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PubMed1987

[Effects of factors of nutrition and husbandry on the heat production of rats and broilers. 1. Heat production of growing broiler chicks kept in groups depending on the environmental temperature].

In 2 experiments with young broiler chickens, origin Tetra B, heat production was measured in dependence on ambient temperature indirectly and with the gas exchange both over 24 h and in 20-minute periods beginning on their 5th day of live. The chickens, divided into 2 X 2 groups according to sex, were constantly kept in a climatic chamber changed in to a respiration chamber during the 8- or 11-week-long experiments. The maximum variation of the temperature was between 5 and 35 degrees C. In the periods of 24-h measurements over 4 days each, the ambient temperature was changed from day to day in steps of 5 degrees C. Heat production was influenced by the age of the chickens, energy intake and ambient temperature. The results of the measurements at the same age and the same energy intake and a temperature variation between 5 and 35 degrees C can well be described by polynomes of the 3rd degree up to the 8th week of live. The thermoregulatory conditioned heat production per 1 degree C below the critical temperature decreased with the age of the chickens. In the first few weeks of life it was 20 kJ, in the 6th and 7th weeks of life 10-15 kJ and then decreased to 4-5 kJ/kg life weight 0.75.d. degrees C. Based on the temperature of minimal heat production, the heat production of 16- to 30-day-old chickens increased to 60-80% at an ambient temperature of 5 degrees C; the metabolism of chickens older than 7 weeks was only increased by about 20%. For the first 2 weeks 35 degrees C were ascertained as critical temperature, for the 3rd to 6th weeks 30 degrees C and for the 7th and 8th weeks 25 degrees C.

Animals↗
PubMed2002

Toward sustainable production of protein-rich foods: appraisal of eight crops for Western Europe. Part I. Analysis of the primary links of the production chain.

Increased production of plant protein is required to support the production of protein-rich foods that can replace meat in the human diet to reduce the strain that intensive animal husbandry poses to the environment. The suitability of lupin (Lupinus spp.), pea (Pisum sativum), quinoa (Chenopodium quinoa Willd.), triticale (x Triticosecale), lucerne (Medicago sativa), grasses (Lolium and Festuca spp.), rapeseed/canola (Brassica napus), and potato (Solanum tuberosum) for protein production in Western Europe was studied on the basis of a chain approach. The aspects considered are the familiarity of farmers with the cultivation of the crop, prospects for rapid crop improvement, protein production (kg/ha), protein quality (absence of unwanted substances) and familiarity with the usage for human food in Western Europe. Pea, lucerne, and grasses are the most promising, fair prospects are foreseen for lupin, triticale, rapeseed, and potato, whereas the possibilities for quinoa are judged to lag far behind. Estimated protein production for pea, lucerne, and grasses is 1250, 2500, and 2500 kg/ha, respectively.

Agriculture↗
PubMed1953

Growth and phage production of B. megatherium. I. Growth of cells after infection with C phage. II. Rate of growth, phage yield, and RNA content of cells. III. Effect of various substances on growth rate and phage production.

I. Lysogenic B. megatherium 899a (de Jong, 1931) produces two types of phage (Gratia, 1936 c) T and C. The T phage forms cloudy plaques and gives rise to fresh lysogenic strains (Gratia, 1936 b) when added to the sensitive strain of megatherium. It may or may not cause lysis, depending on the media (Northrop, 1951). The C phage occurs very rarely) forms clear plaques, does not give rise to lysogenic strains, and causes complete lysis of the sensitive strain under all conditions tested, provided infection occurs. If C phage is added to the sensitive strain, and the mixture allowed to stand, or made into a hanging drop preparation, the infected cells stop growing and lyse completely after 60 to 80 minutes with the liberation of from 50 to 200 phage particles per cell. If, however, C phage is added to a rapidly growing culture of B. megatherium and the suspension shaken at 34 degrees , the cells continue to grow and divide for 50 to 60 minutes, after infection has occurred. They then lyse, with the liberation of from 1000 to 2500 phage particles per cell. II. The following determinations have been made on megatherium sensitive cells growing in 5 per cent peptone at different stages of growth. (1) Growth rate of infected and uninfected cells; (2) RNA, DNA, and protein content; (3) volume of the cell; (4) phage yield per cell by plaque count; (5) phage yield per cell by cell and plaque count; (6) lysis time. The growth rate decreases as the cell concentration increases. The lysis time and the protein N per cell are nearly independent of the growth rate; all the other values increase as the growth rate increases. The ratio See PDF for Equation is nearly constant. RNA and DNA per cell increase less rapidly than the volume, so that NA per unit volume is not constant, but decreases as the size of the cell increases. The phage yield measured under conditions in which the infected cells do not grow (by plaque count) is very nearly proportional to the size of the cell. The phage yield per cell, under conditions in which the infected cells do grow, increases more rapidly than the size of the cells. The phage yield per cell under these conditions may be calculated by the equation See PDF for Equation The determining factor for the variation in phage yield is the growth rate of the cells. This, in turn, is determined by the composition of the medium. III. The growth and phage production of megatherium 899a have been determined in the presence of the following substances: aureomycin, bacitracin, chloromycetin, gramicidin, Merck AB631, Merck AB191, Merck AB624, penicillin, streptomycin, terramycin, tyrothricin, usnic acid, acetone, chloroform, ethyl alcohol, formaldehyde, gentian violet, glycerin, maleic hydrazide, methyl alcohol, phenyl mercuric acetate, sodium fluoride, sulfanilamide, toluene, and urethane. In every case, the lowest concentration of the substance which completely inhibits growth, is also the lowest concentration which completely inhibits phage production. One antibiotic, Merck AB81, causes increased phage production in concentrations which partially inhibit growth, and low phage production in concentrations which completely inhibit growth (as determined by turbidity). Short exposure to ultraviolet light also decreases the growth rate, with increase in phage production. Longer exposure, which completely inhibits growth (as determined by turbidity) results in lysis and phage liberation.

Bacillus↗
PubMed2006

Production and processing of soybeans and nutrition and safety of isoflavone and other soy products for human health.

Functional foods are intended to help consumers reduce or manage the risks for certain diseases while maintaining body function and structure. Functional foods are regulated differently depending upon the country. For example, the United States has not defined the term functional food in regulation. Thus, functional foods are treated just like conventional foods for obtaining regulatory safety approval. However, the sales of soy products, soy-enriched foods, and dietary supplements have grown tremendously during the past 3 years because of the increasing consumer awareness of soy as a healthy food ingredient. Isoflavones in soy are believed to have preventive effects for several hormone-dependent diseases, mainly due to their weak estrogenic activity. This mini-review discusses some of the important issues to be considered in using soy and isoflavone products as health foods, including production, composition, products, and processing of soy products, and the fate of isoflavones during processing, their bioavailability, and safety. Some of these issues may affect the choice of raw or basic material sources, processing conditions, quality control procedures/measures, and marketing strategies for both soy-based foods and isoflavones.

Biological Availability↗
PubMed1979

Observations on the composition of milk-substitute products for treatment of inborn errors of amino acid metabolism. Comparisons with human milk. A proposal to rationalize nutrient content of treatment products.

We tabulated and compared the stated compositions of four milk-substitute products, now in wide use for the treatment of various inborn errors of amino acid metabolism, and the known composition of human milk. Variations between the treatment products is great not only in the content of amino acids but also in minerals and vitamins, for example. Different source materials and rationales for their manufacture appear to explain these differences. All four products deviate in many ways from the composition of human milk. Although the existing treatment products are quite effective clinically, we propose that a more rational approach to the feeding of young infants whose nutrition is compromised by inborn errors of metabolism would begin with a synthetic product based on the composition of human milk that could be modified specifically to fit the needs and tolerance of the individual patient.

Amino Acid Metabolism, Inborn Errors↗
PubMed2001

Effects of co-stimulation by CD58 on human T cell cytokine production: a selective cytokine pattern with induction of high IL-10 production.

CD58 is the ligand for the CD2 molecule on human T cells and has been shown to provide a co-stimulatory signal for T cell activation. However, its physiological role is still unclear. We studied the effects of co-stimulation by CD58 on the production of T(h)1-type (IL-2- and IFN-gamma) or T(h)2 type (IL-4, IL-5 and IL-10) cytokines in an in vitro culture system of purified human T cells with CD58-transfected P815 cells and with anti-CD3 as the primary stimulus. Co-stimulation of T cells by CD58 potently induced IL-10 and IFN-gamma production (at the protein and at the mRNA level), and transforming growth factor-ss production (at the mRNA level), comparable to what can be found in CD80 co-stimulated T cell cultures. In contrast, we found low to absent IL-2, IL-4, IL-5, IL-13 and tumor necrosis factor-alpha production after CD58 co-stimulation, and this was not due to suppressive effects of endogenously produced IL-10. CD80 co-stimulation strongly induced all these cytokines. Intracellular staining for cytokine expression revealed the existence of a T cell subpopulation induced by CD58 co-stimulation to produce both IFN-gamma and IL-10. We furthermore found that the selective cytokine profile induced by CD58 co-stimulation is further accentuated by rIL-12 and by rIFN-alpha. Using cyclosporin A as an inhibitor of the calcineurin enzyme, we could show that production of all cytokines in this system is calcium dependent. CD58 co-stimulation thus induces a cytokine pattern corresponding to that described for T regulatory (T(r)) 1 cells and to the pattern reported to be induced by the newly identified B7 family member, B7-H1.

Adult↗
PubMed1985

Assessment of interrelationships among levels of intake and production, organ size and fasting heat production in growing animals.

Although the concept of metabolic body size (kg0.75) has gained widespread use in the field of energy metabolism, its application to the growing animal has been questioned. Fasting heat production, or maintenance, rather than being a constant function of body size, has been shown to vary because of breed, sex, condition, physiological state, production level, nutrition level and environmental conditions. Data are presented to show that fasting heat production and maintenance vary with nutritional level or rate of growth in animals postweaning. Variation in these energy expenditures are related to variation in weight of metabolically active internal organs. Weights of liver and gut and fasting heat production are shown to be functions of body size and level of production. More information is needed to ascertain the primary components of energy expenditures in animals and to quantitatively relate these components to animal energy metabolism.

Animal Nutritional Physiological Phenomena↗
PubMed1987

Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products.

We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the dctB gene product (DctB) suggested that its N-terminal region may be located in the periplasm and its C-terminal region in the cytoplasm. The C-terminal region of DctB was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, including ntrB, envZ, virA, phoR, cpxA, and phoM. The N-terminal domains of the products of several regulatory genes thought to be transcriptional activators, including ntrC, ompR, virG, phoB and sfrA. In addition, the central and C-terminal regions of DctD were strongly conserved with the products of ntrC and nifA, transcriptional activators that require the alternate sigma factor rpoN (ntrA) as co-activator. The central region of DctD also contained a potential ATP-binding domain. These results are consistent with recent results that show that rpoN product is required for dctA activation, and suggest that DctB plus DctD-mediated transcriptional activation of dctA may be mechanistically similar to NtrB plus NtrC-mediated activation of glnA in E. coli.

Amino Acid Sequence↗
PubMed1997

Major histocompatibility complex class II DNA polymorphisms in chicken strains selected for Marek's disease resistance and egg production or for egg production alone.

The objective of this study was to investigate frequencies of major histocompatibility complex (MHC) class II restriction fragments in two groups of White Leghorn strains. Each group consisted of an unselected control, a strain selected for egg production traits, and a strain selected for egg production traits and Marek's disease (MD) resistance. PvuII-digested genomic DNA was hybridized with a chicken genomic MHC class II probe. The MHC class II DNA fragment frequencies in the selected strains differed from those in the related unselected control and in the strain selected using the same criteria from a different base population. Based on the sizes of the breeding populations, particularly those in the control strain and in the strain selected for egg production, it was considered unlikely that the observed changes of the MHC class II fragment frequencies were due to random genetic drift. The data suggested that some MHC class II bands are associated with production traits or with MD resistance, and that these associations tend to be unique to each genetic background. Hence, MHC class II genes are likely candidates for the investigation of quantitative trait loci in egg production and disease resistance traits such as those for which the studied strains were selected.

Animals↗
PubMed2004

Effect of vitamin D2- and D3-enriched diets on egg vitamin D content, production, and bird condition during an entire production period.

Vitamin D insufficiency during winter is a common problem for humans in Europe. One way to ease this problem is through the production of vitamin D-fortified eggs. To evaluate such a production process, the effects of vitamin D supplementation during an entire production period were assessed. Transfer of vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol) from the diet to egg yolks was measured using 2 different levels of both vitamins (6,000 and 15,000 IU/kg feed) relative to a control treatment (2,500 IU vitamin D3/kg feed). During the experiment, production parameters, egg quality (egg weight, Haugh unit, specific gravity, eggshell fracture force, and Ca content of eggshell), and the condition of hens were monitored. At the end of the experiment histopathological tests were performed. Supplementing diets with vitamin D3 increased egg yolk vitamin D content more effectively than did supplementation with vitamin D2. For groups of hens receiving 6,000 or 15,000 IU of vitamin D3/kg feed, egg yolk vitamin D3 content ranged from 9.1 to 13.6 and from 25.3 to 33.7 microg/100 g, respectively. Corresponding values for birds fed vitamin D2 were 4.7 to 7.0 and 13.3 to 21.0 microg/100 g. Both supplements enhanced vitamin D3 content of egg yolks relative to the control diet (2.5 to 5.0 microg/100 g of egg yolk). Vitamin D supplements had no effects on production parameters compared with the control diet. However, especially vitamin D3 improved bone strength (P < 0.05). Autopsy at the end of the experiment indicated no detrimental accumulation of calcium in the kidneys, liver, heart, muscles, or lungs.

Animals↗
PubMed2005

Trans, trans-2,4-decadienal, a product found in cooking oil fumes, induces cell proliferation and cytokine production due to reactive oxygen species in human bronchial epithelial cells.

Dienaldehydes are by-products of peroxidation of polyunsaturated lipids and commonly found in many foods or food-products. Both National Cancer Institute (NCI) and NTP have expressed great concern on the potential genotoxicity and carcinogenicity of dienaldehydes. Trans, trans-2,4-decadienal (tt-DDE or 2,4-De), a specific type of dienaldehyde, is abundant in heated oils and has been associated with lung adenocarcinoma development in women due to their exposure to oil fumes during cooking. Cultured human bronchial epithelial cells (BEAS-2B cells) were exposed to 0.1 or 1.0 microM tt-DDE for 45 days, and oxidative stress, reactive oxygen species (ROS) production, GSH/GSSG ratio, cell proliferation, and expression of TNFalpha and IL-1beta were measured. The results show that tt-DDE induced oxidative stress, an increase in ROS production, and a decrease in GSH/GSSG ratio (glutathione status) in a dose-dependent manner. Treatment of BEAS-2B cells with 1.0 microM tt-DDE for 45 days increased cell proliferation and the expression and release of pro-inflammatory cytokines TNFalpha and IL-1beta. Cotreatment of BEAS-2B cells with antioxidant N-acetylcysteine prevented tt-DDE-induced cell proliferation and release of cytokines. Therefore, these results suggest that tt-DDE-induced changes may be due to increased ROS production and enhanced oxidative stress. Since increased cell proliferation and the release of TNF-alpha and IL-1beta are believed to be involved in tumor promotion, our results suggest that tt-DDE may play a role in cancer promotion. Previous studies on dienaldehydes have focused on their genotoxic or carcinogenic effects in the gastrointestinal tract; the present study suggests a potential new role of tt-DDE as a tumor promoter in human lung epithelial cells.

Acetylcysteine↗
PubMed1989

Luteal production of steroids and prostaglandins during simulated early pregnancy in the primate: differential regulation of steroid production by chorionic gonadotropin.

Stimulation of the primate corpus luteum (CL) by endogenous chorionic gonadotropin (CG) in early pregnancy, or by exogenous human (h)CG in simulated early pregnancy, results in a transient elevation of serum progesterone (P) and a persistent elevation of serum 17 beta-estradiol (E). Luteal prostaglandins (PG) may play a role in these responses. The objective of the current study was to correlate luteal PG production and steroidogenic response of CL in vitro with patterns of serum steroids during simulated early pregnancy. CL were removed from rhesus monkeys (n = 26) at 0 h, 9 h, 3 days, 6 days, and 10 days, during prolonged CG exposure of simulated early pregnancy. Dispersed cells were incubated in vitro at 37 degrees C for 8 h. Changes in basal production of P were not significantly correlated with patterns of serum steroids. Maximal stimulation of P production by hCG in vitro (stimulated minus basal) continuously declined (p less than 0.01) from 0 h (means +/- SE, 59.6 +/- 17.9 ng/ml) to 10 days (4.7 +/- 1.8 ng/ml) of simulated early pregnancy. In contrast to patterns of response to hCG, the level of enhancement in P production in response to a maximally stimulatory dose of dibutyryl (db) cyclic adenosine 3',5'-monophosphate (cAMP) declined (p less than 0.05) from 0 h (52.4 +/- 17.6 ng/ml) to 3 days (20.3 +/- 8.4 ng/ml), but was maintained through 10 days (23.7 +/- 11.6 ng/ml) of simulated early pregnancy. As such, desensitization to gonadotropin, which occurred in terms of P production, appears to involve an event subsequent to stimulation of adenylate cyclase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed2003

Development and reliability analysis of the Work Productivity Short Inventory (WPSI) instrument measuring employee health and productivity.

The Work Productivity Short Inventory (WPSI), also known as the Wellness Inventory, was developed to quickly assess the prevalence of medical problems that may influence work productivity and the financial implications of those problems. The WPSI asks respondents to note the amount of time missed from work resulting from 15 medical conditions and the amount of unproductive time spent at work when affected by the condition. Three versions of the WPSI were compared that differed according to the length of the recall period (12 months, 3 months, or 2 weeks). The reliability of the financial metrics generated from the WPSI was assessed for each version and found to be adequate, ranging from 0.66-0.74 in this application. The WPSI was found to be a highly reliable tool for estimating the prevalence of medical conditions that influence work productivity. The dollar impact of the associated productivity losses were found to be reliable enough to meet the instrument's intended purpose, which is to help employers understand relationships between disease and productivity, thereby contributing to the design of interventions to relieve these problems. The needs of the researcher should dictate which version of the WPSI to use.

Absenteeism↗
PubMed1980

Productive and abortive infection of L cells by fowl plague virus (FPV): comparison of in vivo and in vitro translation products of the virus mRNAs.

The abortive infection of L cells by the Dobson strain of fowl plague virus (FPV) and the productive infection by a mammalian cell-adapted mutant have been compared. The mRNA population during the abortive cycle is characterized by a lower production compared to the productive system of mRNA 7 (which codes for the M polypeptide) early in the cycle, and a lower production of mRNAs 4, 6 and 7 (which code for HA, NA and M) late in the cycle. Differences in the amounts of the corresponding polypeptides can also be detected when these mRNA populations are used to programme a wheat germ cell-free system. However, analysis of the polypeptides synthesized in vivo by the two viruses show that equivalent amounts of all virus polypeptides are synthesized during the productive and the abortive cycles. Possible reasons for differences between in vivo and in vitro translation of the virus mRNAs during the abortive cycle are discussed.

Animals↗
PubMed2006

Large variation in t(11;14)(q13;q32) and t(14;18)(q32;q21) translocation product size is confirmed by sequence analysis of PCR products.

Polymerase chain reaction is commonly used to detect t(11;14)(q13;q32) and t(14;18)(q32;q21) chromosomal translocations associated with mantle cell lymphoma and follicular lymphoma. We tested a total of 482 samples from patients with suspected non-Hodgkin's lymphoma and sequenced unusual-sized t(11;14)(q13;q32) and t(14;18)(q32;q21) products from 33 of these patients. BCL-1 or BCL-2 gene rearrangements were confirmed in 23 of 33 patients (70%). Considerable size variation was observed using t(11;14) primers, with MTCA and MTCB t(11;14) products ranging from 234 to 934 bp and 143 to 560 bp respectively. Less variability was observed for t(14;18) Major Breakpoint Region (MBR) products (100-252 bp) but Minor Cluster Region (MCR) products ranged from 217 to 498 bp. We demonstrate the utility of sequence analysis to confirm unusual-sized translocation products and reduce false-positive results because of nonspecific amplification.

Chromosomes, Human, Pair 11↗
PubMed1996

Expression of oncogene products, anti-oncogene products and oncofetal antigens in intraductal papillary-mucinous neoplasm of the pancreas.

A few previous studies have demonstrated the expression or mutations of oncogenes and anti-oncogenes as well as that of oncofetal antigens in intraductal papillary-mucinous neoplasm of the pancreas. In this study, we have investigated the immunohistochemical expression of oncogene (ras and c-erbB-2) and anti-oncogene (p53 and retinoblastoma [Rb]) products and oncofetal antigens (CEA, CA19-9 and DUPAN-2) in nine such tumours of the pancreas. In normal pancreas (5 cases), the Rb gene product and CA19-9 were expressed in all cases, while ras and c-erbB-2 gene products, p53 protein, CEA and DUPAN-2 were not expressed. In intraductal papillary-mucinous tumours (n = 9), ras, c-erbB-2, p53 and Rb gene products were present in 4/9 (44%), 7/9 (78%), 0.9 (0%) and 6/9 (67%) cases, respectively. CEA, CA19-9 and DUPAN-2 were expressed in 8/9 (89%), 9/9 (100%) and 2/9 (22%) cases respectively. In invasive ductal adenocarcinoma of the pancrease (7 cases), ras, c-erbB-2, p53 and Rb gene products were expressed in 3/7 (43%), 6/7 (86%), 2/7 (29%) and 3/& (43%) cases respectively. CEA, CA19-9 and DUPAN-2 were expressed in 7/7 (100%), 7/7 (100%) and 6/7 (86%) cases, respectively. The extent and intensity of the expression of these antigens was greater in invasive ductal adenocarcinomas. These data suggest that activation of ras and c-erbB-2 oncogenes and inactivation of Rb anti-oncogene may contribute to the development and progression of intraductal papillary-mucinous tumours of the pancreas and that there is neo-expression of CEA and DUPAN-2 during the development and progression of these tumours.

Adenocarcinoma, Mucinous↗
PubMed2006

Histamine and prostaglandin E up-regulate the production of Th2-attracting chemokines (CCL17 and CCL22) and down-regulate IFN-gamma-induced CXCL10 production by immature human dendritic cells.

Effector memory T helper 2 (Th2) cells that accumulate in target organs (i.e. skin or bronchial mucosa) have a central role in the pathogenesis of allergic disorders. To date, the factors that selectively trigger local production of Th2-attracting chemokines remain poorly understood. In mucosa, at the sites of allergen entry, immature dendritic cells (DC) are in close contact with mast cells. Histamine and prostaglandin E2 (PGE2) are two mediators released by allergen-activated mast cells that favour the polarization of maturing DC into Th2-polarizing cells. We analysed here the effects of histamine and PGE2 on the prototypic, Th2-(CCL17, CCL22) versus Th1-(CXCL10) chemokine production by human DC. We report that histamine and PGE2 dose-dependently up-regulate CCL17 and CCL22 by monocyte-derived immature DC. These effects were potentiated by tumour necrosis factor-alpha, still observed in the presence of the Th1-cytokine interferon-gamma (IFN-gamma) and abolished by the immunomodulatory cytokine interleukin-10. In addition, histamine and PGE2 down-regulated IFN-gamma-induced CXCL10 production by monocyte-derived DC. These properties of histamine and PGE2 were observed at the transcriptional level and were mediated mainly through H2 receptors for histamine and through EP2 and EP4 receptors for PGE2. Finally, histamine and PGE2 also up-regulated CCL17 and CCL22 and decreased IFN-gamma-induced CXCL10 production by purified human myeloid DC. In conclusion, these data show that, in addition to polarizing DC into mature cells that promote naïve T-cell differentiation into Th2 cells, histamine and PGE2 may act on immature DC to trigger local Th2 cell recruitment through a selective control of Th1/Th2-attracting chemokine production, thereby contributing to maintain a microenvironment favourable to persistent immunoglobulin E synthesis.

Cells, Cultured↗
PubMed1997

Neonates at risk of atopy show impaired production of interferon-gamma after stimulation with bacterial products (LPS and SEE)

Recent studies demonstrate reduced interferon-gamma (IFN-gamma) secretion in neonates who became atopic later in life. The underlying pathomechanism is still unknown. We therefore examined the effects of bacterial products on neonatal IFN-gamma production acting through different T-cell- or antigen-presenting-cell (APC)-stimulating mechanisms: cord-blood mononuclear cells (CBMC) were incubated with lipopolysaccharide (LPS), staphylococcal enterotoxin E (SEE), or a combination of both and restimulated with PMA and ionomycin. LPS and SEE as single stimuli induced IFN-gamma production to the same extent in CBMC of neonates with high and low risk of atopy. In contrast, a combination of LPS and SEE had a multiplying effect on IFN-gamma secretion only in CBMC of neonates with low risk of atopy. Phenotype analysis revealed that only memory T cells showed impaired IFN-gamma synthesis (median 3.6% IFN-gamma-producing cells vs 14.2% in controls: P < 0.01), whereas IFN-gamma production by naive T cells did not differ in either group. Taken together, these results point to the existence of a disturbed function of costimulatory mechanisms in neonates at high risk of atopy, provoking reduced memory T-cell IFN-gamma production.

Antigen Presentation↗