Barriers to genetic testing among persons at risk for alpha-1 antitrypsin deficiency.

The alpha coded testing (ACT) study offers free and confidential testing for alpha-1 antitrypsin deficiency (AATD) and includes surveys to provide data to study the psychosocial correlates of genetic testing. The purpose of the current study is to better understand reasons why some individuals complete genetic testing while others do not. Survey measures were compared between participants who requested and returned a genetic test for AATD (n = 703), and a random sample of individuals who requested a test kit, but did not return it within 3 months of their request (n = 83). Increasing decile of age (odds ratio [OR] = 0.74 [95% confidence interval = 0.60-0.82]) and fingerstick fear (OR = 0.74 [0.60-0.93]) were associated with a decreased likelihood of returning the test, while assurance of confidentiality was associated with an increased likelihood (OR = 1.26 [1.01-1.57]) of returning the genetic test. General anxiety as measured by the Beck Anxiety Inventory, family functioning as measured by the general functioning subscale of the Family Assessment Device, and stress induced by genetic testing as measured by the Impact of Events Scale did not significantly differ between responder groups (p = not significant). Results of this study help characterize factors driving genetic testing in AATD and may offer insight into population responses with other genetic tests.

Oxytetracycline does not cause growth promotion in finfish.

Until recently, use of antibiotics to enhance terrestrial animal growth performance was a common, U.S. Food and Drug Administration (FDA)-approved, but controversial practice. There are no FDA-approved production claims for antibiotic drug use in fish, but it is a common misconception that antibiotics are widely used for this purpose in U.S. aquaculture. Antibiotics are not thought to be effective growth promoters in fish, but there is little quantitative data available to address whether there are growth-promoting effects that might incentivize the use of antibiotics in this way, despite legal prohibitions. Therefore, this study was conducted to determine if oral administration of oxytetracycline, an antibiotic with known growth-promoting effects in terrestrial livestock, has a similar effect when applied to channel catfish Ictalurus punctatus, hybrid striped bass Morone chrysops × M. saxatilis, Nile tilapia Oreochromis niloticus, or rainbow trout Oncorhynchus mykiss. Oxytetracycline products with production claims are typically applied at doses substantially lower than the approved therapeutic doses for the same products. Medication (0, 0.24, or 1.2 g oxytetracycline dihydrate kg-1 feed) and feeding rates (3% BW d-1) were selected to achieve target daily doses of 0, 16, or 80 mg kg-1 fish representing control, subtherapeutic, and therapeutic treatments. Replicate groups of fish (N = 4) were fed accordingly for 8 wk. Overall, oral administration of oxytetracycline did not affect survival or promote growth of the selected taxa, with no significant differences observed for weight gain, feed conversion ratio, or specific growth rate (P > 0.05 in all cases). Few differences were observed in organosomatic indices and in the frequency of tissue abnormalities; where present, these differences tended to suggest a negative effect of long-term dietary exposure to oxytetracycline. These data demonstrate that there is no benefit to dietary supplementation with oxytetracycline for nontherapeutic purposes in a range of economically important finfish species. As such, our results indicate there is little incentive to misuse oxytetracycline products for purposes of growth promotion in U.S. aquaculture.