Evaluation of the overall impact of antibiotics growth promoters on broiler health and productivity during the medication and withdrawal period.

The effectiveness of some common combination of antibiotic growth promoters (AGP) on growth performance, gut health, and meat quality was evaluated during the medication and withdrawal period in broilers. A total of 540 male Arbor Acre broilers at 0 D of age were randomly assigned to 5 treatments, with 6 replicates of 18 chicks. Broilers received diets during the medication period (0 to 42 D) as follows: NC (control diet without AGP), EN (NC + enduracidin 8 ppm + colistin sulfate 8 ppm), BZ (NC + bacitracin zinc 40 ppm + colistin sulfate 8 ppm), CT (NC + chlortetracycline 50 ppm + colistin sulfate 8 ppm), and VG (NC + virginiamycin 20 ppm + colistin sulfate 8 ppm). Broilers were switched to the same finisher diet without AGP during the withdrawal period (43 to 49 D). The feed:gain ratio in EN, BZ, CT, and VG groups were significantly decreased by 0.07, 0.10, 0.06, and 0.05 during 0 to 42 D (P < 0.05), but increased by 0.19 (P > 0.05), 0.33 (P > 0.05), 0.49 (P < 0.05), and 0.69 (P < 0.05) during the withdrawal period, respectively. The jejunum villus height (VH) increased in EN group (P < 0.05) and crypt depth (CD) reduced in BZ, CT, and VG groups (P < 0.05) at 42 D, while jejunum VH increased in EN and BZ groups (P < 0.05) at 49 D compared to NC group (P < 0.05). Meat quality detection at 49 D found all AGP groups with the higher cook loss of the breast muscle, while CT group with the higher cook loss of thigh muscle. Consequently, the overall effects of 4 AGP combinations in the whole period were not significant on growth performance. Their poor growth performance during the withdrawal period should be partly attributed to the falling off a cliff of most digestive enzyme activities from 42 to 49 D. Attention should be paid to the adverse effects of AGP supplementation on meat quality, especially cook loss.

Comparison of performance and feed digestibility of the non-antibiotic feed supplement (Novacid) and an antibiotic growth promoter in broiler chickens.

Antibiotic growth promoters have been widely used in poultry to improve overall performance. The emergence of antibiotic resistance has resulted in sanctions imposed on the use of antibiotics in poultry diets, and alternatives such as herbal extracts are being considered to improve growth performance. The aim of this study was to compare the performance and feed digestibility of the feed supplement Novacid, which contains organic acids, glucomannan, and phytochemicals, with that of the antibiotic growth promoter bacitracin methylene disalicylate (BMD) in commercial broiler chickens. Six hundred 1-d-old Ross × Ross 308 male broiler chicks were randomly and equally assigned to six treatment groups with five replicates each (20 chicks per replicate). The chicks were fed a corn-soybean meal basal diet, and divided into two groups: unchallenged and challenged with E. coli (400 mg/kg Escherichia coli inoculation). Each of these groups was divided into three study groups: untreated, treated with 0.05% Novacid, and treated with 400 mg/kg BMD. At day 42, inclusion of Novacid or BMD significantly (P < 0.05) improved the performance in the unchallenged groups relative to the control group. However, in E. coli-challenged groups, Novacid and BMD did not improve performance. Ileal digestibility of crude fat, crude protein, and gross energy were reduced in the Novacid group (P < 0.05). BMD and Novacid were equally effective in controlling ileal nutrient digestibility and feed coliform count (P < 0.05). Novacid reduced cecal E. coli and Salmonella count compared to BMD and control. Thus, a phytochemical feed supplement with organic acids and glucomannan could be an effective substitute for antibiotic growth promoters in broiler diets, but cannot replace antibiotics to counter potent infectious agents such as E. coli.

Premature delivery influences the immunological composition of colostrum and transitional and mature human milk.

Human breast milk is the ideal nutrition for the newborn, and in addition to its nutritional contribution, necessary for infant growth and development, it contains various immune bioactive factors that confer some of the numerous beneficial effects of breastfeeding. The current study analyzed the concentrations of IgA, growth factors such as epidermal growth factor (EGF), TGFß1, and TGFß2, cytokines IL-6, IL-8, IL-10, IL-13, and TNFα, and TNF-receptor I (TNF-RI) in colostrum and transitional and mature milk from mothers with mature, premature, and very premature infants. Human milk samples were collected from mothers delivering at term (T), preterm (PT), and very preterm (VPT). Milk from all the mothers was collected at 3 different time points after delivery corresponding to colostrum and transitional and mature milk. After obtaining milk whey, IgA, EGF, TGFß1, and TGFß2 were determined by ELISA and IL-6, IL-8, IL-10, IL-13, TNFα and TNF-RI by cytometric bead array immunoassay. The colostrum of the PT group was extremely rich in most of the factors studied, but higher concentrations than in the T group were only found for IL-6 (P = 0.051), TGFß1, and TGFß2 (P < 0.05). Conversely, the colostrum of the VPT group had lower concentrations of IgA, IL-8, IL-10, and TNFα than those in the T group (P < 0.05). Results suggest that maternal lactogenic compensatory mechanisms accelerating the development of immature breast-fed preterm infants may take effect only after wk 30 of gestation.

Utility of hyperbaric oxygen in treatment of bisphosphonate-related osteonecrosis of the jaws.

Bisphosphonates suppress bone turnover by disrupting osteoclast signal transduction, maturation, and longevity. In some patients, it has been hypothesized that suppressed turnover can impair oral wound healing, leading to a distressing, osteopetrosis-like jaw necrosis called bisphosphonate-related osteonecrosis of the jaws (BRONJ). Hyperbaric oxygen (HBO), as an adjunct to surgery and antibiotics, might have utility in the treatment of BRONJ because it produces reactive oxygen and nitrogen species that positively modulate the redox-sensitive intracellular signaling molecules involved in bone turnover. The efficacy of HBO in the treatment of BRONJ is currently under investigation in randomized controlled trials at Duke University and the University of Minnesota, and the early results have been encouraging. This report discusses osteoclast biology, how HBO has the potential to augment bone turnover by way of the signaling effects on osteoclasts, the available clinical data on HBO in the treatment of BRONJ, the ongoing randomized controlled trials of HBO, and the study-associated efforts to find biomarkers to characterize an individual's risk of developing this disease.

Effects of docosahexaenoic acid-rich n-3 fatty acid supplementation on cytokine release from blood mononuclear leukocytes: the OmegAD study.

BACKGROUND: Dietary fish or fish oil rich in n-3 fatty acids (n-3 FAs), eg, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), ameliorate inflammatory reactions by various mechanisms. Whereas most studies have explored the effects of predominantly EPA-based n-3 FAs preparations, few have addressed the effects of n-3 FAs preparations with DHA as the main FA. OBJECTIVE: The objective was to determine the effects of 6 mo of dietary supplementation with an n-3 FAs preparation rich in DHA on release of cytokines and growth factors from peripheral blood mononuclear cells (PBMCs). DESIGN: In a randomized, double-blind, placebo-controlled trial, 174 Alzheimer disease (AD) patients received daily either 1.7 g DHA and 0.6 g EPA (n-3 FAs group) or placebo for 6 mo. In the present study blood samples were obtained from the 23 first randomized patients, and PBMCs were isolated before and after 6 mo of treatment. RESULTS: Plasma concentrations of DHA and EPA were significantly increased at 6 mo in the n-3 FAs group. This group also showed significant decreases of interleukin (IL)-6, IL-1beta, and granulocyte colony-stimulating factor secretion after stimulation of PBMCs with lipopolysaccharide. Changes in the DHA and EPA concentrations were negatively associated with changes in IL-1beta and IL-6 release for all subjects. Reductions of IL-1beta and IL-6 were also significantly correlated with each other. In contrast, this n-3 FA treatment for 6 mo did not decrease tumor necrosis factor-alpha, IotaL-8, IL-10, and granulocyte-macrophage colony-stimulating factor secretion. CONCLUSION: AD patients treated with DHA-rich n-3 FAs supplementation increased their plasma concentrations of DHA (and EPA), which were associated with reduced release of IL-1beta, IL-6, and granulocyte colony-stimulating factor from PBMCs. This trial was registered at clinicaltrials.gov as NCT00211159.

Minireview: the neuroendocrine regulation of puberty: is the time ripe for a systems biology approach?

The initiation of mammalian puberty requires an increase in pulsatile release of GnRH from the hypothalamus. This increase is brought about by coordinated changes in transsynaptic and glial-neuronal communication. As the neuronal and glial excitatory inputs to the GnRH neuronal network increase, the transsynaptic inhibitory tone decreases, leading to the pubertal activation of GnRH secretion. The excitatory neuronal systems most prevalently involved in this process use glutamate and the peptide kisspeptin for neurotransmission/neuromodulation, whereas the most important inhibitory inputs are provided by gamma-aminobutyric acid (GABA)ergic and opiatergic neurons. Glial cells, on the other hand, facilitate GnRH secretion via growth factor-dependent cell-cell signaling. Coordination of this regulatory neuronal-glial network may require a hierarchical arrangement. One level of coordination appears to be provided by a host of unrelated genes encoding proteins required for cell-cell communication. A second, but overlapping, level might be provided by a second tier of genes engaged in specific cell functions required for productive cell-cell interaction. A third and higher level of control involves the transcriptional regulation of these subordinate genes by a handful of upper echelon genes that, operating within the different neuronal and glial subsets required for the initiation of the pubertal process, sustain the functional integration of the network. The existence of functionally connected genes controlling the pubertal process is consistent with the concept that puberty is under genetic control and that the genetic underpinnings of both normal and deranged puberty are polygenic rather than specified by a single gene. The availability of improved high-throughput techniques and computational methods for global analysis of mRNAs and proteins will allow us to not only initiate the systematic identification of the different components of this neuroendocrine network but also to define their functional interactions.

Identification of a switch in neurotrophin signaling by selective tyrosine phosphorylation.

Neurotrophins, such as nerve growth factor and brain-derived neurotrophic factor, activate Trk receptor tyrosine kinases through receptor dimerization at the cell surface followed by autophosphorylation and recruitment of intracellular signaling molecules. The intracellular pathways used by neurotrophins share many common protein substrates that are used by other receptor tyrosine kinases (RTK), such as Shc, Grb2, FRS2, and phospholipase C-gamma. Here we describe a novel RTK mechanism that involves a 220-kilodalton membrane tetraspanning protein, ARMS/Kidins220, which is rapidly tyrosine phosphorylated in primary neurons after neurotrophin treatment. ARMS/Kidins220 undergoes multiple tyrosine phosphorylation events and also serine phosphorylation by protein kinase D. We have identified a single tyrosine (Tyr(1096)) phosphorylation event in ARMS/Kidins220 that plays a critical role in neurotrophin signaling. A reassembled complex of ARMS/Kidins220 and CrkL, an upstream component of the C3G-Rap1-MAP kinase cascade, is SH3-dependent. However, Tyr(1096) phosphorylation enables ARMS/Kidins220 to recruit CrkL through its SH2 domain, thereby freeing the CrkL SH3 domain to engage C3G for MAP kinase activation in a neurotrophin dependent manner. Accordingly, mutation of Tyr(1096) abolished CrkL interaction and sustained MAPK kinase activity, a response that is not normally observed in other RTKs. Therefore, Trk receptor signaling involves an inducible switch mechanism through an unconventional substrate that distinguishes neurotrophin action from other growth factor receptors.

Ginkgo biloba extract alleviates liver fibrosis induced by CCl in rats.

AIMS: To investigate the protective effect of Ginkgo biloba extract (GbE) on liver fibrosis induced by carbon tetrachloride (CCl4) in rats and expressions of transforming growth factor beta1 (TGF-beta1) and collagen I during this period. METHODS: The effect of GbE on liver fibrogenesis was detected by hematoxylin and eosin staining (H&E staining), Masson's trichrome staining, and electron microscope study. Blood samples were collected for measurement of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and albumin. Malondialdehyde (MDA) in liver tissue was detected by the thiobarbituric acid (TBA) method. Immunohistochemistry assay and RT-PCR were used to examine the protein expressions and mRNA levels of TGF-beta1 and collagen I, respectively. RESULTS: H&E, Masson's trichrome stainings and electron microscope study showed liver fibrosis in rats was greatly alleviated when treated with GbE. Additionally, there was a remarkable improvement of serum ALT, AST, albumin and MDA in the GbE-treated group. Immunohistochemistry and RT-PCR results showed GbE intervention significantly inhibited TGF-beta1 and collagen I expressions in rat liver. No side effects of GbE were found during these experiments. But GbE could not reverse the pathological changes of liver fibrosis completely when compared with normal control. CONCLUSION: GbE can partially protect rat liver from the fibrogenesis induced by CCl4. The mechanism may lie in its effect of inhibiting oxidative stress caused by liver injury and expressions of signal molecules such as TGF-beta1. GbE may thus be of potential help as a medicament or food additive for alleviation of liver fibrogenesis.

Trapping of growth factors by catechins: a possible therapeutical target for prevention of proliferative diseases.

The prevention of cancer through dietary intervention is currently receiving considerable attention. Several epidemiological studies substantiate that green tea has a protective effect against a variety of malignant proliferative disorders such as lung cancer, breast cancer and prostate cancer. This preventive potential of green tea against cancer is attributed to the biologically active flavonoids called catechins. Epigallocatechin 3-o-gallate, the major catechin found in green tea, mediates diverse physiological and pharmacological actions in bringing about the regression of the tumors and also lowers the risk of nonmalignant cardiovascular proliferative diseases. Much of the current research is being focused on how these catechins specifically bring about the regression of the experimentally induced tumors both in vitro and in vivo. These catechins exert diverse physiological effects against proliferative diseases by several mechanisms, most of which are not completely characterized. This review summarizes the mechanisms by which these catechins play an essential role in regulating the process of carcinogenesis, with a special emphasis on how these catechins antagonize the growth factor-induced proliferative disorders.

A study of Q-switched Nd:YAG laser irradiation and paracrine function in human skin cells.

BACKGROUND AND OBJECTIVES: This preliminary laboratory-based study looks at the paracrine release from human skin cells subject to sublethal Q-switched Nd:YAG 532 nm laser irradiation. STUDY DESIGN/MATERIALS AND METHODS: Human dermal fibroblast and keratinocyte cultures were exposed to sublethal energy using the Nd:YAG 532 nm laser. Altered gene expression was then screened using RT-PCR for a range of paracrine factors known to affect melanogenesis, basic fibroblast growth factor (b-FGF), hepatocyte growth factor (HGF), stem cell factor (SCF), melanocyte stimulating hormone (MSH), endothelin-1 (ET-1), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and protease-activated receptor-2 (PAR-2). Enzyme-linked immunosorbent assay (ELISA) was used to confirm protein production. Conditioned medium was used to assess altered melanogenesis in a melanoma cell line. RESULTS: Fibroblasts exposed to sublethal radiation showed upregulation of b-FGF, HGF and SCF. This contrasts with keratinocytes which showed upregulation of IL-6. Elevated protein levels of b-FGF and SCF were confirmed by ELISA assay. Conditioned fibroblast medium was shown to stimulate melanogenesis in a melanoma cell line. CONCLUSIONS: This preliminary laboratory study reports, for the first time, specific gene upregulation using the Q-switched Nd:YAG 532 nm laser.

Structural requirements of the extracellular to transmembrane domain junction for erythropoietin receptor function.

The erythropoietin receptor (EpoR) is crucial for erythrocyte formation. The x-ray crystal structures of the EpoR extracellular domain lack the juxtamembrane (JM) region and the junction to the transmembrane (TM) domain. Yet the JM-TM regions are important for transmitting the conformational change imposed on the receptor dimer by Epo binding. Cysteine-scanning mutagenesis of the JM-TM regions identified three novel constitutively active mutants, demonstrating close disulfide-bonded juxtapositioning of these residues in the JM (L223C) and N-terminal TM domain (L226C, I227C). Chemical cross-linking defined the interface of the active helical TM dimer and revealed that the JM-TM segment encompassing Leu(226)-Leu(230) is non-helical. Molecular dynamics and NMR studies indicated that the TM-JM junction forms an N-terminal helix cap. This structure is important for EpoR function because replacement of this motif by consecutive leucines rendered the receptor constitutively active.

The phosphoinositol 3,4-bisphosphate-binding protein TAPP1 interacts with syntrophins and regulates actin cytoskeletal organization.

Syntrophins are scaffold proteins of the dystrophin glycoprotein complex (DGC), which target ion channels, receptors, and signaling proteins to specialized subcellular domains. A yeast two-hybrid screen of a human brain cDNA library with the PSD-95, Discs-large, ZO-1 (PDZ) domain of gamma1-syntrophin yielded overlapping clones encoding the C terminus of TAPP1, a pleckstrin homology (PH) domain-containing adapter protein that interacts specifically with phosphatidylinositol 3,4-bisphosphate (PI(3,4)P(2)). In biochemical assays, the C terminus of TAPP1 bound specifically to the PDZ domains of gamma1-, alpha1-, and beta2-syntrophin and was required for syntrophin binding and for the correct subcellular localization of TAPP1. TAPP1 is recruited to the plasma membrane of cells stimulated with platelet-derived growth factor (PDGF), a motogen that produces PI(3,4)P(2). Cell migration in response to PDGF stimulation is characterized by a rapid reorganization of the actin cytoskeleton, which gives rise to plasma membrane specializations including peripheral and dorsal circular ruffles. Both TAPP1 and syntrophins were localized to PDGF-induced circular membrane ruffles in NIH-3T3 cells. Ectopic expression of TAPP1 potently blocked PDGF-induced formation of dorsal circular ruffles, but did not affect peripheral ruffling. Interestingly, coexpression of alpha1- or gamma1-syntrophin with TAPP1 prevented the blockade of circular ruffling. In addition to syntrophins, several other proteins of the DGC were enriched in circular ruffles. Collectively, our results suggest syntrophins regulate the localization of TAPP1, which may be important for remodeling the actin cytoskeleton in response to growth factor stimulation.

Direct cell cycle regulation by the fibroblast growth factor receptor (FGFR) kinase through phosphorylation-dependent release of Cks1 from FGFR substrate 2.

Fibroblast growth factors (FGFs) are upstream activators of the mitogen-activated protein kinase pathway and mitogens in a wide variety of cells. However, whether the mitogen-activated protein kinase pathway solely accounts for the induction of cell cycle or antiapoptotic activity of the FGF receptor (FGFR) tyrosine kinase is not clear. Here we report that cell cycle inducer Cks1, which triggers ubiquitination and degradation of p27(Kip1), associates with the unphosphorylated form of FGFR substrate 2 (FRS2), an adaptor protein that is phosphorylated by FGFR kinases and recruits downstream signaling molecules. FGF-dependent activation of FGFR tyrosine kinases induces FRS2 phosphorylation, causes release of Cks1 from FRS2, and promotes degradation of p27(Kip1) in 3T3 cells. Since degradation of p27(Kip1) is a key regulatory step in activation of the cyclin E/A-Cdk complex during the G(1)/S transition of the cell cycle, the results suggest a novel mitogenic pathway whereby FGF and other growth factors that activate FRS2 directly activate cyclin-dependent kinases.

Anti-tumor activity of calcitriol: pre-clinical and clinical studies.

1,25-Dihydroxycholecalciferol (calcitriol) is recognized widely for its effects on bone and mineral metabolism. Epidemiological data suggest that low Vitamin D levels may play a role in the genesis of prostate cancer and perhaps other tumors. Calcitriol is a potent anti-proliferative agent in a wide variety of malignant cell types. In prostate, breast, colorectal, head/neck and lung cancer as well as lymphoma, leukemia and myeloma model systems calcitriol has significant anti-tumor activity in vitro and in vivo. Calcitriol effects are associated with an increase in G0/G1 arrest, induction of apoptosis and differentiation, modulation of expression of growth factor receptors. Glucocorticoids potentiate the anti-tumor effect of calcitriol and decrease calcitriol-induced hypercalcemia. Calcitriol potentiates the antitumor effects of many cytotoxic agents and inhibits motility and invasiveness of tumor cells and formation of new blood vessels. Phase I and II trials of calcitriol either alone or in combination with carboplatin, taxanes or dexamethasone have been initiated in patients with androgen dependent and independent prostate cancer and advanced cancer. Data indicate that high-dose calcitriol is feasible on an intermittent schedule, no dose-limiting toxicity has been encountered and optimal dose and schedule are being delineated. Clinical responses have been seen with the combination of high dose calcitriol+dexamethasone in androgen independent prostate cancer (AIPC) and apparent potentiation of the antitumor effects of docetaxel have been seen in AIPC. These results demonstrate that high intermittent doses of calcitriol can be administered to patients without toxicity, that the MTD is yet to be determined and that calcitriol has potential as an anti-cancer agent.

A new simplified technique for producing platelet-rich plasma: a short technical note.

A possible strategy to promote the wound-healing cascade in both soft and hard tissues is the preparation of an autologous platelet-rich plasma (PRP) to encourage the release of growth factors from activated platelets. In this process, PRP combines the advantage of an autologous fibrin clot that will aid in hemostasis as well as provide growth factors in high concentrations to the site of a tissue defect. The PRP preparation can be used as a biological enhancer in the healing of fractures and lumbar fusions. The local application of growth factors seems to promote initiation and early maturation of bone formation. Autologous bone or bone substitutes can be added to this mixture to increase the volume of grafting material. A simplified technique utilizing a commercially available separation system (GPS-Gravitational Platelet Separation System) is described. This system provides a less costly alternative to other previously described augmentation techniques and also presents a patient-friendly and operator-safe alternative. Further experimental studies of the actual concentrations of the growth factors in the PRP samples are necessary in order to validate the platelet concentration and growth-factor activation by laboratory evidence. In further prospective clinical trials, the safety and efficacy of PRP, in combination with autologous bone or bone graft substitutes, must be evaluated.

[Hypothalamic glial cells and endothelial cells as key regulators of GnRH secretion]. / Des acteurs clés de la régulation de la sécrétion de GnRH: les cellules gliales et endothéliales de l'hypothalamus.

During the last decade, compelling evidence has been provided that, in addition of being regulated by transsynaptic inputs, GnRH neuroendocrine secretion is modulated by factors released both by glial cells and the endothelium of pituitary portal blood vessels. Glial cells exert their regulatory influence on GnRH release through the secretion of growth factors, such as TGFbetas and peptides member of the EGF family, that act either directly on GnRH neurons or require prostaglandin release from astrocytes, respectively. On the other hand vascular endothelial cells stimulate GnRH release via NO secretion. In addition, recent studies suggest that both glial cells and endothelial cells of the median eminence can modulate the direct access of GnRH neuroendocrine terminals to the vascular wall and thus control GnRH release efficiency. During the reproductive cycle, direct neurovascular contacts of GnRH nerve endings, that are engulfed in tanycytic endfeet, only occur at periods when massive GnRH release is required, i.e., at the onset of the preovulatory GnRH/LH surge on the day of proestrus. Recent in vitro and in vivo data demonstrate that both glial (TGFalpha and TGFbeta) and endothelial (NO) factors can induce such morphological plasticity. Neuro-glio-endothelial interactions at the median eminence of the hypothalamus thus appear to be key regulatory mechanisms for GnRH neuroendocrine secretion.

Neonatal capsaicin treatment affects rat thymocyte proliferation and cell death by modulating substance P and neurokinin-1 receptor expression.

Herein we provide evidence that substance P (SP) and its neurokinin-1 receptor (NK-1R) expressed on thymocytes counteract thymus depletion induced by neonatal capsaicin (CPS) treatment by affecting thymocyte proliferation and apoptotic death. SP administration reversed the CPS-mediated inhibitory effects on the total thymocyte number and subset distribution, namely CD4+ and CD4- CD8- cells, through its interaction with NK-1R as shown by concomitant NK-1R (SR140333) antagonist administration. SP-induced enhancement of thymus cellularity parallels its ability of inhibiting the thymocyte apoptotic program. Indeed, exogenously administered SP completely nullified CPS-induced apoptosis, and SR140333 abrogated the SP-mediated protective effect. SP administration also stimulated concanavalin A (Con A)-induced thymocyte proliferation of CPS-treated rats, completely reversing the CPS-induced inhibition. The SP-mediated stimulation of Con A-induced thymocyte proliferation was NK-1R dependent as shown by concomitant administration of SP and SR140333 to CPS-treated rats. Our results also demonstrate that CPS treatment induces a marked decrease of thymocyte PPT-A mRNA level and endogenous SP content as evaluated by quantitative RT-PCR, in situ hybridization and cytofluorimetric analysis. By contrast, NK-1R mRNA levels were increased in thymocytes from CPS-treated rats. Exogenous SP administration augmented PPT-A, SP and NK-1R thymocyte expression in CPS-treated rats, and this enhancement was antagonized by SR140333 administration. Overall, our results strongly suggest that the immunomodulatory effects of neonatal CPS treatment on rat thymocyte functions are dependent on vanilloid-mediated regulation of SP and NK-1R functional expression by neuronal and immune cells.

Effects of colostrum feeding and dexamethasone treatment on mRNA levels of insulin-like growth factors (IGF)-I and -II, IGF binding proteins-2 and -3, and on receptors for growth hormone, IGF-I, IGF-II, and insulin in the gastrointestinal tract of neonatal calves.

The somatotropic axis regulates growth of the gastrointestinal tract (GIT). In addition, colostrum feeding and glucocorticoids affect maturation of the GIT around birth in mammals. We have measured mRNA levels of members of the somatotropic axis to test the hypothesis that colostrum intake and dexamethasone treatment affect respective gene expression in the GIT. Calves were fed either colostrum or an isoenergetic milk-based formula, and in each feeding group, half of the calves were treated with dexamethasone (DEXA; 30 microg/kg body weight per day). Individual parameters of the somatotropic axis differed (P < 0.05) among different GIT sections and formula feeding increased (P < 0.05) mRNA levels of individual parameters at various sites of the GIT. Effects of DEXA on the somatotropic axis in the GIT partly depended on different feeding. In colostrum-fed calves, DEXA decreased (P < 0.05) mRNA levels of IGF-I (esophagus, fundus, duodenum, and ileum), IGF-II (fundus), IGFBP-2 (fundus), IGFBP-3 (fundus), IGF1R (esophagus, ileum, and colon), IGF2R (fundus), GHR (fundus), and InsR (esophagus, fundus), but in formula-fed calves DEXA increased mRNA levels of IGF-I (esophagus, rumen, jejunum, and colon). Furthermore, DEXA increased (P < 0.05) mRNA levels of IGF-II (pylorus), IGFBP-3 (duodenum), IGF2R (pylorus), and GHR (ileum), but decreased mRNA levels of IGFBP-2 (ileum), and IGF1R (fundus). Whereas formula feeding had stimulating effects, effects of DEXA treatment on the gene expression of parameters of the somatotropic axis varied among GIT sites and partly depended on feeding.

Pulsed electromagnetic field stimulation of bone marrow cells derived from ovariectomized rats affects osteoclast formation and local factor production.

This study examined the effects of a specific pulsed electromagnetic field (PEMF) stimulation on osteoclast formation in bone marrow cells from ovariectomized rats and to determine if the signal modulates the production of cytokines associated with osteoclast formation. Adult female Wistar rats were subjected to bilateral or sham ovariectomy, and primary bone marrow cells were harvested at 4 days (Subgroup I) and 7 days (Subgroup II) after surgery. Primary bone marrow cells were subsequently placed in chamber slides and set inside solenoids powered by a pulse generator (300 micros, 7.5 Hz) for 1 h per day for 9 days (OVX + PEMF group). Others (INT, SHAM, and OVX groups) were cultured under identical conditions, but no signal was applied. Recruitment and authentication of osteoclast-like cells were evaluated by determining multinuclear, tartrate-resistant acid phosphatase (TRAP) positive cells on day 10 of culture and by pit formation assay, respectively. The PEMF signal caused significant reductions in osteoclast formation in both Subgroups I (-55%) and II (-43%). Tumor necrosis factor-alpha (TNF-alpha), interleukin 1beta (IL-1beta), and interleukin 6 (IL-6) in OVX + PEMF group of Subgroup I were significantly reduced at 5, 7, and 9 days as compared to OVX group. The results found in this study suggest that osteoclastogenesis can be inhibited by PEMF stimulation, putatively due to a concomitant decrease in local factor production. Bioelectromagnetics 25:134-141, 2004.