Traffic-related air pollution
The number of premature deaths in Canada attributable to air pollution may be 9 times greater than the number attributable to motor vehicle collisions. Traffic-related air pollution is causally related to worsening asthma and strongly linked to adult-onset asthma, cardiovascular disease and lung cancer. Integrated population-level and geographic mitigation strategies would reduce traffic-related air pollution and improve health. See Commentary, page 1557
Crystal meth predicts injection drug use
Noninjection use of crystal methamphetamine predicted subsequent injection initiation. Also, crystal methamphetamine was the most commonly used drug at the time of first injection. In this prospective cohort study, Werb and colleagues assessed patterns of first-injection drug use among street-involved youth enrolled in the At-Risk Youth Study in Vancouver. Their findings highlight the importance of effective public health measures and mobilization of addiction resources to limit the progression to injection drug use in this susceptible population. See Research, page 1569
Better outcomes in brain injury
The percentage of patients with brain injury who progress to neurologic death has decreased over time, especially among those with head trauma. Kramer and colleagues based their findings on a prospective cohort analysis of 2788 adult patients admitted to a neurocritical intensive care unit with brain injury in Alberta over a 10-year period. These findings may indicate ongoing improvement in the management of brain injury; however, there may be important implications for organ donation in the region. See Research, page E838
Alopecia
In the most common type of hair loss (e.g., alopecia areata and male pattern baldness), the hair follicle bulbs are not destroyed and so hair growth is potentially possible with treatment. In the group of disorders that comprise cicatricial alopecia, the hair follicle is irreversibly destroyed and replaced by fibrous tissue. Early identification and treatment to prevent further hair loss is essential, say Filbrandt and colleagues. See Review, page 1579
A 35-year-old man presents with a patch of hair loss on his parietal scalp. What is causing this hair loss? Will the patch get larger? Are there any effective treatments? Aslam and Harries look at the diagnosis and management of alopecia areata. See Practice, page 1591
Severe transient neutropenia
A 30-year-old man presented to the emergency room with fever, vomiting, diarrhea and abdominal pain. He had a history of intravenous morphine and cocaine use. His leukocyte count was low on admission with severe neutropenia, but rebounded by the next day. Was this a viral infection? Levamisole toxicity secondary to adulterated cocaine? Or perhaps endocarditis? Hudgins and Wong walk us through the process until the final diagnosis is made. See Practice, page 1593
Urinary obstruction and magnetic balls
A 26-year-old man presented with a 3-day history of decreased urine output, following the insertion of magnetic beads into his urethra as part of sexual activity with his partner. With increasing interest in sexually adventurous activities, such as male urethral stimulation, clinicians should consider the possibility of foreign object obstruction in the context of lower urinary tract symptoms, say Brooks and colleagues. See Practice, page 1597
Bicuspid aortic valve disease
Bicuspid aortic valves are more than just an anatomic variant. About one-third of initially asymptomatic patients will experience a major cardiovascular event or require surgery over 20 years. Lifelong clinical follow-up and serial echocardiography are required, say Losenno and Chu. See Practice, page 1599
Holiday reading
CMAJ shares the following treats this year: a reflection on seasonal gifts, fiery poems, a doc trapped in a cat’s body, and a look at the effects of gluten-filled beer on a doctor with celiac disease. See Holiday Reading, page 1603