Host and pathogen response to bacteriophage engineered against Mycobacterium abscessus lung infection

Two mycobacteriophages were administered intravenously to a male with treatment-refractory Mycobacterium abscessus pulmonary infection and severe cystic fibrosis lung disease. The phages were engineered to enhance their capacity to lyse M. abscessus and were selected specifically as the most effective against the subject's bacterial isolate. In the setting of compassionate use, the evidence of phage-induced lysis was observed using molecular and metabolic assays combined with clinical assessments. M. abscessus isolates pre and post-phage treatment demonstrated genetic stability, with a general decline in diversity and no increased resistance to phage or antibiotics. The anti-phage neutralizing antibody titers to one phage increased with time but did not prevent clinical improvement throughout the course of treatment. The subject received lung transplantation on day 379, and systematic culturing of the explanted lung did not detect M. abscessus. This study describes the course and associated markers of a successful phage treatment of M. abscessus in advanced lung disease.

Penetration of ceftiofur into sterile vs. Mannheimia haemolytica-infected tissue chambers in beef calves after subcutaneous administration of ceftiofur crystalline free acid sterile suspension in the ear pinna

The effect of Mannheimia haemolytica infection on the penetration of ceftiofur and desfuroylceftiofur metabolites into tissue chambers was studied in cattle after subcutaneous administration of ceftiofur crystalline free acid sterile suspension (CCFA-SS). Four tissue chambers were implanted subcutaneously in each of 12 calves. Approximately 45 days after implantation, two chambers were inoculated with M. haemolytica (10(6) colony-forming units per chamber) while the remaining two chambers were inoculated with sterile phosphate-buffered saline. Twenty-four hours after inoculation, CCFA-SS was administered subcutaneously in the middle third of the caudal ear pinna of each calf. Chamber fluid and blood samples were collected at predetermined times for 10 days following dosing and analyzed for ceftiofur and desfuroylceftiofur metabolites by high-performance liquid chromatography. Concentrations of ceftiofur and desfuroylceftiofur metabolites in plasma and tissue chamber fluid remained above a threshold of 0.2 microg/mL for at least 8 days. Infected tissue chamber fluid concentrations of ceftiofur and desfuroylceftiofur metabolites were significantly higher than those in non-infected tissue chamber fluid, which correlated with significantly higher total protein concentration in infected tissue chambers. These results indicate that single subcutaneous administration of CCFA-SS at 6.6 mg/kg can be expected to provide effective therapy of susceptible bacterial infections for a period of at least 1 week.

Efficacy of computerized infrared imaging analysis to evaluate mammographically suspicious lesions

OBJECTIVE

The purpose of this clinical trial was to determine the efficacy of a dynamic computerized infrared imaging system for distinguishing between benign and malignant lesions in patients undergoing biopsy on the basis of mammographic findings.

SUBJECTS AND METHODS

A 4-year clinical trial was conducted at five institutions using infrared imaging of patients for whom breast biopsy had been recommended. The data from a blinded subject set were obtained in 769 subjects with 875 biopsied lesions resulting in 187 malignant and 688 benign findings. The infrared technique records a series of sequential images that provides an assessment of the infrared information in a mammographically identified area. The suspicious area is localized on the infrared image by the radiologist using mammograms, and an index of suspicion is determined, yielding a negative or positive result.

RESULTS

In the 875 biopsied lesions, the index of suspicion resulted in a 97% sensitivity, a 14% specificity, a 95% negative predictive value, and a 24% positive predictive value. Lesions that were assessed as false-negative by infrared analysis were microcalcifications, so an additional analysis was performed in a subset excluding lesions described only as microcalcification. In this restricted subset of 448 subjects with 479 lesions and 110 malignancies, the index of suspicion resulted in a 99% sensitivity, an 18% specificity, a 99% negative predictive value, and a 27% positive predictive value. Analysis of infrared imaging performance in all 875 biopsied lesions revealed that specificity was statistically improved in dense breast tissue compared with fatty breast tissue.

CONCLUSION

Infrared imaging offers a safe noninvasive procedure that would be valuable as an adjunct to mammography in determining whether a lesion is benign or malignant.

Challenges faced in recruiting patients from primary care practices into a physical activity intervention trial. Activity Counseling Trial Research Group

BACKGROUND

Special challenges are encountered when clinical trial recruitment targets a physician practice-based population, as opposed to recruiting from the community. Since most published information about recruitment has focused on the latter group, summation of successful primary-care-based recruitment strategies could prove useful for future trials recruiting from this population.

METHODS

The Activity Counseling Trial (ACT) is a multicenter, randomized clinical trial that evaluated approaches to primary care-based interventions to increase physical activity in sedentary adults 35-75 years of age. Fifty-four clinicians from eight practices recruited 874 participants from three U.S. sites. Recruitment challenges that related, in great part, to the primary care setting included: (1) focusing on patients from ACT physician practices who had regularly scheduled or intend-to-schedule appointments within the next year; (2) placing trial staff in the clinical offices for recruitment purposes; and (3) placing trial interventionists in the physicians' offices. Other challenges were related to recruitment of minorities and men.

RESULTS

Patient mailing yielded 43.4% of all randomized participants, followed by office-based questionnaires (32.5%) and direct telephone contact (21.6%). Based on a retrospective cost-effective analysis (indirect costs excluded), the self-administered office-based questionnaire was the least costly strategy for one site ($14/randomized participant), followed by patient mailing at another site ($58). The direct telephone contact method utilized at one site serving primarily a minority population yielded a per randomized participant cost of $80.

CONCLUSIONS

Recruitment of clinical trial participants from practice-based populations requires modification of the strategies used to recruit from the community. Multiple strategies should be employed, followed closely for their respective yields, and adapted as needed.

A comparison of Culture-Free Self-Esteem Scale means from different child and adolescent groups

The Culture-Free Self-Esteem Inventory (CFSEI-2) was administered to 7 groups of children: 84 White Catholic school students from a New Orleans suburb, 78 White rural public school students from Virginia, 62 Hispanic Migrant student from Florida, 90 Aboriginal and White students from an isolated Canadian community, 199 African American students attending an inner city school, 60 Hispanic and White international students from Venezuela, and 61 Innuit students from isolated community in Labrador. The four elder groups also wrote three words to describe themselves (the Adjective Generation Technique [AGT]). Significant differences in responding between groups were found on all CFSEI-2 scales and for AGT favorability means. Although several possible reasons for these results are discussed, we conclude that the CFSEI-2 is not culture-free. Recommendations are: change the title of the test to avoid misrepresentation, limit test usage to elementary school children, develop an adolescent version with age appropriate language, and construct local norms before using the CFSEI-2 to make decisions about a child's self-esteem. To determine relevance of scores, a team of professionals and lay persons should review items from this or any test given to children who may be different from the normative or standardization group.

Acidic residues in the DR beta chain third hypervariable region are required for stimulation of a DR(alpha, beta 1*0402)-restricted T-cell clone

We investigated the minimal requirements for stimulation of an antigen-specific HLA-DR(alpha, beta 1*0402)-restricted T-cell clone (Een217) by using transfectants expressing mutant DR beta chains as APCs. Antigen-specific stimulation of Een217 was induced with transfectants expressing DR(alpha, beta 1*0402) and DR(alpha, beta 1*0403) but not other DR4 subtypes that also bind the peptide recognized by this clone. Analysis of the effects of single amino acid substitutions in the beta chains of each of the DR4 subtypes revealed a requirement for acidic residues in the third HVR, particularly amino acid 71, in stimulation of clone Een217. Functional class II mutants were generated from nonstimulatory DR4 subtype beta chains by acidic residue substitutions within the third HVR. These data define the requirement for negatively charged residues in this region for peptide-induced stimulation of this T-cell clone. The required acidic residues can be located at either position 70, 71, or 74 in the DR beta chain. The negative charge in this segment of the DR beta chain alpha-helix may be required for direct interactions with the T-cell receptor of Een217 or may affect peptide conformation.

Heterozygote ornithine transcarbamylase deficiency presenting as symptomatic hyperammonemia during initiation of valproate therapy

Ornithine transcarbamylase is a mitochondrial urea cycle enzyme. Women with heterozygous ornithine transcarbamylase deficiency may have no symptoms or have episodic, symptomatic hyperammonemia, which can be fatal. We report a previously undiagnosed heterozygote ornithine transcarbamylase-deficient patient who had symptomatic hyperammonemia during initiation of valproate therapy. This is the second such patient reported. Symptomatic hyperammonemia during valproate therapy may indicate ornithine transcarbamylase deficiency. Since valproate inhibits ureagenesis and can be toxic to mitochondria, it should be used extremely cautiously, or not at all, in ornithine transcarbamylase-deficient patients.