Lopinavir and atazanavir in pregnancy: comparable infant outcomes, virological efficacies and preterm delivery rates.

OBJECTIVES: The aim of the study was to identify differences in infant outcomes, virological efficacy, and preterm delivery (PTD) outcome between women exposed to lopinavir/ritonavir (LPV/r) and those exposed to atazanavir/ritonavir (ATV/r). METHODS: A retrospective case note review was carried out. The case notes of 493 women who conceived while on LPV/r or ATV/r or initiated LPV/r or ATV/r during pregnancy and who delivered between 1 September 2007 and 30 August 2012 were reviewed. Data collected included demographics, antiretroviral use, HIV markers, and pregnancy and infant outcomes. Infant outcomes, virological efficacies and PTD rates for LPV/r and ATV/r were compared. RESULTS: A total of 306 women received LPV/r (82 conceiving while on the drug and 224 commencing it post-conception) and 187 received ATV/r (96 conceiving while on the drug and 91 commencing it post-conception). Comparing the two protease inhibitors (PIs), viral suppression rates were similar and, in women starting antiretroviral therapy (ART) post-conception, the median times to first undetectable HIV viral load were not significantly different (P = 0.64). PTD rates did not differ by therapy overall (ATV/r, 13%; LPV/r, 14%) or when considering the timing of first exposure (conceiving on ART, P = 0.81; commencing ART in pregnancy, P = 0.08). Poor fetal outcomes were very uncommon. There were two transmissions, giving a mother-to-child transmission (MTCT) rate of 0.4% (95% confidence interval 0.05-1.5%). CONCLUSIONS: Both ART regimens were well tolerated and successful in preventing MTCT. No significant differences in tolerability or in pregnancy or infant outcomes were observed, which supports the provision of a choice of PI in pregnancy.

PAR(2) expression in peripheral blood monocytes of patients with rheumatoid arthritis.

OBJECTIVES: Proteinase-activated receptor 2 (PAR(2)) is a G protein-coupled receptor activated by serine proteinases with proinflammatory activity. A study was undertaken to investigate the presence and functional significance of PAR(2) expression on rheumatoid arthritis (RA)-derived leucocyte subsets. METHODS: Venous blood was obtained from patients with RA and osteoarthritis (OA) as well as healthy control subjects. Surface expression of PAR(2) on peripheral blood mononuclear cells (PBMCs) was analysed by flow cytometry and interleukin 6 (IL-6) generation by ELISA. RESULTS: Patients with RA had elevated but variable surface expression of PAR(2) on CD14+ monocytes compared with control subjects (median (1st to 3rd quartiles) 1.76% (0.86-4.10%) vs 0.06% (0.03-0.81%), p<0.0001). CD3+ T cells showed a similar pattern with significantly higher PAR(2) expression in patients with RA compared with controls (3.05% (0.36-11.82%) vs 0.08% (0.02-0.28%), p<0.0001). For both subsets, PAR(2) expression was significantly higher (p<0.00001) in patients with high levels of disease activity: PAR(2) expression for both CD14+ and CD3+ cells correlated to C reactive protein and erythrocyte sedimentation rate. Furthermore, in a cohort of patients with newly diagnosed RA, elevated PAR(2) expression in both CD14+ and CD3+ cells was significantly reduced 3 months after methotrexate or sulfasalazine treatment and this reduction correlated significantly with the reduction in the 28-joint Disease Activity Scale score (p<0.05). PAR(2) expression on cells from patients with OA was low, similar to levels seen in control subjects. Generation of IL-6 by monocytes in response to a selective PAR(2) agonist was significantly greater in patients with RA than in patients with OA and control subjects (p<0.05). CONCLUSIONS: These findings are consistent with a pathogenic role for PAR(2) in RA.

Hemispherical differences in the shape and topography of asteroid (101955) Bennu.

We investigate the shape of near-Earth asteroid (101955) Bennu by constructing a high-resolution (20 cm) global digital terrain model from laser altimeter data. By modeling the northern and southern hemispheres separately, we find that longitudinal ridges previously identified in the north extend into the south but are obscured there by surface material. In the south, more numerous large boulders effectively retain surface materials and imply a higher average strength at depth to support them. The north has fewer large boulders and more evidence of boulder dynamics (toppling and downslope movement) and surface flow. These factors result in Bennu's southern hemisphere being rounder and smoother, whereas its northern hemisphere has higher slopes and a less regular shape. We infer an originally asymmetric distribution of large boulders followed by a partial disruption, leading to wedge formation in Bennu's history.

Shape of (101955) Bennu indicative of a rubble pile with internal stiffness.

The shapes of asteroids reflect interplay between their interior properties and the processes responsible for their formation and evolution as they journey through the Solar System. Prior to the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) mission, Earth-based radar imaging gave an overview of (101955) Bennu's shape. Here, we construct a high-resolution shape model from OSIRIS-REx images. We find that Bennu's top-like shape, considerable macroporosity, and prominent surface boulders suggest that it is a rubble pile. High-standing, north-south ridges that extend from pole to pole, many long grooves, and surface mass wasting indicate some low levels of internal friction and/or cohesion. Our shape model indicates that, similar to other top-shaped asteroids, Bennu formed by reaccumulation and underwent past periods of fast spin leading to its current shape. Today, Bennu might follow a different evolutionary pathway, with interior stiffness permitting surface cracking and mass wasting.

Tumor-suppressor p53 and the cell cycle.

The p53 tumor suppressor is a transcription factor that can activate the expression of some genes and repress the transcription of others. The protein appears to be dispensable for normal murine development, although mice lacking p53 develop tumors at an early age and their fibroblasts are genetically unstable in culture. Human and murine cells lacking wild-type p53 loose the ability to arrest in the G1 phase of the cell cycle in response to gamma-irradiation. Therefore, p53 may be a cell-cycle checkpoint protein that regulates the cycle under adverse conditions.

Effect of etanercept on serum amyloid A protein (SAA) levels in patients with AA amyloidosis complicating inflammatory arthritis.

We assessed changes in serum amyloid A protein (SAA) levels during treatment with etanercept in AA amyloidosis complicating inflammatory arthritis. Five women and four men with AA amyloidosis and inflammatory arthritis received etanercept. SAA levels were recorded before and after commencement of treatment. Previous immunosuppressive drugs included cyclophosphamide (four patients), azathioprine (three patients), methotrexate (two patients) and chlorambucil (in one patient). Two patients received no disease modifying drugs between the time of diagnosis of AA amyloidosis and commencement of etanercept. In seven out of nine patients the median SAA level during etanercept treatment was lower than levels before anti-tumour necrosis factor therapy. In five out of nine patients, the median post treatment level was <11 mg/l. There were no significant changes in serum creatinine or proteinuria during periods (median, 23 months; range, 1-24 months) of etanercept therapy. The etanercept was stopped in four patients because of: acute bacterial endocarditis, psoriasiform rash, psychosis and leukopenia. In two of these patients alternative biologics were commenced (adalimumab or anakinra) and one was restarted on etanercept. One patient died of cerebral haemorrhage during the study. Etanercept therapy was associated with a fall in SAA levels in seven of nine patients, five of whom achieved levels which might be expected to be associated with stable or regressing amyloid deposits. Etanercept represents a useful alternative to immunosuppressant therapy such as cyclophosphamide or chlorambucil. Further work is needed to establish whether organ damage related to AA amyloidosis is slowed by etanercept.

Dust grains fall from Saturn's D-ring into its equatorial upper atmosphere.

The sizes of Saturn's ring particles range from meters (boulders) to nanometers (dust). Determination of the rings' ages depends on loss processes, including the transport of dust into Saturn's atmosphere. During the Grand Finale orbits of the Cassini spacecraft, its instruments measured tiny dust grains that compose the innermost D-ring of Saturn. The nanometer-sized dust experiences collisions with exospheric (upper atmosphere) hydrogen and molecular hydrogen, which forces it to fall from the ring into the ionosphere and lower atmosphere. We used the Magnetospheric Imaging Instrument to detect and characterize this dust transport and also found that diffusion dominates above and near the altitude of peak ionospheric density. This mechanism results in a mass deposition into the equatorial atmosphere of ~5 kilograms per second, constraining the age of the D-ring.

Chemical interactions between Saturn's atmosphere and its rings.

The Pioneer and Voyager spacecraft made close-up measurements of Saturn's ionosphere and upper atmosphere in the 1970s and 1980s that suggested a chemical interaction between the rings and atmosphere. Exploring this interaction provides information on ring composition and the influence on Saturn's atmosphere from infalling material. The Cassini Ion Neutral Mass Spectrometer sampled in situ the region between the D ring and Saturn during the spacecraft's Grand Finale phase. We used these measurements to characterize the atmospheric structure and material influx from the rings. The atmospheric He/H2 ratio is 10 to 16%. Volatile compounds from the rings (methane; carbon monoxide and/or molecular nitrogen), as well as larger organic-bearing grains, are flowing inward at a rate of 4800 to 45,000 kilograms per second.

The p53 tumor suppressor protein does not regulate expression of its own inhibitor, MDM2, except under conditions of stress.

MDM2 is an important regulator of the p53 tumor suppressor protein. MDM2 inhibits p53 by binding to it, physically blocking its ability to transactivate gene expression, and stimulating its degradation. In cultured cells, mdm2 expression can be regulated by p53. Hence, mdm2 and p53 can interact to form an autoregulatory loop in which p53 activates expression of its own inhibitor. The p53/MDM2 autoregulatory loop has been elucidated within cultured cells; however, regulation of mdm2 expression by p53 has not been demonstrated within intact tissues. Here, we examine the role of p53 in regulating mdm2 expression in vivo in order to test the hypothesis that the p53/MDM2 autoregulatory loop is the mechanism by which low levels of p53 are maintained. We demonstrate that basal expression of mdm2 in murine tissues is p53 independent, even in tissues that express functional p53. Transcription of mdm2 is induced in a p53-dependent manner following gamma irradiation, indicating that p53 regulates mdm2 expression in vivo following a stimulus. The requirement for a stimulus to activate p53-dependent regulation of mdm2 expression in vivo appeared to differ from the situation in early-passage mouse embryo fibroblasts, where mdm2 expression is enhanced by the presence of p53. Analysis of mdm2 expression in intact and dispersed embryos revealed that establishment of mouse embryo fibroblasts in culture induces p53-dependent mdm2 expression, suggesting that an unknown stimulus activates p53 function in cultured cells. Together, these results indicate that p53 does not regulate expression of its own inhibitor, except in response to stimuli.

A ras-dependent pathway abolishes activity of a muscle-specific enhancer upstream from the muscle creatine kinase gene.

Differentiation of skeletal myoblasts is accompanied by induction of a series of tissue-specific genes whose products are required for the specialized functions of the mature muscle fiber. The program for myogenic differentiation is subject to negative control by several peptide growth factors and by the products of mutationally activated ras oncogenes, which persistently activate intracellular cascades normally triggered by specific growth factors. Previously, we reported that induction of the muscle creatine kinase (mck) gene during myogenesis was dependent on a distal upstream enhancer that cooperated with a proximal promoter to direct high levels of expression in developing muscle cells (E. A. Sternberg, G. Spizz, W. M. Perry, D. Vizard, T. Weil, and E. N. Olson, Mol. Cell. Biol. 8:2896-2909). To investigate the mechanisms whereby ras blocks the induction of muscle-specific genes, we have examined the ability of mck 5' regulatory elements to direct expression of the linked reporter gene for chloramphenicol acetyltransferase (cat) in C2 myoblasts bearing mutant N-ras and H-ras oncogenes. In this paper we report that expression of activated ras alleles abolishes activity of the mck upstream enhancer but does not affect the activity of the mck promoter. The ability of ras to repress the expression of mck-cat fusion genes that have been transfected either transiently or stably into myoblasts suggests that ras may exert its effects on muscle-specific genes through mechanisms independent of chromatin configurations or DNA methylation. These results also suggest that ras blocks establishment of the myogenic phenotype by preventing the accumulation of regulatory factors required for transcriptional induction of muscle-specific genes.

Defects in transcription coupled repair interfere with expression of p90(MDM2) in response to ultraviolet light.

Ultraviolet (UV) irradiation transiently stabilizes p53 through a mechanism that may require a decrease in the activity of the ubiquitin ligase, p90(MDM2). Conversely, the recovery of low levels of p53 following UV exposure may depend on an increase in p90(MDM2). The level of p90(MDM2) is increased by UV light following the p53-dependent induction of an internal mdm2 promoter, P2. If this induction of mdm2 were critical for the recovery of low levels of p53 following UV exposure, defects in mdm2's transcription would result in a prolonged increase in p53. Cells defective in transcription coupled repair (TCR) maintain high levels of p53 for a prolonged period following UV exposure. Such cells also have defects in general transcription after UV irradiation. We investigated whether TCR-deficient cells express diminished levels of mdm2 mRNA and p90(MDM2) following UV exposure. We found that transcription of mdm2 was reduced in TCR-deficient cells. The uninducible mdm2 promoter, P1, was more sensitive to the inhibitory effects of UV irradiation than the P2 promoter. The decrease in transcription from the P1 promoter was sufficient to reduce the level of p90(MDM2) and correlated with a prolonged increase in p53. Thus, p53-independent transcription of mdm2 appears critical to p53's regulation.

Characterization of the 5' and 3' untranslated regions in murine mdm2 mRNAs.

The murine double minute 2 (mdm2) gene is essential for embryogenesis in mice that express the p53 tumor suppressor protein. Mdm2 levels must be regulated tightly because overexpression of mdm2 contributes to tumorigenesis. We investigated whether the 5' and 3' untranslated regions (UTRs) of murine mdm2 affect the expression of MDM2 proteins. Induction of mdm2 expression by p53 results in synthesis of an mdm2 mRNA with a short 5' UTR. The long 5' UTR increases internal initiation of translation of a minor MDM2 protein, p76(MDM2), without affecting the efficiency of translation of the full-length p90(MDM2). We discovered two alternative 3' untranslated regions in murine mdm2 mRNA expressed in the testis. The longer 3' UTR contains a consensus instability element, but mdm2 mRNAs containing the long and short 3' UTRs have comparable half-lives. The 3' UTRs do not affect either initiation codon use or translation efficiency. Thus, the murine 5' UTR, but not the 3'UTR, influences the ratio of the two MDM2 proteins but neither UTR affects MDM2 abundance significantly.

Selective binding of peripheral blood lymphocytes to the walls of cerebral vessels in frozen sections of human brain.

In order to identify the factors that control the binding of blood leucocytes to cerebral blood vessels we have modified and applied the frozen section assay of Stamper and Woodruff to the study of human brain. Cryostat sections of brain tissue obtained at post mortem were overlaid with blood lymphocytes and experimental conditions were defined which permitted optimum binding of the cells to transected blood vessel walls. The maximal binding of lymphocytes to cerebral vessels occurred when 6 x 10(6) lymphocytes were overlaid onto brain sections for 30 min at 7 degrees C with gentle agitation. Only a small proportion (0.01%) of the added lymphocytes bound to exposed cerebral vessels. However, lymphocytes were far more adherent than monocytes and polymorphonuclear cells (7-fold and 11-fold respectively: p < 0.001) and activation of lymphocytes with IL-2 enhanced their binding to blood vessel walls (mean 130% increase; p < 0.03). Further analysis revealed that CD4-positive T lymphocytes were the predominant cell population binding to the blood vessels. Antibody blocking studies showed that lymphocyte binding to cerebral blood vessels was inhibited by pretreating the lymphocytes with anti-CD11a, anti-CD18 or anti-CD49d (p < or = 0.02) and immunohistochemical studies revealed the presence of the counter-receptors ICAM-1 (CD54) and VCAM-1 (CD106) for these adhesion molecules in addition to the presence of E-selectin (CD62E) and P-selectin (CD62P) on the cerebral blood vessels. The establishment of a technique in situ which measures selective binding of CD4-positive peripheral lymphocytes to sections of cerebral blood vessels will assist in the molecular characterization of factors that control the interaction of leucocytes with the blood-brain barrier in health and disease.

Incidence of fever and bacteremia following transbronchial needle aspiration.

Fiberoptic bronchoscopy and transbronchial needle aspiration were performed on 50 occasions in 47 afebrile patients. The aspirations were followed by endobronchial or transbronchial biopsies in 22 patients, as well as bronchial brushings and washings where appropriate. Blood for cultures was drawn at 5 and 30 minutes following needle aspiration, as well as at the time of any temperature above 38 degrees C during the 24 hours following the procedure. In five (10 percent) of the 50 cases, there was temperature greater than 38 degrees C (100.4 degrees F) in the 24 hours following the bronchoscopy; in no patient were cultures of blood positive, whether done early after the procedure or at the time of fever. We conclude that transbronchial needle aspiration, a new procedure gaining widespread popularity in diagnostic thoracic medicine, is not associated with clinically detectable bacteremia. This procedure should not require antimicrobial prophylaxis in patients susceptible to endocarditis.

Induction of gene amplification by 5-aza-2'-deoxycytidine.

Treatment of Syrian hamster kidney cells with the demethylating agent 5-aza-2'-deoxycytidine (azadC) increased both the frequency and the rate of gene amplification appreciably. AzadC caused substantial DNA demethylation, which is likely to be responsible. The magnitude of the increases depended on the concentrations of both azadC and the drug used for selection. A transient stress response is not responsible since the increases were not dependent on cytotoxicity and were still apparent after several weeks. We discuss mechanisms by which azadC treatment may induce amplification by rendering DNA more prone to this process or by increasing the transcription of genes whose protein products stimulate amplification.

P53 and mdm-2: interactions between tumor suppressor gene and oncogene products.

The p53 tumor suppressor gene is the most commonly mutated gene in human cancers and, although mutation leads to loss of p53 suppression of cell growth, it can also result in new functions which enhance tumorigenicity. These mutations often lead to loss of p53 transcriptional activation activity, which is likely to account for the loss of growth control. The p53 protein induces expression of the GADD45 and mdm-2 genes, and the respective roles of the products of these two genes in the regulation of growth control, apoptosis, amplification, and the response to DNA damage remain to be determined. Although some facts are clear at this juncture, we can surely expect some surprises in the future, including additional functions for the p53 tumor suppressor gene product and a constant reevaluation of our present concepts. The study of the p53 regulatory pathway, however, should lead us to additional important genes and proteins central to an explanation of the origins of cancer.

Burn depth and its histological measurement.

This paper describes a new technique for burn depth measurement, based on the histological assessment of dermal microvascular occlusion in burn biopsies. The technique was validated in a preliminary study of acute progressive microvascular damage in five adults with partial thickness burns. Burn depth was calculated at three time points post burn from the mean histological measurement of the most superficial patent and the deepest blocked vessels in five separate sections from each biopsy. The results were expressed as a percentage of the total dermal thickness and correlated well with the laser Doppler measurement of dermal blood flow and clinical estimation of burn depth. The reproducibility of the technique was tested by the repeated blind analysis of five randomly chosen biopsies on a separate occasion. Altman-Bland plot analysis demonstrated a median variation of 0.1% (95% confidence interval -1 to 2%). A second independent observer (MPHT), who carried out a blind analysis of the same randomly chosen biopsies, tested the precision of the technique. The median variation was 2% (95% confidence interval -5 to 8.5%).

Dermal cellular inflammation in burns. an insight into the function of dermal microvascular anatomy.

The damage caused by thermal trauma is augmented by the subsequent inflammatory response in a similar fashion to reperfusion injury. Animal studies have demonstrated a significant role for neutrophils in this delayed damage, but little is known about the numbers of neutrophils or other leucocytes that enter human skin following burns. We have longitudinally examined profiles of leucocyte migration into five cases of human partial thickness burns in relation to continued dermal microvascular destruction during the acute post-burn period. All burn wounds had a rapid influx of neutrophils that was followed by a delayed influx of macrophages. Compared to the controls, the two superficial burns also had rapid and sustained influx of CD4 and CD8 lymphocytes via patent post capillary venules in the dermal superficial vascular plexus, whilst in the three deeper burns, in which this superficial vascular plexus was occluded, the number of lymphocytes decreased. These results suggest that the patterns of leucocyte extravasation were dependent on the initial level of vascular occlusion, indicating that the dermal microvascular anatomy plays a pivotal role in determining the composition of the extravascular inflammatory cell infiltrates. The potential importance of this finding is highlighted by the differences in wound behaviour associated with the different leucocyte profiles.

The effect of intermediate altitude on the Army Physical Fitness Test.

Official physical training records of personnel stationed at intermediate altitude (elevation 5,280 feet) for at least 1 year were reviewed to gauge the effect of altitude on 2-mile running performance. An average of 48 additional seconds (a 5% increase in time) was required to complete the run compared to sea-level values in the same subjects. Run times gradually diminished during the first 9 months of assignment to altitude before stability was established. These data indicate that acclimatization occurs over several months. Even with acclimatization, substantial loss of performance is associated with habitation at intermediate altitude.