Provider-Level Characteristics Associated With Adolescent Varicella, Meningococcal, and Human Papillomavirus Immunization Initiation.

PURPOSE: We examined patient- and provider-level factors associated with initiation of three adolescent immunizations among 13 to 18 year olds in an adolescent primary care clinic. METHODS: Data were extracted retrospectively from medical records. Logistic regression models identified associations with immunization initiation. Post hoc analyses stratified by gender were conducted to examine provider-type contribution to human papillomavirus (HPV) immunization initiation. RESULTS: Among 2932 adolescents, rates of meningococcal and varicella immunization initiation differed by age. Girls were more likely to have initiated HPV immunization than boys. The probability of girls initiating HPV immunization was the same when last seen by advanced practice nurses (APNs) versus physicians, but the probability of boys initiating HPV immunization was lower when last seen by APNs. CONCLUSIONS: Differences in HPV immunization initiation were observed between genders, and for boys, between APN versus physician at last clinic visit. This may reflect changes to HPV immunization recommendations for boys and APNs having shorter clinic visits.

Enhanced deoxyribozyme-catalyzed RNA ligation in the presence of organic cosolvents.

Deoxyribozyme and aptamer selections are typically conducted in aqueous buffer solutions. Using nonaqueous cosolvents in selection experiments will help expand the activity of deoxyribozymes with non-oligonucleotide substrates and will allow identification of new aptamers for nonprotein targets. We undertook in vitro selections utilizing a small amount of methanol in the reaction to keep the herbicides alachlor and atrazine in solution with the goal of identifying deoxyribozymes that require these herbicides for activity. The resulting deoxyribozymes successfully catalyze RNA ligation, but do not require alachlor or atrazine. Surprisingly, some of these deoxyribozymes displayed better catalytic activity in the presence of methanol over just aqueous buffer. We investigated several organic cosolvents to see if this enhancement was limited to methanol and found that other cosolvents, including ethanol, DMSO, and DMF, supported activity; in some cases, greater enhancement was observed. On the basis of these results, we tested two other previously identified RNA-ligating deoxyribozymes to assess their tolerance of cosolvents and determined that different deoxyribozymes showed different responses to the cosolvents. Our results demonstrate that deoxyribozymes can tolerate and, in some cases, display enhanced activity in alternative solvent conditions. These findings will facilitate the development of responsive deoxyribozyme systems utilizing components with limited water solubility.

Development of an electrochemical insulin sensor based on the insulin-linked polymorphic region.

Here we report the design and fabrication of an electrochemical aptamer-based (E-AB) sensor for detection of insulin. The aptamer used in this study is the insulin-linked polymorphic region (ILPR) sequence, a G-rich sequence that presumably undergoes ligand-induced folding to form a G-quadruplex in presence of insulin. Our circular dichroism data, however, suggests that the ILPR sequence, even in absence of the target, is predominantly in a G-quadruplex-like form. Insulin binding, however, has shown to further induce the formation of the G-quadruplex. To evaluate the potential of the ILPR sequence as a biosensing element, we constructed two E-AB insulin sensors that are identical in all aspects but the location of the methylene blue (MB) redox label. We find that the sensor fabricated with internal MB-modified probes (In-IT) shows enhanced sensing behavior when compared to one fabricated using terminal-MB modified probes (In1). The improvements observed with the In-IT sensor could be attributed to the more effective obstruction of electron transfer upon insulin binding. Overall, both sensors perform well, affording a detection limit of 10 nM and 50 nM for the In-IT and In1 sensors, respectively.