Implications of new anticoagulants in primary practice

BACKGROUND

Effective prophylaxis and treatment of thromboembolic disorders remain suboptimal in many healthcare systems, partly owing to limitations of traditional anticoagulants. New oral anticoagulants have been developed and among these, rivaroxaban, apixaban and dabigatran etexilate are in the most advanced stage of clinical development.

METHOD

A literature search using the PubMed and ClinicalTrials.gov databases was performed to identify English-language publications. The search was performed up to 31 December 2011 with the terms rivaroxaban OR Xarelto, apixaban OR Eliquis and dabigatran OR Pradaxa. Ongoing, completed and published phase III randomised controlled trials were selected as the primary source of information for the clinical development programme of each drug.

RESULTS

The new oral agents demonstrate several advantages over traditional anticoagulants, including administration at fixed doses and no requirement for routine coagulation monitoring On the basis of phase III clinical trials, rivaroxaban, apixaban and dabigatran etexilate have been approved in many countries for the prevention of venous thromboembolism after hip and knee replacement surgery. Dabigatran etexilate and rivaroxaban have also been approved for the prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation in Europe and the US. In addition, rivaroxaban has been approved in Europe for the treatment of acute deep vein thrombosis and prevention of recurrent venous thromboembolism. Approval of these agents and postapproval monitoring of their safety and efficacy will have implications for primary care.

CONCLUSION

Rivaroxaban, apixaban and dabigatran etexilate offer the possibility of simplified prevention and treatment strategies for thromboembolic disorders in the outpatient setting.

Observation of time-reversal violation in the B0 meson system

Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) or ccK(S)(0) final states (referred to as B(+) or B(-)), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B(0) → B(-) and B(-) → B(0), as a function of the time difference between the two B decays. Using 468 × 10(6) BB pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS(T)(+) = -1.37 ± 0.14(stat) ± 0.06(syst) and ΔS(T)(-) = 1.17 ± 0.18(stat) ± 0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.

Precision measurement of the B → Xs γ photon energy spectrum, branching fraction, and direct CP asymmetry A(CP)((B → X(s+d)γ)

The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B → X(s)γ plus B → X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) → BB decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B → X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B → X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.

Evidence for an excess of B→D*τ(-)ν(τ) decays

Based on the full BABAR data sample, we report improved measurements of the ratios R(D(*))=B(B[over ¯]→D(*)τ(-)ν[over ¯](τ))/B(B[over ¯]→D(*)ℓ(ℓ)(-)ν[over ¯](ℓ)), where ℓ is either e or μ. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D)=0.440±0.058±0.042 and R(D(*))=0.332±0.024±0.018, which exceed the standard model expectations by 2.0σ and 2.7σ, respectively. Taken together, our results disagree with these expectations at the 3.4σ level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.

Contralateral distribution of nonmelanoma skin cancer between older Hispanic/Latino and non-Hispanic/non-Latino individuals

BACKGROUND

 A recent review of the SEER database revealed that melanoma and Merkel cell carcinoma occur more commonly on the left side of the body. Similarly, a trend was reported in which nonmelanoma skin cancers (NMSCs) were found to be distributed more frequently on the left side of the body.

OBJECTIVES

 To compare the sidedness of NMSC in a large patient population. There were five primary objectives of the present study: (i) to confirm or refute the left-sided trend of NMSC in the largest patient population studied for asymmetry to date; (ii) to determine whether the left-sided trend existed in Hispanic/Latino individuals; (iii) to examine skin cancer in older individuals across ethnicities; (iv) to compare distribution across anatomical location and ethnicity; and (v) to measure gender differences in the distribution of NMSC.

METHODS

 The last 3026 cases referred to the Mohs surgical unit at the University of Miami Miller School of Medicine during 2008-2011 were reviewed. The patient's age, gender, tumour side, tumour type, anatomical location and ethnicity were recorded.

RESULTS

 There were 1505 (50·2%) right-sided tumours and 1495 (49·8%) left-sided tumours (P=0·52). The Hispanic/Latino group had a nonsignificant right-sided trend with 607 (52·7%) right-sided cases and 545 (47·3%) left-sided cases (P=0·06). The non-Hispanic/non-Latino group between the ages of 60 and 85 years had 605 (46·9%) right-sided tumours and 686 (53·1%) left-sided tumours (P=0·024). The Hispanic/Latino group between the ages of 60 and 85 years demonstrated 404 (54·0%) right-sided tumours and 344 (46·0%) left-sided tumours (P=0·028). One hundred and fifty-four skin cancers were located on the upper extremities of non-Hispanic/non-Latino individuals with 64 (41·6%) being right sided and 90 (58·4%) left sided (P=0·036). Seventy-eight skin cancers were located on the upper extremities of Hispanic/Latino individuals with 49 (62·8%) being right sided and 29 (37·2%) left sided (P=0·024). Males had most of the skin cancers at 2125 (70·8%) cases and females had 875 (29·2%) cases (P<0·001).

CONCLUSIONS

 NMSC appears to be more common on the left side of older non-Hispanic/non-Latino individuals, while it is more common on the right side of older Hispanic/Latino individuals. This is likely to be secondary to an environmental factor, such as ultraviolet radiation. NMSC is significantly more common in males relative to females, which may be attributed to differences in gender roles or referral practices.

Search for low-mass dark-sector Higgs bosons

Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb(-1) of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the standard model-dark-sector mixing angle and the dark-sector coupling constant.

Hair loss in women: medical and cosmetic approaches to increase scalp hair fullness

Androgenetic alopecia affects both men and women. In men it produces male pattern hair loss with bitemporal recession and vertex baldness. In women it produces female pattern hair loss (FPHL) with diffuse alopecia over the mid-frontal scalp. FPHL occurs as a result of nonuniform hair follicle miniaturization within follicular units. Diffuse alopecia is produced by a reduction in the number of terminal fibres per follicular unit. Baldness occurs only when all hairs within the follicular units are miniaturized and is a relatively late event in women. The concepts of follicular units and primary and secondary hair follicles within follicular units are well established in comparative mammalian studies, particularly in sheep. However, discovery of these structures in the human scalp hair and investigation of the changes in follicular unit anatomy during the development of androgenetic alopecia have provided a clearer understanding of the early stages of androgenetic alopecia and how the male and female patterns of hair loss are related. FPHL is the most common cause of alopecia in women and approximately one-third of adult caucasian women experience hair loss. The impact of FPHL is predominantly psychological. While men anticipate age-related hair loss, hair loss in women is usually unexpected and unwelcome at any age. Treatment options to arrest hair loss progression and stimulate partial hair regrowth for FPHL include the androgen receptor antagonists spironolactone and cyproterone acetate, the 5α-reductase inhibitor finasteride and the androgen-independent hair growth stimulator minoxidil. These treatments appear to work best when initiated early. Hair transplantation should be considered in advanced FPHL that is resistant to medical treatments. Hair transplantation requires well-preserved hair growth over the occipital donor area. The psychological impact of FPHL may also be reduced by cosmetic products that improve the appearance of the hair. These agents work to minimize hair fibre breakage, improve hair volume or conceal visible bald scalp.

202 SEX PRE-SELECTION IN RABBITS: AN ATTEMPT TO SKEW OFFSPRING SEX THROUGH PERCOLL AND SWIM-UP SPERM PREPARATION TECHNIQUES

Sperm preparation techniques could have an effect on the birth ratio (male vs female offspring) through enrichment of either X- or Y-bearing sperm populations, although studies have been poorly controlled and results have been inconclusive. In the rabbit, producers may be interested in producing a majority of males (meat producing systems) or females (hybrid producing systems). The objective of this study was to evaluate the effect of modified Percoll and Swim-up protocols on the enrichment of the male and female birth ratios in rabbits. Four hybrid mature bucks of adequate body condition score and proven fertility were used. The same four bucks were used throughout the study (8 replicates). Ejaculates were collected using a warmed, solid, artificial vagina. Progressive motility was assessed at 200× magnification under brightfield microscopy on a heated (37°C) stage. Sperm concentration for each buck was determined using a Neubaur chamber and adjusted (350 × 106 total spermatozoa mL–1); they were then combined (1 mL/buck) to form a heterospermic sample (final heteropsermic sample volume = 4 mL). The heteropsermic sample was then divided into 3 sperm preparation treatments: (1) diluted in commercial tri-buffered extender followed by immediate AI (control); (2) modified Percoll centrifugation in a 90 to 45% density gradient (diluted in human tubal fluid medium); and (3) Swim-up (in human tubal fluid medium). In total, 125 females were inseminated. Does were treated with PMSG (20 UI/doe, 48 h before AI) and inseminated with 30 to 40 × 106 spermatozoa; ovulation was induced with 20 μg of gonadotropin-releasing hormone (GnRH)/doe immediately after AI. Sex of newborn kits was determined 35 days after birth by an experienced technician through external visualization of genitalia. Results were statistically analyzed using ANOVA and Tukey test (Infostat). The insemination of does with heterospermic ejaculates (control) resulted in a progeny distribution of 49 ± 2% males and 51 ± 2% females, which is in good agreement with the expected theoretical 50:50 ratio. Sex ratios from modified Percoll and Swim-up treatments deviated significantly from the control (P < 0.01). Percoll gradient resulted in a progeny distribution of 32 ± 2% males and 68 ± 2% females; Swim-up resulted in a 64 ± 2% male and a 36 ± 2% female distribution (P < 0.01), whereas prolificacy, perinatal mortality and birth weight were not affected by treatment (Table 1). Our results indicate sperm preparation techniques could be used to skew birth ratios towards male or female offspring in rabbits; Percoll preparation could be used to increase proportion of female kits whereas Swim-up could be used to increase the proportion of males. Further studies are needed to determine the underlying mechanisms of action. Table 1.Progeny distribution after Percoll or Swim-up sperm preparation in rabbits

48 EFFECT OF TREHALOSE ADDITION ON IN VITRO VIABILITY OF COOLED RAM SPERMATOZOA

Refrigeration of ovine spermatozoa is a valuable tool for genetic progress. Sugars, in particular disaccharides, have been shown to have positive effects in semen extender, providing energy substrate during cell incubation, decreasing osmotic pressure, causing cell dehydration and ultimately reducing cold shock and cryodamage. Several authors have reported changes in plasma membrane protein organisation and membrane fluidity during cooling. Trehalose, a non-reducing disaccharide has been associated with stabilisation of cellular proteins and interaction with membrane phospholipids due to its ability to replace water at the membrane-solution interface. Many studies have confirmed the beneficial effect of the addition of trehalose during cryopreservation at –196°C; however, its effects during refrigeration (5–7°C) have not been reported. Ejaculates form four fertile Corriedale rams were collected by electroejaculation during the ovine reproductive season in the Southern Hemisphere (May–August); the study was conducted in 12 replicates. After initial quality assessment, ejaculates were pooled into heterospermic samples, diluted in Tris-buffered extender and separated into treatments consisting of (a) no refrigeration (kept at room temperature 22–25°C), (b) refrigeration (cooling rate of 2°C/3 min to reach a final temperature of 5–7°C), or (c) refrigeration with the addition of 150 mOsm trehalose. Samples were evaluated for total motility, progressive motility, hyposmotic swelling test (HOST) and eosin Y (1 step, WHO protocol) live/dead stain at 0, 6, 12, 24 and 48 h post-refrigeration. Results were analysed using 1-way ANOVA with Tukey post-hoc multiple comparison test. Compared with refrigeration without the addition of disaccharides, the refrigeration in presence of trehalose significantly increased (P < 0.05) total motility at 48 h (32 ± 0.9 vs 50 ± 1.1) and progressive motility at 24 (40 ± 0.9 vs 65 ± 0.6) and 48 h (0 vs 38 ± 1.0) post-refrigeration. Trehalose also decreased (P < 0.05) the percentage of damaged spermatozoa as evidenced by HOST and live/dead stain after 12 (42 ± 1.1 vs 29 ± 0.7), 24 (52 ± 0.9 vs 37 ± 0.6) and 48 h (74 ± 0.8 vs 60 ± 1.0) of refrigeration. Although no statistical difference was detected, there was a trend of trehalose to improve total and progressive motility parameters at the initiation of treatments (0 h). In addition, spermatozoa refrigerated in the presence of trehalose was the only treatment group to retain progressive motility after 48 h of storage. Our results indicate that trehalose could be used to extend the in vitro viability of refrigerated ovine spermatozoa for up to 48 h. Further studies are needed to assess the in vivo fertility (pregnancy rate) of refrigerated spermatozoa in the presence of this non-permeating cryoprotectant sugar.

Regulatory T cells contribute to diabetes protection in lipopolysaccharide-treated non-obese diabetic mice

It is well established that viral, parasitic or bacterial infections can prevent type 1 diabetes (T1D) occurrence in non-obese diabetic (NOD) mice. On the other hand, defects in CD4(+) Regulatory T cell (Treg) numbers and/or function contribute to T1D aetiology in NOD mice and in humans. In this work, we formally tested whether the protective role of the bacterial product lipopolysaccharide (LPS) on diabetes incidence results from enhanced Treg activity. We first report that weekly administration of LPS to young prediabetic NOD mice, presenting or not insulitis at the time of treatment, afforded full protection from diabetes. Taking advantage from the high but incomplete penetrance of diabetes in NOD mice raised in specific pathogen free (SPF) conditions we compared untreated disease-free old animals with gender- and age-matched LPS-treated mice. Histological and flow cytometry analysis indicated that LPS treatment did not prevent islet infiltration or priming of diabetogenic T cells but increased Foxp3(+) and CD103(+) Treg frequency and numbers. By performing adoptive transfer experiments into alymphoid NOD/SCID recipients, we further demonstrated that CD25(+) cells from LPS-treated NOD mice, but not from naturally protected animals, maintained diabetogenic cells at check. Our study suggests that T cell regulation represents a cellular mechanism to explain the 'hygiene hypothesis' and reinforces the notion that immune activity consolidates dominant tolerance.

Search for hadronic decays of a light Higgs boson in the radiative decay Υ→γA0

We search for hadronic decays of a light Higgs boson (A(0)) produced in radiative decays of an Υ(2S) or Υ(3S) meson, Υ→γA(0). The data have been recorded by the BABAR experiment at the Υ(3S) and Υ(2S) center-of-mass energies and include (121.3±1.2)×10(6) Υ(3S) and (98.3±0.9)×10(6) Υ(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions B(Υ(nS)→γA(0))B(A(0)→hadrons) (n=2 or 3) that range from 1×10(-6) for an A(0) mass of 0.3 GeV/c(2) to 8×10(-5) at 7 GeV/c(2).

Synthesis and Properties of Magnetic Cobalt–Samarium Nanocluster Assemblies

Bimetallic cobalt–samarium nanoparticles are prepared in the gas phase using a combined laser vaporization-rare gas condensation source and subsequently deposited on various substrates or embedded in non-magnetic metallic matrix using the Low Energy Cluster Beam Deposition technique (LECBD). Structural and magnetic characterizations from assemblies of isolated clusters, reveal Co – Sm clusters with a mean diameter around 3.5 nm, and a loss of magnetization compared to the bulk SmCo 5 phase, probably due to an amorphous state associated to a segregation of the samarium atoms at the cluster surface. Annealing in ultra high vacuum up to 820 K considerably improves the crystallinity and the homogeneity of the mixed clusters leading to a significant increase of the magnetic anisotropy and consequently of the blocking temperature, as large as 400 K, without significantly increasing the mean size (around 6 nm). Such results seem promising for applications to high density memory devices and spintronics.