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1.
Food Chem ; 453: 139688, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-38761722

ABSTRACT

The aim of this study was to evaluate the effect of freezing rates using direct (LF: Liquid nitrogen) and indirect (RF: Cryogenic refrigerator and UF: ultra-freezer) methods at temperatures of (-20, -80, and - 196 °C) on the enzymatic susceptibility with α-amylase for microparticles. In vitro digestibility parameters and technological properties were also analyzed. Lower rates resulted in larger ice crystals, damaging the starch structure. Hydrolysis was more pronounced at slower rates RF: 0.07 °C/min and UF: 0.14 °C/min, yielding maximum values of RDS: 37.63% and SDS: 59.32% for RF. Type A crystallinity remained unchanged, with only a noted increase in crystallinity of up to 6.50% for FR. Starch pastes were classified as pseudoplastic, with RF exhibiting superior textural parameters and apparent viscosity. (RF: 7.18 J g-1 and UF: 7.34 J g-1) also showed lower values of gelatinization enthalpy. Freezing techniques were viable in facilitating the diffusion of α-amylase and reducing RS by up to 81%.


Subject(s)
Digestion , Freezing , Starch , alpha-Amylases , Starch/chemistry , Starch/metabolism , alpha-Amylases/chemistry , alpha-Amylases/metabolism , Hydrolysis , Viscosity , Particle Size
2.
Food Res Int ; 177: 113877, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38225140

ABSTRACT

This study investigated the physical modifications by high hydrostatic pressure (HHP) at 600 MPa for 30 min/30 °C, annealing (AN) at 50 °C/24 h and the combination of both (HHP + AN and AN + HHP) applied to yellow bean starch to verify changes in morphology, X-ray diffraction, molecular order, thermal properties and pasting properties of native (NS) and modified starches. Morphological analysis showed loss of sphericity and increase in diameter with the appearance of pores on the surface after application of treatments. The AN starch showed lower values of syneresis, degree of double helix (DD), order (DO), and viscosity of the paste obtained by RVA. It exhibited a Vh-type classification with the appearance of the amylose-lipid complex. However, the gelatinization temperatures, as well as the enthalpy of gelatinization, were significantly higher. On the other hand, the starch treated with HHP showed a higher Setback (SB) value. The greatest modifications were found for the starches subjected to the combined treatments (AN + HHP) and (HHP + AN), where the order of the treatments was significant for the morpho-structural changes of yellow bean starch. According to the micrographs, the surface aspect was altered, with AN + HHP showing greater irregularities and flat yet irregular faces, as well as a larger granule diameter (147.05). The X-ray diffractogram showed a reduction in crystallinity from 28.14 % (NS) to 18.09 % (AN + HHP) and classified the starch as type "A". The double modification (HHP + AN and AN + HHP) reduced the gelatinization temperature and the enthalpy of gelatinization but had no effect on the bands of the FT-IR spectrum. There was only a reduction in the degree of order and the double helix. Finally, the treatment with AN + HHP is more effective as the gelatinization with AN facilitates the application of HHP. Both methods used are classified as physical (thermal and non-thermal), aiming to minimize environmental impacts and achieve faster and safer morpho-structural modification without leaving chemical residues in the products.


Subject(s)
Amylose , Starch , Starch/chemistry , Hydrostatic Pressure , Spectroscopy, Fourier Transform Infrared , Amylose/chemistry , Temperature
3.
Int J Biol Macromol ; 253(Pt 5): 127030, 2023 Dec 31.
Article in English | MEDLINE | ID: mdl-37742893

ABSTRACT

The objective of this study was to investigate the dual modification of red rice starch using pulsed electric field (PEF) and α-amylase, focusing on morpho-structural, thermal, and viscoamylographic properties. Native starch (Control) underwent various treatments: PEF at 30 kV cm-1 (PEF30), α-amylase at 9.0 U mg-1 (AA0), and a combination of both (PEF30 + α and α + PEF30). The PEF30 + α treatment exhibited the highest degree of digestion (10.66 %) and resulted in morphological changes in the starch granules, which became elongated and curved, with an increased average diameter of 50.49 µm compared to the control. The starch was classified as type A, with a maximum reduction in crystallinity of up to 21.17 % for PEF30. The deconvolution of FT-IR bands indicated an increase in the double helix degree (DDH) for PEF30 and AA0, while the degree of order (DO) was reduced for PEF30, AA0, and PEF30 + α. DSC analysis revealed significant modifications in gelatinization temperatures, particularly for PEF30, and these changes were supported by a reduction in gelatinization enthalpy (ΔH) of up to 28.05 % for AA0. These findings indicate that both individual and combined treatments promote a decrease in starch gelatinization and facilitate the process, requiring less energy. Differences were observed between the formulations subjected to single and alternating dual treatments, highlighting the influence of the order of PEF application on the structural characteristics of starch, especially when applied before the enzymatic treatment (PEF + α). Regarding the viscoamylographic parameters, it was observed that AA0 presented higher values than the control, indicating that α-amylase enhances the firmness of the paste. The double modification with PEF + α was more effective in reducing syneresis and starch retrogradation, leading to improvements in paste properties. This study provided significant insights into the modification of red rice starch using an efficient and environmentally friendly approach.


Subject(s)
Oryza , Starch , Starch/chemistry , alpha-Amylases/chemistry , Oryza/chemistry , Spectroscopy, Fourier Transform Infrared , Temperature
4.
Polymers (Basel) ; 15(6)2023 Mar 09.
Article in English | MEDLINE | ID: mdl-36987150

ABSTRACT

For the purpose of renewable materials applications, Curauá fiber treated with 5% sodium hydroxide was added to high-density biopolyethylene, using an entirely Brazilian raw material of sugarcane ethanol. Polyethylene grafted with maleic anhydride was used as a compatibilizer. With the addition of curauá fiber, the crystallinity was reduced, possibly due to interactions in the crystalline matrix. A positive thermal resistance effect was observed for the maximum degradation temperatures of the biocomposites. When curauá fiber was added (5% by weight), the morphology showed interfacial adhesion, greater energy storage and damping capacity. Although curauá fiber additions did not affect the yield strength of high-density bio polyethylene, its fracture toughness improved. With the addition of curauá fiber (5% by weight), the fracture strain was greatly reduced to about 52%, the impact strength was also reduced, suggesting a reinforcing effect. Concomitantly, the modulus and the maximum bending stress, as well as the Shore D hardness of the curauá fiber biocomposites (at 3 and 5% by weight), were improved. Two important aspects of product viability were achieved. First, there was no change in processability and, second, with the addition of small amounts of curauá fiber, there was a gain in the specific properties of the biopolymer. The resulting synergies can help ensure more sustainable and environmentally friendly manufacturing of automotive products.

5.
Food Chem ; 373(Pt A): 131404, 2022 Mar 30.
Article in English | MEDLINE | ID: mdl-34715632

ABSTRACT

This research evaluated the antioxidant, antimicrobial and toxicity potential of the leaf extract of Croton blanchetianus Baill (ExCb) and its effect on the conservation of lamb ribs. The ExCb (control treatment) revealed higher concentration of 2,5-dihydroxybenzoic acid (190.10 mg/g), catechin (84.10 mg/g), rosmarinic acid (56.01 mg/g), 4-hydroxybenzoic acid (52.05 mg/g) and myricetin (40.00 mg/g). And it showed high phenolic content (204.05 mg GAE/g), antioxidant potential (11.78 µg/mL by DPPH and 140.40 mmol Sulf Fer/g by FRAP) and antimicrobial activity with inhibition for Staphylococcus aureus, Listeria innocua, Salmonella enterica, Escherichia coli and Aspergillus flavus. However, it showed toxicity against brine shrimp (Artemia Salina) (LD50 of 66.26 µg/mL). The 2,5-dihydroxybenzoic acid was indicated as the main compound responsible for the toxicity of ExCb. After treatment in an oven at 110 °C for 15 min, the toxicity of ExCb was reduced by over 7 times, the compound 2,5-dihydroxybenzoic acid was not identified, and still maintained the phenolic compounds content of 94.35% and antioxidant activity compared to the control (without thermal treatment). The application of absorbent containing 50 mg/mL of ExCb added to the packaging maintained the quality and prevented the lipid oxidation of lamb ribs during 10 days of refrigerated storage.


Subject(s)
Croton , Animals , Antioxidants/pharmacology , Phenols , Plant Extracts/pharmacology , Ribs , Sheep
6.
Rev. patol. trop ; 46(3): 221-232, set. 2017.
Article in English | LILACS | ID: biblio-913684

ABSTRACT

Sepsis is a major global health problem leading to the increased incidence of death in intensive care units. In recent years, despite technological advances, the number of cases has grown significantly. Among the main complications presented by septic patients, acute renal dysfunction is largely responsible for the high mortality rate. Initially, the reduction of renal function is associated with focal tubular injury with preserved glomerular morphology and systemic hemodynamic alterations. During sepsis development, the progressive decrease in urinary volume and reduction of the glomerular filtration rate associated with increased serum levels of urea and creatinine are considered classic markers of severe kidney injury. Despite the valuable role of these serum markers regarding renal function, these data provide an incomplete scenario of the patient, since many renal disorders may occur in individuals with increased plasma concentrations of urea and creatinine. Taking into account the important role of systemic inflammatory processes in the development of acute kidney injury induced by sepsis, the search for new markers presenting high sensitivity and specificity capable of detecting early renal injury is still necessary. Thus, the present review summarizes important aspects of pathophysiology of acute kidney dysfunction induced by sepsis and presents an updated view of possible new biomarkers associated with the development of acute kidney injury. Understanding these markers allows important advances leading to new therapeutic approaches, indicating a new horizon in the diagnosis and treatment of acute kidney injury in sepsis


Subject(s)
Sepsis , Biomarkers , Acute Kidney Injury
7.
PLoS One ; 11(11): e0166839, 2016.
Article in English | MEDLINE | ID: mdl-27880847

ABSTRACT

Cardiac dysfunction caused by the impairment of myocardial contractility has been recognized as an important factor contributing to the high mortality in sepsis. Calpain activation in the heart takes place in response to increased intracellular calcium influx resulting in proteolysis of structural and contractile proteins with subsequent myocardial dysfunction. The purpose of the present study was to test the hypothesis that increased levels of calpain in the septic heart leads to disruption of structural and contractile proteins and that administration of calpain inhibitor-1 (N-acetyl-leucinyl-leucinyl-norleucinal (ALLN)) after sepsis induced by cecal ligation and puncture prevents cardiac protein degradation. We also tested the hypothesis that calpain plays a role in the modulation of protein synthesis/degradation through the activation of proteasome-dependent proteolysis and inhibition of the mTOR pathway. Severe sepsis significantly increased heart calpain-1 levels and promoted ubiquitin and Pa28ß over-expression with a reduction in the mTOR levels. In addition, sepsis reduced the expression of structural proteins dystrophin and ß-dystroglycan as well as the contractile proteins actin and myosin. ALLN administration prevented sepsis-induced increases in calpain and ubiquitin levels in the heart, which resulted in decreased of structural and contractile proteins degradation and basal mTOR expression levels were re-established. Our results support the concept that increased calpain concentrations may be part of an important mechanism of sepsis-induced cardiac muscle proteolysis.


Subject(s)
Calpain/metabolism , Dystrophin/metabolism , Proteasome Endopeptidase Complex/metabolism , Sepsis/pathology , TOR Serine-Threonine Kinases/metabolism , Ubiquitin/metabolism , Actins/metabolism , Animals , Calpain/antagonists & inhibitors , Calpain/genetics , Cardiomyopathies/complications , Cardiomyopathies/pathology , Disease Models, Animal , Gene Expression/drug effects , Leupeptins/pharmacology , Leupeptins/therapeutic use , Male , Mice , Mice, Inbred C57BL , Microscopy, Fluorescence , Myocardium/metabolism , Myocardium/pathology , Myosins/metabolism , Proteolysis/drug effects , Sepsis/etiology , Sepsis/prevention & control , TOR Serine-Threonine Kinases/antagonists & inhibitors
8.
Rev. psicol. deport ; 25(1): 43-50, 2016. tab
Article in Spanish | IBECS | ID: ibc-147059

ABSTRACT

La lesión constituye el mayor contratiempo para los deportistas, primordialmente para los de alta competición,convirtiéndose en un tema de interés científico, de manera especial lo relacionado con la recuperación física; en la que el afrontamiento psicológico desempeña un papel crítico. Con el objetivo de conocer la prevalencia de lesiones y qué estrategias de afrontamiento utilizan deportistas de alta competición, evaluamos a 362 kayakistas, 226 hombres y 136 mujeres, inscritos en el Campeonato Nacional de España del 2012. Los participantes respondieron aun cuestionario sobre lesiones deportivas y al Modified Coping Questionnaire adaptado para deportistas (Crocker, 1992). Los resultados pusieron de manifiesto que la probabilidad de sufrir una lesión (.376) es significativa,siendo igual en todas las etapas formativas; que los deportistas no adoptan un estilo de afrontamiento único, mezclando estrategias adaptativas y desadaptativas; que en la etapa de mantenimiento de resultados recurren menos a estrategias desadaptativas; y que kayakistas hombres y mujeres utilizan estrategias diferentes de afrontamiento de las lesiones. Estos resultados prestan apoyo al modelo de Lazarus y Folkman (1984), al tiempo que se derivan implicaciones para la intervención que se discuten


Injury is a major setback for both sportsmen and women, and more so for elite athletes. This has spurred research which is primarily focused on physical recovery and treatment where psychological resilience plays a crucial role in recovery. In order to assess the prevalence of injuries and strategies for coping with them used by elite athletes to recover from their injuries, 362 kayakists (226 men and 136 women) registered in the Spanish National Championship 2012 were assessed. Participants answered a questionnaire on sports injuries and the Athletic Coping Skills Inventory (Crocker, 1992). The results revealed that the probability of suffering a sports injury was significant (.376) and similar in all the different stages of training; athletes do not adopt just one coping style, but a combination of adaptive and maladaptive strategies; in the maintenance stage of performance gains athletes resort to fewer maladaptive strategies; and male kayakists use different strategies to female kayakists to cope with injury. These results lend support to the Lazarus and Folkman model (1984), and the implications for intervention are discussed


lesão constitui um contratempo para os atletas, primordialmente para os de alta competição, convertendo-se num tema de interesse científico,especialmente o relacionado com a recuperação física; na qual o coping psicológico desempenha um papel crítico. Com o objectivo de conhecer a pre-valência de lesões e que estratégias de coping utilizam os desportistas de alta competição, avaliámos 362 caiaquistas, 226 homens e 136 mulheres,inscritos no Campeonato Nacional de Espanha de 2012. Os participantes responderam a um questionário sobre lesões desportivas e ao Inventário deEstilos de Coping Adaptado a Situações Desportivas (Crocker, 1992). Os resultados revelaram que a probabilidade de sofrer uma lesão (.376) é signifi-cativa, sendo igual em todas as etapas formativas; que os desportistas não adoptam um estilo de coping único, combinando estratégias adaptativas e de-sadaptativas; que na etapa de manutenção de resultados recorrem menos a estratégias desadaptativas; e que caiaquistas homens e mulheres utilizamestratégias diferentes de coping face às lesões. Estes resultados suportam o modelo de Lazarus e Folkman (1984), proporcionando de igual modo impli-cações para a intervenção que são discutidas


Subject(s)
Humans , Male , Female , Adult , Athletic Injuries/psychology , Athletic Injuries/rehabilitation , Athletic Performance/psychology , Athletic Performance/statistics & numerical data , Body Weight/physiology , Adaptation, Psychological/physiology , Athletic Injuries/physiopathology , Athletic Injuries/economics , Body Mass Index , Weight by Height/physiology , Surveys and Questionnaires , Data Analysis/methods , Analysis of Variance
9.
J Appl Physiol (1985) ; 113(9): 1456-65, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22936726

ABSTRACT

This study investigated the involvement of prostaglandins and regulated on activation, normal T cell expressed and secreted (RANTES), in fever induced by live Staphylococcus aureus (no. 25923, American Type Culture Collection) injection in rats. S. aureus was injected intraperitoneally at 10(9), 10(10), and 2 × 10(10) colony-forming units (CFU)/cavity, and body temperature (T(b)) was measured by radiotelemetry. The lowest dose of S. aureus induced a modest transient increase in T(b), whereas the two higher doses promoted similar long-lasting and sustained T(b) increases. Thus, the 10(10) CFU/cavity dose was chosen for the remaining experiments. The T(b) increase induced by S. aureus was accompanied by significant decreases in tail skin temperature and increases in PGE(2) levels in the cerebrospinal fluid (CSF) and hypothalamus but not in the venous plasma. Celecoxib (selective cyclooxygenase-2 inhibitor, 2.5 mg/kg po) inhibited the fever and the increases in PGE(2) concentration in the CSF and hypothalamus induced by S. aureus. Dipyrone (120 mg/kg ip) reduced the fever from 2.5 to 4 h and the PGE(2) increase in the CSF but not in the hypothalamus. S. aureus increased RANTES in the peritoneal exudate but not in the CSF or hypothalamus. Met-RANTES (100 µg/kg iv), a chemokine (C-C motif) receptor (CCR)1/CCR5 antagonist, reduced the first 6 h of fever induced by S. aureus. This study suggests that peripheral (local) RANTES and central PGE(2) production are key events in the febrile response to live S. aureus injection. As dipyrone does not reduce PGE(2) synthesis in the hypothalamus, it is plausible that S. aureus induces fever, in part, via a dipyrone-sensitive PGE(2)-independent pathway.


Subject(s)
Chemokine CCL5/biosynthesis , Dinoprostone/biosynthesis , Fever/etiology , Fever/metabolism , Staphylococcal Infections/complications , Staphylococcal Infections/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Ascitic Fluid/metabolism , Celecoxib , Chemokine CCL5/antagonists & inhibitors , Chemokine CCL5/cerebrospinal fluid , Chemokine CCL5/pharmacology , Cyclooxygenase 2 Inhibitors/pharmacology , Dinoprostone/cerebrospinal fluid , Dipyrone/pharmacology , Fever/drug therapy , Hypothalamus/metabolism , Male , Pyrazoles/pharmacology , Rats , Rats, Wistar , Signal Transduction , Staphylococcus aureus/pathogenicity , Sulfonamides/pharmacology
10.
Hig. aliment ; 26(208/209): 125-131, maio-jun. 2012. tab, graf
Article in Portuguese | LILACS | ID: lil-678630

ABSTRACT

O objetivo desse estudo foi avaliar a aceitação do filé do camarão marinho (Litopenaeus vannameii) liofilizado, sob o enfoque da analise sensorial de testes. Foram preparados dois produtos: (1) camarão in natura e (2) camarão liofilizado previamente reidratado, cozido em molho de tomate. Foi também avaliada a intenção de compra, utilizando-se uma escala hedônica de 5 pontos, variando de certamente compraria e certamente não compraria. Os resultados foram submetidos ao teste estatístico t de Student. Na avaliação da interatividade entre os atributos sensoriais e a intenção de compra desenvolveu-se a ACP – Análise de Componentes Principais. As notas médias para o camarão não liofilizado e liofilizado para cada atributo avaliado situaram-se acima de 7 e não apresentaram diferença significativa ao nível de 5%. A intenção de compra resultou em valores iguais a 4,1, não havendo, também, diferença significante. Os testes comprovam que o produto desenvolvido é uma nova e rentável alternativa para o mercado brasileiro carente de novidades produzidas a partir do camarão.


Subject(s)
Humans , Animals , Food Preservation/methods , Food Analysis , Penaeidae , Shellfish , Freeze Drying
11.
Clin Oral Investig ; 16(2): 513-20, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21384127

ABSTRACT

The aim of the present study was to assess the caries experience of children aged 6 to 7 years old in a socially deprived suburban area of Brazil's Federal District, using the ICDAS II system and to investigate determinants of dental caries. The survey was carried out in six public schools by three calibrated examiners, on a sample of 835 children. ICDAS II codes had to be converted into dmf/DMF components at surface and tooth levels, resulting in unfamiliar caries variables, to enable some meaningful reporting of the findings. The prevalence of dental caries, including enamel and dentinal carious lesions, in primary teeth was 95.6% and in permanent teeth it was 63.7%. Mean values of d(2)mf(2)-t (enamel and dentinal lesions), d(3)mf(3)-t (dentine lesions), D(2)MF(2)-T and D(3)MF(3)-T indices were 6.9 ± 3.8, 3.2 ± 3.4, 1.7 ± 1.6 and 0.2 ± 0.5, respectively. Enamel carious lesions predominated in the dmf-t/s and DMF-T/S indices. Seven-year-old children had statistically significantly more enamel and dentine carious lesions in permanent teeth than 6-year-old children had. Using ICDAS II, the prevalence of dental caries in both dentitions was very high. In both dentitions, the decay component predominated, with hardly any restorations or extractions observed. The new ICDAS II system leads to overvaluation of the seriousness of dental caries experience and made reporting of outcomes cumbersome. Guidelines on analysing data and reporting results should be agreed upon before this system can be used in epidemiological surveys globally.


Subject(s)
DMF Index , Dental Caries/epidemiology , Vulnerable Populations/statistics & numerical data , Brazil/epidemiology , Child , Crowns/statistics & numerical data , Cultural Deprivation , Dental Caries/classification , Dental Enamel/pathology , Dental Restoration Failure , Dental Restoration, Permanent/statistics & numerical data , Dental Restoration, Temporary/statistics & numerical data , Dentin/pathology , Epidemiologic Studies , Female , Humans , Incisor/pathology , Male , Molar/pathology , Pit and Fissure Sealants/therapeutic use , Prevalence , Suburban Health/statistics & numerical data , Tooth Extraction/statistics & numerical data , Tooth, Deciduous/pathology , Tooth, Unerupted/epidemiology
12.
Med Microbiol Immunol ; 201(1): 47-60, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21643979

ABSTRACT

Interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6 have been established as important mediators of fever induced by lipopolysaccharide (LPS) from Gram-negative bacteria. Whether these pro-inflammatory cytokines are also important in mediating fever induced by live bacteria remains less certain. We therefore investigated the following: (1) the synthesis of TNF-α, IL-1ß, and IL-6 during E. coli-induced fever and (2) the effect of blocking the action of cytokines within the brain on E. coli-induced fever. Body or tail skin temperature (bT or Tsk, respectively) was measured by biotelemetry or telethermometry, every 30 min, during 6 or 24 h. Depending on the number of colony-forming units (CFU) injected i.p., administration of E. coli induced a long-lasting increase in bT of male Wistar rats. The duration of fever did not correlate with the number of CFU found in peritoneal cavity or blood. Because 2.5 × 10(8) CFU induced a sustained fever without inducing a state of sepsis/severe infection, this dose was used in subsequent experiments. The E. coli-induced increase in bT was preceded by a decrease in Tsk, reflecting a thermoregulatory response. TNF-α, IL-1ß, and IL-6 were detected at 3 h in serum of animals injected i.p. with E. coli. In the peritoneal exudates, TNF-α, IL-1ß, and IL-6 were detected at 0.5 and 3 h after E. coli administration. Moreover, both IL-1ß and IL-6, but not TNF-α, were found in the cerebrospinal fluid (CSF) and hypothalamus of animals injected with E. coli. Although pre-treatment (i.c.v., 2 µl, 15 min before) with anti-IL-6 antibody (anti-IL-6, 5 µg) reduced E. coli-induced fever, pre-treatment with either IL-1 receptor antagonist (IL-1ra, 200 µg) or soluble TNF receptor I (sTNFRI, 500 ng) had no effect on the fever response. In conclusion, replicating E. coli promotes an integrated thermoregulatory response in which the central action of IL-6, but not IL-1 and TNF, appears to be important.


Subject(s)
Cerebrospinal Fluid/immunology , Escherichia coli Infections/immunology , Escherichia coli Infections/physiopathology , Escherichia coli/pathogenicity , Fever/immunology , Interleukin-6/immunology , Animals , Body Temperature , Cytokines/immunology , Cytokines/metabolism , Escherichia coli/immunology , Escherichia coli Infections/microbiology , Escherichia coli Infections/mortality , Fever/microbiology , Fever/mortality , Hypothalamus/immunology , Interleukin-1/immunology , Interleukin-1/metabolism , Interleukin-1beta/immunology , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Male , Rats , Rats, Wistar , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolism
13.
Med Microbiol Immunol ; 201(2): 219-29, 2012 May.
Article in English | MEDLINE | ID: mdl-22203392

ABSTRACT

The purpose of the present study was to better understand the events involved in the febrile response induced by cecal ligation and puncture (CLP), a complex infectious process. To this end, we conducted in vivo experiments in rats examining (1) fever development, (2) bacterial number in the infection focus and in blood, (3) peripheral and hypothalamic synthesis of cytokines, (4) hypothalamic and cerebrospinal fluid (CSF) synthesis of prostaglandin E(2) (PGE(2)), (5) the effect of anti-IL-6 antibody on fever, and (6) the effect of celecoxib on fever and hypothalamic synthesis of PGE(2) after CLP induction. We found that CLP promotes fever and animal death depending on the number of punctures. The peak of CLP-induced fever overlapped with the maximal increase in the number of bacteria in the infectious focus and blood, which occurred at 6 and 12 h. The peak of the febrile response also coincided with increased amounts of interleukin (IL)-1ß, IL-6 and IL-10 in the peritoneal exudate and serum; IL-6 in the hypothalamus and PGE(2) in the CSF and predominantly in the hypothalamus. Moreover, intracerebroventricularly injected anti-IL-6 antibody reduced the febrile response while celecoxib reduced the fever and PGE(2) amount in the hypothalamus induced by CLP. Tumor necrosis factor (TNF)-α peaked at 3 h at all sites studied. Conversely, IL-10 concentration decreased in the hypothalamus. These findings show that the peak of CLP-induced fever is accompanied by an increase of bacteria in peritoneal fluid (local infection) and blood; local synthesis of pyrogenic (IL-1ß, IL-6) and antipyretic (IL-10) cytokines and central production of IL-6 and PGE(2), suggesting that these last are the central mediators of this response.


Subject(s)
Bacterial Infections/physiopathology , Cecum/injuries , Cytokines/metabolism , Dinoprostone/metabolism , Fever/chemically induced , Peritonitis/physiopathology , Animals , Bacteria/isolation & purification , Bacterial Infections/mortality , Bacterial Load , Blood/microbiology , Cytokines/blood , Dinoprostone/cerebrospinal fluid , Disease Models, Animal , Humans , Ligation , Male , Peritoneum/microbiology , Peritonitis/mortality , Punctures , Rats , Rats, Wistar , Survival Analysis
14.
Brain Res ; 1269: 54-60, 2009 May 07.
Article in English | MEDLINE | ID: mdl-19285486

ABSTRACT

The fever induced by lipopolysaccharide (LPS) depends on both prostaglandin-dependent and -independent pathways. One of the prostaglandin-independent pathways is sequentially orchestrated by pre-formed pyrogenic factor derived from LPS-stimulated macrophages (PFPF), corticotrophin releasing factor (CRF), endothelin-1 (ET-1) and interleukin-1 (IL-1). As macrophage-inflammatory-protein (MIP)-1 alpha (synonym CCL3) also induces a prostaglandin independent fever, the aim of the present study was to investigate a possible participation of CCL3/MIP-1 alpha within the prostaglandin-independent pathway of LPS-induced fever which depends on PFPF, CRF and ET-1. Therefore, rats received intracerebroventricular (i.c.v.) pre-treatment with anti-CCL3 monoclonal antibody (1 and 5 ng) at 1 h and 15 min before injection of LPS (lipopolysaccharide from E. coli; 5, 50 or 100 microg kg(-1), i.v.) or CCL3/MIP-1 alpha (500 pg, i.c.v.). Both doses of anti-CCL3 did not change the basal temperature but abolished the fever induced by CCL3/MIP-1 alpha. When given at the higher dose, anti-CCL3 did not influence the fever induced by i.v. injection of different doses of LPS, or i.c.v. administration of PFPF (200 ng), CRF (3 microg) or ET-1 (1 pmol). Bosentan, a non-selective ET(A/B) receptors antagonist (10 microg kg(-1), i.v.), reduced the fever induced by LPS but not that induced by CCL3/MIP-1 alpha. In contrast, alpha-helical CRF(9-41) (a non-selective CRF R1/R2 receptor antagonist; 25 microg injected i.c.v.) reduced CCL3/MIP-1 alpha-induced fever. In conclusion, the present results indicate that: i) CCL3/MIP-1 alpha is not an endogenous mediator of LPS-induced fever; ii) it is even not involved in the prostaglandin-independent pathway of the LPS-fever cascade and iii) its pyrogenic activity depends on synthesis/release of CRF.


Subject(s)
Chemokine CCL3/immunology , Corticotropin-Releasing Hormone/metabolism , Fever/chemically induced , Fever/immunology , Lipopolysaccharides/pharmacology , Animals , Antibodies, Monoclonal/pharmacology , Antihypertensive Agents/pharmacology , Bosentan , Chemokine CCL3/pharmacology , Corticotropin-Releasing Hormone/pharmacology , Drug Interactions , Endothelin-1/metabolism , Injections, Intraventricular , Macrophages/immunology , Male , Mice , Peptide Fragments/metabolism , Peptide Fragments/pharmacology , Rats , Rats, Wistar , Recombinant Proteins/immunology , Recombinant Proteins/pharmacology , Sulfonamides/pharmacology
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