Foxg1 bimodally tunes L1-mRNA and -DNA dynamics in the developing murine neocortex

Foxg1 masters telencephalic development via a pleiotropic control over its progression. Expressed within the central nervous system (CNS), L1 retrotransposons are implicated in progression of its histogenesis and tuning of its genomic plasticity. Foxg1 represses gene transcription, and L1 elements share putative Foxg1 binding motifs, suggesting the former might limit telencephalic expression (and activity) of the latter. We tested such prediction, in vivo as well as in engineered primary neural cultures, by loss- and gain-of-function approaches. We showed that Foxg1-dependent, transcriptional L1 repression specifically occurs in neopallial neuronogenic progenitors and post-mitotic neurons, where it is supported by specific changes in the L1 epigenetic landscape. Unexpectedly, we discovered that Foxg1 physically interacts with L1-mRNA and positively regulates neonatal neopallium L1-DNA content, antagonizing the retrotranscription-suppressing activity exerted by Mov10 and Ddx39a helicases. To the best of our knowledge, Foxg1 represents the first CNS patterning gene acting as a bimodal retrotransposon modulator, limiting transcription of L1 elements and promoting their amplification, within a specific domain of the developing mouse brain.

Endogenous CO2 ice mixture on the surface of Europa and no detection of plume activity

Jupiter's moon Europa has a subsurface ocean beneath an icy crust. Conditions within the ocean are unknown, and it is unclear whether it is connected to the surface. We observed Europa with the James Webb Space Telescope (JWST) to search for active release of material by probing its surface and atmosphere. A search for plumes yielded no detection of water, carbon monoxide, methanol, ethane, or methane fluorescence emissions. Four spectral features of carbon dioxide (CO2) ice were detected; their spectral shapes and distribution across Europa's surface indicate that the CO2 is mixed with other compounds and concentrated in Tara Regio. The 13CO2 absorption is consistent with an isotopic ratio of 12C/13C = 83 ± 19. We interpret these observations as indicating that carbon is sourced from within Europa.

Impacts of Heterogeneous Chemistry on Vertical Profiles of Martian Ozone

We show a positive vertical correlation between ozone and water ice using a vertical cross-correlation analysis with observations from the ExoMars Trace Gas Orbiter's Nadir and Occultation for Mars Discovery instrument. This is particularly apparent during L _S = 0°-180°, Mars Year 35 at high southern latitudes, when the water vapor abundance is low. Ozone and water vapor are anti-correlated on Mars; Clancy et al. (2016, https://doi.org/10.1016/j.icarus.2015.11.016) also discuss the anti-correlation between ozone and water ice. However, our simulations with gas-phase-only chemistry using a 1-D model show that ozone concentration is not influenced by water ice. Heterogeneous chemistry has been proposed as a mechanism to explain the underprediction of ozone in global climate models (GCMs) through the removal of HO _x . We find improving the heterogeneous chemical scheme by creating a separate tracer for the HO _x adsorbed state, causes ozone abundance to increase when water ice is present (30-50 km), better matching observed trends. When water vapor abundance is high, there is no consistent vertical correlation between observed ozone and water ice and, in simulated scenarios, the heterogeneous chemistry has a minor influence on ozone. HO _x , which are by-products of water vapor, dominate ozone abundance, masking the effects of heterogeneous chemistry on ozone, and making adsorption of HO _x have a negligible impact on ozone. This is consistent with gas-phase-only modeled ozone, showing good agreement with observations when water vapor is abundant. Overall, the inclusion of heterogeneous chemistry improves the ozone vertical structure in regions of low water vapor abundance, which may partially explain GCM ozone deficits.

Global Variations in Water Vapor and Saturation State Throughout the Mars Year 34 Dusty Season

To understand the evolving martian water cycle, a global perspective of the combined vertical and horizontal distribution of water is needed in relation to supersaturation and water loss and how it varies spatially and temporally. The global vertical water vapor distribution is investigated through an analysis that unifies water, temperature and dust retrievals from several instruments on multiple spacecraft throughout Mars Year (MY) 34 with a global circulation model. During the dusty season of MY 34, northern polar latitudes are largely absent of water vapor below 20 km with variations above this altitude due to transport from mid-latitudes during a global dust storm, the downwelling branch of circulation during perihelion season and the intense MY 34 southern summer regional dust storm. Evidence is found of supersaturated water vapor breaking into the northern winter polar vortex. Supersaturation above around 60 km is found for most of the time period, with lower altitudes showing more diurnal variation in the saturation state of the atmosphere. Discrete layers of supersaturated water are found across all latitudes. The global dust storm and southern summer regional dust storm forced water vapor at all latitudes in a supersaturated state to 60-90 km where it is more likely to escape from the atmosphere. The reanalysis data set provides a constrained global perspective of the water cycle in which to investigate the horizontal and vertical transport of water throughout the atmosphere, of critical importance to understand how water is exchanged between different reservoirs and escapes the atmosphere.

Global Vertical Distribution of Water Vapor on Mars: Results From 3.5 Years of ExoMars-TGO/NOMAD Science Operations

We present water vapor vertical distributions on Mars retrieved from 3.5 years of solar occultation measurements by Nadir and Occultation for Mars Discovery onboard the ExoMars Trace Gas Orbiter, which reveal a strong contrast between aphelion and perihelion water climates. In equinox periods, most of water vapor is confined into the low-middle latitudes. In aphelion periods, water vapor sublimated from the northern polar cap is confined into very low altitudes-water vapor mixing ratios observed at the 0-5 km lower boundary of measurement decrease by an order of magnitude at the approximate altitudes of 15 and 30 km for the latitudes higher than 50°N and 30-50°N, respectively. The vertical confinement of water vapor at northern middle latitudes around aphelion is more pronounced in the morning terminators than evening, perhaps controlled by the diurnal cycle of cloud formation. Water vapor is also observed over the low latitude regions in the aphelion southern hemisphere (0-30°S) mostly below 10-20 km, which suggests north-south transport of water still occurs. In perihelion periods, water vapor sublimated from the southern polar cap directly reaches high altitudes (>80 km) over high southern latitudes, suggesting more effective transport by the meridional circulation without condensation. We show that heating during perihelion, sporadic global dust storms, and regional dust storms occurring annually around 330° of solar longitude (L _S) are the main events to supply water vapor to the upper atmosphere above 70 km.

Foxg1 Antagonizes Neocortical Stem Cell Progression to Astrogenesis

Neocortical astrogenesis follows neuronogenesis and precedes oligogenesis. Among key factors dictating its temporal articulation, there are progression rates of pallial stem cells (SCs) towards astroglial lineages as well as activation rates of astrocyte differentiation programs in response to extrinsic gliogenic cues. In this study, we showed that high Foxg1 SC expression antagonizes astrocyte generation, while stimulating SC self-renewal and committing SCs to neuronogenesis. We found that mechanisms underlying this activity are mainly cell autonomous and highly pleiotropic. They include a concerted downregulation of 4 key effectors channeling neural SCs to astroglial fates, as well as defective activation of core molecular machineries implementing astroglial differentiation programs. Next, we found that SC Foxg1 levels specifically decline during the neuronogenic-to-gliogenic transition, pointing to a pivotal Foxg1 role in temporal modulation of astrogenesis. Finally, we showed that Foxg1 inhibits astrogenesis from human neocortical precursors, suggesting that this is an evolutionarily ancient trait.

Atazanavir and darunavir in pregnant women with HIV: evaluation of laboratory and clinical outcomes from an observational national study

Background

Atazanavir and darunavir represent the main HIV PIs recommended in pregnancy, but comparative data in pregnant women are limited. We assessed the safety and activity profile of these two drugs in pregnancy using data from a national observational study.

Methods

Women with atazanavir or darunavir exposure in pregnancy were evaluated for laboratory measures and main pregnancy outcomes (e.g. preterm delivery, low birthweight, non-elective caesarean section and neonatal gestational age-adjusted birthweight Z-score).

Results

Final analysis included 500 pregnancies with either atazanavir (n = 409) or darunavir (n = 91) exposure. No differences in pregnancy outcomes, weight gain in pregnancy, drug discontinuations, undetectable HIV-RNA, haemoglobin, ALT, total cholesterol, HDL cholesterol and LDL cholesterol were observed between the two groups. At third trimester, exposure to darunavir was associated with higher levels of plasma triglycerides (median 235.5 versus 179 mg/dL; P = 0.032) and a higher total cholesterol/HDL cholesterol ratio (median 4.03 versus 3.27; P = 0.028) and exposure to atazanavir was associated with higher levels of plasma bilirubin (1.54 versus 0.32 mg/dL; P < 0.001).

Conclusions

In this observational study, the two main HIV PIs currently recommended by perinatal guidelines showed similar safety and activity in pregnancy, with no evidence of differences between the two drugs in terms of main pregnancy outcomes. Based on the minor differences observed in laboratory measures, prescribing physicians might prefer either drug in some particular situations where the different impacts of treatment on lipid profile and bilirubin may have clinical relevance.

Rate, correlates and outcomes of repeat pregnancy in HIV-infected women

OBJECTIVES

The aim of the study was to assess the rate, determinants, and outcomes of repeat pregnancies in women with HIV infection.

METHODS

Data from a national study of pregnant women with HIV infection were used. Main outcomes were preterm delivery, low birth weight, CD4 cell count and HIV plasma viral load.

RESULTS

The rate of repeat pregnancy among 3007 women was 16.2%. Women with a repeat pregnancy were on average younger than those with a single pregnancy (median age 30 vs. 33 years, respectively), more recently diagnosed with HIV infection (median time since diagnosis 25 vs. 51 months, respectively), and more frequently of foreign origin [odds ratio (OR) 1.36; 95% confidence interval (CI) 1.10-1.68], diagnosed with HIV infection in the current pregnancy (OR: 1.69; 95% CI: 1.35-2.11), and at their first pregnancy (OR: 1.33; 95% CI: 1.06-1.66). In women with sequential pregnancies, compared with the first pregnancy, several outcomes showed a significant improvement in the second pregnancy, with a higher rate of antiretroviral treatment at conception (39.0 vs. 65.4%, respectively), better median maternal weight at the start of pregnancy (60 vs. 61 kg, respectively), a higher rate of end-of-pregnancy undetectable HIV RNA (60.7 vs. 71.6%, respectively), a higher median birth weight (2815 vs. 2885 g, respectively), lower rates of preterm delivery (23.0 vs. 17.7%, respectively) and of low birth weight (23.4 vs. 15.4%, respectively), and a higher median CD4 cell count (+47 cells/μL), with almost no clinical progression to Centers for Disease Control and Prevention stage C (CDC-C) HIV disease (0.3%). The second pregnancy was significantly more likely to end in voluntary termination than the first pregnancy (11.4 vs. 6.1%, respectively).

CONCLUSIONS

Younger and foreign women were more likely to have a repeat pregnancy; in women with sequential pregnancies, the second pregnancy was characterized by a significant improvement in several outcomes, suggesting that women with HIV infection who desire multiple children may proceed safely and confidently with subsequent pregnancies.

Suprapubic-assisted Transurethral Excision of a Vaginal Mesh Eroded Into the Bladder

A 56-year-old woman with irritative voiding symptoms and recurrent urinary infections was found to have erosion into the bladder of a tension-free vaginal tape placed 61 months before. To achieve radical excision, a 26Fr Amplatz sheath was placed suprapubically under endoscopic vision. A rigid nephroscope with grasping forceps was used to pull the eroded mesh out of the bladder wall while excising it transurethrally with a resectoscope. Postoperative course was uneventful; 12 months after surgery the patient remains asymptomatic. This novel technique provides an effective means of radically removing a mesh eroded into the bladder either transurethrally or suprapubically.

Birth defects in a national cohort of pregnant women with HIV infection in Italy, 2001-2011

OBJECTIVE

We used data from a national study of pregnant women with HIV to evaluate the prevalence of congenital abnormalities in newborns from women with HIV infection.

DESIGN

Observational study.

SETTING

University and hospital clinics.

POPULATION

Pregnant women with HIV exposed to antiretroviral treatment at any time during pregnancy.

METHODS

The total prevalence of birth defects was assessed on live births, stillbirths, and elective terminations for fetal anomaly. The associations between potentially predictive variables and the occurrence of birth defects were expressed as odds ratios (ORs) with 95% confidence intervals (95% CIs) for exposed versus unexposed cases, calculated in univariate and multivariate logistic regression analyses.

MAIN OUTCOME MEASURES

Birth defects, defined according to the Antiretroviral Pregnancy Registry criteria.

RESULTS

A total of 1257 pregnancies with exposure at any time to antiretroviral therapy were evaluated. Forty-two cases with major defects were observed. The total prevalence was 3.2% (95% CI 1.9-4.5) for exposure to any antiretroviral drug during the first trimester (23 cases with defects) and 3.4% (95% CI 1.9-4.9) for no antiretroviral exposure during the first trimester (19 cases). No associations were found between major birth defects and first-trimester exposure to any antiretroviral treatment (OR 0.94, 95% CI 0.51-1.75), main drug classes (nucleoside reverse transcriptase inhibitors, OR 0.95, 95% CI 0.51-1.76; non-nucleoside reverse transcriptase inhibitors, OR 1.20, 95% CI 0.56-2.55; protease inhibitors, OR 0.92, 95% CI 0.43-1.95), and individual drugs, including efavirenz (prevalence for efavirenz, 2.5%).

CONCLUSIONS

This study adds further support to the assumption that first-trimester exposure to antiretroviral treatment does not increase the risk of congenital abnormalities.

HIV-1 viral DNA is present in ejaculated abnormal spermatozoa of seropositive subjects

BACKGROUND

Semen is the major vehicle for HIV-1 infection as it contains free and cell-associated virions and infected cells. However, the presence of HIV-1 in spermatozoa has been a matter of debate, since the sperm cell fraction may contain somatic infected cells that jeopardize the attribution of the detected virus to the spermatozoa.

METHODS

Spermatozoa from 12 HIV-1 seropositive subjects were purified by multilayered Percoll gradient followed by osmotic shock. Residual presence of non-seminal cells (NCS) in purified spermatozoa, was then evaluated by cytometric and molecular analysis. HIV-1 DNA was revealed by nested PCR and in situ PCR after sperm chromatin decondensation. DNA-fragmented ejaculated spermatozoa in semen of infected subjects were detected by terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling (TUNEL) analysis.

RESULTS

Purification procedure adopted allowed complete removal of NCS. On purified sperm cells, HIV-1 DNA was detected in 5 out of 12 subjects by nested-PCR. On crude semen of 10 out of 12 subjects, HIV-1 DNA was in situ detected in a small percentage of abnormal spermatozoa with a wide range of structural alterations. TUNEL analysis revealed an increased percentage of DNA-fragmented ejaculated spermatozoa in semen of infected subjects.

CONCLUSIONS

We report molecular evidence demonstrating that HIV-1 infected subjects can ejaculate small amounts of HIV-1 DNA-positive abnormal spermatozoa. Their possible role in HIV-1 sexual transmission remains to be clarified.

Access to gynecological services and Papanicolau tests in HIV-infected Italian women: a questionnaire survey

The objective of the study was to evaluate the access to Papanicolau (Pap) tests of HIV-infected women in Italy. A cross-sectional survey on a cohort of HIV-infected women seen at 27 HIV clinics was performed. At each clinic a female physician involved in the care of HIV-infected women was asked questions on clinic and patients' characteristics and on access to Pap tests. The outcome of the study was to find the percentage of women who had not had a Pap test before coming to the HIV clinic and the percentage having had a Pap test in 2001. In the survey, 7,600 HIV-infected women were represented. Women who came to the clinic without having ever had a Pap test were 62+/-22%, while women who had had a Pap test in 2001 were 43+/-36%. Women who reported never having had a Pap test before coming to the HIV clinic were more often from the south than the north of Italy (17.9+/-49% from the north, 18+/-53% from the center and 9.3+/-83.9% from the south; p<0.001). This a difference disappeared when comparing the women who had had a Pap test in 2001 (28+/-39.6% from the north, 31.6+/-44.2% from the center and 25.6+/-45.7% from the south; p=0.88). Despite the published guidelines in Italy, only 38% of women had ever had a Pap test before coming to the HIV clinic and only 43% had had a Pap test in 2001. Strategies aimed to improve these proportions should be rapidly implemented at all levels of care organization.

Penetration of didanosine in semen of HIV-1-infected men

OBJECTIVES

The disposition of antiretroviral agents into genital tissue and fluids is one of the factors implicated in the control of viral replication within the male genital tract and should be an objective of highly active antiretroviral therapy. We have investigated didanosine penetration in seminal plasma of 16 HIV-infected patients.

PATIENTS AND METHODS

A total of 16 patients on didanosine (200 mg every 12 h or 400 mg once daily) participated in the pharmacokinetic study. After the didanosine morning dose, peripheral blood plasma and semen plasma were collected within the intervals 0-4, 4-8 and 8-12 h in the twice-daily regimen and 0-4, 4-12 and 12-24 h in the once-daily regimen.

RESULTS

Within each sampling time interval didanosine concentrations in seminal plasma were higher than in blood. The interquartile range of concentrations in seminal plasma was 292-1217 ng/mL, compared with 50-150 ng/mL in blood plasma. Didanosine could be detected in 14 of the 16 semen samples analysed and in 8 of the 16 blood samples.

CONCLUSIONS

We have demonstrated that didanosine penetrates into the seminal plasma in higher concentrations than in blood plasma.

Helicobacter pylori infection: anything new should we know?

Over the past year, 2003-4, there have been a number of studies consolidating previous work in relation to pathogenesis of disease, diagnosis and management of Helicobacter pylori. Studies into the pathogenesis of disease have identified the main adhesin of H. pylori as an important virulence marker and as a potential target for therapy. Molecular investigations of both the strain and host variations have identified the action of several of the virulence factors, e.g. cagA, vacA, on disrupting host cell signalling and the consequences in respect of the release of chemokines from the damaged gastric epithelium and the effect on apoptosis. Over the past year, there have been further diagnostic kits developed based on modifications of current technology. Two promising areas of research for diagnosis are the use of host/strain genome polymorphisms as a means of identifying high-risk patients who may develop severe disease and the use of proteomics to identify potential antigens of diagnostic (or therapeutic) use. The three main antibiotics that are used in first-line eradication regimens are clarithromycin, metronidazole and amoxycillin. Of these, metronidazole has the highest prevalence of resistance, followed by clarithromycin; amoxycillin resistance is only rarely reported. The decreasing success of current first-line therapy is the driving force for the development of new antibiotic combinations and a search for novel sources for chemotherapeutic agents and novel therapeutic targets.

Prognostic significance of cyclooxygenase-2 (COX-2) and expression of cell cycle inhibitors p21 and p27 in human pleural malignant mesothelioma

BACKGROUND

A study was undertaken to analyse the potential prognostic value of the immunohistochemical expression of cyclooxygenase-2 (COX-2) and p27 in 29 malignant mesotheliomas already screened for the expression of p21 and p53.

METHODS

Immunohistochemistry was used to determine the expression of COX-2 and p27. The correlation with survival of these factors and of p21 and p53 expression was assessed by univariate and multivariate analyses.

RESULTS

A positive statistically significant correlation was found between p27 and p21 expression (p<0.0001), but there was a negative correlation between COX-2 expression and both p27 (p = 0.001) and p21 (p<0.0001). No statistically significant correlation was recorded between p53 and all the other immunohistochemical parameters. Univariate analysis showed that overall survival was strongly influenced by p21, p27, and COX-2 expression, but multivariate Cox regression analysis showed that the only immunohistochemical parameter to influence overall survival of patients with mesothelioma was COX-2.

CONCLUSIONS

These findings suggest that COX-2 expression may be a useful prognostic parameter for mesothelioma.

Analysis of cell cycle regulator proteins in non-small cell lung cancer

BACKGROUND/AIMS

Abnormalities of the proteins involved in cell cycle checkpoints are extremely common among almost all neoplasms. This study aimed to investigate the expression of four components of the cell cycle machinery-p21, p16, p53, and proliferating cell nuclear antigen (PCNA)-in non-small cell lung cancer (NSCLC).

METHODS

The expression of p21, p16, p53, and PCNA was examined in 68 well characterised NSCLC specimens using immunohistochemistry. The coregulation of these proteins and their influence on survival were analysed using both univariate and multivariate analyses.

RESULTS

By univariate analysis, the expression of all the proteins examined, except for PCNA, was significantly correlated with survival. In multivariate analysis, the only immunohistochemical parameter able to influence overall survival was p16, confirming the hypothesis that the RB-p16 tumour suppressor pathway is inactivated in most lung cancer samples. Finally, the group of patients with NSCLC who were negative for both p21 and p16 had a significantly shorter overall survival.

CONCLUSIONS

These results suggest that loss of control of cell cycle checkpoints is a common occurrence in lung cancers, and support the idea that functional cooperation between different cell cycle inhibitor proteins constitutes another level of regulation in cell growth control and tumour suppression.

[Aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio in health surveillance of workers exposed to vinyl chloride monomer: preliminary results]

An AST/ALT ratio > 1 is predictive of liver fibrosis and cirrhosis in patients with chronic hepatitis C virus infection. The aim of this case-control study is to assess AST/ALT ratio in 150 workers exposed to VCM (E) from the beginning of the 1960s to the end of the 1990s. The non-exposed group (NE) consists in 150 male workers employed in the production of a food industry. At least since 1983 exposed subjects worked at VCM environmental concentrations < 3 ppm. All the workers underwent venous blood collection for assessment of AST and ALT. Exposed workers presented mean AST/ALT ratio and frequency of AST/ALT ratio > 1 significantly higher than non-exposed. The mean AST/ALT ratio results significantly higher in the exposed group, also after stratification for alcohol consumption. In exposed workers who consume alcoholic beverages and are operating since before 1983 AST/ALT ratio is significantly and positively influenced only by the working age until 1983. If these results will be confirmed, AST/ALT ratio could be proposed to be included in the periodic medical surveillance of VCM workers.

HCV and GBV-c/HGV infection in HIV positive patients in southern Italy

Flaviviridae-hepatitis C virus (HCV) and GB virus C/hepatitis G virus (GBV-C/HGV)--and human immunodeficiency virus (HIV) frequently show similar modes of transmission. HCV and GBV-C/HGV infection was assessed in 134 consecutive patients with evidence of HIV infection, living in Campania, Italy. Data obtained from this cohort were compared with those obtained from 252 age- and sex-matched HCV infected patients without evidence of HIV infection (HCV control group). Following enzymatic immunoassays, samples were tested for the presence of HCV-RNA by RT-PCR. The HCV-RNA positive sera were genotyped by LiPA procedure. The prevalence of HCV infection in HIV patients was 19.40% and the largest group of HIV-HCV co-infected patients (84.62%) was represented by intravenous drug users (IVDU). The distribution of HCV genotypes in HIV-HCV patients was different, compared to that observed in HCV control group. HCV genotypes la (50%) and 3a (23.08%) were more frequently detected in HIV HCV patients, compared to HCV control group (5.16 and 5.56% for la and 3a, respectively). Conversely, HCV genotypes lb (55.70%) and 2a/2c (30.26%) were more represented in HCV control group, compared to HIV-HCV patients (15.38 and 0% for lb and 2a/2c, respectively). GBV-C/HGV seroprevalence was 41.04% in HIV patients and 6.54% in healthy control individuals. Differently from HCV, GBV-C/HGV infection did not correlate to a preferential risk behaviour in the HIV cohort. Comparative analysis of HCV and GBV-C/HGV infection indicates that the use of injecting drugs might play a key role in the epidemiology of HCV and, in particular, of la and 3a HCV genotypes, in HIV patients.

Factors related to virologic failure among HIV-positive injecting drug users treated with combination antiretroviral therapy including two nucleoside reverse transcriptase inhibitors and nevirapine

Treatment strategies in human immunodeficiency virus (HIV)-positive active injecting drug users (IDUs) must take into account their lifestyles, that often result in low adherence to therapy. The nonnucleoside reverse transcriptase inhibitors (NNRTI) offer simpler treatment regimens, but the appearance of drug resistance during treatment failure may cause high levels of cross-resistance to all NNRTIs. We adopted a combination therapy of two NRTIs and nevirapine (NVP) for treatment of IDU patients to evaluate its feasibility in such patients. From October 1998 to December 1999, demographic, clinical, and laboratory data from 80 IDUs on this regimen were collected. Fisher's exact test, Kaplan Meier method, and Cox model were used for statistical analysis. Overall, 20 IDUs discontinued the treatment because of side effects and 20 IDUs experienced treatment failure. Considering the treatment failure as an end point, 55.6% (95% confidence interval [CI]: 37.9%-72.6%) of patients was still undergoing treatment after 12 months compared to 44.6% (31.8%-58.6%) when discontinuation was also taken into account. An increasing trend over time was observed in the CD4+ lymphocyte count, among failing and nonfailing IDUs. By multivariate analysis, baseline HIV-RNA, treatment breaks and low adherence and active injecting drug use turned out to be significantly associated with treatment failure. Our results show that continuing injecting drug use and treatment breaks are the main factors that can lead to treatment failure in IDUs and easily to NNRTI class resistance.

The effect of potent antiretroviral therapy and JC virus load in cerebrospinal fluid on clinical outcome of patients with AIDS-associated progressive multifocal leukoencephalopathy

A multicenter analysis of 57 consecutive human immunodeficiency virus-positive patients with progressive multifocal leukoencephalopathy (PML) was performed, to identify correlates of longer survival. JC virus (JCV) DNA was quantified in the cerebrospinal fluid (CSF) by polymerase chain reaction. Two months after therapy, 4% of the patients without highly active antiretroviral therapy (HAART) and 26% with HAART showed neurologic improvement or stability (P=.03), and 8% and 57%, respectively, reached undetectable JCV DNA levels in the CSF (P=.04). One-year probability of survival was.04 without HAART and.46 with HAART. HAART and lack of neurologic progression 2 months after diagnosis were independently associated with longer survival. Among HAART-treated patients, a baseline JCV DNA <4.7 log, and reaching undetectable levels after therapy predicted longer survival. Survival of AIDS-related PML is improved by HAART when JCV replication is controlled.

A combination of nucleoside analogues and a protease inhibitor reduces HIV-1 RNA levels in semen: implications for sexual transmission of HIV infection

Direct contact with semen is the major route of sexual acquisition of human immunodeficiency virus (HIV) in homosexual and heterosexual partners of seropositive men. In this study, we show that concentrations of HIV-1 RNA molecules in plasma and semen of seropositive patients are related to the duration and type of antiretroviral agents used in treatment. In patients treated with zidovudine alone, 1, 3 and 6 months after the start of therapy, the mean HIV-1 load in plasma was reduced by 0.57, 0.38 and 0.21 log10 and in semen by 0.66, 0.50 and 0.15 log10, respectively. In patients treated with zidovudine plus didanosine at months 1, 3 and 6, the mean decrease in plasma HIV-1 RNA was 1.40, 1.25 and 1.12 log10 and in semen 1.10, 1.41 and 1.32 log10, respectively. In patients treated with a combination of a protease inhibitor and two nucleoside analogues the mean log10 decrease was 1.77, 1.83, 1.71 and 2.38 log10 in plasma and 1.17, 1.74, 2.19 and 3.02 log10 in semen at 1, 2, 3 and 4 months, respectively. Treatment with a combination of a protease inhibitor and two nucleoside analogues caused a dramatic decrease in cell-free HIV-1 RNA in semen, which is a reliable measure of viral load. These findings could have implications for the sexual transmission of HIV-1.

Rare mutations in a domain crucial for V3-loop structure prevail in replicating HIV from long-term non-progressors

OBJECTIVE

To evaluate the role of the selective forces exerted by the host on the HIV-1 structures involved in viral entry.

DESIGN AND METHODS

The V3 region of the env gene was analysed in cell-free HIV-1 RNA from 17 infected subjects: 11 long-term non-progressors (LTNP) and six symptomless, typical progressor patients. To evaluate the potential biological significance of one of the rare variants detected in the LTNP, it was reproduced by recombinant PCR into a HIV-1 molecular clone.

RESULTS

The intrapatient divergence of the V3-loop sequences averaged 8.62% in LTNP and 5.29% in progressors, although LTNP displayed lower divergence from the clade B consensus than progressors (16.65 and 19.76%, respectively). The analysis of non-synonymous and synonymous substitutions indicated that selective pressure was exerted in this region in both LTNP and progressors. Individual peculiarities (unique and rare V3-loop variants) emerged, however, in most sequences from LTNP, and variants bearing mutations in a domain crucial for the V3-loop structure were more prevalent in LTNP (P = 0.0012). The pNL4-3-derived mutant reproducing a V3-loop variant detected in a LTNP was efficiently expressed upon transfection, but the mutant virus was nearly completely unable to infect CD4+ cell lines, activated primary peripheral blood lymphocytes, or monocyte-derived macrophages, suggesting that a defect impaired the entry phase of the replication cycle.

CONCLUSIONS

The results indicate that host factors impose selective constraints on the evolution of the HIV-1 structures involved in viral entry. In LTNP, these factors are likely to force the virus into attenuated variants.

Analysis of HIV-1 load in blood, semen and saliva: evidence for different viral compartments in a cross-sectional and longitudinal study

OBJECTIVES

To quantify the HIV-1 load (measured as copies of viral RNA/ml using competitive reverse transcription-polymerase chain reaction) in blood, semen and saliva and to look for relationships between the viral burden, the clinical and immunological status and antiretroviral therapy.

METHODS

Peripheral blood, semen and whole saliva samples were collected from 26 anti-HIV-1-seropositive patients selected for a cross-sectional study. Nine of the 26 patients provided samples of the three biological fluids for a longitudinal study.

RESULTS

HIV-1 RNA was detected in 26 out of 26 samples of plasma, in 25 out of 26 samples of semen and in 24 out of 25 samples of saliva. The median number of HIV-1 copies in plasma was 14 817/ml (range: 167-254 880), in semen was 515/ml (range: 0-196 050) and in saliva was 162/ml (range: 0-72 080). The viral load in semen and in saliva was significantly lower than in plasma (P < 0.0001). The HIV-1 RNA levels in plasma and in saliva were correlated (P < 0.05), but levels in semen were not correlated with either plasma or saliva levels. The HIV-1 copy number in plasma was significantly higher in symptomatic patients than in asymptomatic subjects (P < 0.05). Plasma and saliva HIV-1 RNA levels were higher in subjects with a CD4+ cell count < 200 x 10(6)/l than in subjects with a CD4+ cell count > 200 x 10(6)/l (P < 0.05). The HIV-1 RNA load in either plasma, semen or saliva is not related to antiretroviral therapy.

CONCLUSIONS

The absence of a correlation between plasma and semen loads suggests that semen and blood are distinct viral compartments. Viral load in semen is not related to the clinical stage of HIV infection or to the CD4+ lymphocyte count. Consequently, HIV-1-infected subjects are potentially infectious at all stages of immuno-deficiency and adequate precautions must always be taken to prevent the sexual transmission of HIV.

Weber's syndrome due to a possible solitary brainstem toxoplasmosis as a presenting sign of AIDS

We report the case of a young man, with a previous history of parenteral drug abuse, who developed a Weber's syndrome. Brain computed tomographic scan and nuclear magnetic resonance imaging showed a single ring enhancing lesion in the right mesencephalic site. After the demonstration of seropositivity for human immunodeficiency vims, a presumptive diagnosis of cerebral toxoplasmosis in an AIDS patient was made and a specific treatment was started. A partial neuroradiological and clinical improvement were obtained. Opportunistic cerebral lesions, as first manifestation of AIDS, should be always considered in subjects at risk for AIDS who present a brainstem syndrome.

Presence of HIV-1 proviral sequences in saliva of infected individuals in relation with clinical stage and CD4+ lymphocyte count

We detected by PCR (Polymerase Chain Reaction) HIV-1 proviral sequences in saliva cells of 89 HIV+ subjects at different stages of disease. Twenty negative individuals not at risk of HIV infection were considered as controls. The amplification of DNA was performed using the primers of genomic env region SK68 and SK69. The presence of HIV-1 in DNA was found in 16/89 (18.0%) saliva samples from HIV-1 subjects but in none of the 20 saliva samples from healthy subjects. No statistically significant difference in the presence of HIV-1 proviral sequences in saliva was observed when comparing patients receiving AZT or no treatment and patients at different stages of infection. Conversely, a statistically significant difference among subjects with CD4+ cell counts > 400/cmm and those with CD4+ cell counts from 200 to 400/cmm, was found stratifying the subjects according to their CD4+ cell counts.

Cerebral toxoplasmosis and AIDS. Clinical, neuroradiological and immunological findings in 15 patients

Cerebral toxoplasmosis is the most common cause of focal CNS disease complicating AIDS and its incidence ranges from 3% to 40% of such patients. This opportunistic infection is generally due to reactivation of chronic toxoplasmosis as a consequence of severe immune deficiency. We present the clinical, neuroradiological and immunological findings of 15 AIDS patients with cerebral toxoplasmosis. All patients had focal neurological signs. CT-scan (13 cases) and NMR (2 cases) showed single or multiple mass lesions and edema. Serum IgG anti-Toxoplasma antibodies were positive in 14 patients; CSF specific IgG were positive in 5 out of 7 studied patients, while serum and CSF specific IgM were negative in all subjects. The intrathecal synthesis of anti-Toxoplasma antibodies were high in all 7 patients. A presumptive diagnosis of cerebral toxoplasmosis is based on the focal cerebral signs and neuroradiological findings. It is more frequently confirmed by the improvement of the clinical and neuroradiological picture during the treatment with pyrimethamine-sulphadiazine or clindamycin.

[HIV-1 proviral DNA sequences in the saliva of patients with HIV infection]

In order to understand the significance of presence of HIV-1 in saliva, we searched for by PCR HIV-1 proviral sequences in the saliva cells of 49 HIV-1 infected patients. Seven out 49 specimens resulted positive, 4 of which were from patients with PGL, 1 with ARC and 2 with AIDS. Four patients had a CD4+ lymphocyte counts < 200/cmm and in 3 patients the CD4+ lymphocyte count ranged from 200 to 400/cmm. Two patients were treated with AZT, 1 with DDI and 4 had no antiretroviral treatment. In conclusion, although HIV-1 proviral sequences have been found in saliva of HIV-1 infected patients, a larger group of patients should be investigated to define more precisely the role of HIV-1 in saliva.

Serum beta 2-microglobulin levels and p24 antigen, lymphocyte depletion and disease progression in human immunodeficiency virus infection

Abnormally elevated serum beta 2-microglobulin levels have been associated with progression of human immunodeficiency virus disease. In this study we have analyzed the relationship between serum beta 2-microglobulin levels of patients at different stages of the disease and serological and immunological parameters commonly used for monitoring the infection. The investigation was performed on 150 patients and 30 controls during the period from March 1989 to March 1990. At that time, 30 patients had the acquired immunodeficiency syndrome or its related complex and 120 had persistent generalized lymphadenopathy or were asymptomatic. Thirty-nine antibody-negative subjects, belonging to a high-risk group for the acquired immunodeficiency syndrome, were used as controls. All patients had normal renal function. There was a significant relationship between increased serum beta 2-microglobulin levels and the presence of p24 antigen, a decrease in the total number of lymphocytes (less than or equal to 1500/mm3) and a decrease in CD4+ T lymphocytes (less than or equal to 200/mm3). No significant relationship between serum beta 2-microglobulin levels and CD3+ T lymphocytes was found.