Search for universal extra dimensions in pp collisions

We present a search for Kaluza-Klein (KK) particles predicted by models with universal extra dimensions (UED) using a data set corresponding to an integrated luminosity of 7.3 fb(-1), collected by the D0 detector at a pp center-of-mass energy of 1.96 TeV. The decay chain of KK particles can lead to a final state with two muons of the same charge. This signature is used to set a lower limit on the compactification scale of R(-1)>260 GeV in a minimal UED model.

Search for charged massive long-lived particles

We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2  fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx) inconsistent with muons produced in beam collisions. CMLLPs are predicted in several theories of physics beyond the standard model. We exclude pair-produced long-lived gauginolike charginos below 267 GeV and Higgsino-like charginos below 217 GeV at 95% C.L., as well as long-lived scalar top quarks with mass below 285 GeV.

Evidence for spin correlation in t ̅t production

We present a measurement of the ratio of events with correlated t and t ̅t spins to the total number of t ̅t events. This ratio f is evaluated using a matrix-element-based approach in 729 t ̅t candidate events with a single lepton ℓ (electron or muon) and at least four jets. The analyzed p ̅p collisions data correspond to an integrated luminosity of 5.3 fb(-1) and were collected with the D0 detector at the Fermilab Tevatron collider operating at a center-of-mass energy √s=1.96 TeV. Combining this result with a recent measurement of f in dileptonic final states, we find f in agreement with the standard model. In addition, the combination provides evidence for the presence of spin correlation in t ̅t events with a significance of more than 3 standard deviations.

Search for doubly charged Higgs boson pair production in pp¯ collisions at √s=1.96 TeV

We present a search for pair production of doubly charged Higgs bosons in the processes qq¯→H(++)H(--) decaying through H(±±)→τ(±)τ(±),μ(±)τ(±),μ(±)μ(±). The search is performed in pp¯ collisions at a center-of-mass energy of √s = 1.96 TeV using an integrated luminosity of up to 7.0 fb(-1) collected by the D0 experiment at the Fermilab Tevatron Collider. The results are used to set 95% C.L. limits on the pair production cross section of doubly charged Higgs bosons and on their mass for different H(±±) branching fractions. Models predicting different H(±±) decays are investigated. Assuming B(H(±±)→τ(±)τ(±))=1 yields an observed (expected) lower limit on the mass of a left-handed H(L)(±±) boson of 128 (116) GeV and assuming B(H(±±)→μ(±)τ(±))=1 the corresponding limits are 144 (149) GeV. In a model with B(H(±±)→τ(±)τ(±))=B(H(±±)→μ(±)τ(±))=B(H(±±)→μ(±)μ(±))=1/3, we obtain M(H(L)(±±))>130 (138) GeV.

Wγ production and limits on anomalous WWγ couplings in pp collisions at sqrt[s] = 1.96 TeV

We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W(→lν) + γ production in eγ and μγ final states. Using data corresponding to an integrated luminosity of 4.2  fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider, the measured cross section times branching fraction for the process pp → Wγ + X → lνγ + X and the distribution of the charge-signed photon-lepton rapidity difference are found to be in agreement with the standard model. These results provide the most stringent limits on anomalous WWγ couplings for data from hadron colliders: -0.4<Δκ(γ)<0.4 and -0.08<λ(γ)<0.07 at the 95% C.L.

Search for a fermiophobic and standard model Higgs boson in diphoton final states

We present a search for the standard model Higgs boson and a fermiophobic Higgs boson in the diphoton final states based on 8.2  fb(-1) of pp collisions at sqrt[s]=1.96  TeV collected with the D0 detector at the Fermilab Tevatron Collider. No excess of data above background predictions is observed and upper limits at the 95% C.L. on the cross section multiplied by the branching fraction are set which are the most restrictive to date. A fermiophobic Higgs boson with a mass below 112.9 GeV is excluded at the 95% C.L.

Search for neutral minimal supersymmetric standard model Higgs bosons decaying to tau pairs produced in association with b quarks in pp collisions at √s = 1.96 TeV

We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb(-1). This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymmetric extension (MSSM) at high tanβ. We search for Higgs bosons decaying to tau pairs with one tau decaying to a muon and neutrinos and the other to hadrons. The data are found to be consistent with SM expectations, and we set upper limits on the cross section times branching ratio in the Higgs boson mass range from 90 to 320 GeV/c(2). We interpret our result in the MSSM parameter space, excluding tanβ values down to 25 for Higgs boson masses below 170 GeV/c(2).

Precision measurement of the ratio B(t→Wb)/B(t→Wq) and extraction of V(tb)

We present a measurement of the ratio of top quark branching fractions R=B(t→Wb)/B(t→Wq), where q can be a d, s, or b quark, in the lepton+jets and dilepton tt final states. The measurement uses data from 5.4 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R=0.90±0.04, and we extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |V(tb)| as |V(tb)|=0.95±0.02, assuming unitarity of the 3×3 CKM matrix.

The hard-tick fauna of mainland Portugal (Acari: Ixodidae): an update on geographical distribution and known associations with hosts and pathogens

This work is an updated revision of the available information on Portuguese ixodid tick species. It includes data on tick biology, ecology, taxonomy and host/pathogen-associations. The current list of Portuguese ixodid ticks comprises twenty species: Dermacentor marginatus (Sulzer, 1776), Dermacentor reticulatus (Fabricius, 1794), Haemaphysalis hispanica Gil Collado, 1938, Haemaphysalis inermis Birula, 1895, Haemaphysalis punctata Canestrini & Fanzago, 1878, Hyalomma lusitanicum Koch, 1844, Hyalomma marginatum Koch, 1844, Ixodes acuminatus Neumann, 1901, Ixodes bivari Dias, 1990, Ixodes canisuga Johnston, 1849, Ixodes frontalis (Panzer, 1798), Ixodes hexagonus Leach, 1815, Ixodes ricinus (Linnaeus, 1758), Ixodes simplex Neumann, 1906, Ixodes ventalloi Gil Collado, 1936, Ixodes vespertilionis Koch, 1844, Rhipicephalus (Boophilus) annulatus (Say, 1821), Rhipicephalus bursa Canestrini & Fanzago, 1878, Rhipicephalus pusillus Gil Collado, 1938, and Rhipicephalus sanguineus (Latreille, 1806).

Search for a fourth generation t' Quark in p ̄p collisions at √s = 1.96 TeV

We present a search for pair production of a fourth generation t' quark and its antiparticle, followed by their decays to a W boson and a jet, based on an integrated luminosity of 5.3 fb(-1) of proton-antiproton collisions at √s = 1.96  TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the t' ̄t' production cross section that exclude at the 95% C.L. a t' quark that decays exclusively to W+jet with a mass below 285 GeV. We observe a small excess in the μ+jets channel which reduces the mass range excluded compared to the expected limit of 320 GeV in the absence of a signal.

Precise measurement of the top quark mass in the dilepton channel at D0

We measure the top quark mass (m(t)) in p ̄p collisions at a center of mass energy √s = 1.96 TeV using dilepton t ̄t→W(+)bW(-) ̄b→ℓ(+)ν(ℓ)bℓ(-) ̄ν(ℓ) ̄b events, where ℓ denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider. We obtain m(t)=174.0±1.8(stat)±2.4(syst) GeV, which is in agreement with the current world average m(t)=173.3±1.1 GeV. This is currently the most precise measurement of m(t) in the dilepton channel.

Measurement of spin correlation in tt production using a matrix element approach

We determine the fraction of tt events with spin correlation, assuming that the spin of the top quark is either correlated with the spin of the top antiquark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study tt spin correlation. We use tt → W+ b W- b → ℓ+ νbℓ- ν b final states produced in pp collisions at a center-of-mass energy sqrt(s)=1.96  TeV, where ℓ denotes an electron or a muon. The data correspond to an integrated luminosity of 5.4  fb(-1) and were collected with the D0 detector at the Fermilab Tevatron collider. The result agrees with the standard model prediction. We exclude the hypothesis that the spins of the tt are uncorrelated at the 97.7% C.L.

Search for Resonant WW and WZ Production in pp collisions at √s=1.96 TeV

We search for resonant WW or WZ production by using up to 5.4 fb(-1) of integrated luminosity collected by the D0 experiment in run II of the Fermilab Tevatron Collider. The data are consistent with the standard model background expectation, and we set limits on a resonance mass by using the sequential standard model W' boson and the Randall-Sundrum model graviton G as benchmarks. We exclude a sequential standard model W' boson in the mass range 180-690 GeV and a Randall-Sundrum graviton in the range 300-754 GeV at 95% C.L.

Bounds on an anomalous dijet resonance in W+jets production in pp collisions at √s = 1.96 TeV

We present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W boson in data corresponding to an integrated luminosity of 4.3 fb(-1) collected with the D0 detector at √s = 1.96 TeV. We find no evidence for anomalous resonant dijet production and derive upper limits on the production cross section of an anomalous dijet resonance recently reported by the CDF Collaboration, investigating the range of dijet invariant mass from 110 to 170 GeV/c(2). The probability of the D0 data being consistent with the presence of a dijet resonance with 4 pb production cross section at 145 GeV/c(2) is 8×10(-6).

Search for the standard model Higgs boson in the H→WW→lνq'q decay channel

We present a search for the standard model Higgs boson (H) in pp collisions at sqrt(s)=1.96  TeV in events containing a charged lepton (ℓ), missing transverse energy, and at least two jets, using 5.4  fb(-1) of integrated luminosity recorded with the D0 detector at the Fermilab Tevatron Collider. This analysis is sensitive primarily to Higgs bosons produced through the fusion of two gluons or two electroweak bosons, with subsequent decay H→WW→ℓνq'q, where ℓ is an electron or muon. The search is also sensitive to contributions from other production channels, such as WH→ℓνbb. In the absence of a signal, we set limits at the 95% C.L. on the cross section for H production σ(pp→H+X) in these final states. For a mass of M(H)=160  GeV, the limit is a factor of 3.9 larger than the cross section in the standard model and consistent with an a priori expected sensitivity of 5.0.

Precise study of the Z/γ* boson transverse momentum distribution in pp collisions using a novel technique

Using 7.3 fb⁻¹ of pp collisions collected by the D0 detector at the Fermilab Tevatron, we measure the distribution of the variable φ(η)*, which probes the same physical effects as the Z/γ* boson transverse momentum, but is less susceptible to the effects of experimental resolution and efficiency. A QCD prediction is found to describe the general features of the φ(η)* distribution, but is unable to describe its detailed shape or dependence on boson rapidity. A prediction that includes a broadening of transverse momentum for small values of the parton momentum fraction is strongly disfavored.

Search for single vectorlike quarks in pp ̄ collisions at √s=1.96 TeV

We present a search for hypothetical vectorlike quarks in pp ̅ collisions at √s=1.96  TeV. The data were collected by the D0 detector at the Fermilab Tevatron Collider and correspond to an integrated luminosity of 5.4  fb(-1). We select events with a final state composed of a W or Z boson and a jet consistent with a heavy object decay. We observe no significant excess in comparison to the background prediction and set limits on production cross sections for vectorlike quarks decaying to W+jet and Z+jet. These are the most stringent limits to date for electroweak single vectorlike quark production at hadron colliders.

Determination of the width of the top quark

We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3  fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69)  GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 10(-25)   s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V(tb')| < 0.63 at 95% C.L.

Search for ZH → l+ l- bb production in 4.2 fb(-1) of pp collisions at sqrt[s] =1 .96 TeV

We present a search for the standard model Higgs boson produced in association with a Z boson in 4.2 fb(-1) of pp collisions, collected with the D0 detector at the Fermilab Tevatron at sqrt[s] =1 .96 TeV. Selected events contain one reconstructed Z → e+ e- or Z → μ+ μ- candidate and at least two jets, including at least one b-tagged jet. In the absence of an excess over the background expected from other standard model processes, limits on the ZH cross section multiplied by the branching ratios are set. The limit at M(H) = 115  GeV is a factor of 5.9 larger than the standard model prediction.

Search for diphoton events with large missing transverse energy in 6.3 fb(-1) of pp collisions at √s=1.96 TeV

We report a search for diphoton events with large missing transverse energy produced in pp collisions at √s=1.96  TeV. The data were collected with the D0 detector at the Fermilab Tevatron Collider and correspond to 6.3  fb(-1) of integrated luminosity. The observed missing transverse energy distribution is well described by the standard model prediction, and 95% C.L. limits are derived on two realizations of theories beyond the standard model. In a gauge-mediated supersymmetry breaking scenario, the breaking scale Λ is excluded for Λ<124  TeV. In a universal extra dimension model including gravitational decays, the compactification radius R(c) is excluded for R(c)(-1)<477  GeV.

Search for new fermions ("quirks") at the Fermilab Tevatron collider

We report results of a search for particles with anomalously high ionization in events with a high transverse energy jet and large missing transverse energy in 2.4 fb⁻¹ of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron pp collider. Production of such particles (quirks) is expected in scenarios with extra QCD-like SU(N) sectors, and this study is the first dedicated search for such signatures. We find no evidence of a signal and set a lower mass limit of 107, 119, and 133 GeV for the mass of a charged quirk with strong dynamics scale Λ in the range from 10 keV to 1 MeV and N=2, 3, and 5, respectively.

Search for events with leptonic jets and missing transverse energy in pp collisions at √s=1.96 TeV

We present the first search for pair production of isolated jets of charged leptons in association with a large imbalance in transverse energy in pp collisions using 5.8 fb⁻¹ of integrated luminosity collected by the D0 detector at the Fermilab Tevatron Collider. No excess is observed above the standard model background, and the result is used to set upper limits on the production cross section of pairs of supersymmetric chargino and neutralino particles as a function of "dark-photon" mass, where the dark photon is produced in the decay of the lightest supersymmetric particle.

Search for sneutrino production in eμ final states in 5.3 fb-1 of pp collisions at square root s =1.96 TeV

We report the results of a search for R parity violating (RPV) interactions leading to the production of supersymmetric sneutrinos decaying into eμ final states using 5.3 fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. Having observed no evidence for production of eμ resonances, we set direct bounds on the RPV couplings λ311' and λ312 as a function of sneutrino mass.

The effect of habitat fragmentation on the genetic structure of a top predator: loss of diversity and high differentiation among remnant populations of Atlantic Forest jaguars (Panthera onca)

Habitat fragmentation may disrupt original patterns of gene flow and lead to drift-induced differentiation among local population units. Top predators such as the jaguar may be particularly susceptible to this effect, given their low population densities, leading to small effective sizes in local fragments. On the other hand, the jaguar's high dispersal capabilities and relatively long generation time might counteract this process, slowing the effect of drift on local populations over the time frame of decades or centuries. In this study, we have addressed this issue by investigating the genetic structure of jaguars in a recently fragmented Atlantic Forest region, aiming to test whether loss of diversity and differentiation among local populations are detectable, and whether they can be attributed to the recent effect of drift. We used 13 microsatellite loci to characterize the genetic diversity present in four remnant populations, and observed marked differentiation among them, with evidence of recent allelic loss in local areas. Although some migrant and admixed individuals were identified, our results indicate that recent large-scale habitat removal and fragmentation among these areas has been sufficiently strong to promote differentiation induced by drift and loss of alleles at each site. Low estimated effective sizes supported the inference that genetic drift could have caused this effect within a short time frame. These results indicate that jaguars' ability to effectively disperse across the human-dominated landscapes that separate the fragments is currently very limited, and that each fragment contains a small, isolated population that is already suffering from the effects of genetic drift.

Detection of antibodies against Anaplasma phagocytophilum in Algerian mice (Mus spretus), Portugal

The recent detection of Anaplasma phagocytophilum in Portugal stimulated further research on the agent's enzootic cycle, which usually involves rodents. Thus a total 322 rodents belonging to five species, including 30 Apodemus sylvaticus (wood mouse), 65 Mus musculus (house mouse), 194 M. spretus (algerian mouse), 5 Rattus norvegicus (brown rat) and 28 R. rattus (black rat), were studied by indirect immunofluorescent assay (IFA) and/or polymerase chain reaction (PCR) for A. phagocytophilum exposure in four sampling areas of mainland and two areas of Madeira Island, Portugal. Overall, 3.6% (7/194) of M. spretus presented with IFA-positive results. Seropositive mice were detected in all three mainland sampling areas where this species was captured, with prevalence of 5.2% (5/96) and 5.0% (1/20) for the Ixodes-areas of Arrábida and Mafra, and 1.3% (1/78) for Mértola, a difference that was not statistically significant (p > 0.05). The majority of IFA-positive mice were detected in spring when considering either Arrábida alone (p = 0.026) or all M. spretus sampling areas together (p = 0.021), although the significance of this association was not evident after Bonferroni correction. Nevertheless, neither the seropositive M. spretus, nor additional samples of 10% seronegative rodents from mainland, and 16% of rodents collected in Madeira Island showed evidence of A. phagocytophilum active infections when spleen and/or lung samples were tested by PCR. Either the M. spretus results represents residual antibodies from past A. phagocytophilum infections, present infections with limited bacteremia, or cross-reactions with closely related agents deserves more investigation.

Serological and molecular survey of Anaplasma species infection in dogs with suspected tickborne disease in Portugal

Fifty-five dogs with suspected tickborne disease were tested by immunofluorescence assay and PCR for Anaplasma phagocytophilum infection. Thirty (54.5 per cent) of the dogs were seropositive and five of them fulfilled the serological criteria for an active infection, with either seroconversion or a fourfold increase in antibody titres. Fragments of DNA of the expected size were detected by PCR in two seropositive and three seronegative dogs. However, direct amplicon sequencing failed to identify active A phagocytophilum infections, but revealed the presence of Anaplasma platys DNA in the PCR-positive animals.

Structure–activity relationship study of flavone compounds with anti-HIV-1 integrase activity: A density functional theory study

Human immunodeficiency virus type-1 integrase (HIV-1 IN) is an essential enzyme for effective viral replication. Flavone compounds have been very much studied due to their activity during the inhibition process of HIV-1 IN. In this study, we employed density functional theory (DFT) using the B3LYP hybrid functional to calculate a set of molecular properties for 32 flavonoid compounds with anti-HIV-1 IN activity. The stepwise discriminant analysis (SDA), principal component analysis (PCA) and hierarchical cluster analysis (HCA) methods were employed to reduce dimensionality and investigate possible relationship between the calculated properties and the anti-HIV-1 IN activity. These analyses showed that the molecular hydrophobicity (ClogP), charge on atom 11 and electrophilic index (omega) are responsible for the separation between anti-HIV-1 IN active and inactive compounds.

Ticks and Tick-Borne Rickettsiae Surveillance in Montesinho Natural Park, Portugal

This study constitutes the first contribution to the knowledge of tick dynamics and its implication in the epidemiology of rickettsial diseases in Montesinho Natural Park (MNP), Bragança district of Portugal. Of 76 ticks collected, 12 (15.8%) were Dermacentor (D.) marginatus, 36 (47.4%) D. reticulatus, and 28 (36.8%) Rhipicephalus (R.) sanguineus. Isolation assays were performed by shell-vial technique on 41 ticks. Israeli spotted fever strain was an isolate from R. sanguineus, and three isolates of Rickettsia slovaca were obtained from D. reticulatus. All 76 ticks were screened by PCR for Rickettsia sp., Ehrlichia (E.) chaffeensis, and Anaplasma (A.) phagocytophilum. Rickettsia RpA4 strain DNA was detected in 10 D. marginatus and 2 D. reticulatus, and Israeli spotted fever strain in 1 R. sanguineus. No E. chaffeensis or A. phagocytophilum infection was detected. New host records are provided for D. reticulatus. Also described for the first time in Portugal is the isolation of R. slovaca from D. reticulatus and the isolation of Israeli spotted fever strain from R. sanguineus. This confirms the association of the last rickettsiae strain with the same vector tick as previously described in Israel and Sicily.

Human Exposure to Anaplasma phagocytophilum in Portugal

A retrospective study to detect Anaplasma phagocytophilum antibodies by indirect immunofluorescence (IFA) and Western blot (WB) assay was conducted in 367 potentially exposed patients from Portugal. The study included 26 patients with confirmed Lyme borreliosis (LB), 77 with suspected LB, 264 seronegative patients studied for possible tick-transmitted LB and boutonneuse fever (LB/BF) infection, and 96 healthy blood donors. Overall, patients with LB and suspected LB (n = 2 [7.7%] and n = 6 [7.8%], respectively) were more often seropositive (n = 8 [7.8%]; P < 0.001), whereas only 1 (0.4%; P = 0.046) patient in the LB/BF seronegative group had confirmed disease. This study is the first evidence of human exposure to A. phagocytophilum or an antigenically similar bacterium in Portugal, and suggests that LB patients are significantly more likely to contact A. phagocytophilum.

Clinical efficacy and safety of preseasonal sublingual immunotherapy with grass pollen carbamylated allergoid in rhinitic patients. A double-blind, placebo-controlled study

BACKGROUND

The aim of this study was to confirm the clinical efficacy and safety of a preseasonal sublingual immunotherapy (SLIT) in a group of allergic patients with seasonal rhinoconjunctivitis with or without mild intermittent or mild persistent asthma. The immunotherapy was administered through the oral mucosa with a monomeric carbamylated allergoid (allergoid SLIT) for grass pollens. A secondary endpoint was to evaluate the effect of the allergoid SLIT on nasal reactivity.

METHODS AND RESULTS

A single-center, randomized, double-blind, placebo-controlled study was performed. Patients were selected and randomly allocated to two groups: one group received active treatment (allergoid SLIT) for 2 years and the other received placebo. Both groups received the necessary drug treatment throughout the trial. Thirty-three outpatients (20 men and 13 women, mean age: 30 years; range: 19-43) attending our center were enrolled in the study. Symptoms and medications were scored on diary cards during the pollen season. An allergen nasal challenge was performed at baseline and after 2 years of SLIT to evaluate nasal reactivity. Because the clinical scores were non-normally distributed, the Mann-Whitney and the Chi-square tests for intergroup comparisons and the Wilcoxon test for intragroup comparisons were used. The results were evaluated after 1 and 2 years of treatment. Between the first and second years of treatment, no changes in the scores for the placebo group were found, while for the active vaccine group significant decreases were found in rhinorrhea (p < 0.03), sneezing (p < 0.03), and conjunctivitis (p < 0.02). Symptom scores after nasal challenge decreased (p < 0.03) after 2 years' treatment. Nasal steroid use significantly decreased in the active treatment group during May and June in both the years of treatment (p < 0.02). Only two mild local adverse events were reported in the active group and none was reported in the placebo group.

CONCLUSIONS

The results of this study show that the allergoid SLIT is safe and effective in decreasing symptom scores and drug use in rhinitic patients allergic to grass pollen.

Monoid sublingual immunotherapy

Sublingual monoid immunotherapy with monomeric allergoids has been largely used in Europe in the last few years. An open trial of allergoid in tablets has been done in rhinitic patients allergic to house dust mites, grass pollens and Parietaria with clear improvement in clinics and drug consumption scores. In a second phase a double blind placebo controlled trial of grass pollens allergoids have been done in hay fever patients with significant decrease on the scores of rhinorrea, sneezing and conjunctivitis nasal steroid consumption and clinical score after serial nasal challenges. Monomeric allergoids are an efficace and safe immunotherapy in allergic rhinitis.

Detection of a Non-Pathogenic Variant of Anaplasma phagocytophilum in Ixodes ricinus from La Rioja, Spain

Our aim was to identify variants of Anaplasma phagocytophilum 16S rRNA gene sequences among products amplified from Ixodes ricinus collected in La Rioja, Spain. A. phagocytophilum AP-variant 1, reported as non-pathogenic, was detected in 12 samples (two adults and ten nymphs). This finding could justify the low incidence of human anaplasmosis in our area, despite the high prevalence of A. phagocytophilum in ticks.

Ultrastructural study of the infection process of Rickettsia conorii in the salivary glands of the vector tick Rhipicephalus sanguineus

This work was designed to study the infection process of Rickettsia conorii in the salivary glands of experimentally infected Rhipicephalus sanguineus ticks. One hundred six uninfected engorged nymphs were intracelomically inoculated with approximately 2 x 10(3) plaque-forming units of a rickettsial suspension. After the molt, unfed and fed adults were dissected, and the salivary glands were extracted and processed for transmission electron microscopy observation. Three different uninfected control groups were used for (1) evaluating the impact of the inoculation procedure, (2) establishing the feeding period of infected ticks, and (3) ultrastructural characterization of the salivary glands. Overall, 75.5% (80 of 106) of the nymphs inoculated with rickettsiae died during the molt or soon after hatching into adult instars; 50% (12 of 24) of the remaining infected adults showed severe malformations compromising their viability. In apparently healthy specimens, time of engorgement was longer. The contrast with the negative control groups was statistically significant, suggesting that R. conorii exerts a strong negative effect on the vector ticks. The ultrastructural study showed that in the salivary glands of infected ticks, rickettsial growth occurs preferentially in central, peripheral, and interstitial acini cells.

Effect of specific immunotherapy versus loratadine on serum adhesion molecules

OBJECTIVE

To evaluate comparatively the effect on serum ICAM-1 and VCAM-1 values of specific immunotherapy versus loratadine in the treatment of allergic rhinitis.

POPULATION

65 patients with mild to moderate House Dust Mite allergic rhinitis.

METHODS

Patients were divided into three groups, according to patients' preference: a control group with patients receiving only rescue therapy (antihistamines and/or nasal cromoglycate when needed); an antihistamine group with patients receiving daily loratadine 10 mg (and nasal cromoglycate as rescue therapy); an immunotherapy group with patients receiving subcutaneous house dust mite specific immunotherapy (and antihistamines or nasal cromoglycate when needed). In all groups we measured soluble ICAM-1 and VCAM-1 serum levels before the start of the study period and at the end of the study period. The duration of the study was one year for the control group and for the immunotherapy group. In patients taking daily antihistamines we measured serum adhesion molecules one month after the beginning of the therapy. We used Student's T test for statistical analysis.

RESULTS

Patients in the control group didn't have significant variations in serum ICAM-1 (p = 0.239) or VCAM-1 (p = 0.38) levels. Patients receiving loratadine showed significant decreases in serum VCAM-1 levels (p = 0.0012) but not in serum ICAM-1 levels (p = 0.224). Patients receiving immunotherapy also showed a similar pattern, with significant decreases in serum VCAM-1 levels (p = 0.012) but not in serum ICAM-1 levels (p = 0.254).

CONCLUSIONS

Specific house dust mite immunotherapy and regular daily loratadine therapy are able to lower significantly serum levels of soluble VCAM-1. However, this effect, which can be interpreted as an anti-inflammatory action, is not applied to soluble ICAM-1 levels, which raises the possibility of a differential action of these therapies on the mechanisms of allergic inflammation. Patients on rescue medication alone did not show any significant differences in these parameters.

Leukotriene receptor antagonists (Montelukast) in the treatment of asthma crisis: preliminary results of a double-blind placebo controlled randomized study

OBJECTIVE

Evaluate the efficacy of oral Montelukast 10 mg as an add-on therapy to the usual emergency therapy of an asthma crisis in an emergency room (ER).

POPULATION

Twenty adults that sought medical attention in the ER of our Hospital and in whom, on admission, it appeared unnecessary to give systemic steroids.

METHODS

All patients received the usual therapy of the asthma crisis. Simultaneously it was randomly administered a capsule containing 10 mg Montelukast or placebo, in a double-blind protocol. In both groups we evaluated the evolution of Peak-Flow values, the duration of stay in the ER as well as the need for additional therapy with systemic aminophylline or steroids, representing an insufficient response to the initial treatment. Student's T test was used to evaluate the statistical differences between these two groups.

RESULTS

Both the Montelukast (MK) and Placebo (PL) groups were comparable regarding age and sex distribution, Peak-Flow values and Arterial O2 values on admission. During therapy, MK group had a shorter duration of ER stay (MK = 2.5 h; PL = 2.9 h) and a better evolution of Peak-Flow values (medium increase of 55% from baseline versus 44% in PL group). However these differences did not reach statistical significance. In the MK group one patient needed systemic steroids and 4 received systemic aminophylline while in the PL group 4 patients received systemic steroids and 8 aminophylline. This difference was significant (p = 0.03). We did not observe any significant side effects during therapy.

CONCLUSIONS

Despite a small trend favourable to Montelukast we did not observe significant differences between groups regarding duration of stay or Peak-Flow evolution during therapy in ER, most probably due to the small sample size. However patients in the MK group needed significantly less systemic therapy with aminophylline or steroids. These data, in view of the very good safety profile of Montelukast, allow us to conclude that this is a useful additional therapy, which should be considered in the ER treatment of the asthma crisis.

Assessment of the antitumour activity of targeted immunospecific albumin microspheres loaded with cisplatin and 5-fluorouracil: toxicity against a rodent ovarian carcinoma in vitro

The 3-(4,5 dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay is used successfully to estimate the number of viable cells in drug screening trials. We used the MTT assay to assess the viability of a rodent ovarian carcinoma cell line (DMBA-OC-1R) after exposure to combinations of cisplatin and 5-fluorouracil as free drug and in encapsulated (conjugated and unconjugated) forms. After 48 h of exposure to free drugs, a significant trend towards cell cytotoxicity could be observed and this was well established by 120 h. Cells treated with drug-containing immuno-microspheres showed a similar initial decrease in cell viability after 96 h, and this was maintained for 128 h. These results suggest that immuno-microspheres loaded with chemotherapeutic drugs have the potential to be successfully used in the treatment of ovarian cancer.

[Pediatric varicocele]

The treatment of pediatric varicocele has recently been given a special importance due to clinical and experimental evidence of testicular atrophy and histological changes in 50% of homolateral and sometimes in contralateral testis. Those changes are progressive and similar to those in infertile adults with varicocele. Between 1st January 1990 and 31st December 1994, 41 boys (five to 15 years old--mean age 11.9 years) were presented for evaluation of primary varicocele at the Pediatric Surgery Department of Dona Estefânia Hospital. The varicocele was left sided in 39 boys, bilateral in one and another on the right, with a predominance of grade II. Forty patients underwent varicocelectomy, 31 (77%) by the Ivanisevìc technique. Varicocele recurred in four cases (10%). The authors discuss the results and make some considerations concerning the management of varicocele in children.

Programme for the surveillance of influenza in Portugal: results of the period 1990-1996

OBJECTIVES

To describe the situation of the influenza in Portugal through the estimates of the incidence rates and the identification of the viral strains implicated on it during the period 1990-1996.

DESIGN

The integrated clinical and laboratory surveillance system for influenza in Portugal is based on the Portuguese sentinel network. Influenza cases are identified by general practitioners (GP) and notified to Division of Epidemiology (DEP) and to National Influenza Centre. Clinical and epidemiological data based on the clinical diagnosis are recorded and incidence rates are computed for the whole country. Throat swabs and blood samples are taken from the patients with influenza and sent to the National Influenza Centre to identify and classify the viral strains implicated.

PARTICIPANTS

Lists of patients of the GPs collaborating on "Médicos-Sentinela" network.

RESULTS

In 1990-1991, 1992-1993, and 1994-1995 there was a higher prevalence of influenza B virus and the highest influenza activity occurred in February and March in contrast with 1991-1992, 1993-1994, and 1995-1996 where the highest numbers of influenza cases occurred in November and December, and were associated with influenza A.

CONCLUSIONS

During the past six years, 1990-1996, the influenza activity has been moderate in Portugal. From 1990-1996 influenza A and B viruses were prevalent every second year. The prevalence of influenza A was associated with the occurrence of the highest number of influenza cases during December and January and the prevalence of influenza B with the occurrence of the highest number of influenza cases during February and March.

Short-term efficacy of nasal immunotherapy

The purpose of this study was to evaluate the efficacy of nasal immunotherapy in the management of allergic rhinitis. Sixteen patients (10 Female; 6 Male) aged 15-60 years (mean age--31.9) were selected on the bases of clinical history, skin prick tests and RAST positivity. Allergen extract is a "macronized" powder form (Allerkin), it was supplied by Laboratorio Farmaceutico Lofarma (Milano Italy) and administered for 12 months to 8 patients with perennial rhinitis (Dermatophagoides extract) and for 6 months to 8 patients with seasonal rhinitis (grass or Parietaria pollens extract). This treatment was carried out by self administration in two phases: the first one (3 months) consisted of administration of increasing doses; the second phase (maintenance period) was carried out 3 months in seasonal rhinitis and 9 months in perennial rhinitis. All the patients were evaluated before and after immunotherapy and scores from 0 to 3 were attributed according to the symptoms presented and need of drugs for symptomatic relief. Scores before and after immunotherapy were compared using the Wilcoxon Matched-Pairs Signed-Ranks Test and a significant decrease was observed for every symptom in seasonal and perennial rhinitis (p < 0.05). In conclusion, this trial shows that nasal immunotherapy in powder form can be a valuable short-term option in patients with allergic rhinitis.

Molecular characteristics of Machado-Joseph disease mutation in 25 newly described Brazilian families

Machado-Joseph disease (MJD) is a form of autosomal dominant spinocerebellar ataxia first described in North-American patients originating from the Portuguese islands of the Azores. Clinically this disorder is characterized by late onset progressive ataxia with associated features, such as: ophthalmoplegia, pyramidal and extrapyramidal signs and distal muscular atrophies. The causative mutation is an expansion of a CAG repeat in the coding region of the MJD1 gene. We have identified 25 unrelated families segregating the MJD mutation during a large collaborative study of spinocerebellar ataxias in Brazil. In the present study a total of 62 family members were genotyped for the CAG repeat in the MJD1 gene, as well as 63 non-MJD individuals (126 normal chromosomes), used as normal controls. We observed a wide gap between the size range of the normal and expanded CAG repeats: the normal allele had from 12 to 33 CAGs (mean = 23 CAGs), whereas the expanded alleles ranged from 66 to 78 CAGs (mean = 71.5 CAGs). There were no differences in CAG tract length according to gender of affected individuals or transmitting parent. We observed a significant negative correlation between age at onset of the disease and length of the CAG tract in the expended allele (r = -0.6, P = 0.00006); however, the size of the expanded CAG repeat could explain only about 40% of the variability in age at onset (r2 = 0.4). There was instability of the expanded CAG tract during transmission from parent to offspring, both expansions and contractions were observed; however, there was an overall tendency for expansion, with a mean increase of +2.4 CAGs. The tendency for expansion appeared to the greater in paternal (mean increase of +3.5 CAGs) than in maternal transmissions (mean increase of +1.3 CAGs). Anticipation was observed in all transmissions in which ages at onset for parent and offspring were known; however, anticipation was not always associated with an increase in the expanded CAG repeat length. Our results indicate that the molecular diagnosis of MJD can be confirmed or excluded in all suspected individuals, since alleles of intermediary size were not observed.

Nasal allergen challenge and mediators release

Nasal allergen challenges, despite not reproducing exactly natural allergen exposure, are a very useful method to understand the complex cellular kinetics and cellular interactions that occur in allergic rhinitis. Cell-specific soluble mediator measurements can give useful diagnostic information. In this paper we present data concerning eosinophil cationic protein (ECP) and tryptase measurements after nasal allergen challenge.

Frequency of the different mutations causing spinocerebellar ataxia (SCA1, SCA2, MJD/SCA3 and DRPLA) in a large group of Brazilian patients

Spinocerebellar ataxia type 1 (SCA1), spinocerebellar ataxia type 2 (SCA2) and Machado-Joseph disease or spinocerebellar ataxia type 3 (MJD/SCA3) are three distinctive forms of autosomal dominant spinocerebellar ataxia (SCA) caused by expansions of an unstable CAG repeat localized in the coding region of the causative genes. Another related disease, dentatorubropallidoluysian atrophy (DRPLA) is also caused by an unstable triplet repeat and can present as SCA in late onset patients. We investigated the frequency of the SCA1, SCA2, MJD/SCA3 and DRPLA mutations in 328 Brazilian patients with SCA, belonging to 90 unrelated families with various patterns of inheritance and originating in different geographic regions of Brazil. We found mutations in 35 families (39%), 32 of them with a clear autosomal dominant inheritance. The frequency of the SCA1 mutation was 3% of all patients; and 6% in the dominantly inherited SCAs. We identified the SCA2 mutation in 6% of all families and in 9% of the families with autosomal dominant inheritance. The MJD/SCA3 mutation was detected in 30% of all patients; and in the 44% of the dominantly inherited cases. We found no DRPLA mutation. In addition, we observed variability in the frequency of the different mutations according to geographic origin of the patients, which is probably related to the distinct colonization of different parts of Brazil. These results suggest that SCA may be occasionally caused by the SCA1 and SCA2 mutations in the Brazilian population, and that the MJD/SCA3 mutation is the most common cause of dominantly inherited SCA in Brazil.

Study of the Adsorption of Some Amino Acids by Silica Chemically Modified with Aminobenzenesulfonic and Phosphate Groups

Two silica gels, one modified with aminobenzenesulfonic (SABS) groups and the other with phosphate (SZP) groups, were prepared to adsorb some amino acids. Chemical analysis of the modified silica gave 0.65 mmol g-1 aminobenzenesulfonic groups and 0.56 mmol g-1 phosphate groups. The maximum adsorption capacities for amino acids determined by batch experiments for SABS were 1.37, 0.67, 0.76, and 0.59 mmol g-1 for glycine, lysine, histidine, and leucine, respectively, and those for SZP were 0.75, 0.58, 0.44, and 0.75 mmol g-1 for glycine, lysine, histidine, and leucine, respectively. The adsorption capacity of SABS was significantly affected by the solution pH, showing a higher selectivity than SZP. The materials were very stable, allowing their use several times without changes in adsorption capacity.