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Bioactive peptides (BAPs) derived from samples of animals and plants have been widely recommended and consumed for their beneficial properties to human health and to control several diseases. This work presents the applications of experimental designs (DoE) used to perform factor screening and/or optimization focused on finding the ideal hydrolysis condition to obtain BAPs with specific biological activities. The collection and discussion of articles revealed that Box Behnken Desing and Central Composite Design were the most used. The main parameters evaluated were pH, time, temperature and enzyme/substrate ratio. Among vegetable protein sources, soy was the most used in the generation of BAPs, and among animal proteins, milk and shrimp stood out as the most explored sources. The degree of hydrolysis and antioxidant activity were the most investigated responses in obtaining BAPs. This review brings new information that helps researchers apply these DoE to obtain high-quality BAPs with the desired biological activities., Competing Interests: Conflict of interestThe authors declare that no personal or financial interests may interfere with the work written in this article. We, CALJ and ECV, as the corresponding authors and on behalf of the staff, certify that there is no conflict of interest., (© The Korean Society of Food Science and Technology 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Several species during evolution suffered random mutations in response to various environmental factors, which resulted in the formation of venom in phylogenetically distant species. The composition of the venom of most species is poorly known. Snake venom is well characterized while most species have poorly known composition. In contrast, snake venoms are well characterized which proteins and peptides are the main active and most abundant constituents. 42 protein families have been identified, including metalloproteins known as metalloproteinases. These macromolecules are enzymes with zinc in their active site derived from the disintegrin A and metalloproteinase (ADAM) cellular family and are categorized into three classes (PI, PII and PIII) according to their domain organization. The snake venom metalloproteinases (SVMP) are cytotoxic, neurotoxic, myotoxic and/or hematotoxic with a crucial role in the defense and restraint of prey. In this scenario envenoming represents a danger to human health and has been considered a neglected disease worldwide, particularly in tropical and subtropical countries. Nevertheless, recently advances in "omics" technologies have demonstrated interesting biological activities of SVMPs such as antimicrobial, anticancer, against cardiovascular diseases and nervous system disorders. Metalloproteins have the therapeutic potential to be converted into drugs as other components of the venom have undergone this process (e.g., captopril, tirefiban and eptifibatide). So, this chapter is focused on the metalloproteins found in the secretions of venomous species, highlight some aspects such as structure, biological activity, pharmacological therapeutic potential and on., (Copyright © 2024. Published by Elsevier Inc.)

Buriti (Mauritia flexuosa L.) is a significant source of carotenoids, but these compounds have been extracted using laborious and low-effective methods. The present work evaluated the high-intensity ultrasound combined with a chemometric approach to developing an optimal extraction method of carotenoids from buriti pulp. The multivariate optimization was carried out through two steps. First, a simplex-lattice mixture design was used to optimize the extractor solution finding higher extraction yield (903 ± 21 µg g -1 ) with the acetone:ethanol (75/25) mixture. After, sample mass (80 mg) and sonication time (30 min) were optimized applying central composite design (CCD) which provided a 14% improvement in the extraction method yield. So, the total carotenoid content (TCC) with optimal extraction conditions was 1026 ± 13 µg g -1 which is almost twice the yield of methods known in the literature for buriti. The RP-HPLC-DAD analysis revealed that the carotenoids are gently extracted and β-carotene is the major compound in the extracts. To confirm the accuracy, buriti samples spiked with β-carotene standard and the developed method showed recovery >84% and precision <6.5%. Furthermore, the optimized ultrasound-assisted extraction (UAE) method was applied to other samples (tomato, guava, carrot, mango, acerola, papaya, and pumpkin) and presented a yield to 5.5-fold higher when compared to the reported methods indicating high robustness. Based on results, the UAE method developed has demonstrated feasibility and reliability for the study of carotenoids in buriti pulp as well as in other plant matrices with high biological relevance., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Carotenoids are an essential component of cashew and can be used in pharmaceuticals, cosmetics, natural pigment, food additives, among other applications. The present work focuses on optimizing and comparing conventional and ultrasound-assisted extraction methods. Every optimization step took place with a 1:1 (w:w) mixture of yellow and red cashew apples lyophilized and ground in a cryogenic mill. A Simplex-centroid design was applied for both methods, and the solvents acetone, methanol, ethanol, and petroleum ether were evaluated. After choosing the extractor solvent, a central composite design was applied to optimize the sample mass (59-201 mg) and extraction time (6-34 min). The optimum conditions for the extractor solvent were 38% acetone, 30% ethanol, and 32% petroleum ether for CE and a mixture of 44% acetone and 56% methanol for UAE. The best experimental conditions for UAE were a sonication time of 19 min and a sample mass of 153 mg, while the CE was 23 min and 136 mg. Comparing red and yellow cashews, red cashews showed a higher carotenoid content in both methodologies. The UAE methodology was ca. 21% faster, presented a more straightforward composition of extracting solution, showed an average yield of superior carotenoid content in all samples compared to CE. Therefore, UAE has demonstrated a simple, efficient, fast, low-cost adjustment methodology and a reliable alternative for other applications involving these bioactive compounds in the studied or similar matrix., (Copyright © 2022. Published by Elsevier B.V.)

Aerobic training (AT) promotes several health benefits that may attenuate the progression of obesity associated diabetes. Since AT is an important nitric oxide (NO - ) inducer mediating kidney-healthy phenotype, the present study is aimed at investigating the effects of AT on metabolic parameters, morphological, redox balance, inflammatory profile, and vasoactive peptides in the kidney of obese-diabetic Zucker rats receiving L-NAME (N(omega)-nitro-L-arginine methyl ester). Forty male Zucker rats (6 wk old) were assigned into four groups ( n = 10, each): sedentary lean rats (CTL-Lean), sedentary obese rats (CTL-Obese), AT trained obese rats without blocking nitric oxide synthase (NOS) (Obese+AT), and obese-trained with NOS block (Obese+AT+L-NAME). AT groups ran 60 min in the maximal lactate steady state (MLSS), five days/wk/8 wk. Obese+AT rats improved glycemic homeostasis, SBP, aerobic capacity, renal mitochondria integrity, redox balance, inflammatory profile (e.g., TNF- α , CRP, IL-10, IL-4, and IL-17a), and molecules related to renal NO - metabolism (klotho/FGF23 axis, vasoactive peptides, renal histology, and reduced proteinuria). However, none of these positive outcomes were observed in CTL-Obese and Obese+AT+L-NAME ( p < 0.0001) groups. Although Obese+AT+L-NAME lowered BP (compared with CTL-Obese; p < 0.0001), renal damage was observed after AT intervention. Furthermore, AT training under conditions of low NO - concentration increased signaling pathways associated with ACE-2/ANG1-7/MASr. We conclude that AT represents an important nonpharmacological intervention to improve kidney function in obese Zucker rats. However, these renal and metabolic benefits promoted by AT are dependent on NO - bioavailability and its underlying regulatory mechanisms., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Rodrigo Vanerson Passos Neves et al.)

Patients in maintenance hemodialisys (HD) present sleep disorders, increased inflammation, unbalanced redox profiles, and elevated biomarkers representing endothelial dysfunction. Resistance training (RT) has shown to mitigate the loss of muscle mass, strength, improve inflammatory profiles, and endothelial function while decreasing oxidative stress for those in HD. However, the relation between those factors and sleep quality are inadequately described. The aim of this study was to verify the effects of 3 months of RT on sleep quality, redox balance, nitric oxide (NO) bioavailability, inflammation profile, and asymmetric dimethylarginine (ADMA) in patients undergoing HD. Our primary goal was to describe the role of RT on sleep quality. Our secondary goal was to evaluate the effect of RT on NO, metabolism markers, and inflammatory and redox profiles as potential mechanisms to explain RT-induced sleep quality changes. Fifty-five men undergoing maintenance hemodialysis were randomized into either a control (CTL, n = 25) and RT group (RTG; n = 30). Participants in the RT group demonstrated an improvement in sleep pattern, redox, inflammatory profiles, and biomarkers of endothelial function (NO 2 - and ADMA). This group also increased muscle strength (total workload in RT exercises of upper and lower limbs). These findings support that RT may improve the clinical status of HD patients by improving their sleep quality, oxidative and inflammatory parameters.

Ulcerative colitis is an inflammatory bowel disease that affects the mucous membrane of the colon. The pathogenesis is not clear, but there is evidence of a complex interaction between genetic, environmental, and immunological factors. In this regard, we highlight the role of zinc in the immune system and probable control of the disease. This study evaluated the effect of zinc supplementation on the inflammatory response in patients with ulcerative colitis. A blind interventional study involving 41 patients of both sexes, who underwent either zinc gluconate supplementation (n = 23), or treatment with a placebo (corn starch) (n = 18). Patients were evaluated for dietary zinc intake, plasma and erythrocyte zinc concentrations, and serum levels of Th1/Th2/Th17 type cytokines at baseline (T0) and 30 (T1) and 60 (T2) days after intervention. Patients in the zinc supplementation group had a lower probability of having an adequate zinc intake than placebo. In this same group, there was a significant difference between plasma zinc concentrations (T1 in relation to T0, T2 in relation to T1, and T2 in relation to T0) and erythrocyte zinc (T1 in relation to T0 and T2 in relation to T1). Zinc supplementation resulted in significant changes in the concentrations of IL-2 and IL-10 without differences in the other interleukins. Zinc gluconate intervention in patients with ulcerative colitis improves the nutritional status of this mineral in these patients and positively influences their clinical outcome, reinforcing the role of zinc as an important dietary component in disease control.

An extraction method based on a multivariate analytical approach was developed for enhancement of the phenolic compounds in cashew nut extracts. The different extractor solvents (acetone, water, ethanol, and methanol) and their binary, ternary, and quaternary combinations were evaluated using a simplex-centroid design and surface response methodology. The special cubic model exhibits no lack of fit and explains 89.2% of the variance. The total phenolic measurements by the Folin-Ciocalteu method revealed the highest values for ethanol (5.93 mg GAE g -1 ) and acetone-methanol-ethanol ternary mixture (5.92 mg GAE g -1 ) extracts. ESI (-)-Q/TOFMS analyses combined with PCA and HCA revealed the presence of fatty acids, phospholipids, and sugars in the ternary mixture cashew extract, while for the ethanol extract only phenolic compounds, such as anacardic acids and derivatives, were found. The proposed approach was adequate to reach the optimal extractor which ethanol, a low-toxicity solvent, enabled the selective extraction of a high content of phenolic compounds from cashew nuts., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Protein extraction from goat meat was carried out based on the combination of response surface methodology and factorial design to optimize the variables: temperature (25-50 °C), extraction time (8-20 min), volume (3-10 mL) and extractor concentration (0.05-0.1 mol L -1 ). The proposed model did not present a lack of fit, explaining 96% of the total data variance (R 2  = 0.96). The optimum extraction conditions were: 0.05 mol L -1 for extractor concentration, extraction time of 10 min, temperature of 44 °C and extractor volume of 3.5 mL. The protein content (19.3 g/100 g) obtained by the optimized method was higher than some results reported in the literature. HPLC-SEC-DAD analysis revealed that the extraction conditions used did not significantly modify the protein structure. The proposed method proves to be simple, fast, robust, cheap and adequate for native protein extraction, being a potential approach for proteomic research focusing in goat meat., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Aim: To investigate the effects of bariatric surgery on metabolic parameters, incretin hormone secretion, and duodenal and ileal mucosal gene expression., Methods: Nine patients with type 2 diabetes mellitus (T2DM), chronic serum hyperglycemia for more than 2 years, and a body mass index (BMI) of 30-35 kg/m(2) underwent metabolic surgery sleeve gastrectomy with transit bipartition between May 2011 and December 2011. Blood samples were collected pre and 3, 6 and 12 mo postsurgery. Duodenal and ileal mucosa samples were collected pre- and 3 mo postsurgery. Pre- and postoperative blood samples were collected in the fasting state before ingestion of a standard meal (520 kcal) and again 30, 60, 90, and 120 min after the meal to determine hemoglobin A1c (HbA1c) levels and the lipid profile, which consisted of triglyceride and total cholesterol levels. Intestinal gene expression of p53 and transforming growth factor (TGF)-β was analyzed using quantitative reverse-transcription PCR. Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were quantified using the enzyme-linked immunoassay method and analyzed pre- and postoperatively. Student's t test or repeated measurements analysis of variance with Bonferroni corrections were performed as appropriate., Results: BMI values decreased by 15.7% within the initial 3 mo after surgery (31.29 ± 0.73 vs 26.398 ± 0.68, P < 0.05) and then stabilized at 22% at 6 mo postoperative, resulting in similar values 12 mo postoperatively (20-25 kg/m(2)). All of the patients experienced improved T2DM, with 7 patients (78%) achieving complete remission (HbA1c < 6.5%), and 2 patients (22%) achieving improved diabetes (HbA1c < 7.0% with or without the use of oral hypoglycemic agents). At 3 mo postoperatively, fasting plasma glucose had also decreased (59%) (269.55 ± 18.24 mg/dL vs 100.77 ± 3.13 mg/dL, P < 0.05) with no further significant changes at 6 or 12 mo postoperatively. In the first month postoperatively, there was a complete withdrawal of hypoglycemic medications in all patients, who were taking at least 2 hypoglycemic drugs preoperatively. GLP-1 levels significantly increased after surgery (149.96 ± 31.25 vs 220.23 ± 27.55) (P < 0.05), while GIP levels decreased but not significantly. p53 gene expression significantly increased in the duodenal mucosa (P < 0.05, 2.06 fold) whereas the tumor growth factor-β gene expression significantly increased (P < 0.05, 2.52 fold) in the ileal mucosa after surgery., Conclusion: Metabolic surgery ameliorated diabetes in all of the patients, accompanied by increased anti-proliferative intestinal gene expression in non-excluded segments of the intestine.

Objective: To evaluate the prevalence and factors associated with metabolic syndrome in the elderly., Methods: Cross-sectional study, with 133 individuals randomly selected in the Unified Health System in Goiania, Goiás. The following variables were researched: anthropometric (BMI, waist circumference, fat percentage by Dual X-ray absorptiometry), sociodemographic (gender, age, color, income, marital status and years of schooling), lifestyle (physical activity, smoking and risk alcohol consumption) and food intake (risk and protective foods). The metabolic syndrome was assessed according to harmonized criteria proposed by the World Health Organization (WHO). The combinations were tested by Poisson regression for confounding factors., Results: The prevalence of metabolic syndrome was 58.65% (95%CI 49.8 - 67.1), with 60.5% (95%CI 49.01 - 71.18) for females and 55.7% (95%CI 41.33 - 69.53) for males. Hypertension was the most prevalent component of the syndrome in both men, with 80.8% (95%CI 64.5 - 90.4), and women, with 85.2% (95%CI 75.5 - 92.1). After the multivariate analysis, only the excess of weight measured by body mass index (prevalence ratio = 1.66; p < 0.01) remained associated with the metabolic syndrome., Conclusions: The prevalence of metabolic syndrome in this sample was high, indicating the need for systematic actions by health workers in the control of risk factors through prevention strategies and comprehensive care to the elderly.

Graft-versus-host disease is observed mainly in recipients of hematopoietic cell transplantation and is expressed by cutaneous or systemic signals and symptoms. Graft-versus-host disease is clinically classified as acute or chronic. Chronic Graft-versus-host disease occurs in up to 70% of hematopoietic cell transplanted patients and its clinical manifestations have important impact on morbidity and quality of life. The authors report an expressive cutaneous, oral and adnexal involvement in a patient with chronic Graft-versus-host disease with multiple lesions of lichenoid and atrophic pattern.

The scope of this paper was to evaluate the provision of building maintenance services in health units, by means of a descriptive, quantitative and cross-sectional study, considering the five types of facilities (Primary Health, Emergency, Specialty, Hospital and Mental Health Units). The research was approved by the Research Ethics Comittee of FHEMIG with the Terms of Agreement signed with the Unified Health System of Betim. Comparative analysis was conducted by checking the requirements of "Physical-Functional Structure Management" of the "Brazilian Hospital Accreditation Manual" of the National Accreditation Organization. Nonconformities were noted in the physical-functional management of the health centers, especially the primary health units. The assessment was important, considering that compliance with formal, technical and structural requirements, welfare activities, according to the service organization and appropriate to the profile and complexity, can collaborate to minimize the risks of users. To improve the quality of health care establishments, it is essential that managers, backed by "top management," prioritize financial, human and material resources in planning to ensure compliance with security requirements of users in buildings.

Aim: Diabetic nephropathy (DN) is a frequent complication in patients with long-standing type 1 diabetes mellitus (DM1). The objective of this study was to assess the prevalence of DN in DM1 patients diagnosed during childhood and its association with clinical and metabolic variables, such as age at diagnosis of DM1, glucose control, dyslipidemia, hypertension and the occurrence of diabetic retinopathy (DR)., Methods: The medical records of 205 patients admitted to the Pediatric Endocrinology Division at the Hospital das Clinicas da Universidade Federal de Minas Gerais, in Belo Horizonte, Brazil, were analyzed. For the analysis of survival and prognostic factors, the Kaplan-Meyer method and the COX regression model were used., Results: The mean disease duration was 11.32 +/- 4.02 years and the mean age at diagnosis was 6.10 +/- 3.54 years. Microalbuminuria was present in 11.2% of them, proteinuria in 6.8% and end-stage renal disease (ESRD) in 2.9%. There was a significant association between the occurrence of microalbuminuria or proteinuria and poor glucose control (p=0.025 and p=0.005, respectively), higher LDL cholesterol levels (p=0.006 and p=0.004, respectively) and age greater than 6 years at diagnosis (p=0.049 and p=0.05, respectively). Proteinuria was also associated to the occurrence of DR (p=0.016)., Conclusion: Our data showed that the prevalence of DN was higher than expected in this young population studied, especially considering the most severe forms. Clinical and laboratory factors associated to ND were: poor long-term glucose control, higher levels of LDL-C, higher age at diagnosis and the occurrence of DR.

Background and Aim: Although prophylaxis with beta-blockers has been shown to decrease variceal pressure and wall tension in cirrhotic patients, this has not been demonstrated in non-cirrhotic portal hypertension caused by Schistosoma mansoni infection., Methods: Thirteen patients without history of previous gastrointestinal bleeding were included. All of them had high-risk esophageal varices at endoscopy. An endoscopic gauge and a high-frequency endoscopic ultrasonography miniprobe were used to assess transmural variceal pressure and wall tension before and after achieving beta-blockade with propranolol., Results: Baseline variceal pressure decreased from 13.3 +/- 3.5 to 8.2 +/- 2.0 mmHg (P < 0.0001) and wall tension from 500.2 +/- 279.8 to 274.0 +/- 108.3 mg.mm(-1). The overall effect of propranolol on decreasing variceal pressure and wall tension expressed in percentage change in relation to baseline values was 35.7 +/- 18.4% and 35.9 +/- 26.7%, respectively (P = 0.9993)., Conclusion: Propranolol significantly reduced variceal pressure and wall tension in schistosomiasis.

Lactobacillus delbrueckii UFV-H2b20 has been shown to increase clearance of bacteria injected into the blood of germ-free mice. Moreover, it induces the production of type 1 cytokines by human peripheral mononuclear cells. The objective of the present study was to investigate the production of inflammatory cytokines [interleukin-12 (IL-12 p40), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma)] triggered in vitro by live, heat-killed or lysozyme-treated L. delbrueckii UFV-H2b20 and in vivo by a live preparation. Germ-free, L. delbrueckii-monoassociated and lipopolysaccharide (LPS)-resistant C3H/HeJ mice were used as experimental models. UFV-H2b20 induced the production of IL-12 p40 and TNF-alpha by peritoneal cells and IFN-gamma by spleen cells from germ-free or monoassociated Swiss/NIH mice and LPS-hyporesponsive mice (around 40 ng/mL for IL-12 p40, 200 pg/mL for TNF-alpha and 10 ng/mL for IFN-gamma). Heat treatment of L. delbrueckii did not affect the production of these cytokines. Lysozyme treatment decreased IL-12 p40 production by peritoneal cells from C3H/HeJ mice, but did not affect TNF-alpha production by these cells or IFN-gamma production by spleen cells from the same mouse strain. TNF-alpha production by peritoneal cells from Swiss/NIH L. delbrueckii-monoassociated mice was inhibited by lysozyme treatment. When testing IL-12 p40 and IFN-gamma levels in sera from germ-free or monoassociated Swiss/NIH mice systemically challenged with Escherichia coli we observed that IL-12 p40 was produced at marginally higher levels by monoassociated mice than by germ-free mice (40 vs 60 ng/mL), but IFN-gamma was produced earlier and at higher levels by monoassociated mice (monoassociated 4 and 14 ng/mL 4 and 8 h after infection, germfree 0 and 7.5 ng/mL at the same times). These results show that L. delbrueckii UFV-H2b20 stimulates the production of type 1 cytokines in vitro and in vivo, therefore suggesting that L. delbrueckii might have adjuvant properties in infection in which these cytokines play a major role.

A simple flow injection potentiometric (FIP) system, which uses a tubular cobalt electrode, has been developed for phosphorus nutritional evaluation of seeds and grains. Inorganic phosphorus, P(i), is determined using a 1 x 10(-2) mol.L(-1) potassium phthalate buffer solution adjusted at pH 4. A sensitivity of 47 mV/decade and an operating range from 10 to 1000 mg.L(-1) (1 x 10(-4)-1 x 10(-2) M) of dihydrogen phosphate are obtained. The inositol phosphates amount, which is referred to the organic phosphorus, P(org), is directly determined from extracts using a 1 x 10(-2) mol.L(-1) Tris-HCl buffer solution adjusted at pH 8. A sensitivity of 127 mV/decade and an operating range of 10-1000 mg.L(-1) (2.5 x 10(-4)-5 x 10(-3) M) of P(org) (expressed as inositol hexakisphosphoric acid monocalcium) are achieved. Some samples of seed and grain are analyzed by an ICP-OES and a spectrophotometric method to compare results to the developed flow system; no significant differences at the 95% confidence level are observed using a paired t test. Other samples such as animal nursing feed, soybean meal, and corn are also analyzed with the proposed FIP system, showing a good correlation to the ICP-OES values.

In order to investigate the importance of the host microbiota on differentiation of T cell subsets in response to infection, Swiss/NIH germ-free mice and conventional (microbiota-bearing) mice were infected with Leishmania major, and lesion development, parasite loads, and cytokine production were assessed. Germ-free mice failed to heal lesions and presented a higher number of parasites at the site of infection than their conventional counterparts. In addition, histopathological analysis indicated a higher density of parasitized macrophages in lesions from germ-free mice than in conventional mice. The initial production of interleukin (IL)-12 and interferon-gamma (IFN-gamma) in germ-free mice was comparable to the conventional controls. Also, germ-free mice produced elevated levels of IFN-gamma and lower levels of IL-4 throughout the course of infection, suggesting the development of a Th1 response. Macrophages from germ-free mice exposed to IFN-gamma and infected with amastigotes in vitro were not as efficient at killing parasites as macrophages from conventional animals. These observations indicate that the microbiota is not essential for the development of Th1 immune responses, but seems to be important for macrophage activation.

A flow injection spectrophotometric procedure with enzymatic hydrolysis was developed for determination of orthophosphate, phytate and total phosphorus in cereal samples. Phosphorus species were extracted from cereals with 0.05 mol L(-1) potassium hydrogen phthalate buffer solution at pH 5.7. Orthophosphate was directly determined in the extracts by molybdenum blue spectrophotometric method. The phytate was hydrolyzed by the enzyme phytase coupled to a solid phase packed into an enzymatic reactor, and the resulting hydrolyzed orthophosphate was also determined by spectrophotometry at 650 nm. After optimization for phosphorus species extraction and enzymatic hydrolysis, a linear calibration graph was obtained up to 196 x 10(-6) mol L(-1) orthophosphate (P conc = -2.67 + 0.52x, r = 0.9998). Measurements are characterized by relative standard deviation of 1.6% for a standard of 72 x 10(-6) mol L(-1) orthophosphate and no baseline drift was observed during 4 h operation periods. It provides 72 measurements per hour, with 2.4 x 10(-)6) mol L(-1) and 7.9 x 10(-6) mol L(-1) as detection and quantification limits, respectively.

We studied the effects of alpha-tocopheryl acetate supplementation on the development of fatty streaks and its ability to modulate the expression of monocyte chemoattractant protein (MCP)-1 in aortic lesions of apolipoprotein E knockout mice. For this purpose, 16-week-old apolipoprotein E knockout mice received alpha-tocopherol supplementation (800 mg)/kg diet) for 6 weeks. After this time, total and lipoprotein cholesterol in the serum, hepatic tocopherol, aortic lesion area and MCP-1 (protein and mRNA) expression were analysed. Our present results showed that the dietary supplementation with alpha-tocopherol did not reduce serum cholesterol nor change lipoprotein profile, but it reduced the area of the aortic lesion by 55 %. The reduction in the lesion size was correlated with the reduced expression of MCP-1 mRNA and protein, as detected by real-time quantitative polymerase chain reaction and immunohistochemistry respectively. In conclusion, the results obtained here are relevant to the study of atherosclerosis, as they correlate the effectiveness of vitamin E supplementation in inhibiting the plaque formation with diminished expression of MCP-1 at the aortic lesion.

In this study, we examined glucose homeostasis and insulin secretion in transgenic mice overexpressing the human apolipoprotein CIII gene (apo CIII tg). These mice have elevated plasma levels of triglycerides, FFA and cholesterol compared to control mice. The body weight, plasma glucose, and insulin levels, glucose disappearance rates, areas under the ipGTT curve for adult (4 - 8 mo. old) and aged (20 - 24 mo. old) apo CIII tg mice and the determination of insulin during the ipGTT were not different from those of control mice. However, an additional elevation of plasma FFA by treatment with heparin for 2 - 4 h impaired the ipGTT responses in apo CIII tg mice compared to saline-treated mice. The glucose disappearance rate in heparin-treated transgenic mice was slightly lower than in heparin-treated controls. Glucose (22.2 mmol/l) stimulated insulin secretion in isolated islets to the same extent in saline-treated control and apo CIII tg mice. In islets from heparin-treated apo CIII tg mice, the insulin secretion at 2.8 and 22.2 mmol glucose/l was lower than in heparin-treated control mice. In conclusion, hypertriglyceridemia per se or a mild elevation in FFA did not affect insulin secretion or insulin resistance in adult or aged apo CIII tg mice. Nonetheless, an additional elevation of FFA induced by heparin in hypertriglyceridemic mice impaired the ipGTT by reducing insulin secretion.

Although the role of oxidized lipoproteins is well known in atherogenesis, the role of vitamin E supplementation is still controversial. There is also little information about cholesterol metabolism (hepatic concentration and fecal excretion) in the new models of atherosclerosis. In the present study, we evaluated the effect of moderate vitamin E supplementation on cholesterol metabolism and atherogenesis in apolipoprotein E (apo E)-deficient mice. Apo E-deficient mice were fed an atherogenic diet containing 40 or 400 mg/kg of alpha-tocopherol acetate for 6 weeks. Total cholesterol in serum and liver and 3-OH-alpha-sterols in feces, and fecal excretion of bile acids were determined and histological analyses of aortic lesion were performed. A vitamin E-rich diet did not affect body weight, food intake or serum cholesterol. Serum and hepatic concentrations of cholesterol as well as sterol concentration in feces were similar in both groups. However, when compared to controls, the alpha-tocopherol-treated mice showed a reduction of about 60% in the atherosclerotic lesions when both the sum of lesion areas and the average of the largest lesion area were considered. These results demonstrate that supplementation of moderate doses of alpha-tocopherol was able to slow atherogenesis in apo E-deficient mice and to reduce atherogenic lipoproteins without modifying the hepatic pool or fecal excretion of cholesterol and bile acids.

Background: This study was carried out to determine whether early inoculation of the plasmid-free human Escherichia coli into human newborns would reduce the frequency of acute diarrhea during a 1-year period. The plasmid-free E. coli strain isolated from the fecal microbiota of a healthy adult was nontoxigenic in vivo and in vitro and sensitive to all usual antibiotics., Methods: In the experimental group, 51 healthy newborns were inoculated orally with 106 viable cells of the bacteria within 2 hours after birth. In the control group, the same number of newborns received the heat-killed bacteria. The clinical trial was double blind, and the newborns were randomly assigned to the experimental and control groups., Results: Six months and 1 year after bacterial inoculation, infants in the experimental group showed a higher mean body weight (7.59 +/- 1.15 kg and 9.88 +/- 1.31 kg, respectively; P < 0.05) when compared with the control group (7.03 +/- 1.09 kg and 8.92 +/- 1.38 kg, respectively). At the end of the clinical trial, 48% (23/48) of the infants in the experimental group had shown at least one diarrhea episode during the 1-year period, as opposed to 71% (34/48) in the control group. These values were significantly different (P = 0.037), showing a 32.3% protective effect of inoculation., Conclusions: The present study shows that protection against diarrhea was obtained by oral inoculation with a single dose of plasmid-free human E. coli soon after birth.

High protein content in the diet during childhood and adolescence has been associated to the onset insulin-dependent diabetes mellitus. We investigated the effect of interleukin-1beta (IL-1beta) on insulin secretion, glucose metabolism, and nitrite formation by islets isolated from rats fed with normal protein (NP, 17%) or low protein (LP, 6%) after weaning. Pretreatment of islets with IL-1beta for 1 h or 24 h inhibited the insulin secretion induced by glucose in both groups, but it was less marked in LP than in NP group. Islets from LP rats exhibited a decreased IL-1beta-induced nitric oxide (NO) production, lower inhibition of D-[U(14)C]-glucose oxidation to (14)CO(2) and less pronounced effect of IL-1beta on alpha-ketoisocaproic acid-induced insulin secretion than NP islets. However, when the islets were stimulated by high concentrations of K(+) the inhibitory effect of IL-1beta on insulin secretion was not different between groups. In conclusion, protein restriction protects beta-cells of the deleterious effect of IL-1beta, apparently, by decreasing NO production. The lower NO generation in islets from protein deprived rats may be due to increased free fatty acids oxidation and consequent alteration in Ca(2+) homeostasis.

Cholera vibrios sometimes survive, probably in low-level silent populations, in the small intestine of chronic carriers or pass through the gastrointestinal tract of a few individuals without causing diarrhoea or colonisation. To understand these situations, the present study used plate cultures (ex-vivo test) to investigate the frequency of appearance of an inhibitory halo against Vibrio cholerae produced by faecal specimens from 92 healthy volunteers (40 females, 52 males) aged 4-61 years. The frequency of inhibitory halo was 20.6% in the whole group. An apparently higher percentage (27.3%) was observed in the age range 20-40 years when compared with the range 4-19 years (10.7%), but not the range 41-61 years (20.0%). Frequency was significantly higher in males (30.8%) than females (7.5%). The dominant microbiota of a volunteer whose faeces produced an inhibitory halo was isolated by plate culture of decimal dilutions in an anaerobic chamber. Potential isolates of 26 apparently different morphologies were associated with germ-free NIH mice. One week later, the inhibitory test showed an antagonistic halo around the faeces from the associated animals, but not from the axenic mice. Of the 26 bacteria isolated, two (Lactobacillus sp. and Peptostreptococcus sp.) produced a compound antagonistic against V. cholerae in an in-vitro assay. When bi-associated with germ-free mice those strains eliminated the vibrio from the intestinal ecosystem in c. 5 days.

The effect of gelatin ingestion on cholesterol metabolism and on atheroma formation was evaluated in both wild type (n=14) and apoprotein E (apoE) knock out (apoE(-/-)) (n=20) C57BL/6 7-week-old mice. Animals were fed a cholesterol-free isoproteic semi-purified diet containing 20% of casein (control diet) or 10% of casein plus 10% of gelatin (gel diet) for 8 weeks. In wild type mice, dietary gelatin caused a reduction in the serum triacylglycerols levels associated with an increase in the fecal excretion. No difference in blood cholesterol was seen at the sixth week of experiment. At the eighth week of experiment, there was a modest but significant reduction of serum total and high density lipoprotein (HDL) cholesterol in apoE(-/-) mice fed on gel diet compared to the control. Total cholesterol/HDL cholesterol ratio was 2-fold higher in the gel group than that seen in the control group (14.39 and 7.84, respectively). Histological analyzes showed a 2.2-fold increase in the dimension of the atherosclerotic plaques in the proximal aorta in apoE(-/-) mice fed on a gel diet compared to those fed on a control diet. The gel diet also promoted a reduction in the fecal excretion of bile acids. Hepatic cholesterol was similar in both groups. In conclusion, although gelatin reduced total serum cholesterol, this reduction was associated to a decrease of HDL cholesterol and consequent increase of total cholesterol/HDL cholesterol ratio, resulting in an acceleration of atherogenesis.

Eggplant (Solanum melongena) is consumed extensively in Brazil. It has been believed that infusion of a powdered preparation of the fruit may reduce serum cholesterol. However, there are few documented reports on its effects on cholesterol metabolism and its possible hypocholesterolemic effect has not been proved by well-controlled studies. The aim of the present study was to observe the effects of S. melongena on the serum cholesterol and triglycerides of 38 hypercholesterolemic human volunteers ingesting S. melongena infusion for five weeks. Thirty-eight hypercholesterolemic subjects receiving either S. melongena infusion (N = 19) or placebo (N = 19) participated in two clinical experiments in which the effect of S. melongena infusion was studied with (N = 16) or without (N = 38) dietary orientation. Total cholesterol and its fractions, triglycerides, and apolipoproteins A and B were measured in blood at the beginning of the experiment and three and five weeks thereafter. No differences were observed compared to control. Intraindividual analysis showed that S. melongena infusion significantly reduced the blood levels of total and LDL cholesterol and of apolipoprotein B. After dietary orientation, no intra- or intergroup differences were seen for any of the parameters analyzed. The results suggest that S. melongena infusion had a modest and transitory effect, which was not different from that obtained with standard orientation for dyslipidemia patients (diet and physical activities).

The effect of Saccharomyces boulardii on the immune system was evaluated, comparing germ-free Swiss/NIH mice monoassociated with the probiotic with germ-free mice. Saccharomyces boulardii colonized the gut of germ-free mice and survived the gastrointestinal conditions. An increase in sIgA production, both total and anti-S. boulardii, was observed in the intestinal contents of monoassociated mice when compared with germ-free controls. The number of Kupffer cells was significantly higher in monoassociated mice than in germ-free controls. In S. boulardii-monoassociated mice, clearance of Escherichia coli B41 was higher than in germ-free controls. TNF-alpha, IFN-gamma and IL-12 serum levels were higher at earlier time points in monoassociated mice when compared with germ-free mice. These results show that the yeast S. boulardii modulates the host immune responses. This effect may be of interest for improving the resistance to enteropathogenic bacterial infections.

The heat shock response has imparted protective effects in animal models of septic shock and endotoxemia. This study has tested the hypothesis that it could be protective in experimental burns. One hundred and fifteen adult male Fischer rats were randomly divided into four groups. Rats in the first group (n = 12) were anesthetized and shaved. In the second group (n = 15) rats were anesthetized and heated in a 45 degrees C water bath. In the third group (n = 44), rats were anesthetized, shaved and submitted to 26-30% body surface third-degree burns using a brass bar. In the fourth group (n = 44), rats were anesthetized, heated and, 1 day after, they were burnt. Mortality rates were measured at 3, 7, 15 and 25 days. Liver and lung samples were collected from all groups for heat-shock protein 70 detection. Heat-shock protein 70 was positive in heated animals. No animals died in the first or second group. Heated and burnt animals showed significantly decreased mortality at days 3 (p < 0.05, Fischer's exact test) and at days 7, 15 and 25 (p < 0.01) after burns, when compared to unheated burnt animals. In conclusion, eliciting the heat-shock response significantly reduced mortality rates in this model of experimental burns.

To study the possible influence of intestinal micro-organisms on the course of strongyloidiasis in mice, a method was developed to obtain axenic infective larvae of Strongyloides venezuelensis. Cultured larvae from conventional mice were treated with sodium hypochlorite 0.25% for 10 min, washed in distilled water and then exposed to various combinations of antibiotics for 30 or 60 min. Success was achieved with a combination of penicillin 180 mg/L and ceftazidime 1 mg/ml. Decontamination of the larvae was determined by aerobic and anaerobic culture and by inoculation into gnotobiotic mice. Viability was established by subcutaneous inoculation of larvae into germ-free and conventional mice. Preliminary results showed that gnotobiotic mice were more susceptible than conventional mice to infection with axenic S. venezuelensis larvae as judged by faecal egg excretion, recovery of worms in the small intestine and histopathological examination of the duodenal mucosa. These results suggest that the normal intestinal flora protects the host against experimental infection with S. venezuelensis.

Recent studies have shown that the intestinal microbiota is essential for the pathogenicity but not for the multiplication of Giardia duodenalis in the intestinal lumen. The microbial components responsible for this phenomenon are not known. Twenty-eight facultative and three strictly anaerobic micro-organisms were isolated from the dominant duodenal microbiota of five patients with symptomatic giardiasis. The bacterial combinations from each patient were associated with groups (GN) of germ-free mice. Five days after the association, when their faecal populations ranged from 10(7) to 10(9) cfu/g, all groups were inoculated intragastrically with 10(5) viable trophozoites of G. duodenalis strain BT6. Two groups of germ-free (GF) and conventional (CV1) mice were also infected. Gnotobiotic animals were killed 10 days after infection and GF and CV1 animals were killed 10, 20 and 30 days after infection. More marked pathological alterations were detected in CV1 mice when compared with GF animals. Gnotobiotic animals showed intermediate pathological alterations between CV1 and GF mice. The CV1 and GF groups became infected by day 3 and faecal cyst levels were similar in both groups throughout the experiment. Total and G. duodenalis-specific IgA levels in the intestinal fluid and G. duodenalis-specific IgM and IgG levels in the serum increased during the infection and were higher in CV1 animals at all times tested when compared with GF mice. The present results confirm the stimulatory activity of the intestinal microbiota on the pathogenicity of G. duodenalis, and some combinations of microbial components of the dominant duodenal ecosystem from patients with symptomatic giardiasis can partially develop this function. However, none of these combinations was able to stimulate the protozoan pathogenicity in the same manner as the entire intestinal microbiota.

Lactobacillus acidophilus, Saccharomyces boulardii and Escherichia coli are probiotic strains used individually to protect against enteropathogenic agents. In order to determine if a synergistic effect of the individual protective mechanisms ordinarily attributed to each of these biotherapeutic agents is possible, we orally administered Lact. acidophilus H2B20, S. boulardii and E. coli EMO (LSE) to germfree mice. Ten days after colonization of the digestive tract, groups of animals associated (experimental) or not (control) with LSE were challenged orally with streptomycin resistant (Sfr) or streptomycin sensitive (Sfs) Shigella flexneri strains or Salmonella enteritidis subsp. typhimurium. Bacterial counts in faeces from experimental mice showed that the Sfr strain was eliminated 11 d after challenge while Sfs and S. enteritidis subsp. typhimurium colonized the digestive tract and continued to be present at high population levels (108 CFU g-1 of faeces), which is similar to that observed in control animals. All possible di- and monoassociations of the three probiotics with gnotobiotic mice were also performed before experimental oral infection with Sfr. The data showed that antagonism was obtained only when E. coli EMO was present. Different sensitivity of Sh. flexneri Sfr and Sfs to E. coli EMO antagonism could be explained by the different generation times between Sfr and Sfs, as shown by colonization kinetic experiments in the digestive tract of gnotobiotic mice.

This work evaluated the efficacy of an improved method used to determine the frequency of bacterial infiltration and bacterial population levels and morphotypes in cavities restored with adhesive composites in conventional mice. By using the alternative methodology suggested in this work, bacteria from microleakage were recovered and identified in cavities subjected to restoration procedures that used acid etching of the dentin and dentin adhesives used with light-curing resin. The methodology presented herein seems to be more effective than the one normally used to investigate the presence of bacteria, which uses acid demineralization of dental structures for the histological processing of tissues. The results suggest that the methodology presented in this work made it possible to recover and identify Gram-negative and Gram-positive bacteria from microleakage. Frequencies of microleakage and bacterial population levels in restored cavities using two different adhesive systems were not statistically different (p < 0.05).

In germfree mice, the administration of short-chain fatty acids (SCFA) protected the intestinal mucosa from damage produced by 1-beta-D-arabinofuranosylcytosine (Ara-C). Animals receiving SCFA and Ara-C had intestinal morphologies closer to normal than the control animals, which had severe intestinal lesions. We concluded that orally administrated SCFA reduce intestinal lesions, improving the mucosa pattern of the small intestine and colon.

Helicobacter spp. have been the focus of considerable research because of the role of this genus in gastrointestinal diseases. We infected NIH germ-free mice with Helicobacter trogontum, a recently described intestinal bacterium of rats, in order to study the distribution of this bacterium in the gastrointestinal tract and the histopathological changes it can induce in this host. Sixteen mice were challenged with a single dose of H. trogontum (test group) and killed one and six weeks after inoculation (eight animals at each point). Eight animals were challenged with 0.85% saline alone (control group) and killed at the same time points (four at each point). Fragments from the gastric and intestinal mucosa were obtained for microbiological and histological examination. H. trogontum was isolated from the cecum and colon of all test mice and also from the gastric mucosa of several of them. All infected animals presented histological changes in at least one region of the bowel. Alterations in the gastric mucosa were also observed mainly in the six-week-infected group. The predominant histological change observed was a moderate diffuse inflammatory infiltrate of mononuclear cells in the lamina propria, often accompanied by a mild infiltration of polymorphonuclear cells. Two animals presented focal infiltration of inflammatory cells in the liver, although no bacteria were found in the liver of any animal. H. trogontum is an intestinal species that is able to elicit inflammatory responses in other regions of the gastrointestinal tract such as the gastric mucosa and the liver of gnotobiotic mice.

Infection of Swiss/NIH mice with Leishmania major was compared with infection in isogenic resistant C57BL/6 and susceptible BALB/c mice. Swiss/NIH mice showed self-controlled lesions in the injected foot pad. The production of high levels of interferon-gamma (IFN-gamma) and low levels of interleukin-4 (IL-4) by cells from these animals suggests that they mount a Th1-type immune response. The importance of the indigenous microbiota on the development of murine leishmaniasis was investigated by infecting germfree Swiss/NIH in the hind footpad with L. major and conventionalizing after 3 weeks of infection. Lesions from conventionalized Swiss/NIH mice were significantly larger than conventional mice. Histopathological analysis of lesions from conventionalized animals showed abscesses of variable shapes and sizes and high numbers of parasitized macrophages. In the lesions from conventional mice, besides the absence of abscess formation, parasites were rarely observed. On the other hand, cells from conventional and conventionalized mice produced similar Th1-type response characterized by high levels of IFN-gamma and low levels of IL-4. In this study, we demonstrated that Swiss/NIH mice are resistant to L. major infection and that the absence of the normal microbiota at the beginning of infection significantly influenced the lesion size and the inflammatory response at the site of infection.

The ability of Bifidobacterium bifidum from a commercial bifidus milk to antagonize Salmonella enteritidis subsp. typhimurium in vivo, and to reduce the pathological consequences for the host, was determined using conventional and gnotobiotic mice. Conventional animals received daily, by gavage, 0.1 ml bifidus milk containing about 10(9) cfu B. bifidum and germ-free animals received a single 0.1 ml dose. The conventional and gnotobiotic groups were challenged orally with 10(2) cfu of the pathogenic bacteria 5 and/or 10 d after the beginning of treatment. Control groups were treated with milk. Bifidus milk protected both animal models against the challenge with the pathogenic bacteria, as demonstrated by survival and histopathological data. However, to obtain the protective effect in gnotobiotic animals, the treatment had to be initiated 10 d before the challenge. In experimental and control gnotobiotic mice, Salm. enteritidis subsp. typhimurium became similarly established at levels ranging from 10(8) to 10(9) viable cells g-1 of faeces and remained at these high levels until the animals died or were sacrificed. It was concluded that the protection against Salm. enteritidis subsp. typhimurium observed in conventional and gnotobiotic mice treated with bifidus milk was not due to the reduction of the intestinal populations of the pathogenic bacteria.

Probiotics are formulations containing live microorganisms or microbial stimulants that have some beneficial influence on the maintenance of a balanced intestinal microbiota and on the resistance to infections. The search for probiotics to be used in prevention or treatment of enteric infections, as an alternative to antibiotic therapy, has gained significant impulse in the last few years. Several studies have demonstrated the beneficial effects of lactic acid bacteria in controlling infection by intestinal pathogens and in boosting the host's nonspecific immune response. Here, we studied the use of Lactobacillus acidophilus UFV-H2b20, a lactic acid bacterium isolated from a human newborn from Viçosa, Minas Gerais, Brazil, as a probiotic. A suspension containing 10(8) cells of Lactobacillus acidophilus UFV-H2b20 was inoculated into groups of at least five conventional and germfree Swiss mice to determine its capacity to stimulate the host mononuclear phagocytic activity. We demonstrate that this strain can survive the stressing conditions of the intestinal tract in vivo. Moreover, the monoassociation of germfree mice with this strain for seven days improved the host's macrophage phagocytic capacity, as demonstrated by the clearance of a Gram-negative bacterium inoculated intravenously. Monoassociated mice showed an undetectable number of circulating E. coli, while 0.1% of the original inoculum was still present in germfree animals. Mice treated with viable or heat-killed Lactobacillus acidophilus UFV-H2b20 presented similarly improved clearance capacity when compared with germfree controls. In addition, monoassociated mice had twice the amount of Kupffer cells, which are responsible for the clearance of circulating bacteria, compared to germfree controls. These results suggest that the L. acidophilus strain used here stimulates a nonspecific immune response and is a strong candidate to be used as a probiotic.

Germfree (GF) and conventional (CV) mice were fed on diets containing 4.4, 13.2 or 26.4% of protein (weight/weight). CV mice fed on low protein diet did not gain weight during four weeks, whereas the protein deficient diet did not affect the growth of GF mice. After four weeks on these diets, the mice were inoculated with 5 x 10(3) trypomastigotes of Trypanosoma cruzi. The protein deficiency affected less the GF than the CV mice, according to the following parameters: weight gain, hemoglobin, plasma protein and albumin levels and water and protein contents of the carcass. Infection with T. cruzi produced a significant decrease in hemoglobin levels, red blood cell count, and water and protein contents in the carcass. This decrease was more pronounced in the GF mice. Histopathologically, there was no difference between the treatments in animals with the same microbiological status (GF or CV). However, the disease was more severe in the GF than in the CV mice.

A small animal model was evaluated to study the interrelationships between microorganisms after their implantation in root canals (inferior central incisors) using germ-free (GF) and conventional (CV) mice. The selected microorganisms were: Porphyromonas endodontalis (ATCC 35406), Eubacterium lentum (ATCC 25559), Peptostreptococcus anaerobius (ATCC 27337), Fusobacterium nucleatum (ATCC 10953), Escherichia coli (ATCC 25922), and Enterococcus faecalis (ATCC 4083). Only P. anaerobius, E. coli, and E. faecalis, respectively, were able to colonize when inoculated alone into the root canal of both CV and GF mice. E. lentum, when inoculated alone colonized only in CV animals. P. endodontalis and F. nucleatum were unable to colonize in CV and GF animals after single inoculation. It is concluded that the experimental animal model presented herein is valuable for ecological studies of root canal infections and that only some strict anaerobic bacteria are able to colonize mice root canals when inoculated by themselves alone in pure culture.

The association of vertebrate hosts with the indigenous microbiota and its effect on the response to infections has long been a subject of scientific curiosity. From the first theory supported by Louis Pasteur that life would be impossible in the absence of associated microorganisms to the development of germfree mammals for research, a lot was learned about how the normal microbiota influences the environment in which pathogens may find themselves. In the present review, we attempt to summarize the more recent results from our group and others on the influence of the normal microbiota on the outcome of parasitic infections. Our results and those of others point to a complex relationship between the mammalian system and its indigenous microbiota, leading to greater resistance to some infections and enhanced susceptibility to others.

Swiss mice fed commercial or elemental diets and an oral short-chain fatty acid (SCFA) solution or saline were treated with the cytostatic drug Ara-C (cytarabine, 3.6 mg/mouse/day) for two or four days. Histopathological examination revealed less damage (atrophy, inflammation, or necrosis) to the small intestine and colon caused by Ara-C when SCFA was administered. Accordingly, protein and nucleotide concentrations in the intestinal mucosa were higher in the group receiving SCFA than in the group receiving a placebo of the same pH and osmolarity. Improvement by SCFA treatment was correlated with an increase in the height of the intestinal villi, with no alterations of the crypts. Furthermore, the number of intraepithelial lymphocytes was similar to normal values in animals receiving SCFA and Ara-C. When large doses of SCFA were administered, xanthomized enterocytes appeared, suggesting an accumulation of fatty acids in these cells. We conclude that oral administration of SCFA at close to physiological proportions reduces the inflammation and necrosis caused by Ara-C administration, thus representing a potential factor for the improvement of patients with mucositis caused by cancer treatment.

Saccharomyces boulardii was shown to be capable of inhibiting multiplication of enteropathogenic bacteria in vitro and is currently used for its anti-diarrhoea properties. We studied the capacity of this yeast to antagonize Salmonella typhimurium and Shigella flexneri in the intestinal tract of conventional or gnotobiotic NMRI mice. Conventional animals were given daily 10 mg doses of S. boulardii, whereas germ-free animals were given a single 10 mg dose. Both groups were challenged orally 5 d later with the pathogenic bacteria (10(8) or 10(2) viable cells, respectively). Control groups were treated with saline instead of S. boulardii. Mortality and/or histopathological data showed a protective effect against the pathogenic bacteria in yeast-treated mice. Saccharomyces boulardii colonized the digestive tract of gnotobiotic mice and the number of viable cells ranged around 10(10) g-1 of faeces. In experimental and control gnotobiotic animals, Salm. typhimurium and Sh. flexneri became rapidly established at a level of about 10(10) viable cells g-1 of faeces and remained at high levels until the animals died or were sacrificed. The protection against Salm. typhimurium and Sh. flexneri obtained in conventional and/or gnotobiotic mice previously associated with S. boulardii is not due to the reduction of the bacterial populations in the intestines.

Germ-free (GF) and heteroxenic (Hx) rats were given a hypocholesterolemic diet (Hyper) with or without 5% guar gum (GG) for 4 weeks. The GF and Hx rats fed GG diets showed a lower hepatic and plasmatic cholesterol level when compared with Hyper groups. This reduction of cholesterolemia was due to a decrease in the chylomicron + very low density lipoprotein (VLDL) fraction. The caecal and portal concentrations of propionate were 30% higher in Hx rats fed the GG diet than in Hx rats fed the Hyper diet. These results exclude the participation of the intestinal microflora in the hypocholesterolemic effect of GG, and show that guar gum nullifies the effect of the hypocholesterolemic diet in the GF rats.

1. Twenty-two axenic (germfree) or thirty heteroxenic (axenic colonized with human flora) 2.5-3.5 months old female Fisher rats were fed for four weeks either a hypercholesterolemic (HYPER) diet or a HYPER diet containing 5% guar gum (GG) sterilized by heat or by gamma irradiation. 2. Axenic rats fed the irradiated GG diet had higher cholesterolemia than their counterparts fed an autoclaved diet (4.50 vs 2.29 mmol/l), whereas the method of sterilization had no effect on plasma cholesterol in axenic HYPER or heteroxenic animals (7.35 vs 6.51 mg/dl). 3. The levels of hepatic esterified cholesterol were higher in heteroxenic animals fed the irradiated GG diet than in their counterparts fed the autoclaved GG diet (5.65 vs 3.57 mmol/g tissue). 4. The composition of volatile fatty acids in the cecal content of heteroxenic rats was dependent on the method of sterilization regardless of the presence of fiber: the levels of butyrate were 2.88 and 0.85 mumol/g for rats fed the autoclaved and irradiated diets, respectively. 5. Gamma irradiation abolished the cholesterol-lowering effect of guar gum, whereas sterilization by heat preserved this effect. 6. The hypocholesterolemic effect of guar was reduced by gamma irradiation sterilization and was probably mediated by qualitative changes in the intestinal microflora which interfered with bile acid absorption.

A strain of Bacteroides fragilis, isolated from the marmoset Callithrix penicillata, produced protein(s) with bacteriocin activity (fragicilin). Two active fractions (36 and 150 kDa) were isolated by chromatography. The bacteriocin exhibited iso- and heteroantagonism. It remained stable between pH 3 and 10 and at 60 degrees C for 24 h. Pronase, trypsin, proteinase K and type VII protease inactivated the bacteriocin, giving evidence of its protein nature.

1. Conventional (CV) and gnotobiotic (GN) female CFW mice were infected with the Y strain of Trypanosoma cruzi. 2. After infection, both CV and GN groups received injections of iron-dextran or desferrioxamine. Non-injected mice served as controls. 3. The parasitemia was more intense in iron-dextran-treated mice. 4. The iron levels in serum, liver, and spleen were: (a) not decreased by desferrioxamine and (b) increased by iron-dextran treatments. 5. An increase in leukocyte numbers was observed in all GN and CV groups after infection. 6. There was no difference in total iron binding capacity (TIBC) and iron saturation transferrin (IST) between GN and CV mice before infection. 7. In CV groups, after infection, TIBC was decreased whereas the levels of IST were increased; in GN the opposite occurred. 8. Trypanosome-specific IgG and IgM antibody levels were raised in the GN group but not in the CV group.

A new intracellular bacteriocin isolated from a human fecal strain of Bacteroides ovatus was partially purified through ammonium sulfate precipitation, ion exchange chromatography, gel filtration, and preparative polyacrylamide gel electrophoresis (PAGE). The bacteriocin is stable at a pH range of 3-10, at 60 degrees C for 24 h, and at -70 degrees C for 6 months. It is inactivated by proteolytic enzymes. The molecular weight, estimated by sodium dodecyl sulfate--PAGE, is 78 kDa. Fifty strains of the Bacteroides fragilis group were isolated from fecal samples, and 41 of the isolates were shown to produce an antagonistic substance against at least 1 indicator strain. Iso-, auto-, and hetero-antagonisms were observed.