Changes in distribution of lectin receptors in macrophages activated by Nocardia water soluble molecules

Lectin-histochemical studies were performed on macrophages activated by Nocardia opaca water soluble molecules (NWSM) and elicited by phosphate buffered saline (PBS) as control to demonstrate the pattern of carbohydrate residues. Ten different biotinylated lectins were used as probes and avidin-biotin-peroxidase complex (ABC) was used as visualizer. The lectins wheat germ agglutinin (WGA) and Griffonia simplicifolia agglutinin-I (GS-I) stained macrophages only after activation by NWSM and not macrophages elicited by PBS. Both macrophages did not stain by succinylated wheat germ agglutinin (S-WGA). The difference in lectin-binding patterns between NWSM-activated and PBS-elicited macrophages, suggests that activation of macrophages by the NWSM is associated with modification in the distribution of specific membrane carbohydrates, including enhancement in the expression of sialyl and alpha-galactosyl residues.

[The effect of beta-carotene on the development of adjuvant arthritis and interleukin-1 production in rats]

The production of interleukin 1 (IL1) by peritoneal and splenic macrophages from rats with adjuvant-induced arthritis on day 17 postadjuvant treatment was not altered compared with normal. Treatment of arthritic rats with beta-carotene reduced hind paw swelling and significantly increased ability of macrophages to secrete IL1 as well as stimulated spontaneous proliferation of splenic lymphocytes. No direct relationship between the release of IL1 from peritoneal and splenic macrophages and increase of hind paw swelling was revealed.

Macrophage prostaglandin E2 and oxidative responses to endotoxin during immunosuppression associated with anaesthesia and transfusion

The widespread use of blood transfusion in major surgical procedures has led to concern about the immunosuppressive effect of transfusion on patients with underlying malignancy. Transfusion may also suppress the host response to infection. The cellular mechanisms of transfusion-associated immunosuppression may involve macrophage prostaglandin E2 (PGE2) in modulating the host response to cancer and infection. We previously observed that the transfusion of blood increased PGE2 production by unstimulated macrophages. To investigate this PGE2 associated immunosuppression, we studied the effect of transfusion of rats using a physiological stimulus of macrophage PGE2 production, bacterial endotoxin. In the same macrophages, we analysed intracellular oxidative activity. Both allogeneic and syngeneic blood transfusion were associated with increased PGE2 release by macrophages. This stimulation of PGE2 increased with duration of storage of blood. A similar effect of serum indicated that a humoral factor was involved. Endotoxin (50 ng/ml-500 micrograms/ml) stimulated PGE2 production in all transfused subjects. The lowest endotoxin concentration gave proportionately the greatest stimulation. Oxidative activity was down-regulated in macrophages of transfused rats, supporting an immunosuppressive role of PGE2 within the macrophage. An effect of surgery on the oxidative response was also detected.

Both mannose and beta-glucan receptors are involved in phagocytosis of unopsonized, heat-killed Saccharomyces cerevisiae by murine macrophages

We studied the involvement of lectin-like receptors in phagocytosis of unopsonized heat-killed yeast (Saccharomyces cerevisiae) by murine macrophage-like cell lines and murine peritoneal resident macrophages. For this purpose we used a technique that allowed us to discriminate ingested and adsorbed heat-killed yeast. The internalization can be partly inhibited by soluble polyosides such as laminarin (beta-glucan) or alpha-mannan. However, when they were used together (0.4 mg/ml alpha-mannan and 0.4 mg/ml laminarin), almost complete inhibition of phagocytosis was obtained. These observations suggest that phagocytosis of unopsonized heat-killed yeast by murine macrophage-like cell lines as well as murine peritoneal resident macrophages is mediated by both mannose and beta-glucan receptors. The respective activity of these two types of receptors is a function of in vitro cell differentiation. To achieve maximal phagocytosis of unopsonized heat-killed yeast, coexpression of both mannose and beta-glucan receptors is required.

IL-10 neutralization augments mouse resistance to systemic Mycobacterium avium infections

In this contribution, we examined the involvement of the cytokine IL-10 in the progression of experimental murine Mycobacterium avium infections in susceptible BALB/c mice. Addition of anti-IL-10 antibodies in the supernatants of peritoneal macrophages infected with virulent M. avium resulted in a significantly enhanced mycobacteriostatic activity of macrophages. In BALB/c mice infected with the B101 or B102 virulent M. avium strains, examination of the cytokine release profile in splenocytes from infected mice showed that infection was associated with an initial copious release of both IFN-gamma and IL-10. IL-10 production increased as the infection progressed, whereas IFN-gamma levels diminished. Infected mice were given repeated infusions of a rat mAb against mouse IL-10 or rat IgM. Examination of IgM serum levels in anti-IL-10-treated mice (infected or not) showed that depletion of endogenous IL-10 resulted in much decreased IgM levels. Results showed that infusions of large dosages of the monoclonal anti-IL-10 resulted in a very significantly diminished bacterial growth in the spleens. These findings indicate that IL-10 may have a negative impact on resistance to M. avium infections, due, at least in part, to decreased macrophage activity.

Arginine-dependent generation of reactive nitrogen intermediates is instrumental in the in vitro killing of protoscoleces of Echinococcus multilocularis by activated macrophages

The interaction between protoscoleces of Echinococcus multilocularis and activated murine macrophages was examined in this study. Marked protoscolicidal activity was displayed by peritoneal macrophages (PM) activated with interferon-gamma (IFN-gamma), or IFN-gamma plus lipopolysaccharide. Pretreatment of the parasites with heat-inactivated specific murine infection serum, but not with normal serum rendered them more susceptible to PM killing. NG-monomethyl-L-arginine, a competitive inhibitor of L-arginine completely inhibited the killing activity of activated PM, while reconstitution of arginine-free medium with L-arginine restored the killing properties of the activated PM. The results show that activated PM have the ability to kill E. multilocularis protoscoleces in vitro and suggest that reactive nitrogen intermediates (RNI) play an important role in the mechanism. An oxygen-mediated mechanism did not appear to play a role because scavengers of reactive oxygen species did not reduce the killing activity. The arginine-dependent killing mechanism was enhanced by superoxide dismutase (SOD), probably because SOD might prolong the effect of nitric oxide. Secretion of RNI by activated macrophages may be capable of a significant role in preventing of the dissemination of E. multilocularis infection in vivo.

Antitumor activity and immuno-potentiating actions of Achyranthes bidentata polysaccharides

Achyranthes bidentata polysaccharides (ABP), isolated from the root of Achyranthes bidentata Blume, 50 mg.kg-1 ip or 250 mg.kg-1 to ICR mice inhibited the growth of sarcoma 180. ABP 50 and 100 mg.kg-1 ip prolongated the survival days of mice bearing Ehrlich carcinoma. ABP 50-800 micrograms.ml-1 did not exert direct cytotoxic effect in vitro on S180 cells, but enhanced the cytotoxicity of peritoneal macrophages against S180 cells. ABP 50 mg.kg-1 ip x 17 d or 250 mg.kg-1 ig x 16 d promoted the plaque forming cells (PFC) response to sheep red blood cells (SRBC) and serum IgG level as well as splenocyte proliferation induced by mitogen Con A or LPS in tumor-induced immunodeficient mice. ABP also elevated the NK cell activity and serum TNF content in mice bearing S180. These results indicated that the antitumor effect of ABP may be related to its potentiating effect on both specific and nonspecific host immunological responses.

Activation of murine macrophages by polysaccharide fractions from marine algae (Porphyra yezoensis)

Two discrete immunomodulating fractions were obtained from marine algae (Porphyra yezoensis): one was the Porphyra water-soluble fraction (PWSF) which was extracted with hot water from the whole body of algae, and the other was the Porphyra acid-soluble fraction (PASF) which was extracted with acid from the residue. The major constituent in both PWSF and PASF was a polysaccharide, the total sugar concentration in PWSF (56.4%) being lower than that in PASF (82.2%). The high contents of 3,6-anhydrogalactose and sulfate indicated the porphyran structure in PWSF and PASF. The results of an in vitro culture assay with proteose peptone-induced macrophages from mice revealed the PWSF and PASF both enhanced glucose consumption, as well as the production of nitrite and tumor necrosis factor (TNF), but that these were increased more by PWSF than by PASF. PWSF augmented IL-I secretion from these macrophages, while PASF did not. On the other hand, the carbon clearance activity of phagocytes from mice injected intraperitoneally with PASF was higher than that from PWSF-injected mice. The injection of PASF into mice also enhanced the carbon clearance activity in a dose-dependent manner. These results suggest that the two individual fractions possessed the ability to activate macrophages in vitro and in vivo in different ways.

Induction of IFN-gamma in macrophages by lipopolysaccharide

In this paper we report that macrophages can be stimulated to express detectable levels of IFN-gamma-specific mRNA. Macrophages from lipopolysaccharide (LPS)-responsive, C3H/OuJ mice are induced by LPS to increase steady-state levels of IFN-gamma-specific mRNA, while those from LPS-hyporesponsive C3H/HeJ mice are not. This interstrain variation is apparently the result of LPS-specific signal differences since macrophages derived from both Lpsn and Lpsd mouse strains are able to produce comparable levels of IFN-gamma-specific mRNA following stimulation with polyinosinic-polycytidylic acid. The identity of the cell type responsible for this IFN-gamma message appears to be the macrophage as IFN-gamma-specific mRNA was also detectable following T and natural killer cell depletion, in the LPS-stimulated RAW 264.7 cell line, and in a homogeneous population of mature macrophages propagated in vitro by stimulation of bone marrow progenitors with recombinant colony stimulating factor-1. Immunofluorescent staining of fixed and permeabilized LPS-stimulated macrophages confirmed the presence of immunoreactive IFN-gamma protein. The possible significance of IFN-gamma production by macrophages is discussed in the context of normal macrophage differentiation as well as the inflammatory immune response.

The role of antigen-presenting cells in the regulation of delayed-type hypersensitivity. II. Epidermal Langerhans' cells and peritoneal exudate macrophages

A new mechanism for regulation of delayed-type hypersensitivity (DTH) was investigated. The subcutaneous injection without adjuvant of syngeneic epidermal Langerhans' cells (LC) pulsed with keyhole limpet hemocyanin (KLH) into BALB/c mice gave rise to DTH upon challenge of the ear with the same antigen. When such cells were transferred intravenously, DTH did not occur, although the titer of anti-KLH antibodies was high. Peritoneal exudate macrophages (M phi) pulsed with KLH gave rise to neither DTH nor antibody production. The intravenous transfer of KLH-pulsed LC into mice immunized subcutaneously with KLH in complete Freund's adjuvant at the same time (in the sensitization phase) had a suppressive effect on DTH in an H-2-restricted way. M phi did not have immunoregulatory effects. When radiolabeled LC and M phi were transferred intravenously, they migrated into the spleen, but when they were transferred subcutaneously, they stayed in the skin or migrated into the lymph nodes. In splenectomized mice immunized with KLH, the intravenous transfer of LC pulsed with KLH neither caused the production of anti-KLH antibodies nor suppressed DTH. When Ia was expressed on the surface of M phi, the cells could present antigens, as LC could. These findings suggest that the anatomic sites at which an antigen is presented (i.e., spleen or draining lymph nodes) rather than the kind of cell that first presents an antigen to the immune system is important in deciding whether the immune response that takes place is DTH or antibody production.

Antitumor activity and tumor necrosis factor production of Phytolacca acinosa polysaccharides I in mice

The antitumor activities of Phytolacca acinosa polysaccharides I (PAP-I) and its effects on the induction of tumor necrosis factor (TNF) and immunological cytotoxicity of peritoneal macrophages were studied. PAP-I was given ip 5-20 mg.kg-1.d-1 x 7 d to ICR mice as priming agent with subsequent lipopolysaccharides (10 micrograms/mouse) iv for TNF production. TNF activity was measured by crystal violet staining assay using L929 cells. PAP-I showed priming activity for TNF production with hepto-splenic hyperplasia in a dose-dependent manner. The peritoneal macrophages treated with PAP-I 10 and 20 mg.kg-1 showed 67 and 74%, respectively, cytotoxicity (the control 34% cytotoxicity) against Meth A cells at effector:target = 40:1. PAP-I 10 and 20 mg.kg-1 prolonged the survival time of mice bearing ascites Meth A tumor from 21 +/- 4 to 32 +/- 10 and 38 +/- 8 d and inhibited the solid Meth A tumor growth with inhibition rate of 28.5 and 55.7%, respectively. These results suggested that the antitumor activities of PAP-I were based on the activation of macrophages and induction of TNF.

Activity of the Keggin polyoxotungstate PM-19 against herpes simplex virus type 2 infection in immunosuppressed mice: role of peritoneal macrophage activation

The in vivo antiviral activity of the Keggin polyoxotungstate PM-19 [K7(PTi2W10O40).6H2O] against herpes simplex virus type 2 (HSV-2) was investigated in mice immunosuppressed by cyclophosphamide (CY). When PM-19 was administered intraperitoneally to immunosuppressed mice for 3 days (once daily) starting at the time of infection, it prevented death due to HSV-2 encephalitis in a dose-dependent manner (10-25 mg/kg). The in vivo anti-HSV-2 activity of PM-19 was superior to that of acyclovir. Intraperitoneal administration of PM-19 to the immunosuppressed mice significantly increased the number of peritoneal cells, especially macrophages. PM-19 did not stimulate interferon-inducing activity or natural killer cell activity, but markedly enhanced peritoneal macrophage functions: (1) phagocytic activity as assessed by measuring the amount of 51Cr-labeled sheep red blood cells taken into the macrophages, and (2) extrinsic antiviral activity as monitored by reduction in the numbers of plaque formed upon cocultivation of HSV-2-infected HEL cells with the macrophages. These results point to the role of peritoneal macrophage activation in the activity of PM-19 against HSV-2 infection in immunosuppressed mice.

Fate of the fish pathogen Aeromonas salmonicida in the peritoneal cavity of rainbow trout

A model was developed to study the fate of the fish pathogen Aeromonas salmonicida in vivo, inside a specialized intraperitoneal chamber implanted in rainbow trout, Oncorhynchus mykiss. Although normally recalcitrant to lytic agents in vitro, owing to the presence of its regular surface array (S layer), A. salmonicida was rapidly killed in the peritoneal cavity by a host-derived, soluble lytic activity present in peritoneal fluid. Peritoneal fluid was also found to kill other bacteria and lyse various types of erythrocytes, but was particularly lytic to A. salmonicida. Intraperitoneal survival of injected (free) A. salmonicida cells was several orders of magnitude higher than survival of implanted (restrained) cells. Injected free cells could evade the lytic activity of peritoneal fluid because they readily spread, initiating lethal infections. One evasion strategy was envisioned to be the penetration of peritoneal and (or) tissue macrophages. In spite of the killing mechanisms of these phagocytic cells, A. salmonicida was still able to survive and even replicate inside head kidney macrophages, thereby supporting the notion of A. salmonicida as a facultatively intracellular pathogen. Intraperitoneal chambers in rainbow trout may constitute a valuable experimental tool for studying the in vivo fate of A. salmonicida, and perhaps of other fish pathogens as well.

[Activation of peritoneal macrophages in rats with caerulein-induced pancreatitis]

We examined the stimulatory state of peritoneal macrophages (M phi) in caerulein-induced pancreatitis. Edematous pancreatitis was developed by the intravenous continuous injection of caerulein (5 micrograms/kg/hr) for 4 hr. Thereafter peritoneal M phi were collected and the activity for free radical production was measured by the reduction of nitro blue tetrazorium in the presence of phorbol myristate acetate. The increase in free radical production reached a statistical significance at 12 hr and a maximum at 20 hr after the beginning of caerulein infusion. These results suggested that the peritoneal M phi are activated even in mild edematous pancreatitis, and that their activation is involved into the mechanism of the development of remote organ failure in acute pancreatitis.

Production of an early release, M(r) 36,000 monokine by stimulated rat macrophages

Supernatants from rat peritoneal macrophage cultures stimulated with bacterial products contain a M(r) 36,000 factor that protects immature cortical thymocytes from loss of viability over a 4-hr incubation period in vitro. This effect could not be produced with purified transforming growth factor-beta or recombinant interleukin-6 (IL-6). Further, the partially purified M(r) 36,000 fraction was inactive in bioassays for IL-1 and tumour necrosis factor. Maximal production of the factor occurred 2 hr after the addition of 20 micrograms/ml of lipopolysaccharide, as assessed by the titre resulting in 100% protection of thymocytes in a viability assay. The detection of protective activity within 5 min after addition of the stimulant could be attributed to the release of intracellular stores but protein synthesis was required to account for the increasing titre up to peak levels. The titre fell rapidly after 2 hr so that activity could not be detected at 4 hr. This profile of release was refractory to repeated stimulation with lipopolysaccharide. Conjoint addition of lipopolysaccharide and indomethacin, did, however, allow release in response to subsequent challenge. Related to this finding, prostaglandin E2 completely inhibited the release of protective activity.

[Studies on the antitumor effect of Clerodendrum bungei Steud or C. foetidum Bge]

Clerodendrum B(I) at dosage of 100g/kg ip or sc for 7 days was shown to have antitumor effect on hepatic carcinoma and sarcoma 180 in mice. In the mean time, 100g/kg sc of (I) interrupted 3H-TdR incorporation into DNA of sarcoma 180 cells in mice, 100, 10g/kg sc of (I) could suppress the phagocytic activity of the peritoneal macrophage against the CRBC (chicken red blood cells) in mice, 100g/kg sc of (I) also made the production of serum hemolysin less than one half of that of the control in mice immunized with SRBC. Clerodendrum C at 100g/kg could inhibit the growth of hepatic carcinoma in mice.

Immunostimulant activity of a novel lipopeptide and its protective action against Leishmania donovani

Novel lipopeptides 84/201 and 86/450 synthesized in this laboratory stimulated antibody and delayed type hypersensitivity (DTH) response to ovalbumin in guinea pigs. Lipopeptide 86/450 also stimulated antibody and DTH responses in albino mice and enhanced nonspecifically macrophage migration index (MMI), phagocytic activity and incorporation of [14C] glucosamine in peritoneal macrophages of the treated animals. Proliferative response of splenocytes from lipopeptide 86/450 treated animals was significantly higher than that from untreated controls. Peritoneal macrophages from lipopeptide 86/450 treated mice were less susceptible to Leishmania donovani promastigote invasion when co-cultured in vitro. The treated animals on challenge with L. donovani promastigote/amastigote showed 80 to 90% lower intake of infection than the control animals.

Immunogenic peptides bind to class II MHC molecules in an early lysosomal compartment

Exogenous protein Ag are processed within endocytic compartments to produce peptides that bind to class II MHC (MHC-II) molecules for presentation to T cells. We have now identified a subcellular compartment in which immunogenic peptides bind to MHC-II as a subset of high density lysosomes. Immunoelectron microscopy of whole cells and dense Percoll gradient subcellular fractions showed early tubulovesicular lysosomes with high levels of MHC-II. Typical mature lysosomes contained less MHC-II. Pulse-chase biosynthetic labeling of macrophages followed by immunoprecipitation of MHC-II from dense lysosomal fractions showed that MHC-II molecules targeted efficiently to lysosomes after biosynthesis. Moreover, lysosomal MHC-II molecules were rapidly loaded with immunogenic peptide (as detected by T cells) soon after exposure of macrophages to Ag and before similar expression of peptide-MHC-II complexes on the plasma membrane; this loading was blocked at 18 degrees C. We propose that nascent MHC-II molecules target to early tubulovesicular lysosomes and bind immunogenic peptides therein; the resulting peptide-MHC-II complexes are then transported to the plasma membrane.

The contribution of a serum component(s) modified by B cells to the mechanism for macrophage activation by liposomes

The effects of liposomes on the activation of mouse peritoneal macrophages were investigated in vitro by measuring the phagocytosis of opsonized sheep red blood cells (SRBC) via Fc receptors on the surface of macrophages. The addition of liposomes to mouse peritoneal exudate cells in RPMI-1640 medium with 10% fetal calf serum (FCS) caused an increase in the ingestion activity. In the absence of FCS, this increase was not observed, suggesting that some component(s) present in FCS is the causative factor(s) for this activation. When liposomes were added to the macrophage monolayer, the ingestion activity did not increase, showing that liposomes did not activate peritoneal macrophages directly, and that non-adherent cells may be involved. Following addition of the culture medium (conditioned medium), which was prepared by incubation of FCS with liposome-treated non-adherent cells or cell ghosts, to the macrophage monolayer, the ingestion activity of macrophages increased in either case. When the conditioned medium prepared with liposome-treated B cells was used for cultivation of liposome-untreated macrophages, a markedly enhanced ingestion activity was observed. However, the conditioned medium prepared with liposome-treated T cells did not affect the ingestion activity. These findings demonstrate that liposome-activated B cells modify some component(s) in FCS, and that the modified component(s) subsequently activates the phagocytosis of opsonized SRBC via Fc receptors on macrophages.

Modulation of cytotoxic activity of resident macrophages by postsurgical macrophages

The purpose of this study was to determine if the secretion of cytotoxic molecules, such as tumor necrosis factor or toxic oxygen molecules, by resident peritoneal macrophages is modulated by postsurgical macrophages elicited by peritoneal trauma. Resident macrophages were collected from nonsurgical rabbits and cultured in vitro with either spent media from cultures of postsurgical macrophages harvested at various times or with varying concentrations of standard cytokines. Superoxide anion (O2-) production of resident macrophages increased with exposure to spent culture media from macrophages obtained after intestinal reanastomosis (3, 6, 12, 24 hr). This increase reached maximal levels by 6 hr after surgery and thereafter decreased to resident levels by 24 hr after surgery. Exposure of resident macrophages to spent media from cells collected after peritoneal sidewall abrasion (1, 3, 5, 7, 10, 14 days) elevated the production of O2- on Postsurgical Days 3 and 5; however, no effect was observed following exposure to spent media of macrophages harvested on Postsurgical Day 14. Interleukin-1 alpha (IL-1 alpha), transforming growth factor beta (TGF-beta), and tumor necrosis factor alpha (TNF alpha) stimulated phorbol ester-induced O2- production by resident macrophages in a concentration-dependent manner. The secretion of TNF activity by resident macrophages increased following exposure to spent media of macrophages harvested 6 to 24 hr after intestinal surgery. IL-1 alpha, TGF-beta, and TNF alpha elevated the secretion of TNF activity by resident macrophages in a concentration-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)

MDHM, a macrophage-activating product of Mycoplasma fermentans, stimulates murine macrophages to synthesize nitric oxide and become tumoricidal

In continuation of previous work on macrophage activation by a Mycoplasma fermentans-derived product, originally named "mycoplasma-derived high mol. wt. material" (MDHM), we have investigated whether MDHM was capable of inducing synthesis of the reactive nitrogen intermediate nitric oxide (NO), thus rendering macrophages cytocidal. Mycoplasmas were first delipidated with acetone, and MDHM activity was then extracted with 50 mM 1-O-octyl-beta-D-glucopyranoside to yield a particularly active new preparation of MDHM which we have named MDHM-D (D for detergent). In combination with IFN-gamma, MDHM-D activated macrophages to produce reactive nitrogen intermediates and kill P815 mastocytoma cells in co-culture. P815 target cells were chosen because they are TNF-resistant. Macrophages from the LPS-low responder strain C3H/HeJ were used to minimize interference from possible LPS contamination. MDHM-D activity in this system was strictly IFN-gamma-dependent. In the presence of 25 U/ml IFN-gamma MDHM-D gave a half maximal response at a dilution of 1/100,000, showing a parallel concentration dependency for nitrite production and cytocidal activity.

[Effects of exercise on immune functions in mice]

This study was carried out to examine the effects of forced running exercise on the immune functions of male ICR mice. Mice aged 4 weeks were divided into two groups: a non-exercise group (control) and a group given forced running exercise (exercise group). The exercise applied was forced running at 15m/min on a flat floor without any slope for 60 min a day. The duration of exercise was 5 days per week for 12 weeks. The results obtained were as follows: 1) After 12 weeks of forced running exercise, the weight of the anterior tibialis muscle and succinate dehydrogenase activity in the anterior tibialis muscle increased significantly (p < 0.01) in the exercise group compared with the control group. A tendency for thymus weight to increase was shown in the exercise group, and liver and spleen weights were significantly (p < 0.01) greater than in the control group. 2) The potentiation of phagocytic function of the reticulo-endothelial system, examined by the carbon clearance method, was seen in the exercise group. 3) The ability of peritoneal macrophages (M phi) to phagocytose latex beads significantly increased (p < 0.01) in the exercise group. The acid phosphatase activity of peritoneal M phi remained in both groups. However, lactate dehydrogenase activity of peritoneal M phi significantly increased (p < 0.01) in the exercise group compared with the control group. 4) The proliferation of splenocytes induced by Con A in the exercise group significantly increased (p < 0.01) compared with the control group.(ABSTRACT TRUNCATED AT 250 WORDS)