Prolactin promotes the recruitment of main olfactory bulb cells and enhances the behavioral exploration toward a socio-sexual stimulus in female mice.

Olfactory communication is triggered by pheromones that profoundly influence neuroendocrine responses to drive social interactions. Two principal olfactory systems process pheromones: the main and the vomeronasal or accessory system. Prolactin receptors are expressed in both systems suggesting a participation in the processing of olfactory information. We previously reported that prolactin participates in the sexual and olfactory bulb maturation of females. Therefore, we explored the expression of prolactin receptors within the olfactory bulb during sexual maturation and the direct responses of prolactin upon pheromonal exposure. Additionally, we assessed the behavioral response of adult females exposed to male sawdust after prolactin administration and the consequent activation of main and accessory olfactory bulb and their first central relays, the piriform cortex and the medial amygdala. Last, we investigated the intracellular pathway activated by prolactin within the olfactory bulb. Here, prolactin receptor expression remained constant during all maturation stages within the main olfactory bulb but decreased in adulthood in the accessory olfactory bulb. Behaviorally, females that received prolactin actively explored the male stimulus. An increased cFos activation in the amygdala and in the glomerular cells of the whole olfactory bulb was observed, but an augmented response in the mitral cells was only found within the main olfactory bulb after prolactin administration and the exposure to male stimulus. Interestingly, the ERK pathway was upregulated in the main olfactory bulb after exposure to a male stimulus. Overall, our results suggest that, in female mice, prolactin participates in the processing of chemosignals and behavioral responses by activating the main olfactory system and diminishing the classical vomeronasal response to pheromones.

Early and transitory hypoactivity and olfactory alterations after chronic atrazine exposure in female Sprague-Dawley rats.

Several studies have shown that chronic exposure to the herbicide atrazine (ATR) causes alterations in locomotor activity and markers of the dopaminergic systems of male rats. However, few studies have evaluated the sex-dependent effects of atrazine exposure. The aim of the present study was to evaluate whether chronic ATR exposure causes alterations in behavioral performance and dopaminergic systems of female rats. At weaning, two groups of rats were exposed to 1 or 10 mg ATR/kg body weight daily thorough the food, while the control group received food without ATR for 14 months. Spontaneous locomotor activity was evaluated monthly for 12 months, while anxiety, egocentric and spatial memory, motor coordination, and olfactory function tasks were evaluated between 13 and 14 months of ATR exposure. Tyrosine hydroxylase (TH) and monoamine content in brain tissue were assessed at the end of ATR treatment. Female rats treated with 1 or 10 mg ATR showed vertical hypoactivity compared to the control group only in the first month of ATR exposure. Impairments in olfactory functions were found due to ATR exposure. Nevertheless, no alterations in anxiety, spatial and egocentric memory, or motor coordination tasks were observed, while the levels of TH and dopamine and its metabolites in brain tissue were similar among groups. These results suggest that female rats could present greater sensitivity to the neurotoxic effects of ATR on spontaneous locomotor activity in the early stages of development. However, they are unaffected by chronic ATR exposure later in life compared to male rats. More studies are necessary to unravel the sex-related differences observed after chronic ATR exposure.

Targeted Glutamate Supply Boosts Insulin Concentrations, Ovarian Activity, and Ovulation Rate in Yearling Goats during the Anestrous Season.

The neuroendocrine regulation of the seasonal reproductive axis requires the integration of internal and external signals to ensure synchronized physiological and behavioral responses. Seasonal reproductive changes contribute to intermittent production, which poses challenges for optimizing goat product yields. Consequently, a significant objective in seasonal reproduction research is to attain continuous reproduction and enhance profitability in goat farming. Glutamate plays a crucial role as a modulator in several reproductive and metabolic processes. Hence, the aim of this study was to evaluate the potential impact of exogenous glutamate administration on serum insulin concentration and ovarian function during the out-of-season period in yearling goats. During the anestrous season, animals were randomly located in individual pens to form two experimental groups: (1) glutamate (n = 10, live weight (LW) = 29.1 ± 1.02 kg, body condition score (BCS) = 3.4 ± 0.2 units) and (2) control (n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2), with no differences (p < 0.05) regarding LW and BCS. Then, goats were estrus-synchronized, and blood sampling was carried out for insulin quantification. Ovaries were ultrasonographically scanned to assess ovulation rate (OR), number of antral follicles (AFs), and total ovarian activity (TOA = OR + AF). The research outcomes support our working hypothesis. Certainly, our study confirms that those yearling goats treated with exogenous glutamate displayed the largest (p < 0.05) insulin concentrations across time as well as an augmented (p < 0.05) out-of-season ovarian activity.

Goats as Valuable Animal Model to Test the Targeted Glutamate Supplementation upon Antral Follicle Number, Ovulation Rate, and LH-Pulsatility.

The potential effect of intravenous administration of glutamate on the ovarian activity and the LH secretion pattern, considering the anestrous yearling goat as an animal model, were assessed. In late April, yearling goats (n = 20) were randomly assigned to either (1) Glutamate supplemented (GLUT; n = 10, Live Weight (LW) = 29.6 ± 1.02 kg, Body Condition (BCS) = 3.4 ± 0.2 units; i.v. supplemented with 7 mg GLUT kg−1 LW) or (2) Non-supplemented (CONT; n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2 units; i.v. saline). The oats were estrus-synchronized; blood sampling (6 h × 15 min) was carried out for LH quantification. Response variables included pulsatility (PULSE), time to first pulse (TTFP), amplitude (AMPL), nadir (NAD), and area under the curve (AUC) of LH. Ovaries were ultra-sonographically scanned to assess ovulation rate (OR), number of antral follicles (AF), and total ovarian activity (TOA = OR + AF). LH-PULSE was quantified with the Munro algorithm; significant treatment x time interactions were evaluated across time. The variables LW and BCS did not differ (p > 0.05) between the experimental groups. Nevertheless, OR (1.77 vs. 0.87 ± 0.20 units), TOA (4.11 vs. 1.87 ± 0.47 units) and LH-PULSE (5.0 vs. 2.2 pulses 6 h-1) favored (p < 0.05) to the GLUT group. Our results reveal that targeted glutamate supplementation, the main central nervous system neurotransmitter, arose as an interesting strategy to enhance the hypothalamic−hypophyseal−ovarian response considering the anestrous-yearling goat as an animal model, with thought-provoking while promising translational applications.

Neuroimmunoendocrine Link Between Chronic Kidney Disease and Olfactory Deficits.

Chronic kidney disease (CKD) is a multifactorial pathology that progressively leads to the deterioration of metabolic functions and results from deficient glomerular filtration and electrolyte imbalance. Its economic impact on public health is challenging. Mexico has a high prevalence of CKD that is strongly associated with some of the most common metabolic disorders like diabetes and hypertension. The gradual loss of kidney functions provokes an inflammatory state and endocrine alterations affecting several systems. High serum levels of prolactin have been associated with CKD progression, inflammation, and olfactory function. Also, the nutritional status is altered due to impaired renal function. The decrease in calorie and protein intake is often accompanied by malnutrition, which can be severe at advanced stages of the disease. Nutrition and olfactory functioning are closely interconnected, and CKD patients often complain of olfactory deficits, which ultimately can lead to deficient food intake. CKD patients present a wide range of deficits in olfaction like odor discrimination, identification, and detection threshold. The chronic inflammatory status in CKD damages the olfactory epithelium leading to deficiencies in the chemical detection of odor molecules. Additionally, the decline in cognitive functioning impairs the capacity of odor differentiation. It is not clear whether peritoneal dialysis and hemodialysis improve the olfactory deficits, but renal transplants have a strong positive effect. In the present review, we discuss whether the olfactory deficiencies caused by CKD are the result of the induced inflammatory state, the hyperprolactinemia, or a combination of both.

Acellular fraction from malignant effusions has cytotoxicity in breast cancer cells.

Malignant ascites (MA) and malignant pleural effusion (MPE) are frequently developed in patients with metastatic cancer; however, the biological properties of these fluids have not been clarified. The present study explored the biological role of a low molecular fraction derived from malignant effusions on the activation of peripheral blood mononuclear cells and on the proliferation of breast cancer cells and fibroblast 55x cells. A <10-kDa fraction from effusions of 41 oncological patients and 34 individuals without cancer was purified, and its potential role in inhibiting nitric oxide (NO) production on lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells was explored, as well as its cytotoxicity on MCF-7 breast cancer cells and fibroblast 55x cells. A significant decrease in NO production was observed in the <10-kDa fraction from malignant effusions. In addition, the acellular fraction from MA decreased the viability of breast cancer cells without affecting human fibroblasts. These data support the presence of low molecular weight molecules in malignant samples with a specific role in inhibiting the defense mechanisms of peripheral blood mononuclear cells and decreasing the viability of breast cancer cells in vitro.

Low handgrip strength is associated with a higher incidence of pressure ulcers in hip fractured patients.

Pressure ulcers (PUs) are highly frequent in hip fractured elderly patients. This issue has a direct impact in quality of life, mortality as well as healthcare costs. Handgrip strength (HGS) is an efficient, low-cost and straightfoward method to measure functional capacity, as well as the global muscle strength of elderly patients. In this research we are aiming to analyze if low HGS is associated with higher incidence of pressure ulcers within a population of elderly patients with hip fracture from a tertiary hospital from Monterrey, Mexico. This research, designed as an observational-longi- tudinal cohort, included 462 patients admitted at the Hip and Pelvic Surgery Department of the Hospital of Traumatology and Orthopedics No. 21, of the Mexican Institute of the Social Security (IMSS), in Monterrey, Mexico. HGS measurement was performed by a trained physician, using a Jamar® Hydraulic Hand DynamometerPatients were grouped into tertiles according to their grip strength measurement and sex. Every patient was evaluated for presence or absence of PUs during hospital admission and followed until discharge. The general incidence of PUs was 25.7%. The incidence was higher in the weaker subjects (Tertile one 33%, Tertile two 30%, and Tertile three 15%, P=0.001). Pre-fracture Barthel's index, and Mini Nutritional Assessment Scores were lower among participants with PUs. After multivariate analysis, only HGS remained associated with PUs incidence. Low handgrip strength is associated with a higher incidence of pressure ulcers.

A robust biomarker of differential correlations improves the diagnosis of cytologically indeterminate thyroid cancers.

The fine-needle aspiration of thyroid nodules and subsequent cytological analysis is unable to determine the diagnosis in 15 to 30% of thyroid cancer cases; patients with indeterminate cytological results undergo diagnostic surgery which is potentially unnecessary. Current gene expression biomarkers based on well-determined cytology are complex and their accuracy is inconsistent across public datasets. In the present study, we identified a robust biomarker using the differences in gene expression values specifically from cytologically indeterminate thyroid tumors and a powerful multivariate search tool coupled with a nearest centroid classifier. The biomarker is based on differences in the expression of the following genes: CCND1, CLDN16, CPE, LRP1B, MAGI3, MAPK6, MATN2, MPPED2, PFKFB2, PTPRE, PYGL, SEMA3D, SERGEF, SLC4A4 and TIMP1. This 15-gene biomarker exhibited superior accuracy independently of the cytology in six datasets, including The Cancer Genome Atlas (TCGA) thyroid dataset. In addition, this biomarker exhibited differences in the correlation coefficients between benign and malignant samples that indicate its discriminatory power, and these 15 genes have been previously related to cancer in the literature. Thus, this 15-gene biomarker provides advantages in clinical practice for the effective diagnosis of thyroid cancer.

Sexual Behavior Increases Cell Proliferation in the Rostral Migratory Stream and Promotes the Differentiation of the New Cells into Neurons in the Accessory Olfactory Bulb of Female Rats.

We have previously demonstrated, that 15 days after female rats pace the sexual interaction, there is an increase in the number of new cells that reach the granular cell layer (GrL) of the accessory olfactory bulb (AOB). The aim of the present study was to evaluate, if the first sexual experience in the female rat increases cell proliferation in the subventricular zone (SVZ) and the rostral migratory stream (RMS). We also tested if this behavior promotes the survival of the new cells that integrate into the main olfactory bulb (MOB) and AOB 45 days after the behavioral test. Sexually, naive female rats were injected with the DNA synthesis marker 5'-bromo-2'-deoxyuridine (BrdU) on the day of the behavioral test. They were randomly divided into the following groups: Female rats placed alone in the mating cage (1); Females exposed to amyl acetate odor [banana scent, (2)]; Females that could see, hear, and smell the male but physical contact was not possible [exposed to male, (3)]; Female rats that could pace the sexual interaction (4); and females that mated without the possibility of pacing the sexual interaction (5). Animals were sacrificed 2 days after the behavioral test (proliferation) or 45 days later (survival). Our results show that 2 days after females were exposed to banana scent or to the male, they had a higher number of cells in the SVZ. Females, that mated in pace and no-paced conditions had more new cells in the RMS. At 45 days, no significant differences were found in the number of new cells that survived in the MOB or in the AOB. However, mating increased the percentage of new cells, that differentiated into neurons in the GrL of the AOB. These new cells expressed c-Fos after a second sexual encounter just before the females were sacrificed. No significant differences in plasma levels of estradiol and progesterone were observed between groups. Our results indicate that the first sexual experience increases cell proliferation in the RMS and mating 45 days later enhances the number of new cells that differentiate into neurons in the AOB. These new neurons are activated by sexual stimulation.

Sexual Stimulation Increases the Survival of New Cells in the Accessory Olfactory Bulb of the Male Rat.

Sexual behavior in rodents is modulated by the olfactory system. The olfactory bulb (OB) is a structure that undergoes continues neurogenesis in adulthood. We have previously shown that 15 days after males rats pace the sexual interaction and ejaculate 1 or 3 times, there is an increase in the density of new cells that reach the accessory olfactory bulb (AOB). The aim of the present study was to evaluate if sexual behavior in male rats increases the density of new neurons that survive 45 days after sexual behavior in the AOB and in the main OB (MOB). Male rats were randomly divided in four groups: (1) Control (Ctr), males without sexual interaction; (2) Exposed (Exp), males only exposed to a sexually receptive female; (3) No pacing (NP), males that mated in conditions in which the female paced the sexual interaction; (4) One ejaculation (1E), males that paced the sexual interaction with a receptive female and ejaculated once; and (5) Three ejaculations (3E), males that paced the sexual interaction and were allowed to ejaculate three times. All males were injected with the DNA synthesis marker 5-bromo-2-deoxyuridine (BrdU), and were tested in one of the above conditions. 45 days later they were sacrificed, and the OBs were processed to identify new cells and evaluate if they had differentiated into neurons. Our data indicate that males that ejaculated three times showed an increase in the density of new cells that survive in the posterior part of the granular cell layer of the AOB and have more new neurons that the control group. However, no significant differences were found in the percentage of new cells that differentiate into neurons. No significant increase in the density of new cells was observed in the MOB. Our data show that pacing the sexual interaction until three ejaculations increases the density of new cells and neurons in the granular layer of the AOB, confirming that sexual behavior induces long-lasting plastic changes in the OB.

Validation of the FRAIL scale in Mexican elderly: results from the Mexican Health and Aging Study.

BACKGROUND: The aging population in Latin America is characterized by not optimal conditions for good health, experiencing high burden of comorbidity, which contribute to increase the frequency of frailty; thus, identification should be a priority, to classify patients at high risk to develop its negative consequences. AIM: The objective of this analysis was to validate the FRAIL instrument to measure frailty in Mexican elderly population, from the database of the Mexican Health and Aging Study (MHAS). MATERIALS AND METHODS: Prospective, population study in Mexico, that included subjects of 60 years and older who were evaluated for the variables of frailty during the year 2001 (first wave of the study). Frailty was measured with the five-item FRAIL scale (fatigue, resistance, ambulation, illnesses, and weight loss). The robust, pre-frail or intermediate, and the frail group were considered when they had zero, one, and at least two components, respectively. Mortality, hospitalizations, falls, and functional dependency were evaluated during 2003 (second wave of the study). Relative risk was calculated for each complications, as well as hazard ratio (for mortality) through Cox regression model and odds ratio with logistic regression (for the rest of the outcomes), adjusted for covariates. RESULTS: The state of frailty was independently associated with mortality, hospitalizations, functional dependency, and falls. The pre-frailty state was only independently associated with hospitalizations, functional dependency, and falls. CONCLUSIONS: Frailty measured through the FRAIL scale, is associated with an increase in the rate of mortality, hospitalizations, dependency in activities of daily life, and falls.

C allele of the rs2209972 single nucleotide polymorphism of the insulin degrading enzyme gene and Alzheimer's disease in type 2 diabetes, a case control study.

BACKGROUND AND OBJECTIVE: In the last few decades we have witnessed an interesting transformation of the population pyramids throughout the world. As the population's life expectancy increases, there are more chronic diseases such as diabetes mellitus and dementias, and both of them have shown an association. GENERAL OBJETIVE: To determine the association between Alzheimer's disease in diabetic patients and the insulin degrading enzyme in outpatients of a second level Hospital in Monterrey, Mexico. MATERIALS AND METHODS: This was a case control study in which we included outpatients from the Geriatrics Clinic of a Hospital in Northeastern Mexico. Cases were patients with a Mini Mental Score Exam (MMSE) below 24 and DSM-IV criteria for Dementia. Controls were patients who had MMSE scores greater than 24. RESULTS: Data from 97 patients were analyzed. Regarding physical examination and the results of laboratory tests, there were no differences between the two groups (p>0.05). A 98% prevalence of the insulin degrading enzyme was documented in the sample studied. We found an association between a homozygous status for the CC genotype and Dementia with an estimated Odds Ratio (OR) of 2.5 (CI 95% 1.6-3.3) on the bivariate test, while, on the multivariate analysis, the OR was estimated 3.3 (CI 95% 1.3-8.2). CONCLUSIONS: Evidence shows that cognitive impairment is more frequent among those exposed to the C allele of the rs2209972 SNP of the insulin degrading enzyme gene.

Association between polymorphism c.1-765G>C of the COX2 gene and cognitive impairment in individuals 65 years or more with diabetes from a Geriatric Service in Monterrey, Mexico.

BACKGROUND AND OBJECTIVE: Cognitive impairment and dementia are common geriatric syndromes in diabetic patients. Inflammation plays a crucial role in the pathophysiology of Alzheimer's disease and cognitive impairment. Cyclooxygenases (COX) 1 and 2 participate in inflammation. The polymorphism c.1-765G>C of the COX2 gene might be protective against cognitive decline in Mexicans with diabetes mellitus through its reduced promotor activity. To determine the association between polymorphism c.1-765G>C of the COX2 gene and cognitive impairment in elderly adults with diabetes. PATIENTS AND METHODS: Case-control study. We included diabetic patients from the Geriatric Clinic of General Hospital No. 17 who were over 65 years and accepted to participate. Cases were patients with a score of 24 or less on the Mini Mental Status Examination (MMSE) and with DSM IV criteria for dementia. Controls were those with MMSE scores of 25 or greater. Results We included 97 patients (50 cases and 47 controls). There were no differences regarding clinical and laboratory characteristics between cases and controls. The frequency of the C allele and the CG genotype was higher in controls than in cases and this difference remained significant in a multivariate analysis with an odds ratio of 0.012 (95% CI 0.001-0.091) and 0.009 (95% CI 0.001-0.076) in the bivariate and multivariate analysis, respectively, using the GG genotype frequency as a reference. CONCLUSION: Cognitive impairment in Mexican patients with diabetes is associated with less exposure to the CG genotype of the c.1-765G>C polymorphism of COX2.

Galectin labeling of cells from paraffinized tissues may serve as a diagnostic tool in the detection and classification of thyroid carcinomas.

This study seeks to determine whether the relative levels of attachment to galectins 1 and 3 of cells from thyroid tissues embedded in paraffin blocks can differentiate thyroid tumors from normal tissues. A total of 48 thyroid paraffin sample blocks from 4 groups of patients were analyzed: 12 samples served as controls, 12 samples were from patients with thyroid adenoma, 12 samples were from patients with thyroid follicular carcinoma, and 12 samples were from patients with thyroid papillary carcinoma. The relative attachment of cells to galectins 1 and 3 antigens was determined using the InnoCyte™ ECM Cell Adhesion kit at different cell sample concentrations. All of the samples from thyroid tissue preparations showed attachment to galectins 1 and 3. The samples from tissues with a diagnosis of adenoma, follicular and papillary carcinoma showed an increased adherence to galectins 1 and 3 relative to the controls. Significant differences were found between the means of the adherent cells from the adenomas compared with the follicular and papillary carcinoma samples. When the outcomes from the galectins 1 and 3 cell surface binding were compared, no statistical differences were found. The cells from adenoma and carcinoma samples show more adhesion to galectins 1 and 3 than cells from the control samples. The samples prepared from follicular and papillary carcinomas show more cells adherent to galectins 1 and 3 than those from the adenomas.

Entamoeba histolytica: soluble and membrane-associated neutral sphingomyelinase-C and other unidentified esterase activity.

Sphingomyelinase (SMase) activity was measured in Entamoeba histolytica particulate and soluble subcellular fractions. The effects on SMase of incubation time, total protein concentration, pH, and several divalent cations were determined. SMase-C and other unidentified esterase activity were detected in soluble and particulate fractions. SMase-C was 94.5-96.0% higher than the unidentified esterase activity. Soluble and insoluble SMase-C specific activities increased with protein dose and incubation time. Soluble and insoluble SMase-C activities were maximum at pH 7.5 and were dependent on Mg(2+), Mn(2+), or Co(2+), and inhibited by Zn(2+), Hg(2+), Ca(2+), and EDTA. SMase-C was active in the pH range of 3-10 and its maximum activity was at pH 7.5. The soluble and insoluble SMases have remarkably similar physicochemical properties, strongly suggesting that E. histolytica has just one isoform of neutral SMase-C that had not been described before and might be essential for E. histolytica metabolism or virulence.

Trichomonas vaginalis: identification of a phospholipase A-dependent hemolytic activity in a vesicular subcellular fraction.

Trichomonad total extracts (TTE), or vesicular (P30) and soluble (530) subcellular fractions from 3 pathogenic Trichomonas vaginalis strains (GT-3. GT-13. and GT-15), lysed both human and Sprague-Dawley rat erythrocytes in a time- and dose-dependent manner. The entire hemolytic activity of TTE was located in P30, showing 2 peaks of maximum activity, one at pH 6.0 and another at pH 8.0. in the presence of 1 mM Ca2+. Hemolytic activity on rat erythrocytes was greater at pH 6.0 16.71 +/- 0.33 hemolytic units IHU]/mg/hr to 11.60 +/- 0.24 HU/mg/hr) than at pH 8.0 (3.81 +/- 0.30 HU/mg/hr to 5.75 +/- 0.65 HU/mg/hr). and it was greater than that on human red blood cells at pH 6.0 (2.67 +/- 0.19 HU/mg/hr to 4.08 +/- 0.15 HU/mg/hr) or pH 8.0 (2.24 +/- 0.0 9 HU/mg/hr to 2.81 +/- 0.06 HU/mg/hr). The alkaline and acidic hemolytic activity diminished (60-93% at pH 6.0 and 78-93% at pH 8.0) by the effect of 80 microM Rosenthal's inhibitor, which also inhibited 27-45% and 29-54% trichomonad alkaline and acidic phospholipase A activities, respectively. Vesicles, vacuoles, and hydrogenosomes were rich in P30. Trichomonas vaginalis has a hemolytic PLA, which could be involved in its cytopathogenic mechanism.

Detection of a factor released by L5178Y lymphoblasts that inhibits mouse Macrophage-Activation induced by lipopolysaccharides

Background. Several factors inhibit cellular immune response by deactivating macrophages, but very few, such as those described here, prevent macrophage activation. Methods. Ascites liquid from 12-day-old BALB/c mice bearing 5178Y lymphoma tumors was collected, and cell-free ascites liquid (CFAL) was separated from lymphoblasts. The supernatant (SI) was obtained from the homogenized and centrifuged lymphoblasts Then, macrophage cultures contaning 0.2 X 10 a the sixth cells from lymphoma-bearing or hearthly mice were added to 10 µL of CFAL or S1, plus 5 µg of lipopolysaccharides (LPS)/mL, 40 U interferon-ç or a blend of both. Macrophages were incubated with CFAL or S1 prior to or after adding the activators to investigate whether any of the previously mentioned lymphoma fraction inhibited macrophage activation or whether they deactivated them. The effect of CFAL or S1 was estimated as the diminution of the amount of nitric ixide released by the experimental macrophage cultures with respect to controls (activated macrophages treated with none of the lymphoma fractions). Results. LPS, IFN-ç, and the LPS/ç blend activated macrophages from both lymphomabearing and healthy mice. None of the lymphoma fractions deactivated macrophages. CFAL, but not S1, inhibited the macrophage activation, i.e., the percentage of inhibition of nitric oxide releasing 76.7 percent in macrophages from healthy and lymphomabearing mice, respectively. In addition, CFAL was unable to inhibit macrophage-activation effect of IFN-ç or the LPS/IFN-ç blend. Conclusions. Mouse L5178Y Lymphoma releases a factor that in vitro inhibits the macrophage activation induced by LPS, but not by IFN-ç controls