Effects of sub-minimum inhibitory concentration antibiotic levels and temperature on growth kinetics and outer membrane protein expression in Mannheimia haemolytica and Haemophilus somnus          下载免费PDF全文

Brenda Y. Reeks  Franklin R. Champlin  Daniel B. Paulsen  Daniel W. Scruggs    Mark L. Lawrence 《Canadian journal of veterinary research》2005,69(1):1-10

The objective of this study was to determine the effects of sub-minimum inhibitory concentrations (sub-MICs) of 2 veterinary antibiotic preparations, chlortetracycline (CTC) and chlortetracycline-sulfamethazine (CTC + SMZ), on growth kinetics and outer membrane protein expression in Mannheimia haemolytica and Haemophilus somnus at normal and febrile body temperatures. Sub-minimum inhibitory concentrations of both antibiotics reduced the growth rates of M. haemolytica and H. somnus. Growth of both species was not inhibited when grown at 41 degrees C compared to 37 degrees C. There was no detectable consistent effect of antibiotic or temperature on outer membrane protein expression for either species. Our study indicates that sub-MIC levels of CTC and CTC + SMZ markedly impair growth of clinical M. haemolytica and H. somnus isolates, potentially allowing more effective host clearance during infection.  相似文献   

Use of animation-enhanced video clips for teaching abnormal breathing patterns     

Hawkins EC  Hansen B  Bunch BL 《Journal of veterinary medical education》2003,30(1):73-77

The ability to characterize disease of the respiratory tract accurately based on breathing pattern is helpful for the development of differential diagnoses and an efficient diagnostic plan and critical for the stabilization of patients in respiratory distress. Veterinary students do not have sufficient clinical experience to observe personally all types of respiratory diseases and their resultant abnormal breathing patterns. We developed a teaching tool, the animated breathing pattern videotape (ABV), to fill this gap. The ABV is a collection of video clips of small animal patients with normal and abnormal breathing patterns on a conventional videotape of approximately 20 minutes duration. Each video clip is shown for 20 to 40 seconds, followed by the same clip with superimposed animation of rib and diaphragm motion, followed by the initial clip again, without overlying animation. The ABV has since been used in teaching third-year veterinary students, interns, residents, practicing veterinarians, and veterinary technicians. Student evaluations and responses to questionnaires by interns, residents, practicing veterinarians, veterinary technicians, and peer reviewers have been uniformly positive.  相似文献   

A comparison of owner management and complications in 67 cats with esophagostomy and percutaneous endoscopic gastrostomy feeding tubes     

Ireland LM  Hohenhaus AE  Broussard JD  Weissman BL 《Journal of the American Animal Hospital Association》2003,39(3):241-246

Esophagostomy feeding tubes were placed in 46 cats. Percutaneous endoscopic gastrostomy (PEG) feeding tubes were placed in 21 cats. Owner management and complications and facility of use were evaluated retrospectively by review of medical records and owner survey. Both tube types were equally effective for maintenance of body weight, ease of owner management, and complication rates. All of 12 owners surveyed were comfortable with PEG tube management. Ninety-six percent of 24 owners surveyed were comfortable with esophagostomy tube management. The esophagostomy tube can be placed less invasively, without specialized equipment, making it an excellent alternative to the PEG tube.  相似文献   

Acute Reactions in Dogs Treated with Doxorubicin: Increased Frequency with the Use of a Generic Formulation     

Brenda S. Phillips  Susan A. Kraegel  Eric Simonson  Bruce R. Madewell 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1998,12(3):171-172

During a 4-month period, 34 dogs with tumors received a total of 60 doses of a single generic formulation of doxorubicin; 13 acute drug reactions were observed in these 34 dogs, and no acute reactions were observed after replacing the product with the proprietary brand. These reactions were characterized by one or more of the following signs: pruritus; head-shaking; urticaria; erythema of the pinnal, axillary, or inguinal regions; vocalization; vomiting; hyperemic or pale mucous membranes; high heart rate; and high respiratory rate. We propose that a component unique to generic doxorubicin was responsible for the unusually high number of acute drug reactions observed.  相似文献   

Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt     

Basma M. Sheta  Trevon L. Fuller  Brenda Larison  Kevin Y. Njabo  Ahmed Samy Ahmed  Ryan Harrigan  Anthony Chasar  Soad Abdel Aziz  Abdel-Aziz A. Khidr  Mohamed M. Elbokl  Lotfy Z. Habbak  Thomas B. Smith 《Veterinary microbiology》2014

Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n = 1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n = 1242) and wild birds (n = 807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n = 306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p < 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F = 29.5, p < 0.0001).  相似文献   

Hormonal influences on in vitro [35S]-sulfate uptake by gill arches from the goldfish (Carassius auratus L.)     

Tracy A. Marchant  Brenda M. Moroz 《Fish physiology and biochemistry》1993,11(1-6):393-399

A bioassay for insulin-like growth factor (IGF), based on the in vitro incorporation of [³⁵S]-sulfate into gill arch tissue was used to study the hormonal regulation of proteoglycan synthesis in the goldfish (Carassius auratus). [³⁵S]-sulfate incorporation into gill arch tissue was found to be time-dependent with maximal uptake occurring by 48h, suggesting that proteoglycan synthesis in this tissue was maintained for at least 48h in vitro. The addition of human recombinant IGF-I (IGF-I) to the incubation medium was found to significantly stimulate [³⁵S]-sulfate uptake into the gill arches, whereas bovine growth hormone (GH) was without effect. Porcine insulin was also stimulatory, but results indicate that the effects of porcine insulin and IGF-I may be mediated by a single receptor system. Finally, arches from hypophysectomized fish were significantly less responsive to IGF-I than were arches from sham-operated fish. Furthermore, administration of ovine GH in vivo appeared to increase subsequent responsiveness in vitro. Together, these results provide evidence that the growth-promoting actions of GH in the goldfish may be mediated, at least in part, by a peptide related in structure to mammalian IGF-I.  相似文献   

A synthesis of the life history and ecology of juvenile Pacific herring in Prince William Sound,Alaska     

Brenda L. Norcross  Evelyn D. Brown  Robert J. Foy  Michele Frandsen  Shelton M. Gay  Thomas C. Kline  Doran M. Mason  E. Vincent Patrick  A. J. Paul  Kevin D. E. Stokesbury 《Fisheries Oceanography》2001,10(Z1):42-57

Physical and biological variables affecting juvenile Pacific herring (Clupea pallasi) in Prince William Sound (PWS) from 1995 to 1998 were investigated as part of a multifaceted study of recruitment, the Sound Ecosystem Assessment (SEA) program. Though more herring larvae were retained in eastern PWS bays, ages‐0 and ‐1 herring used bays throughout PWS as nursery areas. Water transported into PWS from the Gulf of Alaska (GOA) contributed oceanic prey species to neritic habitats. Consequently, variations in local food availability resulted in different diets and growth rates of herring among bays. Summer food availability and possible interspecific competition for food in nursery areas affected the autumn nutritional status and juvenile whole body energy content (WBEC), which differed among bays. The WBEC of age‐0 herring in autumn was related to over‐winter survival. The limited amount of food consumption in winter was not sufficient to meet metabolic needs. The smallest age‐0 fish were most at risk of starvation in winter. Autumn WBEC of herring and winter water temperature were used to model over‐winter mortality of age‐0 herring. Differences in feeding and energetics among nursery areas indicated that habitat quality and age‐0 survival were varied among areas and years. These conditions were measured by temperature, zooplankton abundance, size of juvenile herring, diet energy, energy source (GOA vs. neritic zooplankton), WBEC, and within‐bay competition.  相似文献   

Genetic analysis of flowering and maturity time in high latitude spring wheat     

Muhammad Iqbal  Alireza Navabi  Donald F. Salmon  Rong-Cai Yang  Brenda M. Murdoch  Steve S. Moore  Dean Spaner 《Euphytica》2007,154(1-2):207-218

Due to the short growing season in the high northern latitudes, the development of early maturing spring wheat (Triticum aestivum L.) cultivars is important to avoid frost damage which can lower production and quality. We investigated earliness of flowering and maturity, and some associated agronomic traits, using a set of randomly selected high northern latitude adapted spring wheat cultivars (differing in maturity) and their F₁ and F₂ crosses made in a one-way diallel mating design. The parents, and their F₁ and F₂ crosses were evaluated under field conditions over 2 years. Anthesis and maturity times were controlled by both vernalization response and earliness per se genes, mainly acting additively. Non-additive genetic effects were more important in controlling grain fill duration, grain yield and plant height. Additive × additive epistatic effects were detected for all traits studied except time to anthesis. Segregation analyses of the F₂ populations for time to anthesis indicated the presence of different vernalization response genes. Molecular genetic analyses revealed the presence of Vrn-A1 and Vrn-B1 genes in the parental cultivars. Narrow-sense heritability was medium to high (60–86%) for anthesis and maturity times but low to medium (13–55%) for grain fill duration, plant height and grain yield. Selection for early flowering/maturity in early segregating generations would be expected to result in genetic improvement towards earliness in high latitude spring wheats. Incorporation of the vernalization responsive gene Vrn-B1 in combination with vernalization non-responsive gene Vrn-A1 into spring wheats would aid in the development of early maturing cultivars with high grain yield potential for the high latitude wheat growing regions of the northern hemisphere.  相似文献   

The early years. Preschool influences on mathematics achievement     

Melhuish EC  Sylva K  Sammons P  Siraj-Blatchford I  Taggart B  Phan MB  Malin A 《Science (New York, N.Y.)》2008,321(5893):1161-1162

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Identifying autism loci and genes by tracing recent shared ancestry   总被引：2，自引：0，他引：2  

Morrow EM  Yoo SY  Flavell SW  Kim TK  Lin Y  Hill RS  Mukaddes NM  Balkhy S  Gascon G  Hashmi A  Al-Saad S  Ware J  Joseph RM  Greenblatt R  Gleason D  Ertelt JA  Apse KA  Bodell A  Partlow JN  Barry B  Yao H  Markianos K  Ferland RJ  Greenberg ME  Walsh CA 《Science (New York, N.Y.)》2008,321(5886):218-223

To find inherited causes of autism-spectrum disorders, we studied families in which parents share ancestors, enhancing the role of inherited factors. We mapped several loci, some containing large, inherited, homozygous deletions that are likely mutations. The largest deletions implicated genes, including PCDH10 (protocadherin 10) and DIA1 (deleted in autism1, or c3orf58), whose level of expression changes in response to neuronal activity, a marker of genes involved in synaptic changes that underlie learning. A subset of genes, including NHE9 (Na+/H+ exchanger 9), showed additional potential mutations in patients with unrelated parents. Our findings highlight the utility of "homozygosity mapping" in heterogeneous disorders like autism but also suggest that defective regulation of gene expression after neural activity may be a mechanism common to seemingly diverse autism mutations.  相似文献