Helicobacter pylori infection as a cause of iron deficiency anaemia of unknown origin

AIM: To assess the aetiological role of Helicobacter pylori (H. pylori) infection in adult patients with ironrefractory or iron-dependent anaemia of previously unknown origin. METHODS: Consecutive patients with chronic irondeficient anaemia (IDA) with H. pylori infection and a negative standard work-up were prospectively evaluated. All of them had either iron refractoriness or iron dependency. Response to H. pylori eradication was assessed at 6 and 12 mo from follow-up. H. pylori infection was considered to be the cause of the anaemia when a complete anaemia resolution without iron supplements was observed after eradication. RESULTS: H. pylori was eradicated in 88 of the 89 patients. In the non-eradicated patient the four eradicating regimens failed. There were violations of protocol in 4 patients, for whom it was not possible to ascertain the cause of the anaemia. Thus, 84 H. pylori eradicated patients (10 men; 74 women) were available to assess the effect of eradication on IDA. H. pylori infection was considered to be the aetiology of IDA in 32 patients (38.1%; 95%CI: 28.4%-48.8%). This was more frequent in men/postmenopausal women than in premenopausal women (75% vs 23.3%; P < 0.0001) with an OR of 9.8 (95%CI: 3.3-29.6). In these patients, anaemia resolution occurred in the first follow-up visit at 6 mo, and no anaemia or iron deficiency relapse was observed after a mean follow-up of 21 ± 2 mo. CONCLUSION: Gastric H. pylori infection is a frequent cause of iron-refractory or iron-dependent anaemia of previously unknown origin in adult patients.

Attenuation of dextran sodium sulphate induced colitis in matrix metalloproteinase-9 deficient mice

AIM: To study whether matrix metalloproteinase-9 (MMP-9) is a key factor in epithelial damage in the dextran sodium sulphate (DSS) model of colitis in mice.METHODS: MMP-9-deficient and wild-type (wt) mice were given 5% DSS in drinking water for 5 d followed by recovery up to 7 d. On d 5 and 12 after induction of colitis, gelatinases, MMP-2 and MMP-9, were measured in homogenates of colonic tissue by zymography and Western blot, whereas tissue inhibitor of metalloproteinases (TIMPs) were measured by reverse zymography. The gelatinolytic activity was also determined in supernatants of polymorphonuclear leukocytes (PMN) isolated from mice blood. Moreover, intestinal epithelial cells were stimulated with TNF-α to study whether these cells were able to produce MMPs. Finally, colonic mucosal lesions were measured by microscopic examination. RESULTS: On d 5 of colitis, the activity of MMP-9 was increased in homogenates of colonic tissues (0.24 ± 0.1 vs 21.3 ± 6.4, P < 0.05) and PMN from peripheral blood in wt (0.5 ± 0.1 vs 10.4 ± 0.7, P < 0.05), but not in MMP-9-deficient animals. The MMP-9 activity was also up-regulated by TNF-α in epithelial intestinal cells (2.5 ± 0.5 vs 14.7 ± 3.0, P < 0.05). Although colitis also led to increase of TIMP-1 activity, the MMP-9/TIMP-1 balance remained elevated. Finally, in the MMP-9-deficient colitic mice both the extent and severity of intestinal epithelialinjury were significantly attenuated when compared with wt mice. CONCLUSION: We conclude that DSS induced colitis is markedly attenuated in animals lacking MMP-9. This suggests that intestinal injury induced by DSS is modu-lated by MMP-9 and that inhibition of this gelatinase may reduce inflammation.

Phylogeography of SARS-CoV-2 pandemic in Spain:a story of multiple introductions,micro-geographic stratification,founder effects,and super-spreaders

Spain has been one of the main global pandemic epicenters for coronavirus disease 2019(COVID-19).Here,we analyzed>41000 genomes(including>26000 high-quality(HQ)genomes)downloaded from the GISAID repository,including 1245(922 HQ)sampled in Spain.The aim of this study was to investigate genome variation of novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and reconstruct phylogeographic and transmission patterns in Spain.Phylogeographic analysis suggested at least 34 independent introductions of SARS-CoV-2 to Spain at the beginning of the outbreak.Six lineages spread very successfully in the country,probably favored by super-spreaders,namely,A2 a4(7.8%),A2 a5(38.4%),A2 a10(2.8%),B3 a(30.1%),and B9(8.7%),which accounted for 87.9% of all genomes in the Spanish database.One distinct feature of the Spanish SARS-Cov-2 genomes was the higher frequency of B lineages(39.3%,mainly B3 a+B9)than found in any other European country.While B3 a,B9,(and an important sub-lineage of A2 a5,namely,A2 a5 c)most likely originated in Spain,the other three haplogroups were imported from other European locations.The B3 a strain may have originated in the Basque Country from a B3 ancestor of uncertain geographic origin,whereas B9 likely emerged in Madrid.The time of the most recent common ancestor(TMRCA)of SARS-CoV-2 suggested that the first coronavirus entered the country around 11 February 2020,as estimated from the TMRCA of B3 a,the first lineage detected in the country.Moreover,earlier claims that the D614 G mutation is associated to higher transmissibility is not consistent with the very high prevalence of COVID-19 in Spain when compared to other countries with lower disease incidence but much higher frequency of this mutation(56.4% in Spain vs.82.4% in rest of Europe).Instead,the data support a major role of genetic drift in modeling the micro-geographic stratification of virus strains across the country as well as the role of SARS-CoV-2 super-spreaders.

Impact of mass screening for gluten-sensitive enteropathy in working population

AIM:To assess:(1)frequency and clinical relevanceof gluten sensitive enteropathy(GSE)detected by serology in a mass screening program;(2)sensitivity of antitransglutaminase(tTGA)and antiendomysium antibodies(EmA);and(3)adherence to gluten-free diet(GFD)and follow-up. METHODS:One thousand,eight hundred and sixtyeight subjects recruited from an occupational health department underwent analysis for tTGA and EmA and, if positive,duodenal biopsy,DQ2/DQ8 genotyping, clinical feature recording,blood tests,and densitometry were performed.Since>98%of individuals had tTGA <2 U/mL,this value was established as the cut-off limit of normality and was considered positive when confirmed twice in the same sample.Adherence to a GFD and follow up were registered. RESULTS:Twenty-six(1.39%)subjects had positive tTGA and/or EmA,and 21 underwent biopsy:six Marsh Ⅲ(oneⅢa,fourⅢb,oneⅢc),nine MarshⅠand six Marsh 0(frequency of GSE 1:125).The sensitivity of EmA for GSE was 46.6%(11.1%for MarshⅠ,100% for MarshⅢ),while for tTGA,it was 93.3%(88.8% for MarshⅠ,100%for MarshⅢ).All 15 patients with abnormal histology had clinical features related to GSE.MarshⅠandⅢsubjects had more abdominal pain than Marsh 0(P=0.029),and a similar trend was observed for distension and diarrhea.No differences in the percentage of osteopenia were found between MarshⅠandⅢ(P=0.608).Adherence to follow-up was 69.2%.Of 15 GSE patients,66.7%followed a GFD with 80%responding to it. CONCLUSION:GSE in the general population is frequent and clinically relevant,irrespective of histological severity.tTGA is the marker of choice.Mass screening programs are useful in identifying patients who can benefit from GFD and follow-up.

Pitfalls of barcodes in the study of worldwide SARSCoV-2 variation and phylodynamics

DEAR EDITOR,Analysis of SARS-CoV-2 genome variation using a minimal number of selected informative sites conforming a genetic barcode presents several drawbacks.We show that purely mathematical procedures for site selection should be supervised by known phylogeny(i)to ensure that solid tree branches are represented instead of mutational hotspots with poor phylogeographic proprieties,and(ii)to avoid phylogenetic redundancy.We propose a procedure that prevents information redundancy in site selection by considering the cumulative informativeness of previously selected sites(as a proxy for phylogenetic-based criteria).This procedure demonstrates that,for short barcodes(e.g.,11 sites),there are thousands of informative site combinations that improve previous proposals.We also show that barcodes based on worldwide databases inevitably prioritize variants located at the basal nodes of the phylogeny,such that most representative genomes in these ancestral nodes are no longer in circulation.Consequently,coronavirus phylodynamics cannot be properly captured by universal genomic barcodes because most SARS-CoV-2 variation is generated in geographically restricted areas by the continuous introduction of domestic variants.

Whole exome sequencing identifies new susceptibility candidates underlying community-acquired pneumonia

Pneumonia is an inflammatory condition of the lung with symptoms that include productive dry cough,fever,chest pain,and difficulty breathing,and it is usually caused by viruses and bacteria,but also other microorganisms(such as fungi and parasites).Community-acquired pneumonia(CAP)is a major cause of infectious diseases,hospitalization,and mortality,especially in the elderly population.

Multi-tissue transcriptomics of a unique monozygotic discordant twin case of severe progressive osseous heteroplasia

Progressive osseous heteroplasia(POH)is an ultra-rare autosomal dominant disabling disorder characterized by heterotopic ossification(HO).It is caused by heterozygous inactivating mutations in the GNAS(guanine nucleotide-binding protein alpha-stimulating activity polypeptide)gene.However,the molecular mechanisms underlying HO remain poorly understood.As a treatment for POH is not yet available,the identification of the mechanisms driving POH in affected tissues using gene expression may be of great help to underestand the molecular basis of POH and develop new therapeutic approaches.

Y-chromosome Peruvian origin of the 500-year-old Inca child mummy sacrificed in Cerro Aconcagua (Argentina)

A frozen mummy was found in Cerro Aconcagua (Argentina)in 1985(Fig.1a-c).Archaeologists identified this mummy as a seven-year-old Inca sacrifice victim living at the time of the Inca Civilization about 500years ago [1].The child was sacrificed following an Incan ritual known as capacocha.The complete mitochondrial DNA (mtDNA) genome of this mummy was recently analyzed in Gomez-Carballa et al.[2].This mitogenome belongs to a new sub-branch of the Native American phylogeny named C1bi dated to approximately 14 thousand years ago (loja).Information retrieved from a large database of mtDNA profiles indicated the existence of a few closely related haplotypes in Peru (including one haplotype retrieved from ancient DNA of an individual belonging to the Wari Empire)and the Aymaras from Bolivia.Overall these data suggested a Peruvian Inca origin for this C1bi haplotype,in good agreement with archaeological reports [1].

Mitochondrial DNA as a Risk Factor for False Positives in Case-Control Association Studies

During the last decade, hundreds of studies have been pub- lished examining whether significant associations exist be- tween mitochondrial DNA （mtDNA） variants and/or haplogroups （clades） and particular diseases （generally com- mon/complex diseases） （Fig. 1）. However, several authors have gathered evidence indicating a high incidence of false positive findings in mtDNA case-control association studies. Raule et al. （2007） and Herrnstadt and Howell （2004） showed various problems affecting mtDNA case-control association studies. Salas et al.

Biogeographical informativeness of Y-STR haplotypes

Research on biogeographical ancestry(BGA)is becoming of growing interest in forensic genetics and in the biomedical literature(1)Thus,for instance,the need to predict ethnicity of an unknown suspect based on DNA profiles found at the crime scene is of maximum interest in criminalistics[2],and several autosomal SNP panels have been designed and tested for BGA investigations[3,4].Most of these panels aim at discriminating three main continental groups(sub-Saharan Africans,Europeans,and Asians)by way of testing a number of ancestry informative markers(AIMs)that run from a few dozens to a few hundred[5](see more background in Supplementary data online).

Comprehensive Analysis of Pan-African Mitochondrial DNA Variation Provides New Insights into Continental Variation and Demography

Africa is the cradle of all human beings, and although it has been the focus of a number of genetic studies, there are many questions that remain unresolved. We have performed one of the largest and most comprehensive meta-analyses of mitochondrial DNA （mtDNA） lineages carried out in the African continent to date. We generated high-throughput mtDNA single nucleotide polymorphism （SNP） data （230 SNPs） from 2024 Africans, where more than 500 of them were additionally genotyped for the control region. These data were analyzed together with over 12,700 control region profiles collected from the literature, representing more than 300 population samples from Africa. Insights into the African homeland of humans are discussed. Phylogeographic patterns for the African continent are shown at a high phylogeographic resolution as well as at the population and regional levels. The deepest branch of the mtDNA tree, haplogroup L0, shows the highest sub-haplogroup diversity in Southeast and East Africa, suggesting this region as the homeland for modem humans. Several demographic estimates point to the coast as a facilitator of human migration in Africa, but the data indicate complex patterns, perhaps mirroring the effect of recent continental-scaled demographic events in re-shaping African mtDNA variability.