Characterization of replication-competent adenovirus isolates from large-scale production of a recombinant adenoviral vector

Replication-deficient adenoviral vectors have been developed for the delivery of DNA sequences encoding a variety of proteins intended for the management of disease through gene therapy. One concern is the occurrence of replication-competent adenovirus (RCA) in the population of replication-deficient adenoviral vectors as a result of recombination or contamination. To address this concern, it is necessary to determine the frequency of occurrence and to fully characterize the molecular structure and biological infectivity of RCA. rAd/p53 is a pIX-deleted p53 gene therapy vector that is designed to lower the RCA occurrence and to deliver the tumor suppressor gene p53 for treatment of various cancers. Multiple preparations of the replication-deficient adenoviral vector rAd/p53 were tested for the presence of RCA, employing a sensitive biological assay. Single plaques from RCA-positive preparations of rAd/p53 were isolated for molecular characterization. All of the RCA isolates displayed a single unique structure that contains the complete E1 sequence of adenovirus type 5 but lacks the p53 sequence. The detailed sequence analysis of the RCA suggests that it is most likely generated as a result of recombination events between the rAd/p53 DNA and the 293 host adenoviral sequence. Results from viral infectivity analysis by flow cytometry demonstrate no substantial difference in infectivity of RCA, rAd/p53, and wild-type adenovirus type 5 in 293 cells.

Flumazenil in drug overdose: randomized, placebo-controlled study to assess cost effectiveness

OBJECTIVE

To investigate cost effectiveness of administration of flumazenil to patients presenting with suspected acute drug overdose.

DESIGN

Double-blind, prospective, placebo-controlled randomized study.

SETTING

University teaching hospital.

PATIENTS

Forty-three adults presenting with suspected drug overdose and having a Glasgow Coma Scale (GCS) score of <13. Patients with known benzodiazepine/tricyclic ingestion were excluded.

INTERVENTIONS

Intravenous administration of flumazenil (up to 2 mg) or placebo.

MEASUREMENTS AND MAIN RESULTS

Individual patient costs were assessed and data aggregated for each treatment group. Major diagnostic and therapeutic interventions were recorded and between group comparisons performed. Clinical response to study drug administration was assessed by obtaining pre- and post-drug GCS scores and observation of the patient for at least 180 mins for signs of resedation. Aggregate cost or number of major diagnostic and therapeutic interventions were not different between groups. Patients randomized to the flumazenil group showed a marked increase in GCS score (7.4 to 11.8) compared with those in the placebo group (8.2 to 8.6).

CONCLUSION

Use of flumazenil in intentional drug overdose of unknown etiology is not cost effective.

Attitudes and practices of pharmacy managers regarding needle sales to injection drug users

OBJECTIVE

To determine Louisiana pharmacy managers' attitudes and practices regarding needle and syringe sales to suspected injection drug users (IDUs) without prescriptions, and to assess which factors affect their decisions to sell nonprescription needles and syringes.

DESIGN

Cross-sectional mail survey.

SETTING

The six most populous cities of Louisiana.

PARTICIPANTS

Pharmacy managers with active permits not affiliated with large hospitals or institutions.

MAIN OUTCOME MEASURES

Selling nonprescription needles to suspected IDUs, willingness to sell nonprescription needles to suspected IDUs, and reasons for not selling nonprescription needles to suspected IDUs.

RESULTS

Approximately one-fourth of the respondents reported that they had sold needles and syringes to suspected IDUs without a prescription. The most frequently cited reason for not selling was fear of increasing drug use; however, many of these pharmacists reported that they would conduct a sale if the customer had a referral from an agency or clinic.

CONCLUSION

Pharmacists can assist in the prevention of HIV transmission through nonprescription needle sales to IDUs. This role can be promoted through education of pharmacists and development of referral systems for IDUs.

Comparison of flow cytometry and laser scanning cytometry for the intracellular evaluation of adenoviral infectivity and p53 protein expression in gene therapy

The determination of recombinant adenoviral (rAd) infectivity and p53 protein expression is important for the evaluation of rAd vectors containing the p53 gene (rAd-CMV-p53) for gene therapy. We have previously reported that rAd5-CMV-p53 vectors can be assessed for infectivity and concomitant p53 protein expression in single- and two-color assays using intracellular staining methodology and flow cytometric analysis. We have compared the flow cytometry-based assays for rAd infectivity (hexon protein) and p53 protein expression with the new slide-based laser scanning cytometry (LSC). We report that LSC analysis of rAd-CMV-p53-infected human 293 cells correlated very well with flow cytometric analysis across a wide range of viral infectivity for both infectivity assessment (r2 = 0.97) and p53 protein expression (r2 = 0.96). Absolute values for infective titer and p53 protein expression titer from an rAd5-CMV-p53 production batch were similar and within experimental error with the two different analytical methods. Finally, bivariate format analysis of rAd-CMV-p53-infected cells revealed comparable results between LSC and flow cytometric analysis. LSC is a reliable and useful tool for the intracellular staining for adenoviral hexon protein expression for determining infectivity and for p53 protein expression from an expressed p53 transgene.

Age limitation on provision of orthopedic therapy and orthognathic surgery

Canadian orthodontists were surveyed by mail to determine the latest skeletal age at which they would recommend orthopedic therapy and orthognathic surgery and the earliest at which they would recommend orthognathic surgery. For the purposes of this introductory study, orthopedic therapy implied stimulation of physiologic response using appliance force, without specification of appliance type. Response rate from 512 orthodontists was 65% (n = 334), with the response rate by item varying from 92% to 95%. By Greulich and Pyle standards, the latest recommended age for orthopedic therapy was at 97% completion of skeletal growth (females 13.5 years, males 15 years), whereas the earliest recommended age for orthognathic surgery was when skeletal growth is 99% complete (females 14.9 years, males 16.5 years). Surgery would be recommended by 32% of respondents for a patient before the age of 8 years, if deformity is severe. For orthognathic surgery, respondents either perceived no age maximum or recommended 69 years, the maximum age on the questionnaire item. Orthodontists' traits influenced recommendations for timing treatment.

TMJ internal derangement and adolescent craniofacial morphology: a pilot study

Intrinsic and extrinsic factors influence the growth of mandibular condylar cartilage. Local environmental factors, such as temporomandibular disc displacement, may alter condylar cartilage growth resulting in facial changes. The aim of this study was to determine if there was an association between identifiable altered craniofacial morphology and disc displacement. Magnetic resonance imaging (MRI) was employed to determine disc position in 25 preorthodontic adolescent patients (mean age 12.8 years, range 10 to 17 years). Magnetic resonance imaging and lateral cephalometric radiography were performed with the teeth held in centric occlusion by means of a polyvinylsiloxane bite registration. Radiographs were traced and variability between tracings within patients was insignificant for all variables (p > 0.04) except Co-Go, S-Go, and SN/Go-Me (p < 0.01). For each patient, 10 linear, 4 angular, and 3 ratio measurements were compared with an age- and sex-matched population in the Craniofacial Growth Series. Multiple regression analysis showed positive and negative associations between disc displacement and cephalometric variables. R-square value was .91 for the left TMJ and .82 for the right. Disc displacement in an adolescent population may be associated with altered craniofacial morphology.

Asking the academics

Assumptions are no match for real consultation. As part of the MRI, the BDJ conducted a special survey to see if academic dentists could predict the primary care research priorities of general dental practitioners. How would the predictions differ from the priorities of the GDPs themselves?

The carboxyl-terminal zinc-binding domain of the human papillomavirus E7 protein can be functionally replaced by the homologous sequences of the E6 protein

The carboxyl-terminus is necessary for the functional and structural integrity of the human papillomavirus (HPV) E7 oncoprotein. Since many mutations in this domain of E7 result in the formation of unstable proteins, we have evaluated the importance of this region by replacing it with structurally related domains derived from HPV E6 proteins. Biological analysis of these mutant chimeric E7/E6 proteins showed that they retained E7-specific biological activities including cooperation with the ras oncogene to transform primary baby rat kidney cells and transcriptional activation of an E2F responsive reporter plasmid. One of the chimeric proteins was impaired in its ability to physically disrupt pRB/E2F complexes in vitro suggesting that there are defined molecular determinants in the carboxyl-terminus of E7 for this activity. In contrast, none of these proteins exhibited E6-like properties including binding to p53 and/or degradation of associated proteins.