospholipids. The protein composition of cholestatic HDL1 was characterized by a smaller proportion of apo A (I, II) and a prominent apo E fraction (39% vs. 9%). These changes involved an increase in degree of molecular packing (order) of HDL1. The addition of cholic acid to serum from healthy individuals altered the lipoprotein distribution, with an increase in LDL, the disappearance of HDL2 and HDL3 and the appearance of HDL1. These HDL1 were characterized by increased phospholipid and reduced apo AI fractions. They also showed a lower density and appeared as spherical particles in contrast to cholestatic HDL. Incubation of healthy HDL with cholic acid in vitro reproduces some of the alteration observed in cholestatic HDL.

Effects of alpha-1 acid glycoprotein on human polymorphonuclear neutrophils: influence of glycan microheterogeneity.

The biological functions of alpha-1 acid glycoprotein (AGP) are poorly understood but appear to depend on glycan microheterogeneity. Variations of AGP glycan structure (in terms of concanavalin A (ConA) reactivity) have been observed during the inflammatory process. We studied these modifications in AGP from patients with chronic renal impairment and investigated the effects of AGP microheterogeneity on healthy polymorphonuclear leukocyte (PMN) chemotaxis and oxidative metabolism. AGP was extracted by a two-step procedure from sera from ten patients with various degrees of renal impairment, selected according to AGP glycan heterogeneity determined by crossed immunoaffinity electrophoresis with ConA. AGP (0.5 g/l) significantly inhibited the chemotactic response of PMN to formyl-methionyl-leucyl-phenylalanine (10(-7) mol/l) and complement fraction C5a, regardless of ConA reactivity. AGP also inhibited superoxide anion generation in response to phorbol myristate acetate (10(-7) mol/l). After stimulation by opsonized zymosan (1 g/l), the effect of AGP appeared to depend on its glycan structure (r = 0.70, P < 0.05), decreasing with ConA non-reactivity. These data suggest that AGP can down-regulate neutrophil responsiveness, an effect that depends in part on its glycan microheterogeneity. Alterations of AGP microheterogeneity in various pathological states, particularly renal failure, may be related to the inflammatory process.

Expression of nuclear retinoic acid receptor in peripheral blood mononuclear cells (PBMC) of healthy subjects.

In vertebrates, both nuclear all-trans and 9-cis retinoic acid receptors (RAR and RXR) belonging to the steroid/thyroid/retinoid nuclear receptor superfamily play a crucial role in the vitamin A action. Qualitative analysis of all known RAR or RXR subtypes in both pooled and non-pooled peripheral blood mononuclear cells (PBMC) from healthy human subjects has been performed by reverse transcription and polymerase chain reaction (RT-PCR). Our data, based on qualitative RT-PCR analysis has shown that human PBMC are capable to express RAR alpha, RAR gamma, RXR alpha, and RXR beta.