"Dip-Pen" nanolithography   总被引：1，自引：0，他引：1  

RD Piner  J Zhu  F Xu  S Hong  CA Mirkin 《Science (New York, N.Y.)》1999,283(5402):661-663

A direct-write "dip-pen" nanolithography (DPN) has been developed to deliver collections of molecules in a positive printing mode. An atomic force microscope (AFM) tip is used to write alkanethiols with 30-nanometer linewidth resolution on a gold thin film in a manner analogous to that of a dip pen. Molecules are delivered from the AFM tip to a solid substrate of interest via capillary transport, making DPN a potentially useful tool for creating and functionalizing nanoscale devices.  相似文献   

Effect of pre-medication on gastroduodenoscopy in isoflurane-anesthetized cats     

AA  Smith  LP Posner  RE Goldstein  JW Ludders  HN Erb  KW Simpson  RD Gleed 《Veterinary anaesthesia and analgesia》2003,30(2):103-103

The pre‐medicant chosen may influence the ease with which gastroduodenoscopy (GD) is performed. The purpose of this study was to evaluate the relative ease of GD in cats under ketamine and isoflurane anesthesia after IM injection of hydromorphone (H, 0.1 mg kg^?1), hydromorphone plus glycopyrrolate (HG, 0.1 mg kg^?1 (H), 0.01 mg kg^?1 (G)), medetomidine (M, 0.03 mg kg^?1), or butorphanol (B, 0.4 mg kg^?1). Eight cats were assigned randomly to receive each treatment in a cross‐over design with at least 7 days between treatments. Twenty minutes after pre‐medication, medetomidine produced greater (p = 0.001) sedation than the other treatments when assessed, using a subjective ordinal scale. The cats were injected with ketamine (10 mg kg^?1 IM), orotracheally intubated, connected to a pediatric circle breathing system, and allowed to spontaneously breathe isoflurane in oxygen. Once end‐tidal isoflurane concentration was stable at 1.4% for 15 minutes, endoscopy was started. A single endoscopist (REG), who was unaware of the treatment used, performed all endoscopies. The endoscopist scored the difficulty of endoscopy subjectively (0–3). The significance of differences between treatments was evaluated using Friedman's test. Time for entering the stomach was 9.4 (4.7–15.9) (median (minimum–maximum)), 6.6 (5.2–11.7), 8.4 (6.3–16.5), and 7.7 (5.1–14.7) seconds and for entering the duodenum from the stomach was 20.5 (13.8–40.9), 18.2 (10.3–39.8), 20.2 (16.2–119.5), and 22.2 (11.8–83.8) seconds for H, HG, M, and B treatments, respectively. There were no significant differences in the time for, or difficulty of, endoscopy. We conclude that any of these drugs can be used satisfactorily at the doses and combinations tested to pre‐medicate cats prior to general anesthesia for GD.  相似文献   

Experimental airborne transmission of Streptococcus suis capsular type 2 in pigs.   总被引：9，自引：0，他引：9  

F Berthelot-Hérault  M Gottschalk  A Labbé  R Cariolet  M Kobisch 《Veterinary microbiology》2001,82(1):69-80

Experimental airborne transmission of Streptococcus suis type 2 was studied in specific pathogen free piglets. Forty piglets were allotted to five groups of eight 7-week-old animals and housed in three separated units. Negative control pigs (group 1) were housed in unit A and infected batches were housed in units B (group 2) and C (groups 4). In units B and C, non-inoculated groups (groups 3 and 5, respectively), 40 cm distant from the respective inoculated group and without any physical contact between them, also took place. Six animals of groups 2 and 4 were inoculated intravenously with 2 x 10(8) colony forming units (cfu) of a mild and a high virulent S. suis strains, respectively. The remaining animals in these groups and pigs from groups 1, 3, 5 received broth medium in the same way. Differences among virulence of S. suis capsular type 2 were observed in inoculated pigs of groups 2 and 4. Pigs from group 2 became carriers, showing only mild symptoms. By contrast, animals from group 4 presented an acute form of the disease. All the indirect contact pigs in groups 3 and 5 had S. suis in palatine tonsils from day 6 after the infection and they presented clinical manifestations similar to those observed in experimentally infected pigs. Two direct contact animals were also contaminated in the upper respiratory tract but surprisingly they did not show any symptoms. Airborne transmission of S. suis in experimentally pigs was demonstrated in the present study. Indirect infections, as described in this study, are a more realistic way to infect pigs than other experimental procedures and may be used to further study the pathogenesis of the infection caused by this important pathogen.  相似文献   

Optimized protocol for multiplex nested polymerase chain reaction to detect and differentiate Haemophilus parasuis,Streptococcus suis,and Mycoplasma hyorhinis in formalin-fixed,paraffin-embedded tissues from pigs with polyserositis     

Ikjae Kang  Duyeol Kim  Kiwon Han  Hwi Won Seo  Yeonsu Oh  Changhoon Park  Jeehoon Lee  Marcelo Gottschalk  Chanhee Chae 《Canadian journal of veterinary research》2012,76(3):195-200

An optimized protocol was developed for the simultaneous detection and differentiation of Haemophilus parasuis, Streptococcus suis, and Mycoplasma hyorhinis in formalin-fixed, paraffin-embedded (FFPE) tissues with multiplex nested polymerase chain reaction (PCR). This method also determines the prevalence of these bacteria in pigs with polyserositis. DNA extraction with a combination of a commercial reagent and proteinase K resulted in more frequent detection of the pathogens than DNA extraction with proteinase K alone. Among FFPE tissue samples from 312 cases of polyserositis in which at least 1 bacterial species was detected, multiplex nested PCR detected H. parasuis in 239 (77%), S. suis in 124 (40%), and M. hyorhinis in 40 (13%). The disease was caused by a single pathogen in 224 (72%) of the cases and multiple pathogens in 88 (28%). Among the pigs positive for H. parasuis, S. suis, and M. hyorhinis by multiplex nested PCR, the pathogen was isolated from only 11%, 35%, and 28%, respectively. Therefore, the PCR protocol developed in this study is a useful diagnostic method when samples are negative after isolation methods and even for samples in which only 1 pathogen was isolated.  相似文献   

Axial forces and bending moments in the loaded rabbit tibia in vivo     

Janin Reifenrath  Daniel Gottschalk  Nina Angrisani  Silke Besdo  Andrea Meyer-Lindenberg 《Acta veterinaria Scandinavica》2012,54(1):21

Background

Different animal models are used as fracture models in orthopaedic research prior to implant use in humans, although biomechanical forces can differ to a great extend between species due to variable anatomic conditions, particularly with regard to the gait. The rabbit is an often used fracture model, but biomechanical data are very rare. The objective of the present study was to measure axial forces, bending moments, and bending axis directly in the rabbit tibia in vivo. The following hypothesis was tested: Axial forces and bending moments in the mid-diaphysis of rabbit tibia differ from other experimental animals or indirectly calculated data.

Methods

A minifixateur system with 4 force sensors was developed and attached to rabbit tibia (n = 4), which were subsequently ostectomised. Axial forces, bending moments and bending angles were calculated telemetrically during weight bearing in motion between 6 and 42 days post operation.

Results

Highest single values were 201% body weight [% bw] for axial forces and 409% bw cm for bending moments. Whereas there was a continous decrease in axial forces over time after day 10 (P = 0.03 on day 15), a decrease in bending moments was inconsistent (P = 0.03 on day 27). High values for bending moments were frequently, but not consistently, associated with high values for axial forces.

Conclusion

Axial forces in rabbit tibia exceeded axial forces in sheep, and differed from indirectly calculated data. The rabbit is an appropriate fracture model because axial loads and bending moments in rabbit tibia were more closely to human conditions than in sheep tibia as an animal model.  相似文献   

Diagnostic and epidemiological features of Lawsonia intracellularis enteropathy in 2 foals     

Dauvillier J  Picandet V  Harel J  Gottschalk M  Desrosiers R  Jean D  Lavoie JP 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(7):689-691

Two clinical cases of equine proliferative enteropathy are described. Both foals had a positive fecal polymerase chain reaction, but shedding of the bacterium stopped <4 days after therapy was initiated. One foal was serologically positive 3 days after onset of clinical signs and remained positive for more than 6 months.  相似文献   

Subchronic toxicity of gamma-Falisan-Universal dry dressing agent to rats     

P Clausing  M Gottschalk  U Mahro  D W Bleyl  G Karg 《Archiv fuer experimentelle veterinaermedizin》1980,34(3):405-416

Doses of 50 mg/kg, 100 mg/kg, and 400 mg/kg of Gamma-Falisan-Universal dry dressing agent (active ingredients including 20 per cent of Lindan and 2.5 per cent of phenyl-mercury acetate) were administered in agar suspension by stomach intubation to rats over 13 weeks, with five applications weekly. The following changes were produced: retardation in body weight, lymphopenia and leucopenia, rise of segment-nuclear neutrophils in peripheral blood, decrease of haematocrit and haemoglobin, as well as rise in activities of leucine aminopeptidase and serum glutamate oxalo-acetate transaminase. The males proved to be more sensitive in the context of their haematological parameters, while the females displayed higher sensitivity in terms of clinico-chemical values. Absolute weight increases were recorded from kidneys and liver of both males and females and from the adrenal gland of females, while weight loss was recorded from the pituitary gland of males. Changes of the same kind were expressed even more strongly, in the context of relative weights of organs. Histopathological changes were recorded from liver, kidneys, and adrenal gland of either sex, and they were histometrically confirmed. Retardation in body weight, rise in activity of leucine aminopeptidase, and weight changes of various organs were significant up to first dosage group. Analogous findings were obtained with regard to microscopic changes in kidneys. Hence, no-effect levels did not occur at all throughout the experiment.  相似文献   

Genomic relatedness among reference strains of different Streptococcus suis serotypes.   总被引：1，自引：0，他引：1       下载免费PDF全文

J Harel  R Higgins  M Gottschalk    M Bigras-Poulin 《Canadian journal of veterinary research》1994,58(4):259-262

Hybridization studies using genomic DNA and a rDNA probe revealed genetic relatedness among reference strains of different Streptococcus suis serotypes. Although most serotype 22 isolates are biochemically atypical, the reference strain of capsular type 22 is genetically related to other S. suis serotypes, but not to Streptococcus pneumoniae. Using DNA digested with BamHI and BglII for ribotyping, some S. suis reference strains had common patterns, but this analysis mainly revealed variations in patterns of S. suis strains of different serotypes.  相似文献   

Susceptibility of Streptococcus suis to penicillin     

M Gottschalk  P Turgeon  R Higgins  M Beaudoin  A M Bourgault 《Journal of veterinary diagnostic investigation》1991,3(2):170-172

  相似文献   

Decrease of the adhesion of Streptococcus suis serotype 2 mutants to embryonic bovine tracheal cells and porcine tracheal rings.   总被引：1，自引：0，他引：1  

J Brassard  M Gottschalk    S Quessy 《Canadian journal of veterinary research》2001,65(3):156-160

Streptococcus suis is an important swine pathogen that may be present in the tonsils of pigs that show no signs of illness. Because adhesion to host cells may be important in the carrier state, this study was undertaken to investigate adhesion to host cells by S. suis mutant strains defective in expression of a 39-kDa protein. Mutant strains of S. suis were generated by transposon Tn916 mutagenesis and were tested for adhesion to embryonic bovine tracheal cells and porcine tracheal rings. Compared with the parent strain, there was a significant reduction in adherence of 3 mutant strains to both bovine tracheal cells and porcine tracheal rings.  相似文献