Quantitative Assessment of the Anatomical Footprint of the C1 Pedicle Relative to the Lateral Mass: A Guide for C1 Lateral Mass Fixation.

STUDY DESIGN: Anatomic study. OBJECTIVES: To determine the relationship of the anatomical footprint of the C1 pedicle relative to the lateral mass (LM). METHODS: Anatomic measurements were made on fresh frozen human cadaveric C1 specimens: pedicle width/height, LM width/height (minimum/maximum), LM depth, distance between LM's medial aspect and pedicle's medial border, distance between LM's lateral aspect to pedicle's lateral border, distance between pedicle's inferior aspect and LM's inferior border, distance between arch's midline and pedicle's medial border. The percentage of LM medial to the pedicle and the distance from the center of the LM to the pedicle's medial wall were calculated. RESULTS: A total of 42 LM were analyzed. The C1 pedicle's lateral aspect was nearly confluent with the LM's lateral border. Average pedicle width was 9.0 ± 1.1 mm, and average pedicle height was 5.0 ± 1.1 mm. Average LM width and depth were 17.0 ± 1.6 and 17.2 ± 1.6 mm, respectively. There was 6.9 ± 1.5 mm of bone medial to the medial C1 pedicle, which constituted 41% ± 9% of the LM's width. The distance from C1 arch's midline to the medial pedicle was 13.5 ± 2.0 mm. The LM's center was 1.6 ± 1 mm lateral to the medial pedicle wall. There was on average 3.5 ± 0.6 mm of the LM inferior to the pedicle inferior border. CONCLUSIONS: The center of the lateral mass is 1.6 ± 1 mm lateral to the medial wall of the C1 pedicle and approximately 15 mm from the midline. There is 6.9 ± 1.5 mm of bone medial to the medial C1 pedicle. Thus, the medial aspect of C1 pedicle may be used as an anatomic reference for locating the center of the C1 LM for screw fixation.

Racial/ethnic and age disparities in HIV prevalence and disease progression among men who have sex with men in the United States.

OBJECTIVES: We examined HIV diagnosis rates and disease progression among men who have sex with men (MSM) according to race/ethnicity and age. METHODS: Using data obtained from the national HIV/AIDS surveillance system, we examined trends in HIV diagnosis rates for 2001 through 2004 using Poisson regression. We used a standardized Kaplan-Meier method to determine differences in time of progression from HIV to AIDS and AIDS survival. RESULTS: HIV diagnosis rates were higher for Black and Hispanic than for White MSM, but trends within age groups from 2001 to 2004 did not differ by race/ethnicity. Diagnosis rates increased among MSM aged 13 to 19 years (14% per year), 20 to 24 years (13%), 25 to 29 years, and 40 to 54 years (3%-6%; P< or = .01 for each). The percentage of MSM who did not have AIDS 3 years after HIV diagnosis was lower among Black (66.8%; 95% confidence interval [CI]=66.1, 67.4) and Hispanic (68.1%; 95% CI=67.5, 68.8) than among White MSM (74.7%; 95% CI=74.2, 75.1). Three-year survival after AIDS diagnosis was lower for Black than for White or Hispanic MSM. CONCLUSIONS: HIV prevention efforts should target young and middle-aged MSM and must offer early diagnosis and treatment for all MSM.

Syphilis increases HIV viral load and decreases CD4 cell counts in HIV-infected patients with new syphilis infections.

BACKGROUND: Syphilitic ulcers are known to facilitate the transmission of HIV infection, but the effect of syphilis infection on HIV viral loads and CD4 cell counts is poorly understood. METHODS: We abstracted medical records for HIV-infected male syphilis patients seen at three clinics in San Francisco and Los Angeles from January 2001 to April 2003. We compared plasma HIV-RNA levels and CD4 cell counts during syphilis infection with those before syphilis infection and after syphilis treatment, using the Wilcoxon signed rank test. RESULTS: Fifty-two HIV-infected men with primary or secondary syphilis had HIV viral load and CD4 cell count data available for analysis; 30 (58%) were receiving antiretroviral therapy. Viral loads were higher during syphilis compared with pre-syphilis levels by a mean of 0.22 RNA log10 copies/ml (P = 0.02) and were lower by a mean of -0.10 RNA log10 copies/ml (P = 0.52) after syphilis treatment. CD4 cell counts were lower during syphilis infection than before by a mean of -62 cells/mm3 (P = 0.04), and were higher by a mean of 33 cells/mm3 (P = 0.23) after syphilis treatment. Increases in the HIV viral load and reductions in the CD4 cell count were most substantial in men with secondary syphilis and those not receiving antiretroviral therapy. CONCLUSION: Syphilis infection was associated with significant increases in the HIV viral load and significant decreases in the CD4 cell count. The findings underscore the importance of preventing and promptly treating syphilis in HIV-infected individuals.

HIV type 1 incidence estimates by detection of recent infection from a cross-sectional sampling of injection drug users in Bangkok: use of the IgG capture BED enzyme immunoassay.

Development of serologic tests to detect recent HIV-1 infection has generated worldwide interest in applying this approach to estimate incidence. We previously devised an IgG-capture BED-EIA (or BED-CEIA) that detects increasing levels of anti-HIV IgG following seroconversion to identify recent infection and to estimate incidence among persons infected with diverse HIV-1 subtypes worldwide. Injection drug users (IDUs; n = 1969) were screened in 1996 for participation in a prospective cohort study. Serum specimens from 594 IDUs were HIV-1 seropositive (30.2%) and were tested with the BED-CEIA. The proportion of recent infections and estimated incidence by different epidemiological risk factors were compared with incidence data measured from the prospective cohort. Of 594 HIV-1-seropositive specimens, 113 (19%) were identified as recent infections. Overall, the estimated annual incidence among persons screened was 17.3%/year (95% CI, 12.8-24.2%/year) compared with 9.0%/year (95% CI, 6.7-11.9%/year) measured from the prospective cohort during the same time period. Estimated incidence was higher among younger aged and unemployed IDUs as well as among those who injected more frequently, confirming previously reported risk factors from this prospective cohort. As persons screened from a cross-sectional sampling probably have higher risk for HIV than selected uninfected individuals who choose to participate and receive risk reduction counseling in a longitudinal cohort study, use of this or other serologic testing strategies to identify populations with high incidence (such as for HIV vaccine trials) may overestimate incidence measured from prospective cohorts.

Trends in antiretroviral therapy use and survival rates for a large cohort of HIV-infected children and adolescents in the United States, 1989-2001.

BACKGROUND: In the United States, HIV-infected children and adolescents are aging and using antiretroviral (ARV) therapy for extended periods of time. OBJECTIVE: To assess trends in ARV use and long-term survival in an observational cohort of HIV-infected children and adolescents in the United States. METHODS: The Pediatric Spectrum of HIV Disease Study (PSD) is a prospective chart review of more than 2000 HIV-infected children and adolescents. Patients were included in the analysis from enrollment until last follow-up. RESULTS: Triple-ARV therapy use (for 6 months or more) increased from 27% to 66% during 1997 to 2001 (P < 0.0001, chi for trend). The proportion of patients receiving 3 or more sequential triple-therapy regimens also increased from 4% to 17% during 1997 to 2001 (P < 0.0001, chi for trend), however, and the durability of triple-therapy regimens decreased from 13 to 7 months from the first to third regimen. Survival rates for the 1997 to 2001 birth cohorts were significantly better than for the 1989 to 1993 and 1994 to 1996 cohorts (P < 0.0001). CONCLUSIONS: Survival rates in the PSD cohort have increased in association with triple-ARV therapy use. With continued changes in ARV regimens, effective modifications in ARV therapy and the sustainability of gains in survival need to be determined.

Efficacy of a booster counseling session 6 months after HIV testing and counseling: a randomized, controlled trial (RESPECT-2).

BACKGROUND: HIV counseling prevents sexually transmitted diseases (STDs), with most of the benefit accumulating in the first 6 months. STUDY: The authors conducted a multicenter, randomized, controlled trial of a 20-minute additional (booster) counseling session 6 months after HIV counseling compared with no additional counseling for prevention of STDs (gonorrhea, chlamydia, trichomoniasis). Participants were 15- to 39-year-old STD clinic patients in Denver, Long Beach, and Newark. RESULTS: Booster counseling was completed by 1120 (67.8%) of 1653 assigned to receive it. An incident STD during the 6 to 12 months after initial counseling (and within the 6 months after scheduled booster counseling) was detected in 141 of 1653 (8.5%) participants in the booster counseling group and 144 of 1644 (8.8%) in the no-booster group (relative risk, 0.97; 95% confidence interval, 0.78-1.22). Three months after booster counseling, sexual risk behaviors were reported less frequently by the booster group than the no-booster group. CONCLUSIONS: Booster counseling 6 months after HIV testing and counseling reduced reported sexual risk behavior but did not prevent STDs.

Relative efficacy of prevention counseling with rapid and standard HIV testing: a randomized, controlled trial (RESPECT-2).

BACKGROUND: Two risk-reduction counseling sessions can prevent sexually transmitted diseases (STDs); however, return rates for test results are low. STUDY: A randomized, controlled trial compared rapid HIV testing and counseling in 1 visit with standard HIV testing and counseling in 2 visits. Main outcomes were STDs (gonorrhea, chlamydia, trichomoniasis, syphilis, HIV) within 12 months. Participants were 15- to 39-year-old STD clinic patients in Denver, Long Beach, and Newark. STD screening and questionnaires were administered every 3 months. RESULTS: Counseling was completed by 1632 of 1648 (99.0%) of the rapid-test group and 1144 of 1649 (69.4%) of the standard-test group. By 12 months, STD was acquired by 19.1% of the rapid group and 17.1% of the standard group (relative risk [RR], 1.11; confidence interval [CI], 0.96-1.29). STD incidence was higher in the rapid-test group than in the standard-test group among men (RR, 1.34; CI, 1.06-1.70), men who had sex with men (RR, 1.86; 95% CI, 0.92-3.76), and persons with no STDs at enrollment (RR, 1.21; 95% CI, 0.99-1.48). Behavior was similar in both groups. CONCLUSIONS: Counseling with either test had similar effects on STD incidence. For some persons, counseling with standard testing may be more effective than counseling with rapid testing.

Trends in diseases reported on U.S. death certificates that mentioned HIV infection, 1987-1999.

To examine trends in the proportions of deaths with various diseases among deaths with HIV infection, we analyzed multiple-cause death certificate data for all deaths in the United States from 1987 through 1999. Disease proportions were adjusted to control for demographic changes. Deaths reported with HIV infection increased from 15,331 in 1987 to 47,977 in 1995 and then decreased to 16,061 in 1999. Among these reported deaths, new trends during the period from 1995 through 1999 included decreases in the proportions with cytomegalovirus disease (from 6.8% to 2.8%), wasting/cachexia (9.8% to 6.8%), and dementia/encephalopathy (6.3% to 3.9%) and increases in the proportions with septicemia/septic shock (from 9.2% to 13.4%) and diseases of the liver (4.9% to 11.6%), kidney (6.3% to 9.1%), and heart (4.2% to 6.9%). Continuations of pre-1995 trends included decreases in the proportions with nontuberculous mycobacteriosis (7.1% to 3.1%) and Kaposi sarcoma (5.3% to 2.6%). Advances in antiretroviral therapy probably caused deaths due to HIV infection to decrease after 1995. Consequently, the proportions of deaths with HIV that were caused by other conditions increased. Improved prophylaxis or treatment of some opportunistic infections could also have reduced the proportions of deaths with those diseases, whereas antiviral drug toxicity could have contributed to increases in the proportions with noninfectious organ diseases.

Performance characteristics of a new less sensitive HIV-1 enzyme immunoassay for use in estimating HIV seroincidence.

Less sensitive (LS) HIV-1 enzyme immunoassays (EIAs) have significantly improved the quantity and quality of HIV surveillance data. The first LS-HIV-1 EIA, the Abbott 3A11-LS, provided reliable incidence data, but the assay required specialized equipment, and the lack of available reagents made testing difficult. This study evaluated the use of an alternate assay, a modified version of the Vironostika HIV-1 EIA (Vironostika-LS), to be used for LS testing. The Vironostika-LS has similar performance characteristics to the Abbott 3A11-LS with additional advantages. This 96-well formatted assay is commonly found in public health laboratories for routine HIV-1 testing and can be used with both serum and dried blood spot specimens. The estimated mean time from seroconversion (defined using a standardized optical density cutoff of 1.0) with the Vironostika-LS was 170 days (95% CI, 145-200 days). When the Vironostika-LS was applied to a matched serum set previously tested with the Abbott 3A11-LS, the Vironostika-LS accurately identified 97% of specimens with recent or long-standing HIV infection. The paper also reports Vironostika-LS quality control guidelines and the results from 3 rounds of proficiency testing.