Biomedical subjects

Amir Cohen

Publications and source records attributed to Amir Cohen.

7 recordsLinked to original sources

PubMed2005

Inherited and acquired interactions between ACHE and PON1 polymorphisms modulate plasma acetylcholinesterase and paraoxonase activities.

The 5.5 Mb chromosome 7q21-22 ACHE/PON1 locus harbours the ACHE gene encoding the acetylcholine hydrolyzing, organophosphate (OP)-inhibitable acetylcholinesterase protein and the paraoxonase gene PON1, yielding the OP-hydrolyzing PON1 enzyme which also displays arylesterase activity. In search of inherited and acquired ACHE-PON1 interactions we genotyped seven polymorphic sites and determined the hydrolytic activities of the corresponding plasma enzymes and of the AChE-homologous butyrylcholinesetrase (BChE) in 157 healthy Israelis. AChE, arylesterase, BChE and paraoxonase activities in plasma displayed 5.4-, 6.5-, 7.2- and 15.5-fold variability, respectively, with genotype-specific differences between carriers of distinct compound polymorphisms. AChE, BChE and arylesterase but not paraoxonase activity increased with age, depending on leucine at PON1 position 55. In contrast, carriers of PON1 M55 displayed decreased arylesterase activity independent of the - 108 promoter polymorphism. Predicted structural consequences of the PON1 L55M substitution demonstrated spatial shifts in adjacent residues. Molecular modelling showed substrate interactions with the enzyme variants, explaining the changes in substrate specificity induced by the Q192R substitution. Intriguingly, PON1, but not BChE or arylesterase, activities displayed inverse association with AChE activity. Our findings demonstrate that polymorphism(s) in the adjacent PON1 and ACHE genes affect each other's expression, predicting for carriers of biochemically debilitating ACHE/PON1 polymorphisms adverse genome-environment interactions.

Acetylcholinesterase↗

PubMed2004

Pituitary apoplexy occurring during large volume liposuction surgery.

A 50-year-old woman developed headache and right-sided ophthalmoplegia upon awakening from general anesthesia after liposuction surgery on her abdomen, hips, and thighs. Neuroimaging showed hemorrhage within a previously undiagnosed pituitary adenoma. The confirmatory surgical specimen contained areas of gross infarction and hemorrhage. The anesthesia record revealed intraoperative reduction of systolic blood pressure to 90 mm Hg for 30 minutes from a baseline of 120 mm Hg. This first reported case of pituitary apoplexy during liposuction surgery probably resulted from intraoperative hypotension attributed to a combination of general anesthesia, the use of subcutaneous lidocaine, sequestration of plasma in injured tissues, and blood loss.

Abdomen↗

PubMed2003

The use of advanced simulation in the training of anesthesiologists to treat chemical warfare casualties.

UNLABELLED: Training anesthesiologists to treat nerve gas intoxication in a mass casualty scenario is a complicated task. The scenario is an unfamiliar medical situation involving the need to decontaminate patients before providing definitive medical treatment, and the need for physical protection to the medical team before decontamination. We describe the development of a simulation-based training program. In one site of a virtual hospital, anesthesiologists were trained in initial airway and breathing resuscitation before decontamination while wearing full protective gear. In another site, they were trained in the treatment of critically-ill patients with combined conventional and chemical injuries or severe intoxication. Intubation simulators of newborn, pediatric, and adult patients, advanced full-scale simulators, and actors simulating patients were used. Initial airway, breathing, and antidotal treatment were performed successfully, with or without full protective gear. The gas mask did not interfere with orotracheal intubation, but limited effective communication within the medical team. Chemical protective gloves were the limiting factor in the performance of medical tasks such as fixing the orotracheal tube. Twenty-two participants (88%) pointed out that the simulated cases represented realistic problems in this scenario, and all 25 participants found the simulated-based training superior to previous traditional training they had in this field. Using advanced simulation, we were able to train anesthesiologists to treat nerve gas intoxication casualties and to learn about the limitations of providing medical care in this setting. IMPLICATIONS: Advanced medical simulation can be used to train anesthesiologists to treat nonconventional warfare casualties. The limitations of medical performance in full protective gear can be learned from this training.

Anesthesiology↗

PubMed2002

Simulation-based training of medical teams to manage chemical warfare casualties.

With chemical warfare becoming an imminent threat, medical systems need to be prepared to treat the resultant mass casualties. Medical preparedness should not be limited to the triage and logistics of mass casualties and first-line treatment, but should include knowledge and training covering the whole medical spectrum. In view of the unique characteristics of chemical warfare casualties the use of simulation-assisted medical training is highly appropriate. Our objective was to explore the potential of simulator-based teaching to train medical teams in the treatment of chemical warfare casualties. The training concept integrates several types of skill-training simulators, including high tech and low tech simulators as well as standardized simulated patients in a specialized simulated setting. The combined use of multistimulation modalities makes this maverick program an excellent solution for the challenge of multidisciplinary training in the face of the looming chemical warfare threat.

Chemical Warfare↗

PubMed2002

[Personal protection against biological warfare agents].

Exposure to biological warfare agents may occur in several ways, the most prominent being aerosol infection, droplet infection, common component infection and via physical contact. These agents may enter the body through the respiratory tract, mucous membranes and through the skin. The mechanism of exposure and the route of entry of the specific agent will dictate the appropriate protection required. Available protective equipment include respiratory protective devices, full face protective masks and surgical masks for respiratory protection, battle dress overgarments, protective gloves and overboots for skin protection. Full protection is needed when the agent has not been identified. When the biological agent is known, the protective measures should be determined by its characteristics. Protection may include several levels of precautions: standard risk, aerosol infection, droplet infection and contact infection. This paper describes the routes of exposure to biological warfare agents, the available protective equipment and the precautions needed when treating biowarfare casualties.

Biological Warfare↗

PubMed2002

[Biological agents turning into weapons].

The use of biological agents as weapons is a well-known and established fact in the modern world. Biological warfare can be used both in terrorist events and in war and they pose a real threat and a formidable challenge to the defender. Biological weapons, in their various forms such as germs, viruses or toxins, can harm both living creatures and their surroundings. The relative simplicity of their production and use, compared to other non-conventional weapons, renders them to be a highly accessible system that can cause numerous casualties. Therefore, it is extremely important to study the threat and learn its characteristics, so as to be appropriately prepared in order to minimize potential damage. This review summarizes the characteristics of biological weapons (physical and biological), the means of use in bioterrorism and war, the advantages and disadvantages, comparisons to other non-conventional weapons and both tactical and strategical uses.

Biological Warfare↗

PubMed2002

[The history of biological warfare].

Selected events in the history of biological weapons are highlighted to increase the physician's awareness of this crucial threat. The deliberate use of biological substances originated in antiquity and has pervaded the history of human wars throughout time until the 21th century. The history of biological warfare is difficult to assess because of a number of confounding factors. These include the difficulty in verification of allegation, the use of the threat of this weapon for propaganda purposes, the lack of microbiological or epidemiological data, and the incidence of natural occurring endemic or epidemic diseases during hostilities. Although it may be problematic to verify at times, the use of such weapons has not been limited to national armies or militia. Frustrated civilians, terrorists and even physicians have used biological substances to promote their interests. Today, the biological threat has become more serious. It's potency, cost-effectiveness, and the ability to manufacture and deploy it with little sophistication, or under the semblance of legitimate commercial endeavors, will ensure that biological weapons remain a constant threat to human health.

Biological Warfare↗