The criminal purchase of firearm ammunition.

OBJECTIVE: Laws that prohibit certain individuals from owning firearms also pertain to ammunition. Whereas retail sales of firearms to criminals are regularly disrupted by instant background checks, sales of ammunition are essentially unchecked and the rate at which criminals acquire ammunition is unknown. This research describes the ammunition market and estimates the rate at which criminals are acquiring ammunition. DESIGN: Criminal background checks conducted on individuals purchasing ammunition in the City of Los Angeles in April and May 2004. SETTING: Los Angeles, CA, USA. SUBJECTS: Ammunition purchasers. MAIN OUTCOME MEASURES: Criminal activity that prohibits one from owning, purchasing, or possessing ammunition. RESULTS: 2.6% (95% CI 1.9% to 3.2%) of ammunition purchasers had a prior felony conviction or another condition that prohibited them from possessing ammunition. During the study period prohibited possessors purchased 10,050 rounds of ammunition in Los Angeles. CONCLUSIONS: These estimates suggest that monitoring ammunition transactions may help reduce the supply of ammunition to criminals and the frequency of injuries from felonious gun assaults. Such a record can also provide information for generating leads on illegal firearm possession.

The collectivity of sexual behaviour.

Human behaviour can be viewed as a collective phenomenon, determined partly by the group to which individuals belong. Collectivities of health behaviour have been found in alcohol consumption, hypertension, obesity, mental illness, and sodium intake in that the average level of risk is associated with the percentage of individuals at extremely high risk.The goal was to investigate whether sexual behaviour may be collectively determined. A cross-sectional US survey was conducted. Across 45 states, the mean number of lifetime sex partners excluding persons with >10, >20, and >40 lifetime partners was strongly associated with the proportion with >10, > 20 and > 40 lifetime sex partners, respectively, among men and women. Sexual activity may represent collectively determined behaviour. If so, interventions to reduce high-risk sexual behaviour to prevent HIV or sexually transmitted diseases (STDs) may be more effective if they address the entire population, rather than target only those at the extremes of risk.

Lack of serum oligoclonal antibody responses to Chlamydophila pneumoniae in multiple sclerosis.

Chlamydophila pneumoniae has been proposed as an aetiological agent in MS via a mechanism involving molecular mimicry. We undertook to investigate whether the presence of CSF oligoclonal IgG OCB or oligoclonal bands correlated with serum IgG raised against C. pneumoniae. Paired serum and CSF of 19 MS patients and 27 control patients with other neurological diseases were studied by IEF and Western blotting. Only 1 of 19 MS patients had serum antibodies against C. pneumoniae compared with 2 of the 26 control patients. This was not significant, leading us to conclude that this study does not support the theory of an association between C. pneumoniae and MS.