Increased Vδ1γδT cells predominantly contributed to IL-17 production in the development of adult human post-infectious irritable bowel syndrome.

BACKGROUND: γδT cells play an important role in the mucosa inflammation and immunity-associated disorders. Our previous study reported that γδ T cells producing IL-17 were involved in the pathogenesis of post-infectious irritable bowel syndrome (PI-IBS). However, their subset characteristic profile in this kind of disease remains unclear. Thus the current study's aim is to investigate the functionally predominant subset and its role in PI-IBS. METHODS: The total T cells were collected from the peripheral blood of patients with PI-IBS. The peripheral proportion of Vδ1 and Vδ2 subset was detected by FACS after stained with anti δ1-PE and anti δ2-APC. The local colonic proportion of this two subsets were measured under laser confocal fluorescence microscope. Vδ1 γδ T cells were enriched from the total peripheral T cells by minoantibody-immuno-microbeads (MACS) method and cultured, functionally evaluated by CCK-8 assay (proliferation), CD69/CD62L molecules expression assay (activation) and ELISA (IL-17 production) respectively. RESULTS: 1. Vδ1 γδ T cells significantly increased while Vδ2 γδ T cells remained unchanged in both the peripheral blood and local colonic tissue from PI-IBS patients (p < 0.05). 2. When cultured in vitro, the Vδ1 γδ T cells remarkably proliferated, activated and produced IL-17 (p < 0.05). CONCLUSIONS: Our results suggest that Vδ1 γδ T cells was the predominant γδ T cells subset in both peripheral and intestinal tissue, and was the major IL-17 producing γδ T cells in PI-IBS.

[Comparison of Bacteria ERIC-PCR Fingerprints of Index Fingers and Contactants].

OBJECTIVES: To explore the bacteria relevance between index fingers and contactant' surfaces （mobile phone touch screen and desktop of personal office table）. METHODS: Bacteria were collected from the index fingers, mobile phone touch screen and desktop of personal office table of 10 volunteers. Enterobacterial repetitive intergenic consensus （ERIC）-PCR fingerprint was established by PCR amplification technique of metagenome. RESULTS: There were 7 volunteers' ERIC-PCR fingerprints of index fingers matched that took from the mobile phone touch screens, and different from each other. There were 3 volunteers' ERIC-PCR fingerprints of index fingers matched that took from desk top of personal office table, and other 7 volunteers' ERIC-PCR fingerprints did not match perfectly with that took from desk top of personal office table, but had at least one similar band for both. CONCLUSIONS: The bacteria on index finger shows individual specificity, which on mobile phone touching screen and personal desktop may be a new biological sample of forensic identification.

Preparation, characterisation and evaluation of curcumin with piperine-loaded cubosome nanoparticles.

OBJECTIVE: In this study, curcumin was designed into the nanoformulation called cubosome with piperine in order to improve oral bioavailability and tissue distribution of curcumin. METHODS: The characteristic of the cubosome was studied by using scanning electron microscope (SEM), Infrared spectrum and small angle X-ray scattering (SAXS) techniques. Tissue distribution of cubosome was measured by liquid chromatography-mass spectrometry (LC-MS) method in mice. RESULTS: The characteristic of the cubosome was demonstrated that the curcumin and piperine were encapsulated in the interior of the cubosome and the crystal form was Pn3m space. The pharmacokinetic test revealed that the cubosome could improve the oral bioavailability significantly compared to the suspension of curcumin with piperine and be mainly absorbed by the spleen. CONCLUSION: These findings provide the reference to a preferable choice of the curcumin formulation and contribute to therapeutic application in clinical research.

Preparation and characterisation of andrographolide niosomes and its anti-hepatocellular carcinoma activity.

OBJECTIVE: In this study, a novel andrographolide (AG) preparation formulation, niosomes, was prepared to improve the bioavailability and tissue distribution of AG. METHODS: The niosomal formulation of AG was prepared by film hydration/sonication method and tissue distribution was measured by liquid chromatography-mass spectrometry (LC-MS) method in mice, and anti-hepatocellular carcinoma (anti-HCC) activity was examined by MTT method in HepG2. RESULTS: Entrapment efficiency, drug-loading ratio and average particle size of AG niosomes were 72.36%, 5.90% and 206 nm, respectively. The tissue distribution in mice demonstrated that the AG niosomes were absorbed in liver much more than the free AG. Furthermore, the anti-HCC activity in HepG2 cells showed that there was no significant difference between free AG and AG niosomes. CONCLUSION: The present results suggest that AG niosomes may have a significant potential of liver targeting, which is valuable in chemotherapy of HCC.

Diversity of nitrogenase (nifH) genes pool in soybean field soil after continuous and rotational cropping.

Diazotrophs diversity in soybean is a topic requiring thorough investigation since the previous researches have focused on only rice, forest, grass, water, etc. In this research, iron-only nitrogenase nifH gene was as genetic marker. PCR-RFLP was used to investigate the difference of diazotrophs community diversity in the soil from the continuous cropping (CC) (the 5-yr tilling of soybean) and the rotational cropping (RC) (soybean-corn) soils in the northeast of China. A total of 36 isolates were genetically characterized. Most of the isolates closely related to Azospirillum and Azotobacter. Eighty-six unique nifH gene sequences were obtained by cloning of the respective PCR products in two soil samples. It was found that the diversity of nifH genes in CC changed obviously compared with RC. Phylogenetic analysis indicated that most of the clones clustered together in a high homogeneity with some sequence retrieved from environmental representatives. The sequence diversity of nifH genes was high and the members of the Alphaproteobacteria were predominant in both samples. The experimental study also revealed the two non-proteobacterial diazotrophs, firmicutes and euryarchaeota. Through this study, it can be assumed that different tillage perhaps affected the nifH gene-containing population diversity.

Regulatory mechanism of lncRNA NORAD on proliferation and invasion of ovarian cancer cells through miR-199a-3p.

OBJECTIVE: To explore the regulatory mechanism of lncRNA NORAD on proliferation and invasion of ovarian cancer cells through miR-199a-3p. PATIENTS AND METHODS: Eighty-six ovarian cancer tissues and 86 tissues adjacent to cancer, human ovarian cancer cell lines SKOV3, HO-8910, A2780, OVCAR-3, and human normal ovarian epithelial cell line IOSE80 were collected. MiR-199a-3p-mimics, miR-199a-3p-inhibitor, miR-NC, si-NORAD, Sh-NORAD, and NC were transfected into HO-8910 and A2780 cells, the expression levels of lncRNA NORAD and miR-199a-3p in ovarian cancer tissues and cells were detected by qRT-PCR, and the expression levels of N-cadherin, E-cadherin, and vimentin in cells were detected by WB. Cell Counting Kit-8 (CCK-8), transwell, and cell scratch tests were used to detect proliferation, invasion, and migration of cells, and the relationship between lncRNA NORAD and miR-199a-3p was confirmed by the Dual-Luciferase reporter assay. RESULTS: LncRNA NORAD was highly expressed and miR-199a-3p was lowly expressed in ovarian cancer, and the expression levels of LNCRNARAD and miR-199a-3p were negatively correlated. Cell experiments showed that inhibiting the expression of lncRNA NORAD or up-regulating the expression of miR-199a-3p could inhibit the proliferation, invasion, migration, and EMT of ovarian cancer cells, while up-regulating the expression of lncRNA NORAD or inhibiting the expression of miR-199a-3p could promote their proliferation, invasion, migration, and EMT. Dual-Luciferase reporter assay confirmed that there was a regulatory relationship between lncRNA NORAD and miR-199a-3p. CONCLUSIONS: LncRNA NORAD was highly expressed in ovarian cancer tissues, while silencing lncRNA NORAD expression could inhibit the proliferation, invasion, migration, and EMT of ovarian cancer cells by regulating miR-199a-3p, which might be a new target for the diagnosis and treatment of ovarian cancer.

Molecular mechanisms of lipid metabolism disorder in livers of ewes with pregnancy toxemia.

Pathogenesis of pregnancy toxemia (PT) is believed to be associated with the disruption of lipid metabolism. The present study aimed to explore the underlying mechanisms of lipid metabolism disorder in the livers of ewes with PT. In total, 10 pregnant ewes were fed normally (control group) whereas another 10 were subjected to 70% level feed restriction for 15 days to establish a pathological model of PT. Results showed that, as compared with the controls, the levels of blood ß-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFAs) and cholesterol were greater (P<0.05) and blood glucose level was lower (P<0.05) in PT ewes. The contents of NEFAs, BHBA, cholesterol and triglyceride were higher (P<0.05) and glycerol content was lower (P<0.05) in hepatic tissues of PT ewes than those of the controls. For ewes with PT, excessive fat vacuoles were observed in liver sections stained with hematoxylin-eosin; furthermore, inner structures of hepatocytes including nuclei, mitochondria and endoplasmic reticulum were damaged seriously according to the results of transmission electron microscope. Real-time PCR data showed that compared with the controls, the expression of hepatic genes involved in fatty acid oxidation (FAO) and triglyceride synthesis (TGS) was enhanced (P<0.05) whereas that related to acetyl-CoA metabolism (ACM) was repressed (P<0.05) in PT ewes. Generally, our results showed that negative energy balance altered the expression of genes involved in FAO, ACM and TGS, further caused lipid metabolism disorder in livers, resulting in PT of ewes. Our findings may provide the molecular basis for novel therapeutic strategies against this systemic metabolic disease in sheep.

Effect of starter diet supplementation on rumen epithelial morphology and expression of genes involved in cell proliferation and metabolism in pre-weaned lambs.

Starter feeding is usually used in lamb production to improve rumen development and to facilitate the weaning process, but molecular mechanism of which is not well understood. Therefore, the objective of this study is to investigate the effect of starter feeding on the expression of ruminal epithelial genes involved in cell proliferation, apoptosis and metabolism in pre-weaned lambs. We selected eight pairs of 10-day-old lamb twins. One twin was fed ewe milk (M, n=8), while the other was fed ewe milk plus starter (M+S, n=8). The lambs were sacrificed at 56 days age. Results showed that the lambs fed M+S had lower pH in the rumen and a higher concentration of acetate, propionate, butyrate and total volatile fatty acid (VFA). Compared with the M group, the concentration of ß-hydroxybutyric acid in plasma had an increased trend, and the concentration of IGF-1 in plasma had an decreased trend in the M+S group. The length, width and surface of rumen papillae increased in the M+S group compared with the M group; this was associated with increased cell layers in the stratum corneum, stratum granulosum and total epithelia. Messenger RNA (mRNA) expression of proliferative genes of cyclin A, cyclin D1 and cyclin-dependent kinase 2 in the ruminal epithelia of M+S lambs was increased compared with M only lambs. The mRNA expression of apoptosis genes of caspase-3, caspase-8, B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) in the M+S group was decreased compared with M group, but the ratio of Bcl-2 to Bax were not changed between the two groups. Expression of IGF-1 mRNA was decreased, but the mRNA expression of IGF-1 receptor was higher in ruminal epithelia in the M+S group. Furthermore, the mRNA expression of VFA absorption and metabolism genes of ß-hydroxybutyrate dehydrogenase isoforms 1 and 3-hydroxy-3-methylglutaryl-CoA lyase had an increased trend in the M+S group than in the M group, but the mRNA expression of 3-hydroxy-3-methylglutaryl-CoA synthase isoform 1, monocarboxylate transporter isoform 1 and putative anion transporter isoform 1 had a decreased trend in the M+S group than in the M group. These results suggest that starter feeding increased proliferation and inhibited apoptosis of ruminal epithelial cells, and may promote the VFA metabolism in ruminal epithelium in pre-weaned lambs. These findings provide new insights into improving rumen development by nutritional intervention strategies in pre-weaned lambs.

Ulinastatin inhibits high glucose-induced cardiomyocyte apoptosis through activating Akt signaling.

OBJECTIVE: Cardiomyocyte apoptosis is closely associated with the development of diabetic cardiomyopathy. Ulinastatin, a urinary trypsin inhibitor, exerts a protective effect on cardiac function. However, the molecular mechanism remains not fully clear. This study aims to explore the effect of ulinastatin on high glucose (HG)-induced cardiomyocyte apoptosis and the potential molecular mechanism. MATERIALS AND METHODS: Neonatal rats cardiomyocytes were cultured and then treated with HG or/and ulinastatin. Cell viability was examined using a MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. Cell apoptosis was detected by flow cytometry. Mitochondrial membrane potential (MMP) was stained using a JC-1 probe and evaluated by fluorescence microscopy. Protein expressions of B-cell lymphoma 2 (Bcl-2) , BCL2-Associated X (Bax), cleaved caspase 3, p-Akt and Akt were determined by Western blot. RESULTS: Ulinastatin increased the HG-induced reduction in cell viability and MMP expression. Ulinastatin also inhibited HG-induced apoptosis. Ulinastatin decreased the Bax/Bcl-2 ratio and cleaved caspase 3 expression in cardiomyocyte treated with HG. Further, ulinastatin increased the phosphorylation level of Akt in cardiomyocyte treated with HG. These effects of ulinastatin were abrogated by LY294002, an Akt inhibitor. CONCLUSIONS: Ulinastatin inhibited HG-induced cardiomyocyte apoptosis through activating Akt signaling.

Serum total bilirubin levels are negatively correlated with metabolic syndrome in aged Chinese women: a community-based study.

We evaluated serum total bilirubin levels as a predictor for metabolic syndrome (MetS) and investigated the relationship between serum total bilirubin levels and MetS prevalence. This cross-sectional study included 1728 participants over 65 years of age from Eastern China. Anthropometric data, lifestyle information, and previous medical history were collected. We then measured serum levels of fasting blood-glucose, total cholesterol, triglycerides, and total bilirubin, as well as alanine aminotransferase activity. The prevalence of MetS and each of its individual component were calculated per quartile of total bilirubin level. Logistic regression was used to assess the correlation between serum total bilirubin levels and MetS. Total bilirubin level in the women who did not have MetS was significantly higher than in those who had MetS (P<0.001). Serum total bilirubin quartiles were linearly and negatively correlated with MetS prevalence and hypertriglyceridemia (HTG) in females (P<0.005). Logistic regression showed that serum total bilirubin was an independent predictor of MetS for females (OR: 0.910, 95%CI: 0.863-0.960; P=0.001). The present study suggests that physiological levels of serum total bilirubin might be an independent risk factor for aged Chinese women, and the prevalence of MetS and HTG are negatively correlated to serum total bilirubin levels.

Poor sleep in middle-aged women is not associated with menopause per se.

Whether sleep problems of menopausal women are associated with vasomotor symptoms and/or changes in estrogen levels associated with menopause or age-related changes in sleep architecture is unclear. This study aimed to determine if poor sleep in middle-aged women is correlated with menopause. This study recruited women seeking care for the first time at the menopause outpatient department of our hospital. Inclusion criteria were an age ≥40 years, not taking any medications for menopausal symptoms, and no sleeping problems or depression. Patients were assessed with the Pittsburgh Sleep Quality Index (PSQI), modified Kupperman Index (KI), and Menopause Rating Scale (MRS). A PSQI score of <7 indicated no sleep disorder and ≥7 indicated a sleep disorder. Blood specimens were analyzed for follicle-stimulating hormone and estradiol levels. A total of 244 women were included in the study; 103 (42.2%) were identified as having a sleep disorder and 141 as not having one. In addition, 156 (64%) women were postmenopausal and 88 (36%) were not menopausal. Follicle-stimulating hormone and estradiol levels were similar between the groups. Patients with a sleep disorder had a significantly higher total modified KI score and total MRS score (both, P<0.001) compared with those without a sleep disorder. Correlations of the PSQI total score with the KI and MRS were similar in menopausal and non-menopausal women. These results do not support that menopause per se specifically contributes to sleep problems.

[The imaging analysis of the age-related changes on maxillary sinus].

Objective:The aim of this study is to investigate the age-related changes rules of maxillary sinus.Method:The 540 patients (1 080 sides) with normal data of deputy sinus in spiral CT were enrolled,including 270 cases of male and female,age from 7 to 81 years old.They are divided into 9 groups according to the age:Group A at the age of 7-12 years old,Group B at the age of 13-17,Group C at the age of 18-20 years old,Group D at the age of 21-24 years old,Group E at the age of 25-28 years,Group F at the age of 29-35 years old,Group G at the age of 36-40 years old,Group H at the age of 41-65 years old,and Group I is more than 65 years old.By the gender,the patients in each group was divided into male and female groups.There are 30 cases in each group(60 sides).The volumes and the three-dimensional diameters of the maxillary sinus were measured,and the coefficient of gasification of them were calculated.Result:The maxillary sinus volume and 3 D lines have almost the same change trend along with the age between the male and female group;From 7 to 20 ages,they are increased linearly,13 to 17 fastest-growing;18 to 20 years old reached to peak;declined slightly in 21-28 years old,29-35 a second growth peak,and 36 to 40 years old have fallen sharply,to reaching a steady state after 41 years old;The gasification coefficient has no difference among all groups.Conclusion:The volume changes with the age-related on maxillary sinus is in the adolescent stage.It reaches a steady state in the middle and old age stage,and gasification coefficient on maxillary sinus has no age-related changes among all groups.

Mesenchymal dental pulp cells attenuate dentin resorption in homeostasis.

Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone-derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal resorption in the root canal, pulp/dentin regeneration, and root resorption in orthodontic tooth movement.

Guar gum effects on plasma low-density lipoprotein and hepatic cholesterol metabolism in guinea pigs fed low- and high-cholesterol diets: a dose-response study.

Guinea pigs were fed semipurified diets containing either 0% or 12.5% guar gum (GG) with 0.04% cholesterol or increasing concentrations of GG (0%, 2.5%, 5%, 7.5%, 10%, and 12.5%) with 0.25% cholesterol (by wt). Compared to the 0% GG diet with 0.04% cholesterol, intake of the 12.5% GG diet with 0.04% cholesterol lowered plasma low-density-lipoprotein (LDL) concentrations, the ratio of LDL cholesteryl ester to protein, hepatic cholesterol concentrations, and the activity of acyl-CoA:cholesterol acyltransferase (ACAT), and increased 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase activity and hepatic apo B/E receptor number (P < 0.01). Intake of GG by animals fed 0.25% cholesterol diets resulted in modest effects on hepatic cholesterol pools and plasma LDL concentrations; however, significant negative correlations were found between both plasma LDL cholesterol and hepatic free cholesterol concentrations with the amount of dietary GG (P < 0.05). Hepatic HMG-CoA reductase was suppressed by the 0.25% cholesterol intake, and GG did not reverse this suppression. In contrast, ACAT activity was negatively correlated with the amount of dietary GG (P < 0.05), and GG intake increased the number of hepatic apo B/E receptors at all intakes with the 0.25% cholesterol diets. These results demonstrate that intake of GG significantly alters endogenous cholesterol metabolism by decreasing hepatic cholesterol pools, altering hepatic cholesterol homeostasis, and reducing plasma LDL concentrations.

Citrus pectin and cholesterol interact to regulate hepatic cholesterol homeostasis and lipoprotein metabolism: a dose-response study in guinea pigs.

Guinea pigs were fed increasing concentrations of citrus pectin (CP) (0-12.5%, wt/wt) with low (LC, 0.04%) or high (HC, 0.25%) cholesterol. Animals fed LC diets had reduced plasma LDL concentrations with 10% and 12.5% CP and hepatic membrane apolipoprotein B/E receptor expression increased with high dosages of CP. Hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity increased with 12.5% CP whereas hepatic cholesterol concentrations and acyl-CoA:cholesterol acyltransferase (ACAT) activity were not different. In contrast, with HC diets, plasma LDL concentrations were reduced in a dose-response manner by 29%, 30%, and 67% with 7.5%, 10%, and 12.5% CP intake (P < 0.001) and apolipoprotein B/E receptor number was increased and inversely correlated with plasma LDL in the HC group (r = -0.81, P < 0.005). Animals fed HC diets had a dose-dependent decrease in hepatic cholesterol and ACAT activity, with intake of 12.5% CP having the major effect. Hepatic HMG-CoA reductase activity was suppressed by HC diets and only intake of 12.5% CP reversed this suppression. The most significant effects of CP on hepatic cholesterol, enzymes of hepatic cholesterol homeostasis, and the apolipoprotein B/E receptor were in animals fed the HC diets. These metabolic alterations partially explain the reduced plasma LDL of guinea pigs fed large amounts of CP.

Carbohydrate-fat exchange and regulation of hepatic cholesterol and plasma lipoprotein metabolism in the guinea pig.

Adult female guinea pigs were fed semipurified diets containing increasing concentrations of saturated fat (2.5%, 7.5%, 15%, and 25% wt/wt) to determine effects of exchanging fat-carbohydrate calories on lipoprotein metabolism. Plasma very-low-density lipoprotein (VLDL) and high-density lipoprotein (HDL) did not vary but plasma low-density lipoprotein (LDL) concentrations increased with increasing fat calories. LDL cholesterol values were 42 +/- 25, 61 +/- 17, 92 +/- 25, and 98 +/- 21 mg/dL (mean +/- SD, n = 5), respectively. The relative proportion of cholesteryl ester increased and triacylglycerol (TAG) decreased for VLDL, LDL, and HDL as dietary fat increased. Plasma lecithin cholesterol acyltransferase (LCAT) activity was positively correlated with HDL cholesteryl ester content. Hepatic cholesterol and TAG concentrations were highest in animals fed 25% fat (P < .01). Hepatic apolipoprotein (apo) B/E receptor maximal binding capacity (Bmax) was 30% higher in animals fed 2.5% and 7.5% fat as compared with those fed 15% and 25% fat (P < .01) and inversely correlated with plasma LDL (r = -.85, P < .01). In contrast, HDL binding to guinea pig hepatic membranes exhibited a significant positive correlation with dietary fat quantity (r = .98, P < .001), consistent with a dose-response with increasing fat calories. The activity of hepatic 3-hydroxy-3-methyl glutaryl coenzyme A (HMG CoA) reductase was not affected by the amount of dietary fat, whereas the activity of acyl CoA:cholesterol acyltransferase (ACAT) was significantly increased in animals fed 25% fat (P < .05). Hepatic free-cholesterol and ACAT activity exhibited a positive correlation for all dietary groups (r = .75, P < .001). These results demonstrate that exchange of saturated dietary fat for carbohydrate calories results in significant modifications in the regulation of metabolic pathways that determine plasma LDL concentrations and hepatic cholesterol homeostasis.

[Influences of inflammatory macrophages on the proliferation of mouse tumor cells in vitro].

Augmented growth of tumor cells of both syngeneic and allogeneic origin was often observed when these cells were cocultured with the peritoneal inflammatory macrophages of C57BL/6 mouse, induced by thioglycollate in vitro. While large doses of macrophage-activating factor (MAF) were required for activating these inflammatory macrophages to exert the tumoricidal activity, and much less (suboptimal) doses of MAF were required for activating their cytostatic effect on tumor cells. Whether the macrophage inhibits or enhances the tumor cell proliferation, depends not only on the degree of the activation of macrophage, but also on the macrophage/tumor cell ratio.