Cristina Alves

In vitro study of cell behaviour on plasma surface modified titanium

Abstract In recent years, several technologies that modify implant surfaces have been emerged. Among these techniques, the plasma nitriding process has been successfully applied in biomedical field. Nevertheless, its use in dental implants is quite limited owing to the high temperatures of the process (between 700 and 800°C), which causes distortion. In order to solve this problem, a new approach is proposed in the present paper, by which nitriding under a hollow cathode discharge is used to modify surfaces. Grade II Ti plates were submitted to nitriding under hollow cathode discharge conditions and treated at a temperature 450°C and pressure of 150 Pa for 1 h. These showed that plasma nitriding helped bring about a significant change in the surface texture of the treated plates. Furthermore, cell proliferation was 2⋅5 times as high as that of the untreated plates.

Hb Yaoundé [β134(H12)Val→Ala] in Association with Hb C [β6(A3)Glu→Lys] in a Caucasian Portuguese Family

Hb Yaoundé [β134(H12)Val→Ala] is a rare, silent and asymptomatic hemoglobin (Hb) variant. It was previously reported in a Black man from Cameroon, in association with Hb Kenitra [β69(E13)Gly→Arg], and was subsequently found and described as Hb Mataro in a sub‐Saharan child. To date, Hb Yaoundé has not been described in Caucasian people and molecular studies have never been performed. Here we describe a three‐generation Caucasian Portuguese family in whom Hb Yaoundé was found in association with Hb C [β6(A3)Glu→Lys] (in the proband) and in a heterozygous state (in the probands mother). The Hb studies of the probands hemolysate, performed by isoelectric focusing (IEF) and low‐pressure cation exchange chromatography, only revealed an Hb variant identified as Hb C by comparison with a control. However, analysis performed by reversed‐phase high‐performance liquid chromatography (HPLC) showed two different β chain variants and a complete absence of the normal β chain. This uncommon Hb variant was identified as Hb Yaoundé by DNA sequencing analysis of the β‐globin gene (codon 134, GTG→GCG). The β‐globin gene haplotypes were determined in all family members using polymerase chain reaction (PCR)‐based methodology; Hb Yaoundé was found to be associated with the Mediterranean haplotype II. This study is the first description of Hb Yaoundé in Caucasian individuals, and its association with a Mediterranean haplotype supports the hypothesis of an independent genetic origin other than African.

Trisomy 15 mosaicism: Challenges in prenatal diagnosis

Keywords: trisomy 15 mosaicism; fetal mosaicism; chorionic villi; prenatal cytogenetics; SNP-array; uniparental disomy

Characterization of dog serum virome from Northeastern Brazil

Domestic dogs share habitats with human, a fact that makes them a potential source of zoonotic viruses. Moreover, knowledge regarding possible bloodborne pathogens is important due to the increasing application of blood transfusion in dogs. In the present study, we evaluated the serum virome of 520 dogs using throughput sequencing (HTS). The serum samples were pooled and sequenced using an Illumina MiSeq platform. Our unbiased method identified prevalent canine pathogens as canine protoparvovirus 1 (canine parvovirus 2), undersearched agents as canine bocaparvovirus 1 (minute virus of canines) and canine circovirus, circular viruses closely related to viruses recently found in human samples, and new parvovirus and anelloviruses. The dog virome described in the present work furthers the knowledge concerning the viral population in domestic animals. The present data includes information regarding viral agents that are potentially transmitted through blood transfusion among dogs.

Discordant Chromosome Placental Mosaicism in a Dichorionic Twin Pregnancy

Chorionic villus sampling (CVS) is now well established as aninvasive test for prenatal diagnosis of chromosome abnormalitiesand some authors argue that this first-trimester procedurehas several advantages over mid-trimester amniocentesis in twinpregnancies [Brambati et al., 2001]. Since twin gestations seem tohave a higher risk of chromosome aberrations when compared tosingleton pregnancies, some centers now offer the possibility offirst-trimester prenatal diagnosis using CVS, including molecularrapidaneuploidy(MRA)testingbyQF-PCRormultiplexligation-dependent probe amplification (MLPA). CVS may provide thepossibility of an earlier result which may be crucial for patientreassurance and pregnancy management but has the disadvantageoftheoccasionalpresenceofplacentalmosaicism,inaround1–2%of cases, that can result from analyzing a tissue chromosomallydifferent from that of the fetus [Ledbetter et al., 1992; Farraet al., 2000]. This mosaicism may affect only the placenta—confined placental mosaicism (CPM)—or extend to the fetus—true fetal mosaicism (TFM)—in the same or in a different degreefrom the one found in the placenta [Kalousek et al., 1989; Gratietal.,2006].CPMoccursasoneofthreeforms:(i)theabnormalcelllineisconfinedtocytotrophoblast(typeI);(ii)oritonlyaffectsthestromalvillouscore(mesenchyme;typeII);(iii)oritinvolvesboth(typeIII)[Gratietal.,2006].Non-mosaicismforeitherdiploidyoraneuploidyispossibleinthefetus.Thekaryotypeofthecelllineagesisusuallyobtainedbydirectpreparations/short-term(cytotropho-blast) or long-term (mesenchyme) CVS cultures. MRA testing ispossible and is thought to test a mixture of DNAs from both thevillouscytotrophoblastandmesenchymalcore[Mannetal.,2007].However, this may yield discrepant results from the full chromo-someanalysisdependingonthemethod,thelevelofmosaicismandthetypeoftissueusedforanalysis.Thedisomy–trisomymosaicismmay have a mitotic (CPM types I and II) or a meiotic origin(CPM type III). The latter is associated with an increased risk ofpregnancy complications and fetal uniparental disomy (UPD)[Grati et al., 2006]. The detection of mosaicism for the commonautosomal trisomies in prenatal samples is relatively rare but hasbeen reported previously, as well as false-positive findings oftrisomy 18 mosaicism in CVS analysis [Schuring-Blomet al., 2002]. On the other hand trisomy 2 is one of the mostfrequently involved trisomies in pseudomosaicism both in amni-otic fluid (AF) and CVS cultures [Benn and Hsu, 2004; Sifakisetal.,2010].ToourknowledgethisisthefirstreportofadiscrepantCPMinadichorionic(DC)twinpairthatinvolvesatrisomy18anda trisomy 2.The patient was a 31-year-old, primigravid woman with DCtwins,conceivedafteraninvitrofertilization(IVF)procedureduetosequelaefrompreviouspelvicinflammatorydisease.Ultrasoundexamination (USE) at 11 weeks showed an umbilical hernia/smallomphalocele in twin B and a smaller crown-rump length (CRL;39 mm vs. 48 mm in twin A, 20th and 50th centile, respectively).First trimester aneuploidy screening on the basis of maternal ageand fetal nuchal translucency yielded normal results for twin A(1/2,499) and not calculable for twin B because the CRL was<45 mm. Since an ultrasound abnormality and early growth