The presence of Waddell signs depends on age and gender, not diagnosis.

AIMS: The aim of this study was to determine if positive Waddell signs were related to patients' demographics or to perception of their quality of life. PATIENTS AND METHODS: This prospective cross-sectional study included 479 adult patients with back pain from a university spine centre. Each completed SF-12 and Oswestry Disability Index (ODI) questionnaires and underwent standard spinal examinations to elicit Waddell signs. The relationship between Waddell signs and age, gender, ODI, Mental Component Score (MCS), and Physical Component Score (PCS) scores was determined. RESULTS: Of the 479 patients, 128 (27%) had at least one positive Waddell sign. There were significantly more women with two or more Waddell signs than men. The proportion of patients with at least one positive Waddell sign increased with age until 55 years, and then declined rapidly; none had a positive sign over the age of 75 years. Functional outcome scores were significantly worse in those with a single Waddell sign (p < 0.01). With one or more Waddell signs, patients' PCS and ODI scores indicated a perception of severe disability; with three or more Waddell signs, patients' MCS scores indicated severe disability. With five Waddell signs, ODI scores indicated that patients perceived themselves as crippled. CONCLUSION: Positive Waddell signs, a potential indicator of central sensitization, indicated a likelihood of having functional limitations and an impaired quality of life, particularly in young women. Cite this article: Bone Joint J 2018;100-B:219-25.

Microdosimetry in 3D realistic mitochondria phantoms: Geant4 Monte Carlo tracking of 250keV photons in phantoms reconstructed from microscopic images.

Mitochondria are considered to be sensitive radiation targets since they control processes vital to the cell's functioning. These organelles are starting to get attention and some studies are investigating the radiation dose inside them. In previous studies, mitochondria are represented as simple ellipsoids inside the cell not taking into consideration the complexity of their shape. In this study, realistic phantoms are built based on deconvolved widefield fluorescent microscopic images of the mitochondrial networks of fibroblast cells. The phantoms are imported into Geant4 as tessellated volumes taking into account the geometrical complexity of these organelles. Irradiation with 250keV photons is performed and the lineal energy is calculated. The lineal energy distributions inside the produced phantoms are compared with those calculated inside simple volumes, a sphere and an ellipsoid, where the effect of the shape and volume is clearly seen on lineal energies.

Increasing the use of bleach and condoms among injecting drug users in Denver: outcomes of a targeted, community-level HIV prevention program.

OBJECTIVE: To evaluate the impact of an HIV risk-reduction program among injecting drug users (IDU) in Denver, Colorado. DESIGN: A targeted, community-level intervention study with multiple, time-phased, cross-sectional measurements assessing HIV high-risk behaviors among IDU in intervention and comparison sites. SETTING: Neighborhoods with high IDU prevalence in Denver, Colorado (intervention site) and Long Beach, California (non-intervention comparison site). PARTICIPANTS: Street-recruited IDU who had injected drugs in the previous 30 days and shared injection equipment in the previous 60 days to evaluate the use of bleach to clean injection equipment; or had sexual intercourse in the previous 30 days, to evaluate condom use. INTERVENTION: A prevention program in which peer volunteers were recruited and trained to distribute and discuss intervention kits that included condoms, bleach bottles and role model stories. MAIN OUTCOME MEASURES: Multiple cross-sectional surveys were conducted in the intervention and comparison sites to assess the impact of the intervention on the consistent use of bleach before sharing injection equipment and the consistent use of condoms for vaginal intercourse with steady and occasional partners. RESULTS: Between February 1991 and December 1993, 1997 IDU were interviewed, 890 at the intervention site and 1107 at the comparison site. In contrast to the comparison site, subjects from the intervention site reported significant increases in consistent use of bleach [odds ratio (OR), 2.6; 95% confidence interval (CI), 1.3-5.1; P < 0.001], and consistent use of condoms with occasional partners (OR, 13.6; 95% CI, 3.2-58.0; P < 0.001). CONCLUSION: This targeted, peer-based intervention was associated with significant HIV risk reduction among IDU in Denver and may be useful in other communities at risk for HIV infection.

Building a peer network for a community level HIV prevention program among injecting drug users in Denver.

As part of a multi-site Centers for Disease Control and Prevention-funded initiative, a community-level HIV prevention project targeting injection drug users was implemented in the FivePoints community in Denver, Colorado. The protocol for the initiative included the use of peer networks to conduct outreach and disseminate intervention materials to injecting drug users. Since April 1993, project staff established a peer network of 119 participants who distribute approximately 3,000 materials per month.

Utility of paired blood cultures and smears in diagnosis of disseminated Mycobacterium avium complex infections in AIDS patients.

For 273 patients evaluated for disseminated Mycobacterium avium complex infection, a total of 1,047 mycobacterial blood cultures (MBCs) were submitted; the M. avium complex was recovered from 140 (13%) of the specimens. Results for the paired MBCs were highly concordant: in 392 of 462 (85%) culture sets, both MBCs were negative, in 53 of 462 (11%) sets, both MBCs were positive, and in only 17 of 462 (4%) sets was one culture positive and the other negative. Acid-fast smears were done on sediments from 671 specimens; smears were positive for 4 of 98 (4%) cultures that grew the M. avium complex. A single MBC should be obtained and then repeated if negative and disseminated M. avium complex infection is still clinically suspected. Use of direct acid-fast smears of sediments is not a reliable means of detecting mycobacteremia.