Extreme plasticity in reproductive biology of an oviparous lizard.

Most oviparous squamate reptiles lay their eggs when embryos have completed less than one-third of development, with the remaining two-thirds spent in an external nest. Even when females facultatively retain eggs in dry or cold conditions, such retention generally causes only a minor (<10%) decrease in subsequent incubation periods. In contrast, we found that female sand lizards (Lacerta agilis) from an experimentally founded field population (established ca. 20 years ago on the southwest coast of Sweden) exhibited wide variation in incubation periods even when the eggs were kept at standard (25°C) conditions. Females that retained eggs in utero for longer based on the delay between capture and oviposition produced eggs that hatched sooner. In the extreme case, eggs hatched after only 55% of the "normal" incubation period. Although the proximate mechanisms underlying this flexibility remain unclear, our results from this first full field season at the new study site show that females within a single cold-climate population of lizards can span a substantial proportion of the continuum from "normal" oviparity to viviparity.

Longitudinal Genetic Characterization Reveals That Cell Proliferation Maintains a Persistent HIV Type 1 DNA Pool During Effective HIV Therapy.

BACKGROUND: The stability of the human immunodeficiency virus type 1 (HIV-1) reservoir and the contribution of cellular proliferation to the maintenance of the reservoir during treatment are uncertain. Therefore, we conducted a longitudinal analysis of HIV-1 in T-cell subsets in different tissue compartments from subjects receiving effective antiretroviral therapy (ART). METHODS: Using single-proviral sequencing, we isolated intracellular HIV-1 genomes derived from defined subsets of CD4(+) T cells from peripheral blood, gut-associated lymphoid tissue and lymph node tissue specimens from 8 subjects with virologic suppression during long-term ART at 2 time points (time points 1 and 2) separated by 7-9 months. RESULTS: DNA integrant frequencies were stable over time (<4-fold difference) and highest in memory T cells. Phylogenetic analyses showed that subjects treated during chronic infection contained viral populations with up to 73% identical sequence expansions, only 3 of which were observed in specimens obtained before therapy. At time points 1 and 2, such clonally expanded populations were found predominantly in effector memory T cells from peripheral blood and lymph node tissue specimens. CONCLUSIONS: Memory T cells maintained a relatively constant HIV-1 DNA integrant pool that was genetically stable during long-term effective ART. These integrants appear to be maintained by cellular proliferation and longevity of infected cells, rather than by ongoing viral replication.

Newly Exerted T Cell Pressures on Mutated Epitopes following Transmission Help Maintain Consensus HIV-1 Sequences.

CD8+ T cells are important for HIV-1 virus control, but are also a major contributing factor that drives HIV-1 virus sequence evolution. Although HIV-1 cytotoxic T cell (CTL) escape mutations are a common aspect during HIV-1 infection, less is known about the importance of T cell pressure in reversing HIV-1 virus back to a consensus sequences. In this study we aimed to assess the frequency with which reversion of transmitted mutations in T cell epitopes were associated with T cell responses to the mutation. This study included 14 HIV-1 transmission pairs consisting of a 'source' (virus-donor) and a 'recipient' (newly infected individual). Non-consensus B sequence amino acids (mutations) in T cell epitopes in HIV-1 gag regions p17, p24, p2 and p7 were identified in each pair and transmission of mutations to the recipient was verified with population viral sequencing. Longitudinal analyses of the recipient's viral sequence were used to identify whether reversion of mutations back to the consensus B sequence occurred. Autologous 12-mer peptides overlapping by 11 were synthesized, representing the sequence region surrounding each reversion and longitudinal analysis of T cell responses to source-derived mutated and reverted epitopes were assessed. We demonstrated that mutations in the source were frequently transmitted to the new host and on an average 17 percent of mutated epitopes reverted to consensus sequence in the recipient. T cell responses to these mutated epitopes were detected in 7 of the 14 recipients in whom reversion occurred. Overall, these findings indicate that transmitted non-consensus B epitopes are frequently immunogenic in HLA-mismatched recipients and new T cell pressures to T cell escape mutations following transmission play a significant role in maintaining consensus HIV-1 sequences.

The HIV-1 reservoir in eight patients on long-term suppressive antiretroviral therapy is stable with few genetic changes over time.

The source and dynamics of persistent HIV-1 during long-term combinational antiretroviral therapy (cART) are critical to understanding the barriers to curing HIV-1 infection. To address this issue, we isolated and genetically characterized HIV-1 DNA from naïve and memory T cells from peripheral blood and gut-associated lymphoid tissue (GALT) from eight patients after 4-12 y of suppressive cART. Our detailed analysis of these eight patients indicates that persistent HIV-1 in peripheral blood and GALT is found primarily in memory CD4(+) T cells [CD45RO(+)/CD27((+/-))]. The HIV-1 infection frequency of CD4(+) T cells from peripheral blood and GALT was higher in patients who initiated treatment during chronic compared with acute/early infection, indicating that early initiation of therapy results in lower HIV-1 reservoir size in blood and gut. Phylogenetic analysis revealed an HIV-1 genetic change between RNA sequences isolated before initiation of cART and intracellular HIV-1 sequences from the T-cell subsets after 4-12 y of suppressive cART in four of the eight patients. However, evolutionary rate analyses estimated no greater than three nucleotide substitutions per gene region analyzed during all of the 4-12 y of suppressive therapy. We also identified a clearly replication-incompetent viral sequence in multiple memory T cells in one patient, strongly supporting asynchronous cell replication of a cell containing integrated HIV-1 DNA as the source. This study indicates that persistence of a remarkably stable population of infected memory cells will be the primary barrier to a cure, and, with little evidence of viral replication, this population could be maintained by homeostatic cell proliferation or other processes.

Changes in seroadaptive practices from before to after diagnosis of recent HIV infection among men who have sex with men.

OBJECTIVE: We assessed changes in sexual behavior among men who have sex with men (MSM), before and for several years after HIV diagnosis, accounting for adoption of a variety of seroadaptive practices. METHODS: We collected self-reported sexual behavior data every 3 months from HIV-positive MSM at various stages of HIV infection. To establish population level trends in sexual behavior, we used negative binomial regression to model the relationship between time since diagnosis and several sexual behavior variables: numbers of (a) total partners, (b) potentially discordant partners (PDP; i.e., HIV-negative or unknown-status partners), (c) PDPs with whom unprotected anal intercourse (UAI) occurred, and (d) PDPs with whom unprotected insertive anal intercourse (uIAI) occurred. RESULTS: A total of 237 HIV-positive MSM contributed 502 interviews. UAI with PDPs occurred with a mean of 4.2 partners in the 3 months before diagnosis. This declined to 0.9 partners/3 months at 12 months after diagnosis, and subsequently rose to 1.7 partners/3 months at 48 months, before falling again to 1.0 partners/3 months at 60 months. The number of PDPs with whom uIAI occurred dropped from 2.4 in the pre-diagnosis period to 0.3 partners/3 months (an 87.5% reduction) by 12 months after enrollment, and continued to decline over time. CONCLUSION: Within months after being diagnosed with HIV, MSM adopted seroadaptive practices, especially seropositioning, where the HIV-positive partner was not in the insertive position during UAI, resulting in a sustained decline in the sexual activity associated with the highest risk of HIV transmission.

Hematopoietic precursor cells isolated from patients on long-term suppressive HIV therapy did not contain HIV-1 DNA.

BACKGROUND: We address the key emerging question of whether Lin(-)/CD34(+) hematopoietic precursor cells (HPCs) represent an important latent reservoir of human immunodeficiency virus type 1 (HIV-1) during long-term suppressive therapy. METHODS: To estimate the frequency of HIV-1 infection in bone marrow, we sorted Lin(-)/CD34(+) HPCs and 3 other cell types (Lin(-)/CD34(-), Lin(-)/CD4(+), and Lin(+)/CD4(+)) from 8 patients who had undetectable viral loads for 3-12 years. Using a single-proviral sequencing method, we extracted, amplified, and sequenced multiple single HIV-1 DNA molecules from these cells and memory CD4(+) T cells from contemporaneous peripheral blood samples. RESULTS: We analyzed 100,000-870,000 bone marrow Lin(-)/CD34(+) HPCs from the 8 patients and found no HIV-1 DNA. We did isolate HIV-1 DNA from their bone marrow Lin(+)/CD4(+) cells that was genetically similar to HIV-1 DNA from lymphoid cells located in the peripheral blood, indicating an exchange of infected cells between these compartments. CONCLUSIONS: The absence of infected HPCs provides strong evidence that the HIV-1 infection frequency of Lin(-)/CD34(+) HPCs from bone marrow, if it occurred, was <.003% (highest upper 95% confidence interval) in all 8 patients. These results strongly suggest that Lin(-)/CD34(+) HPCs in bone marrow are not a source of persistent HIV-1 in patients on long-term suppressive therapy.

Transmitted drug resistance in persons with acute/early HIV-1 in San Francisco, 2002-2009.

BACKGROUND: Transmitted HIV-1 drug resistance (TDR) is an ongoing public health problem, representing 10-20% of new HIV infections in many geographic areas. TDR usually arises from two main sources: individuals on antiretroviral therapy (ART) who are failing to achieve virologic suppression, and individuals who acquired TDR and transmit it while still ART-naïve. TDR rates can be impacted when novel antiretroviral medications are introduced that allow for greater virologic suppression of source patients. Although several new HIV medications were introduced starting in late 2007, including raltegravir, maraviroc, and etravirine, it is not known whether the prevalence of TDR was subsequently affected in 2008-2009. METHODOLOGY/PRINCIPAL FINDINGS: We performed population sequence genotyping on individuals who were diagnosed with acute or early HIV (<6 months duration) and who enrolled in the Options Project, a prospective cohort, between 2002 and 2009. We used logistic regression to compare the odds of acquiring drug-resistant HIV before versus after the arrival of new ART (2005-2007 vs. 2008-2009). From 2003-2007, TDR rose from 7% to 24%. Prevalence of TDR was then 15% in 2008 and in 2009. While the odds of acquiring TDR were lower in 2008-2009 compared to 2005-2007, this was not statistically significant (odds ratio 0.65, 95% CI 0.31-1.38; p = 0.27). CONCLUSIONS: Our study suggests that transmitted drug resistance rose from 2003-2007, but this upward trend did not continue in 2008 and 2009. Nevertheless, the TDR prevalence in 2008-2009 remained substantial, emphasizing that improved management strategies for drug-resistant HIV are needed if TDR is to be further reduced. Continued surveillance for TDR will be important in understanding the full impact of new antiretroviral medications.

Brief cognitive counseling with HIV testing to reduce sexual risk among men who have sex with men: results from a randomized controlled trial using paraprofessional counselors.

OBJECTIVES: To test the efficacy and acceptability of a single-session personalized cognitive counseling (PCC) intervention delivered by paraprofessionals during HIV voluntary counseling and testing. METHODS: HIV-negative men who have sex with men (MSM; n = 336) were randomly allocated to PCC or usual counseling (UC) between October 2002 and September 2004. The primary outcome was the number of episodes of unprotected anal intercourse (UAI) with any nonprimary partner of nonconcordant HIV serostatus in the preceding 90 days, measured at baseline, 6 months, and 12 months. Impact was assessed as "intent to treat" by random-intercept Poisson regression analysis. Acceptability was assessed by a standardized client satisfaction survey. RESULTS: Men receiving PCC and UC reported comparable levels of HIV nonconcordant UAI at baseline (mean episodes: 4.2 vs. 4.8, respectively; P = 0.151). UAI decreased by more than 60% to 1.9 episodes at 6 months in the PCC arm (P < 0.001 vs. baseline) but was unchanged at 4.3 episodes for the UC arm (P = 0.069 vs. baseline). At 6 months, men receiving PCC reported significantly less risk than those receiving UC (P = 0.029 for difference to PCC). Risk reduction in the PCC arm was sustained from 6 to 12 months at 1.9 (P = 0.181), whereas risk significantly decreased in the UC arm to 2.2 during this interval (P < 0.001 vs. 6 months; P = 0.756 vs. PCC at 12 months). Significantly more PCC participants were "very satisfied" with the counseling experience (78.2%) versus UC participants (59.2%) (P = 0.002). CONCLUSIONS: Both interventions were effective in reducing high-risk sexual behavior among MSM repeat testers. PCC participants demonstrated significant behavioral change more swiftly and reported a more satisfying counseling experience than UC participants.

Priapism and quetiapine: a case report.

Priapism is a "persistent erection not accompanied by sexual desire or stimulation, usually lasting more than six hours and typically involving only the corpora cavernosa." Here we report on a gay male patient from our HIV/AIDS mental health clinic who developed serious priapism on quetiapine and recreational amphetamine. Gay men are at high risk for amphetamine use, and as such, this potential association between priapism, quetiapine, and amphetamine use should be considered in making prescription decisions with these patients.

Late diagnosis of HIV infection: trends, prevalence, and characteristics of persons whose HIV diagnosis occurred within 12 months of developing AIDS.

BACKGROUND: Persons diagnosed late in the course of HIV infection may be unknowingly transmitting infection and once diagnosed may have worse outcomes and greater medical expenses. METHODS: Persons diagnosed with AIDS in San Francisco between 2001 and 2005 were included. Late testers were persons diagnosed with HIV 12 months or less before their AIDS diagnosis. Prevalence trends, demographic and risk correlates, and predictors of late testing were measured. RESULTS: Among 2139 persons included, 830 (38.8%) were late testers. The prevalence of late testing was stable between 2001 and 2005. Late testing was more likely among persons <30 years old (Odds ratio [OR]: 1.99, 95% confidence interval [CI]: 1.4, 2.8), heterosexuals (OR: 1.88, 95% CI: 1.1, 3.1), persons without a reported risk (OR: 2.88, 95% CI: 1.7, 5.0), persons with private insurance (OR: 1.82, 95% CI: 1.4, 2.4), no insurance (OR: 1.83, 95% CI: 1.4, 2.4), born outside of the United States (OR: 1.64, 95% CI: 1.2, 2.2), and whose initial AIDS diagnosis was an opportunistic infection (OR: 2.24, 95% CI: 1.8, 2.8). CONCLUSIONS: A large proportion of persons with AIDS have tested late in the course of HIV infection and this proportion has not declined in recent years. Routine testing in medical settings, and use of rapid oral-fluid testing in traditional and nontraditional settings may increase early HIV diagnosis.

Amphetamine use is associated with increased HIV incidence among men who have sex with men in San Francisco.

We examined the association between amphetamine use and HIV incidence for 2991 men who have sex with men (MSM) who tested anonymously for HIV in San Francisco. HIV incidence among 290 amphetamine users was 6.3% per year (95% CI 1.9-10.6%), compared with 2.1% per year (95% CI 1.3-2.9%) among 2701 non-users (RR 3.0, 95% CI 1.4-6.5). HIV prevention programmes in San Francisco should include efforts to reduce amphetamine use and associated high-risk sexual behaviors.

Comparison of three methods to measure HIV incidence among persons seeking voluntary, anonymous counseling and testing.

OBJECTIVES: The authors compared 3 practical methods to estimate human HIV incidence rates using existing data from persons seeking anonymous testing in San Francisco between 1996-2002. Each method was assessed for strengths and limitations. METHODS: Three different approaches were used to determine HIV incidence: one based on self-reported dates of prior tests, one based on linking records of prior tests using an anonymous unique testing code, and one based on the Serologic Testing Algorithm for Recent HIV Seroconversion (STARHS). RESULTS: The 3 methods found comparable rates of seroconversion overall (1.0, 1.2, and 1.3 per 100 person-years) and among men who have sex with men (1.4, 1.6, and 2.0 per 100 person-years). Incidence for all 3 methods saw a peak during 1999 followed by a decline. Greatest variability of incidence was observed among lower-risk populations, in whom few infections were expected. CONCLUSIONS: The 3 methods had complementary strengths and limitations, which may prevent proper interpretation of HIV incidence if any one method is analyzed alone. HIV incidence rates among persons seeking HIV testing should be interpreted cautiously using corroborative data on risk behavior and sexually transmitted diseases and other contextual information.

Association of negotiation strategies with consistent use of male condoms by women receiving an HIV prevention intervention in Zimbabwe.

One of the fundamental aspects of HIV counselling for women is condom negotiation strategy development. The present research sought to identify condom request strategies used by Zimbabwean women and to determine which were most effective in persuading male partners to use condoms. Of six types of strategies used by women after a prevention intervention, one was significantly associated with consistent condom use 2 months later. Implications for the development of counselling and testing protocols are discussed.