Patients with homocystinuria, a rare autosomal recessive disease characterized by very high plasma homocysteine levels, frequently have osteoporosis and fractures — an observation that led the authors to examine the association between homocysteine levels and osteoporotic fracture in the context of normal aging. The multivariable-adjusted relative risk of incident osteoporotic fracture was 1.4 (95 percent confidence interval, 1.2 to 1.7) for each increase of 1 SD in the natural-log–transformed homocysteine level.

Increased homocysteine levels are a strong and independent risk factor for osteoporotic fracture in older adults.

This article examines the association between the total homocysteine concentration and the risk of hip fracture in Framingham Study participants during a median follow-up period of 12.3 years for men and 15.0 years for women. Age-adjusted incidence rates for hip fracture increased progressively from the lowest to the highest quartile of homocysteine. For men in the highest quartile, the risk increased by a factor of almost four, and for women, by 1.9.

Homocysteine concentrations, which are easily modifiable through dietary intervention, may be an important risk factor for hip fracture in older persons.

Concern about the possibility of inadequate resection and recurrent cancer with the use of laparoscopically assisted colectomy prompted this randomized trial comparing laparoscopically assisted with open surgery for colon cancer. The trial involved 863 patients and 66 surgeons at 48 hospitals. Rates of cancer recurrence, operative complications, and survival were similar in the two groups.

The results of this multicenter trial suggest that laparoscopically assisted surgery does not result in higher rates of recurrent cancer and is an acceptable alternative to open surgery for colon cancer.

In this study, the lifetime risk of reactivation tuberculosis among persons in the United States who have had a positive tuberculin skin test was estimated from published data. The lifetime risk is 20 percent or higher among persons with skin-test induration of 10 mm or greater and either human immunodeficiency virus infection or evidence of old, healed tuberculosis.

The treatment of latent infection is a major goal of the strategy for eliminating tuberculosis in the United States; the groups at greatest risk represent the highest priority for treatment. Knowledge of their risk may help to improve compliance among persons for whom treatment of latent tuberculosis is recommended.

This review considers the pathogenesis, scope, and treatment of autoimmune polyendocrine syndromes. Although some of the component disorders such as thyroid autoimmunity and celiac disease are common, others such as Addison's disease and myasthenia gravis are rare.

The recognition that patients diagnosed with multiple autoimmune disorders may have a specific genetic syndrome, may be at increased risk for additional autoimmune disorders, and may have relatives at increased risk should spur the clinician toward early diagnosis and treatment.

A 31-year-old man noted fluctuating, painless testicular enlargement over a period of two months. There was no evidence of feminization, and the levels of the subunit of human chorionic gonadotropin and alpha-fetoprotein were normal. The discussants review the differential diagnosis of testicular enlargement in a young adult, the diagnostic testing needed to establish a diagnosis, and the treatment of the unusual lesion that was ultimately diagnosed.

A recent study shows how a virulence factor of Streptococcus pyogenes activates leukocytes and ultimately damages host tissue.