Linezolid: a review of its properties, function, and use in critical care

Seyed MohammadReza Hashemian,1,2 Tayebeh Farhadi,1 Mojdeh Ganjparvar3 1Chronic Respiratory Disease Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Clinical Tuberculosis and Epidemiology Research Center, National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran; 3Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran Abstract: Linezolid can be considered as the first member of the class of oxazolidinone antibiotics. The compound is a synthetic antibiotic that inhibits bacterial protein synthesis through binding to rRNA. It also inhibits the creation of the initiation complex during protein synthesis which can reduce the length of the developed peptide chains, and decrease the rate of reaction of translation elongation. Linezolid has been approved for the treatment of infections caused by vancomycin-resistant Enterococcus faecium, hospital-acquired pneumonia caused by Staphylococcus aureus, complicated skin and skin structure infections (SSSIs), uncomplicated SSSIs caused by methicillin-susceptible S. aureus or Streptococcus pyogenes, and community-acquired pneumonia caused by Streptococcus pneumoniae. Analysis of high-resolution structures of linezolid has demonstrated that it binds a deep cleft of the 50S ribosomal subunit that is surrounded by 23S rRNA nucleotides. Mutation of 23S rRNA was shown to be a linezolid resistance mechanism. Besides, mutations in specific regions of ribosomal proteins uL3 and uL4 are increasingly associated with linezolid resistance. However, these proteins are located further away from the bound drug. The methicillin-resistant S. aureus and vancomycin-resistant enterococci are considered the most common Gram-positive bacteria found in intensive care units (ICUs), and linezolid, as an antimicrobial drug, is commonly utilized to treat infected ICU patients. The drug has favorable in vitro and in vivo activity against the mentioned organisms and is considered as a useful antibiotic to treat infections in the ICU. Keywords: linezolid, intensive care unit, MRSA, VRE, antibacterial drug

Epidemiological study of child casualties of landmines and unexploded ordnances: A national study from Iran

Background Despite landmine-risk education programs and extensive demining activities on the Western border of Iran, landmines and unexploded ordnance (UXOs) still cause civilian and child casualties three decades after the Iraq-Iran war (1980-1988). The objective of this study was to understand the epidemiological patterns and risk factors of injury in child casualties of landmines and UXOs in Western and Southwestern Iran. Methods Children who were 18 years old or younger at the time of study and who sustained injuries from landmines and UXOs were identified through a search at the Iranian National Veterans Registry. These children participated in a 5-day gathering. The information on socioeconomic status, health-related issues, quality of life, health care utilization, and clinical profiles concerning the landmine and UXO injuries were collected. The method of data collection consisted of three component surveys: health interview, social survey, and medical examinations. Social surveys and health interviews were conducted in a face-to-face method by utilizing a questionnaire consisting of 39 questions addressing household and individual components, including information on time and type of injuries, physical activity, mental health, and quality of life. A comprehensive team of physicians in different subspecialties evaluated and examined children to assess the current medical and psychiatric conditions and physical activity, and recommended and arranged further medical, rehabilitation, or surgical planning. Results Seventy-eight child casualties were identified and participated in the study. The mean age of the participants at the time of study was 16.11 years old (SD=2 years). The mean age of victims at the time of injury was 8.2 years (SD=3.12 years; ranged from 2 to 15 years old). Sixty-seven (85.9) of the children were male. Provinces of Kurdistan and Kermanshah had the highest number of casualties, with a total number of 54 children (68.3). Eighty percent of the injuries were caused by landmines, and UXO explosions were reported in 20 of the cases. Overall, 24 children (30) had received some landmine-risk education before or after the events. Sixty percent of the explosions had happened in the morning between 9:00 am and 12:00 pm. Playing and grazing livestock were the most prevalent activities/reasons at the time of injury, which were reported in 77 of the subjects. Sixty-three percent of incidents had multiple casualties and in only 13 explosions were the children the only victims of the explosion. The most prevalent injuries were amputations in 41 subjects (52.56), followed by hearing loss in 23 subjects (29.5). Amputations were more common in upper extremities (62) than in lower extremities (38). Conclusion Landmines and UXOs comprise a significant safety hazard to the children living in the Western border of Iran decades after the Iraq-Iran War. The large number of injuries and lack of risk training among victims suggest that landmine cleanings and landmine-risk education should be age-specifically targeted and expanded substantially. © World Association for Disaster and Emergency Medicine 2015

Mental health disorders in child and adolescent survivors of post-war landmine explosions

BACKGROUND: To describe the mental health status of 78 child and adolescent survivors of post-war landmine explosions. METHODS: Child and adolescent survivors of landmine explosions who were younger than 18 years old at the time of the study were identified and enrolled in this study. The mental health status of the participants was assessed by general health assessment and psychiatric examinations. Psychiatric assessment and diagnosis were undertaken using the Diagnostic and Statistical Manual for mental disorders (DSM-IV) criteria. A psychiatrist visited and interviewed each survivor and identified psychiatric disorders. RESULTS: Seventy-eight child and adolescent survivors with a mean age of 16.11 ± 2 years old were identified and agreed to participate in the study. The mean age of the victims at the time of injury was 8.2 ± 3.12 years old (range 2–15). Thirty-seven (47.4 %) of the adolescent survivors suffered from at least one psychiatric disorder. Twenty-nine survivors (37.1 %) were newly diagnosed and needed to start medication and psychiatric treatment. The most common findings were anxiety disorders (34.6 %), including posttraumatic stress disorder (PTSD) in 20 (25.6 %), and generalized anxiety disorder (GAD) in 7 (9 %) subjects. Mild-Moderate depression was found in 5 (6.4 %) subjects. No personality disorders were observed, and two patients suffered from mental retardation. The study results revealed a significant association between age of casualty, duration of injury and limb amputation, and types of psychological disorders. CONCLUSION: Child and adolescent survivors of landmine explosions had a high prevalence of psychiatric disorders