To control the effects of confounders which were likely risk factors for Guangxiese HCC, controls were frequently matched to cases based on ethnicity (Han, Minority), sex, age (± 5 years), and hepatic B virus (HBV) and HCV infection.
432 normal controls were frequently matched by age (±5 years) and gender with patients randomly selected from a census of digestion diseases that we had conducted previously from March 2003 to July 2005 in Xinxiang County of Henan Province.
Controls were frequently matched to cases by screening round, single year of birth, and place of residence (single towns with more than 5,000 inhabitants or aggregated rural areas comprising smaller towns).
In normal tissue, the regulation of Myc transcription and turnover is tightly controlled by mitogenic and growth inhibitory cues [ 20], and in tumour cells these controls are frequently lost, either by chromosomal translocations or amplifications, or indirectly by mutations in regulatory pathways.
Since single strain controls are frequently used in these studies [ 9, 14], this may lead to the incorrect identification of the absence of genes associated with the accessory genome and may contribute to the variable success of this technique in identifying different groups of strains within the same species.
Poor postoperative pain control is frequently associated with complications and delayed discharge from a hospital.
The Rb/E2F-regulated G1 checkpoint control is frequently disrupted in cancer cells.
Poor blood pressure control is frequently attributed to low rates of medication adherence.
Evaluation of safety improvement initiatives is notoriously challenging [ 30], and pre-post intervention comparisons with a suitable control is frequently the most realistic approach [ 31].
Also, digestive secretory function (essential for degradation of more complex nutrients) may be qualitatively or quantitatively affected, as neurohumoral control is frequently impaired.
