Replicate plating: does it increase reliability?

As a part of a clinical study to evaluate the antibacterial effect of a topically applied erythromycin gel, microbiological specimens were taken from two groups of patients: one group using 2% erythromycin gel and the other group using a placebo gel. These specimens were plated in triplicate using a common source on bacteriological media using standard procedures. After the appropriate incubation times, the numbers of aerobic and anaerobic organisms were counted separately from each of three plates.

Acute postural change--a novel approach to blood pressure tracking in children.

Among 1443 children, aged 5 to 18, followed for five consecutive years, we identified 68 who tracked consistently in the lowest blood pressure (BP) quartile and 114 in the highest. BP and corresponding heart rate were taken with subjects in the supine, sitting and erect postures. BP quartiles were established for each height category.

Trends of lung cancer in northern Florida.

Although the entire state of Florida has experienced an increase in lung cancer mortality during the present decade, a differential rise among white men has been observed in Duval, a county in its northeastern region. This increase is not explained by population changes or migration of cases. It is hypothesized that an industrial exposure involving paper and pulp manufacturing, shipbuilding, or petroleum may account for these findings.

A comparison of growth: Spanish-surnamed with non-Spanish-surnamed children.

Weight, height, and head circumference measurements of 4,167 Spanish-surnamed school-aged children were compared with similar data from 2,322 non-Spanish surnamed children who resided in the same Denver, Colorado neighborhoods. These data were also compared with data from six other studies. Both male and female Spanish-surnamed children were found to weigh less, be shorter, and have smaller head circumferences than non-Spanish-surnamed children living in the same Denver neighborhoods.