Avirulence and immunogenicity in mice of a bovine mastitis Staphylococcus aureus mutant.          下载免费PDF全文

C Bogni  M Segura  J Giraudo  A Giraudo  A Calzolari    R Nagel 《Canadian journal of veterinary research》1998,62(4):293-298

An avirulent mutant, designated RC122, was derived from Staphylococcus aureus bovine mastitis strain RC108 after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. Mutant RC122, which was isolated on the basis of reduced colony size, showed diminished virulence in mice (LD50 of RC122: 3.1 x 10(10) cfu vs LD50 of RC108: 2.3 x 10(7) cfu). Mutant RC122 grew more slowly than its parental strain and showed decreased production of several exoproteins, such as alpha- and beta-hemolysin, DNAse and coagulase. The production of its capsule was induced only under in vivo growth conditions. Clearance studies performed in the mouse kidney revealed that the kinetics of disappearance of the mutant was similar to that of its parental strain. Protection experiments carried out by intraperitoneal administration in mice showed that mutant RC122 conferred a good degree of protection from challenge with homologous and heterologous strains.  相似文献   

Phaseolus vulgaris L. Leaves Increase Short-Chain Fatty Acid (SCFA) Production,Ameliorating Early Metabolic Alterations     

Becerril-Campos  Adriana Araceli  Ocampo-Anguiano  Perla Viridiana  Mondragón-Jacobo  Candelario  Escobar-García  Konisgmar  Camacho-Barrón  Mariela  Anaya-Loyola  Miriam Aracely  Feregrino-Perez  Ana Angélica  García-Gasca  Teresa  Ahumada-Solórzano  Santiaga Marisela 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(3):421-426

Plant Foods for Human Nutrition - High-fat/high-fructose diets promote early metabolic disorders in weight and lipid and glucose metabolism. Bioactive compounds such as polyphenols and fiber...  相似文献   

Starch Digestion in Infants: An Update of Available In Vitro Methods—A Mini Review     

Rodríguez  Marianela Desireé  León  Alberto Edel  Bustos  Mariela Cecilia 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(3):345-352

Plant Foods for Human Nutrition - Complementary feeding starts at around six months of age because neither breast milk nor formula assure the proper nutrition of infants. Therefore, along...  相似文献   

Arsenic(V) Adsorption onto Biogenic Hydroxyapatite: Solution Composition Effects     

Mariela Czerniczyniec  Silvia Farías  Jorge Magallanes  Daniel Cicerone 《Water, air, and soil pollution》2007,180(1-4):75-82

This study qualifies and quantifies the effects of pH, hardness, alkalinity, salinity and bone calcination temperature related with the adsorption of As(V) onto biogenic hydroxyapatite (HAPb) obtained from cow-charred bones. Arsenic contamination of surface and subsurface waters is widely extended in Argentina. It is a problem of major concern, particularly in rural and suburban areas where there are not water treatment plants for supplying of drinking water. HAPb is a natural material, whose absorbent properties can be used for the design of low-cost technologies for As(V) abatement in water. In this work HAPb has been characterized by physical and chemical analysis (XRD, SEM, EDAX, BET, and electrophoretic mobility). A Plackett–Burman screening experimental design allowed us to determine the main variables affecting the efficiency of As(V) sorption onto HAPb. Based on these variables and with a design of higher order we developed a model of the system to study its behaviour. Data collection was planned through a Doehlert experimental design and a back propagation artificial neural network was used to work it out. Results showed that salinity is the major variable affecting the efficiency of the As(V) immobilization process but pH and hardness should be taken into account because of associations among them.  相似文献   

Temperatures, winds, and composition in the saturnian system     

Flasar FM  Achterberg RK  Conrath BJ  Pearl JC  Bjoraker GL  Jennings DE  Romani PN  Simon-Miller AA  Kunde VG  Nixon CA  Bézard B  Orton GS  Spilker LJ  Spencer JR  Irwin PG  Teanby NA  Owen TC  Brasunas J  Segura ME  Carlson RC  Mamoutkine A  Gierasch PJ  Schinder PJ  Showalter MR  Ferrari C  Barucci A  Courtin R  Coustenis A  Fouchet T  Gautier D  Lellouch E  Marten A  Prangé R  Strobel DF  Calcutt SB  Read PL  Taylor FW  Bowles N  Samuelson RE  Abbas MM  Raulin F  Ade P  Edgington S  Pilorz S  Wallis B  Wishnow EH 《Science (New York, N.Y.)》2005,307(5713):1247-1251

Stratospheric temperatures on Saturn imply a strong decay of the equatorial winds with altitude. If the decrease in winds reported from recent Hubble Space Telescope images is not a temporal change, then the features tracked must have been at least 130 kilometers higher than in earlier studies. Saturn's south polar stratosphere is warmer than predicted from simple radiative models. The C/H ratio on Saturn is seven times solar, twice Jupiter's. Saturn's ring temperatures have radial variations down to the smallest scale resolved (100 kilometers). Diurnal surface temperature variations on Phoebe suggest a more porous regolith than on the jovian satellites.  相似文献   

Chemical restraint and anaesthetic effects of a tiletamine-zolazepam/ketamine/detomidine combination in cattle     

Re M  Blanco-Murcia FJ  Gómez de Segura IA 《Veterinary journal (London, England : 1997)》2011,190(1):66-70

The immobilisation and anaesthesia of free-ranging cattle requires the administration of appropriate drugs in small volume via rifle or dart. The objective of this randomised controlled study was to test the capacity of a concentrated combination of tiletamine-zolazepam (TZ), ketamine (K) and detomidine (D) (TZKD) to immobilise/anaesthetise calves. Following administration of low, medium and high doses of TZKD to six healthy animals IM, the time-of-onset and duration of anaesthesia were recorded, in addition to standard cardio-respiratory parameters. Two noxious stimuli were applied to assess the analgesic effect of the combination. TZKD produced a dose-dependent anaesthetic action associated with respiratory depression and moderate hypoxaemia. Total recumbency lasted from 1h (with low dose) to 2h (with medium and high doses). The findings indicate that TZKD induces anaesthesia in calves, suitable not only for animal immobilisation, but also to carry out minor surgical procedures with or without additional local analgesia. Respiratory depression was the most severe side-effect and careful patient monitoring is recommended when using this drug combination.  相似文献   

Determination of phytohormones of environmental impact by capillary zone electrophoresis     

Segura Carretero A  Cruces-Blanco C  Soriano Peña M  Cortacero Ramírez S  Fernández Gutiérrez A 《Journal of agricultural and food chemistry》2004,52(6):1419-1422

A test mixture of five phytohormones [naphthaleneacetic acid (NAA), naphthoxyacetic acid (NOA), indoleacetic acid (IAA), indolebutyric acid (IBA), and indolepropionic acid (IPA)] was investigated. These compounds were cleanly separated with good resolution by capillary zone electrophoresis with a UV diode array detector using 20 mM sodium phosphate buffer (pH 7.25). The lowest detection limit was obtained for IPA (0.45 mg L(-)(1) or 0.005 mg kg(-)(1)) and the highest for NAA (1.04 mg L(-)(1) or 0.014 mg kg(-)(1)). The method has been applied for tomato samples fortified with the five phytohormones using a liquid-liquid extraction procedure, obtaining recovery percentages ranging from 91 to 109.0%.  相似文献   

Ketoprofen reduces the minimum alveolar concentration (MAC) in dogs anaesthetized with isoflurane and fentanyl     

ID Gremião  F Marsico  IAG  de Segura †  FO Ascoli  JHN Soares  A Nascimento  PRL Nascimento 《Veterinary anaesthesia and analgesia》2003,30(2):93-93

Non‐steroidal anti‐inflammatory drugs may potentiate the opioid induced reduction in volatile anaesthetic requirements ( Gomez de Segura et al. 1998 ). This study determined the reduction in the MAC of isoflurane (ISO) produced by ketoprofen (KETO) in dogs anaesthetized with fentanyl (FENT) and ISO. Six healthy female crossbred dogs, weighing 13.5 ± 1.3 (mean ± SD) kg and aged 3.0 ± 0.9 years were studied. Approval of the study was obtained from the institutional ethics committee. Anaesthesia was induced in all dogs via a facemask with 5% ISO in 5 L minute^?1 oxygen. The dogs' trachea were intubated and lungs were ventilated to maintain normocapnia (Pe ′CO₂ 4.7–6 kPa, 35–45 mm Hg). A heating pad was used to maintain body temperature. The animals were anaesthetized four times at one week intervals with the following anaesthetic and analgesic protocols randomly administered. Study 1, MAC (ISO); Isoflurane MAC. Study 2, MAC (ISO + FENT); dogs anaesthetized with ISO received a loading dose of 30 µg kg^?1 FENT IV over 20 minutes followed by a maintenance infusion of 0.2 µg kg^?1 minute^?1 FENT. Study 3, MAC (ISO + FENT + KETO1); as study 2 plus 1 mg kg^?1 KETO. Study 4, MAC (ISO + FENT + KETO2); as study 2 plus 2 mg kg^?1 KETO. The MAC was determined in duplicate by applying a standard electrical stimulus (50 V, 50 H₂ over 60 seconds via two needles placed SC over the tarsus). The stimulus was applied 15 minutes after every step change in anesthetic concentration. The Wilcoxon test was applied to data to determine significant differences among MAC measurements. Fentanyl significantly decreased MAC (ISO) from 1.27% ± 0.02% to 0.73% ± 0.08%, a reduction of 42% (p < 0.05). Ketoprofen 1 mg kg^?1 further decreased the MAC value (although not statistically significantly) with a reduction of 47% from MAC (ISO) (0.67% ± 0.13%) and 8% from MAC (ISO + FENT). When KETO 2 mg kg^?1 was given, the reduction in MAC was 50% compared to MAC (ISO) (0.63% ± 0.08%; p < 0.05) and 14% compared to MAC (ISO + FENT) p < 0.05. Administration of KETO further reduces MAC (ISO) compared to levels observed with FENT alone. The observed reduction may have clinical advantages.  相似文献   

Productivity of different cow genetic groups in dual-purpose cattle production systems in south-eastern Mexico     

Magana JG  Tewolde A  Anderson S  Segura JC 《Tropical animal health and production》2006,38(7-8):583-591

The objective was to evaluate the effect of cow genetic group, nutritional level and their interaction on some economically important traits of dual-purpose herds managed under field conditions. Nine herds were monitored during a production cycle in Yucatan, Mexico. Herds were grouped into four nutritional levels (NL) based on the metabolizable energy (ME) apparently available on pasture, nutritional management, and milk production. Cows were classified into three genetic groups (GG): low (≤25%), middle (25–75%) and high (≥75%) graded for Bos taurus inheritance. Total milk sold (TMS), days in milk (DIM), TMS adjusted to DIM within each NL (TMSA), body condition score (BCS) at calving, changes of BCS during lactation (CBCS), calf weaning weight (WW), age at weaning (AW), kg of calf weaned per cow (KWC) and calf mortality were studied. The statistical model included the fixed effects of NL, GG, month of calving (MC), parity number (PN) and BCS at calving and GG × NL interaction. The effects of NL, GG, MC, PN and GG × NL were significant (p < 0.05) for TMS, KWC. As expected, TMS increased with NL from 562.4 ± 106 kg for NL1 to 2366.3 ± 100.1 kg for NL4. KWC was greatest for NL2 (138.6 kg) followed by NL1 (135 kg); the lowest KWC corresponded to NL4 (96.0 kg) (p < 0.05). TMS values for the middle (1727 ± 94.7 kg) and the high graded GG (1603.5 ± 83.5 kg) were twice those for the low graded GG cows (828.5 ± 95 kg) (p < 0.05). KWC was also higher for the middle graded group (152.8 kg) than for the low or (104 kg) or the high graded GG (118 kg) (p < 0.05). With better nutrition cows of all GG improved their milk performance but not the calf traits. CBCS was negative for all GG. The highest BCS lost was for cows in NL1 and NL2 and for cows in the high graded GG (p < 0.05).  相似文献   

Septicaemia secondary to infection by Corynebacterium macginleyi in an Indian python (Python molurus)     

Martínez J  Segura P  García D  Aduriz G  Ibabe JC  Peris B  Corpa JM 《Veterinary journal (London, England : 1997)》2006,172(2):382-385

A seven-year-old female Indian python (Python molurus) weighing about 35kg was euthanased after several clinical episodes of stomatitis, pneumonia, ophthalmitis and dystocia over a period of four years. The animal had been maintained in a terrarium in a circus truck at an adequate temperature. During shows, however, the snake was considered to be exposed to stressful conditions for several hours at a time at low temperatures and with noise and bright lights. A post-mortem examination indicated ulcerative stomatitis, osteomyelitis, severe pneumonia and numerous granulomata and multifocal necrosis in stomach and spleen. Corynebacterium macginleyi was isolated in pure culture from the ulcerative stomatitis, and mixed with Stenotrophomonas maltophilia from the lungs and spleen. The findings indicated that the snake had died from a septicaemic process caused by C. macginleyi, probably originating from the stomatitis. The role of S. maltophilia as a secondary agent is discussed. The stress of the circus show and poor husbandry may have predisposed the animal to infection and septicaemia. This is the first report of C. macginleyi causing disease in a snake.  相似文献