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Biomedical subjects

John J Schaefer

Publications and source records attributed to John J Schaefer.

5 recordsLinked to original sources
PubMed2006

Detection of Hepatozoon canis in stray dogs and cats in Bangkok, Thailand.

A rapidly increasing stray animal population in Bangkok has caused concern regarding transmission of vector-borne and zoonotic diseases. The purpose of this study was to determine if stray animals in Bangkok are a potential reservoir of Hepatozoon, a genus of tick-borne parasites that has received little attention in Thailand. Blood samples were collected from stray companion animals near monasteries in 42 Bangkok metropolitan districts. Both dogs and cats were sampled from 26 districts, dogs alone from 4 districts and cats alone from 12 districts. Samples were collected from a total of 308 dogs and 300 cats. Light microscopy and an 18 S rRNA gene-based PCR assay were used to test these samples for evidence of Hepatozoon infection. Gamonts were observed in blood smears for 2.6% of dogs and 0.7% of cats by microscopy. The PCR assay detected Hepatozoon in buffy coats from 11.4% of dogs and 32.3% of cats tested. The prevalence of infection was the same between male and female dogs or cats, and PCR-positive dogs and cats were found in 36.6% and 36.8% of the districts surveyed, respectively. There was an association between the percentages of PCR-positive dogs and cats in districts where both host species were sampled. Sequences of representative amplicons were closest to those reported for H. canis. These results represent the first molecular confirmation that H. canis is indigenous to Thailand. The unexpectedly high prevalence of Hepatozoon among stray cats indicates that their role in the epizootiology of hepatozoonosis should be investigated.

Animals↗
PubMed2005

Transstadial and intrastadial experimental transmission of Ehrlichia canis by male Rhipicephalus sanguineus.

The acquisition and transmission of rickettsial pathogens by different tick developmental stages has important epidemiological implications. The purpose of this study was to determine if male Rhipicephalus sanguineus can experimentally acquire and transmit Ehrlichia canis in the absence of female ticks. Two trials were performed where nymphal and male R. sanguineus were simultaneously acquisition fed on the same infected donor hosts, and transstadially or intrastadially exposed male ticks were fed on separate pathogen-free dogs as a test for transmission. A single-step p30-based PCR assay was used to test canine and tick hosts for E. canis infections before and after tick feeding. E. canis was detected after either intrastadial or transstadial passage in male ticks, the organism remained detectable in both tick groups after transmission feeding, and both tick groups transmitted the rickettsia to susceptible dogs. Infection of dogs via tick feeding resulted in milder clinical signs and lower antibody titers than intravenous inoculation of carrier blood, but further investigation is needed to understand the mechanisms responsible for this observation. These results demonstrate that male R. sanguineus can take multiple feedings, and that they can both acquire and transmit E. canis in the absence of female ticks. This tick development stage could be important in transmission of E. canis, and perhaps related pathogens, between vertebrate hosts under natural and experimental conditions.

Animals↗
PubMed2004

Simulators and difficult airway management skills.

Although difficult airway management remains one of the leading factors in anaesthetic deaths, there have been tremendous advances in the field in the last few decades. The question is, are advanced airway management skills being taught and used? Of the numerous training tools available, simulators have the advantages of providing whole-task learning with the potential to change behaviour and, when applied to large groups of trainees, the possibility of achieving standardized application of the safest practices for a range of scenarios limited only by the creativity of the program designers. Partial-task trainers include computer-based software programs and simulators. Full-scale simulators include a variety of products from several manufacturers. To take full advantage of simulators as educational tools, curricula should be designed around a set of educational objectives that address the objectives of learning in all three skill domains (cognitive, psychomotor, and affective). Simulation experiences using partial-task or whole-task trainers should be coupled whenever feasible with a structured clinical experience in airway management. This can best be achieved through a dedicated airway management rotation. Monitored procedure logs may also be used. Whether using a simulator or in a clinical rotation, experiences should be graded, for example, gaining experience in an adult population before gaining experience in paediatrics and in each population mastering airway management skills for common scenarios before advancing to more complicated techniques such as fibreoptic bronchoscopy.

Anesthesiology↗
PubMed2004

New aspects on critical care medicine training.

Recently, three fundamental changes have been introduced in medical education, all of particular importance to critical care medicine: (1) clinical teaching and medical practice now emphasize evidence-based medicine, (2) patient safety aspects are increasingly stressed, and (3) use of simulation in medical training is spreading rapidly. In 1999, the disturbingly high frequency of life-threatening or even lethal medical complications was emphasized by the Institute of Medicine in the book To Err Is Human. The Institute of Medicine recommended establishing interdisciplinary team training programs incorporating efficient methods such as simulation. Although simulation has been used by the aviation industry and the military for several decades, only during the past decade has this become a teaching method in medicine. Currently, two full-scale computerized simulators are available: METI, provided by Medical Education Technologies, Sarasota, Florida, and SimMan, manufactured by Laerdal Medical, in Stavanger, Norway. The simulation center at the University of Pittsburgh Medical Center was established in 1994 and has grown quickly to its current large facility, where, in academic year 2003 to 2004, approximately 8000 healthcare professionals were trained on the SimMan. Courses taught include clinical procedures and decision making in perioperative medicine, acute medicine, pharmacology, anesthesiology, airway management, bronchoscopy, pediatric versus adult crisis management, critical events in obstetrics, and crisis team training. Advantages of simulation training over traditional medical education methods include (1) provision of a safe environment for both patient and student during training in risky procedures, (2) unlimited exposure to rare but complicated and important clinical events, (3) the ability to plan and shape training opportunities rather than waiting for a suitable situation to arise clinically, (4) the ability to provide immediate feedback, (5) the opportunity to repeat performance, (6) the opportunity for team training, and (7) lower costs, both direct and indirect. Within the next decade, use of computerized simulators for evidence-based education and training in medicine is expected to develop considerably and spread rapidly into a very important domain of medical schools throughout the entire world.

Computer Simulation↗