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THE STUDY OF BACTERIAL GROWTH ON LOW-DENSITY POLYETHYLENE- LIGNIN COMPOSITE Texte intégral
2011
Nawres N. jaber
In the present study, Low density polyethylene with various contents of lignin films were investigated for their resistance to bacterial adhesion. The disc diffusion method was employed for this purpose. The results of bacterial growth on low-density polyethylene (LDPE )–lignin composite were reported. lignin was added by 1%,2%,3%,4%,5%,10% and 15% of polyethylene weight. We compared initial adhesion and surface growth of staphylococcus aureus , streptococcus pyogens, pseudomonus aerugenosa, eschrishia coli and klebciala spp. A 5 mm of test polymer composites were inoculated in the 9 cm Petri dish for 1-2 days and zone of inhibition and bacterial growing were observed and recorded. After 24 hours the bacterial growing of S. aureus , S. pyogens and E. coli were distributed all over the control agar with no growth on the polymeric composites films while Both P. aeruginosa and K. spp. have a dense growing. After 48 hours a slight adhesion of S. aureus on polyethylene-lignin discs was found with radius of growing was 3 mm .For P. aeruginosa we have more dense growing . It was found that the lignin contents have no clear inhibition against tested bacteria where this might be due to a limitation of the agar disc diffusion method. The vanishing of inhibition zone was combined with the absence of adherent bacteria on the polyethylene films. More concentration of natural lignin is required to get inhibition effect.
Afficher plus [+] Moins [-]Effects of chromium piclonate and ascorbic acid supplementation on growth performance, carcass traits, blood constituents and picture of growing kids under the summer conditions Texte intégral
2011
U. M. Abd El-Monem | M. A. Kandeil
The present work was performed to study the effect of chromium piclonate and ⁄ or ascorbic acid supplementation on the performance of growing kids during hot summer season (33.6oC and 74.2% RH). A total number of twenty four weaned commercial kids were randomly distributed into four treatment groups of 6 kids per each Kids in all treatments were equal in number and had nearly similar initial body weight. The first group was fed the basal diet and served as control (0.0 supplementation), while the other three groups were fed diets supplemented with 75 mg/kg diet chromium piclonate, 800 mg/ kg diet ascorbic acid and 75 mg / kg diet chromium piclonate + 800 mg ascorbic acid, respectively. The results obtained for growing Kids showed that the final live body weight and daily body gain were increased significantly (P < 0.05 or 0.01) during 210 and 270 days for Kids fed diets supplemented with chromium piclonate, ascorbic acid and chromium piclonate + ascorbic acid. However, the supplementation of chromium piclonate + ascorbic acid seemed to be the best significant performance. The results obtained for growing Kids showed that the daily feed intake, feed conversion, water ⁄ feed intake ratio, water ⁄ daily gain ratio were increased significantly (P < 0.05 or 0.01) during the experimental periods for Kids fed diets supplemented with chromium piclonate, ascorbic acid and chromium piclonate + ascorbic acid. The Results showed that water intake, rectum temperature and respiration rate were not significantly affected by previous treatments. The best margin was obtained in group fed on the diet supplemented with chromium piclonate + ascorbic acid. All carcass traits were increased insignificantly due to dietary chromium piclonate and ⁄or ascorbic acid supplementation. Serum total proteins were increased significantly (P < 0.05), in group three only while the cholesterol level and triglycerides decreased significantly (P<0.05) in Kids treated with chromium piclonate as compared with the control group under summer heat stress conditions. Serum albumin, globulin, urea-, creatinine, AST, WBCs, RBCs MCV, MCH and Hb content were insignificantly affected by chromium piclonate and ⁄or ascorbic acid supplementation to the kids’ diets. Finally, it could be concluded that supplementation of 75 mg chromium piclonate + 800 mg ascorbic acid / kg diet to the kid diets is necessary to improve the productivity, under the summer conditions
Afficher plus [+] Moins [-]Ticks infesting cattle in Central Equatoria region of South Sudan Texte intégral
2011
Wani L. Marcellino | Ibrahim I. Julla | Diaeldin A. Salih | Abdel R.M. El Hussein
Ticks infesting cattle represent a serious problem for improvement of cattle productivity in South Sudan. There has been limited information on ticks and tick-borne diseases in southern Sudan. This study was initiated to update the current distribution of ticks infesting cattle in the Central Equatoria region of South Sudan. The surveys for the present study were conducted at various cattle camps in Juba, Mangalla and Terekeka between December 2004 and June 2005. A total of 2322 ticks were collected from the bodies of 88 randomly selected cattle. Ticks were preserved in 70% ethanol for later identification. Seven ixodid tick species were found to infest cattle in Juba whilst six species were recorded in Mangalla and only four species in Terekeka. Amblyomma variegatum was the most common and widely distributed species found on cattle across all the study locations. Amblyomma lepidum was not found during this study. Based on these findings, it would be advisable to preempt the situation and institute containment procedures before possible East Coast fever outbreaks occur.
Afficher plus [+] Moins [-]Scanning electron microscopy investigation of fibrin networks after thermal injury Texte intégral
2011
Etheresia Pretorius | Jeané Olivier | Hester M. Oberholzer | Wendy J. van der Spuy
Scanning electron microscopy investigation of fibrin networks after thermal injury Texte intégral
2011
Etheresia Pretorius | Jeané Olivier | Hester M. Oberholzer | Wendy J. van der Spuy
Injury due to burning is known to impact on coagulation and haemostasis by disturbing the coagulation cascade and is also associated with impaired fibrinolysis. Also, venous thrombosis, pulmonary embolism and hypercoagulability are common during thermal injury. Using a Wistar albino rat model, we investigated in this study whether burn injury affects the ultrastructure of the fibrin networks. A typical fibrin network will contain mostly major, thick fibres with minor, thin fibres distributed amongst them. We found that the clot architecture changes after burn injury, showing more prominent minor, thin fibres in a netted appearance. Also, the clot showed areas of matted fibrin. We suggest that the thrombotic events associated with burn injury are due to the thickened and netlike areas formed when thrombin activates the coagulation cascade. This is due to impaired fibrinolysis activities, causing the resulting fibrin clots not to be successfully disseminated. Small fragments of these netted, clumped areas may therefore break loose and lead to thrombotic events after burn injuries. The current study therefore provided morphological evidence for thrombotic events associated with burn injury.
Afficher plus [+] Moins [-]Scanning electron microscopy investigation of fibrin networks after thermal injury Texte intégral
2011
Pretorius, Etheresia(University of Pretoria Department of Anatomy) | Olivier, Jeané(University of Pretoria Department of Anatomy) | Oberholzer, Hester M.(University of Pretoria Department of Anatomy) | van der Spuy, Wendy J.(University of Pretoria Department of Anatomy)
Injury due to burning is known to impact on coagulation and haemostasis by disturbing the coagulation cascade and is also associated with impaired fibrinolysis. Also, venous thrombosis, pulmonary embolism and hypercoagulability are common during thermal injury. Using a Wistar albino rat model, we investigated in this study whether burn injury affects the ultrastructure of the fibrin networks. A typical fibrin network will contain mostly major, thick fibres with minor, thin fibres distributed amongst them. We found that the clot architecture changes after burn injury, showing more prominent minor, thin fibres in a netted appearance. Also, the clot showed areas of matted fibrin. We suggest that the thrombotic events associated with burn injury are due to the thickened and netlike areas formed when thrombin activates the coagulation cascade. This is due to impaired fibrinolysis activities, causing the resulting fibrin clots not to be successfully disseminated. Small fragments of these netted, clumped areas may therefore break loose and lead to thrombotic events after burn injuries. The current study therefore provided morphological evidence for thrombotic events associated with burn injury.
Afficher plus [+] Moins [-]Effect of sequential hole enlargement on cortical bone temperature during drilling of 6.2-mm-diameter transcortical holes in the third metacarpal bones of horse cadavers Texte intégral
2011
Lescun, Timothy B. | Frank, Elizabeth A. | Zacharias, Joshua R. | Daggy, Joanne K. | Moore, George E.
Objective—To compare the bone temperature and final hole dimensions associated with sequential overdrilling (SO) and single 6.2-mm drill bit (S6.2DB) methods used to create transcortical holes in the third metacarpal bones (MCIIIs) of horse cadavers. Sample—60 MCIIIs from 30 horse cadavers. Procedures—In phase 1, hole diameter, tap insertion torque, peak bone temperature, and postdrilling bit temperature for 6.2-mm-diameter holes drilled in the lateral or medial cortical region of 12 MCIIIs via each of three 2-bit SO methods with a single pilot hole (diameter, 3.2, 4.5, or 5.5 mm) and the S6.2DB method were compared. In phase 2, 6.2-mm-diameter transcortical holes were drilled via a 2-bit SO method (selected from phase 1), a 4-bit SO method, or a S6.2DB method at 1 of 3 locations in 48 MCIIIs; peak bone temperature during drilling, drill bit temperature immediately following drilling, and total drilling time were recorded for comparison. Results—Hole diameter or tap insertion torque did not differ among phase 1 groups. Mean ± SD maximum bone temperature increases at the cis and trans cortices were significantly less for the 4-bit SO method (3.64 ± 2.01°C and 8.58 ± 3.82°C, respectively), compared with the S6.2DB method (12.00 ± 7.07°C and 13.19 ± 7.41°C, respectively). Mean drilling time was significantly longer (142.9 ± 37.8 seconds) for the 4-bit SO method, compared with the S6.2DB method (49.7 ± 24.3 seconds). Conclusions and Clinical Relevance—Compared with a S6.2DB method, use of a 4-bit SO method to drill transcortical holes in cadaveric equine MCIIIs resulted in smaller bone temperature increases without affecting hole accuracy.
Afficher plus [+] Moins [-]Preliminary investigations of the distribution of Escherichia coli O149 in sows, piglets, and their environment Texte intégral
2011
Goswami, Priti S. | Friendship, Robert M. | Gyles, Carlton L. | Poppe, Cornelis | Boerlin, Patrick
Little is known about the sources and kinetics of enterotoxigenic Escherichia coli colonization in pigs during the pre-and post-weaning period. In this study, farrowing pens, sows, and piglets were tested for the presence of E. coli O149 by real-time polymerase chain reaction (PCR) after bacterial culture pre-enrichment on 2 farms, one with a history of post-weaning diarrhea (problem farm — PF) and the other without such a history (non-problem farm — NPF). Unlike those on the PF, the sows from the NPF did not carry E. coli O149 before parturition, although they were colonized to frequencies similar to animals on the PF soon afterwards. Most piglets from the NPF were colonized within a week after birth, whereas only a small proportion of those on the PF were colonized during that period. No difference was observed in the frequency of piglet colonization at the 2 farms either at weaning or during the following week. Post-weaning diarrhea (PWD), which is caused by enterotoxigenic E. coli (ETEC), is a multifactorial disease. The presence of ETEC alone is not always sufficient for the disease to develop. Many other factors are considered to be associated with the occurrence of PWD, including feed type (1,2), feeding regimen (1,3,4), the presence of other infectious agents (3,5), weaning age, and weight (6). Weaning, which is considered to be a major physiological and psychological stress factor, is critical for the disease to occur (7). Although piglets are already colonized with ETEC before weaning (4,8), on many farms, clinical disease occurs only after weaning (1). Both sows (9,10) and the environment (6) could be possible sources of infection for piglets, but results from previous studies have not resolved this issue because of the low sensitivity of ETEC detection methods. This study provides preliminary data based on a sensitive detection method for E. coli O149 in pigs and their environment. The results demonstrate the potential of real-time PCR for future studies on this topic.
Afficher plus [+] Moins [-]Antimicrobial resistance in enteric pathogens isolated from Minnesota pigs from 1995 to 2004 Texte intégral
2011
Malik, Yashpal S. | Chander, Yogesh | Olsen, Karen | Goyal, Sagar M.
This study investigated the occurrence and antimicrobial resistance profiles of Escherichia coli and Salmonella sp. isolated from swine samples submitted to the Minnesota Veterinary Diagnostic Laboratory (MVDL) in Saint Paul, Minnesota from 1995 to 2004. During this time period, a total of 5072 E. coli and 2793 Salmonella sp. was isolated. Most of these isolates were found to be resistant to the tetracycline and beta-lactam group of antibiotics. Resistance to spectinomycin was also frequently observed. An increasing trend in ampicillin resistance and a decreasing trend in apramycin resistance were seen in both pathogens, although ampicillin resistance was relatively higher in E. coli than in Salmonella. Aminoglycoside (amikacin) and quinolone (enrofloxacin) were the only antimicrobials to which minimum or no resistance was observed. The resistance of pig pathogens to several antibiotics indicates the need to routinely monitor the use of these antimicrobials and their associated resistance in pig populations.
Afficher plus [+] Moins [-]Effect of pilot hole diameter and tapping on insertion torque and axial pullout strength of 4.0-mm cancellous bone screws Texte intégral
2011
Kunkel, Kevin A. R. | Suber, Jonathan T. | Gerard, Patrick D. | Kowaleski, Michael P.
Objective—To evaluate the effects of pilot hole diameter and tapping on insertion torque and axial pullout strength of 4.0-mm cancellous bone screws in a synthetic canine cancellous bone substitute. Sample—75 synthetic cancellous bone blocks (15 blocks/group). Procedures—For groups 1 through 5, screw size-pilot hole diameter combinations were 3.5–2.5 mm (cortical screws), 4.0–2.5 mm, 4.0–2.5 mm, 4.0–2.0 mm, and 4.0–2.0 mm, respectively. Holes were tapped in groups 1, 2, and 4 only (tap diameter, 3.5, 4.0, and 4.0 mm, respectively). One 70-mm-long screw was inserted into each block; in a servohydraulic materials testing machine, the screw was extracted (rate, 5 mm/min) until failure. Mean group values of maximum insertion torque, axial pullout strength, yield strength, and stiffness were determined. Results—Mean maximum insertion torque differed significantly among the 5 groups; the group 5 value was greatest, followed by group 3, 4, 2, and 1 values. Group 3, 4, and 5 axial pullout strengths were similar and significantly greater than the group 2 value; all values were significantly greater than that for group 1. Group 5 and 4 yield strengths were similar and significantly greater than the group 3, 2, and 1 values. Stiffness in group 3 was similar to group 4 and 2 values but significantly greater than the group 5 value; all values were significantly greater than that for group 1. Conclusions and Clinical Relevance—These synthetic cancellous bone model findings suggested that tapping a 2.0-mm-diameter pilot hole when placing a 4.0-mm screw is the optimal insertion technique.
Afficher plus [+] Moins [-]Glomerular filtration rate estimation by use of a correction formula for slope-intercept plasma iohexol clearance in cats Texte intégral
2011
Finch, Natalie C. | Syme, Harriet M. | Elliott, Jonathan | Peters, Adrien M. | Gerritsen, Robert | Croubels, Siska | Heiene, Reidun
Objective—To develop a formula for correcting slope-intercept plasma iohexol clearance in cats and to compare clearance of total iohexol (TIox), endo-iohexol (EnIox), and exo-iohexol (ExIox). nimals—20 client-owned, healthy adult and geriatric cats. Procedures—Plasma clearance of TIox was determined via multisample and slope-intercept methods. A multisample method was used to determine clearance for EnIox and ExIox. A second-order polynomial correction factor was derived by performing regression analysis of the multisample data with the slope-intercept data and forcing the regression line though the origin. Clearance corrected by use of the derived formula was compared with clearance corrected by use of Brochner-Mortensen human and Heiene canine formulae. Statistical testing was applied, and Bland-Altman plots were created to assess the degree of agreement between TIox, EnIox, and ExIox clearance. Results—Mean ± SD iohexol clearance estimated via multisample and corrected slope-intercept methods was 2.16 ± 0.35 mL/min/kg and 2.14 ± 0.34 mL/min/kg, respectively. The derived feline correction formula was Clcorrected = (1.036 × (Cl)uncorrected) – (0.062 × (Cl)uncorrected2), in which Cl represents clearance. Results obtained by use of the 2 methods were in excellent agreement. Clearance corrected by use of the Heiene formula had a linear relationship with clearance corrected by use of the feline formula; however, the relationship of the feline formula with the Brochner-Mortensen formula was nonlinear. Agreement between TIox, EnIox, and ExIox clearance was excellent. Conclusions and Clinical Relevance—The derived feline correction formula applied to slope-intercept plasma iohexol clearance accurately predicted multisample clearance in cats. Use of this technique offers an important advantage by reducing stress to cats associated with repeated blood sample collection and decreasing the costs of analysis.
Afficher plus [+] Moins [-]Biomechanical comparison after in vitro laminar vertebral stabilization and vertebral body plating of the first and second lumbar vertebrae in specimens obtained from canine cadavers Texte intégral
2011
Knell, Sebastian C. | Bürki, Alexander | Hurter, Karin | Ferguson, Stephen J. | Montavon, P. M. (Pierre M.)
Objective—To compare biomechanical characteristics of vertebral segments after vertebral body plating or laminar stabilization following complete incision of the annulus fibrosus. Sample—Vertebral segments from T13 through L3 obtained from 18 canine cadavers. Procedures—A 4-point bending moment was applied in flexion and extension to the intact vertebral segments to determine a baseline range of motion (ROM) and neutral zone (NZ). Vertebral columns were then destabilized by creating a defect in the intervertebral disk via complete incision of the ventral aspect of the annulus fibrosus. The bending moment was applied again after stabilization was accomplished via vertebral body plating or with laminar stabilization (n = 9 vertebral segments/stabilization technique). The ROM and NZ were compared with their baseline values and among treatment groups. Finally, load-to-failure testing was performed in flexion. Results—Mean relative ROM and NZ for segments treated with laminar stabilization were significantly lower than those for segments treated with vertebral plates. Conclusions and Clinical Relevance—Analysis of in vitro results suggested that laminar stabilization of vertebral segments provided greater stiffness than did vertebral body plating.
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