246 research outputs found
Amniotic fluid absorption and growth functions in humans: what can we indirectly learn from congenital digestive atresias?
Background: Amniotic fluid (AF) was thought of just as a mechanical cushioning to the foetus. Nowadays, its role
during pregnancy is getting more attention, suggesting hitherto unknown aspects. The aim of the study is to speculate
on AF nutritional functions and its clinical repercussions based on what digestive tract (DT) atresias seem to
suggest.
Methods: A retrospective analysis of the patients admitted to our department for DT atresias between 2000 and
2020 was conducted. Patients’ birth weight (BW), gestational age (GA) at birth and diagnosis were recorded. The following
were excluded from the study: oesophageal atresias (OA) with tracheoesophageal fistula (TOF), colonic and
anal atresias and patients with associated major comorbidities. A control group was made of patients admitted to
our ward in the same period for congenital pulmonary airway malformations (CPAM). To standardize the BW, it was
coupled with birth GA calculating the newborn percentiles. The mean newborn percentiles of OAs, duodenal atresias
(DAs), jejunal atresias (JAs), and ileal atresias (IAs) were independently compared with the control group using Student’s
t-test. Lastly, the significance of the frequencies’ distribution of newborns born small for gestational age (SGA)
between the DT atresias and the control group was evaluated with the χ2 test, and the OR were calculated. A p-value
< 0.05 was considered statistically significant.
Results: A total of 231 patients were eligible for the study: 36 OAs without TOF, mean BW 2488.8 ± 491 g (range
1630–3750 g), mean GA 36.8 ± 2.1 weeks (31–40 weeks), mean newborn percentile 18 ± 22 (1–75); 20 DAs, mean BW
2586.8 ± 577.9 g (1250–3462 g), mean GA 36.2 ± 2.5 weeks (31–40 weeks), mean newborn percentile 31 ± 23 (3–79);
17 JAs, mean BW 2483.5 ± 621.7 g (900–3205 g), mean GA 34.8 ± 2.1 weeks (30–38 weeks), mean newborn percentile
44 ± 28 (4–96); 17 IAs, mean BW 2646.1 ± 769.8 g (1162.0–3888 g), mean GA 35.9 ± 3.2 weeks (30–41 weeks), mean
newborn percentile 44 ± 26 (1–82); and 141 CPAMs with mean BW 3287.4 ± 492.0 g (980–4580 g), mean GA 38.7 ±
1.8 weeks (26–41 weeks), mean newborn percentile 43 ± 26 (1–99). The number of SGA neonates was 18 between
OA patients (50%), 4 between DAs (20%), 1 between JAs (6%), 2 between IAs (12%) and 11 between CPAMs (8%). The
mean percentile of the OAs and DAs was lower than the control group with a p of < .01 and .03 while no statistical significance
was found in the comparison between DAs, JAs, IAs and CPAMs with a p of .06, .86 and .59. The incidence of
SGA in the control group resulted lower than the one in the DT atresias where it becomes higher the more proximal
the atresia is (p < .05). The OR of SGA newborn in the OA group was 11.8, in DA 3.0, in JA 0.7 and in IA 1.6.
Conclusion: AF showed to have a great impact on foetal growth, and its preferred site of absorption seemed to be
the stomach and duodenum. Its nutritional role could have an important predictive value in diagnosing DT atresia
both prenatally and postnatally
Antibodies to Serine Proteases in the Antiphospholipid Syndrome
It is generally accepted that the major autoantigen for antiphospholipid antibodies (aPL) in the antiphospholipid syndrome (APS) is β2-glycoprotein I (β2GPI). However, a recent study has revealed that some aPL bind to certain conformational epitope(s) on β2GPI shared by the homologous enzymatic domains of several serine proteases involved in hemostasis and fibrinolysis. Importantly, some serine protease–reactive aPL correspondingly hinder anticoagulant regulation and resolution of clots. These results extend several early findings of aPL binding to other coagulation factors and provide a new perspective about some aPL in terms of binding specificities and related functional properties in promoting thrombosis. Moreover, a recent immunological and pathological study of a panel of human IgG monoclonal aPL showed that aPL with strong binding to thrombin promote in vivo venous thrombosis and leukocyte adherence, suggesting that aPL reactivity with thrombin may be a good predictor for pathogenic potentials of aPL
Genetic diversity and its impact on disease severity in respiratory syncytial virus subtype-A and -B bronchiolitis before and after pandemic restrictions in Rome
Objectives: To scrutinize whether the high circulation of respiratory syncytial virus (RSV) observed in 2021-2022 and 2022-2023 was due to viral diversity, we characterized RSV-A and -B strains causing bronchiolitis in Rome, before and after the COVID-19 pandemic. Methods: RSV-positive samples, prospectively collected from infants hospitalized for bronchiolitis from 2017-2018 to 2022-2023, were sequenced in the G gene; phylogenetic results and amino acid substitutions were analyzed. Subtype-specific data were compared among seasons. Results: Predominance of RSV-A and -B alternated in the pre-pandemic seasons; RSV-A dominated in 2021-2022 whereas RSV-B was predominant in 2022-2023. RSV-A sequences were ON1 genotype but quite distant from the ancestor; two divergent clades included sequences from pre- and post-pandemic seasons. Nearly all RSV-B were BA10 genotype; a divergent clade included only strains from 2021-2022 and 2022-2023. RSV-A cases had lower need of O2 therapy and of intensive care during 2021-2022 with respect to all other seasons. RSV-B infected infants were more frequently admitted to intensive care units and needed O2 in 2022-2023. Conclusions: The intense RSV peak in 2021-2022, driven by RSV-A phylogenetically related to pre-pandemic strains is attributable to the immune debt created by pandemic restrictions. The RSV-B genetic divergence observed in post-pandemic strains may have increased the RSV-B specific immune debt, being a possible contributor to bronchiolitis severity in 2022-2023
Numerical instability of the Akhmediev breather and a finite-gap model of it
In this paper we study the numerical instabilities of the NLS Akhmediev
breather, the simplest space periodic, one-mode perturbation of the unstable
background, limiting our considerations to the simplest case of one unstable
mode. In agreement with recent theoretical findings of the authors, in the
situation in which the round-off errors are negligible with respect to the
perturbations due to the discrete scheme used in the numerical experiments, the
split-step Fourier method (SSFM), the numerical output is well-described by a
suitable genus 2 finite-gap solution of NLS. This solution can be written in
terms of different elementary functions in different time regions and,
ultimately, it shows an exact recurrence of rogue waves described, at each
appearance, by the Akhmediev breather. We discover a remarkable empirical
formula connecting the recurrence time with the number of time steps used in
the SSFM and, via our recent theoretical findings, we establish that the SSFM
opens up a vertical unstable gap whose length can be computed with high
accuracy, and is proportional to the inverse of the square of the number of
time steps used in the SSFM. This neat picture essentially changes when the
round-off error is sufficiently large. Indeed experiments in standard double
precision show serious instabilities in both the periods and phases of the
recurrence. In contrast with it, as predicted by the theory, replacing the
exact Akhmediev Cauchy datum by its first harmonic approximation, we only
slightly modify the numerical output. Let us also remark, that the first rogue
wave appearance is completely stable in all experiments and is in perfect
agreement with the Akhmediev formula and with the theoretical prediction in
terms of the Cauchy data.Comment: 27 pages, 8 figures, Formula (30) at page 11 was corrected, arXiv
admin note: text overlap with arXiv:1707.0565
Measuring IgA anti-β2-glycoprotein I and IgG/IgA anti-domain I antibodies adds value to current serological assays for the antiphospholipid syndrome
Introduction
Currently available clinical assays to detect antiphospholipid antibodies (aPL) test for IgG and IgM antibodies to cardiolipin (aCL) and beta(2)-glycoprotein I (a beta(2)GPI). It has been suggested that testing for IgA aPL and for antibodies to Domain I (DI), which carries the key antigenic epitopes of beta(2)GPI, could add value to these current tests. We performed an observational, multicenter cohort study to evaluate the utility of IgG, IgM and IgA assays to each of CL, beta(2)GPI and DI in APS.
Methods
Serum from 230 patients with APS (n = 111), SLE but not APS (n = 119), and 200 healthy controls were tested for IgG, IgM and IgA aCL, a beta(2)GPI and aDI activity. Patients with APS were further classified into thrombotic or obstetric APS. Logistic regression and receiver operator characteristic analyses were employed to compare results from the nine different assays.
Results All assays displayed good specificity for APS; IgG aCL and IgG a beta(2)GPI assays however, had the highest sensitivity. Testing positive for IgA a beta(2)GPI resulted in a higher hazard ratio for APS compared to IgM a beta(2)GPI. Positive IgG, IgM or IgA aDI were all associated with APS, and in subjects positive for aCL and/or a beta(2)GPI, the presence of aDI raised the hazard ratio for APS by 3-5 fold. IgG aCL, a beta(2)GPI, aDI and IgA aDI were associated with thrombotic but not obstetric complications in patients with APS.
Conclusion
Measuring IgG aDI and IgA a beta(2)GPI and aDI may be useful in the management of patients with APS, particularly thrombotic APS
A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome
Background: b2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of b2GPI generated by anti-b2GPI antibodies is pathologically important, in contrast to monomeric b2GPI which is abundant in plasma. Principal Findings: We created a dimeric inhibitor, A1-A1, to selectively target b2GPI in b2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of b2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of b2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of b2GPI present in human serum, b2GPI purified from human plasma and the individual domain V of b2GPI. We demonstrated that when b2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of b2GPI to cardiolipin, regardless of the source of b2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of b2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-b2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric b2GPI to cardiolipin. Conclusions: Our results suggest that the approach of using a dimeric inhibitor to block b2GPI in the pathologica
Viral Etiology of Influenza-Like Illnesses in Antananarivo, Madagascar, July 2008 to June 2009
In Madagascar, despite an influenza surveillance established since 1978, little is known about the etiology and prevalence of viruses other than influenza causing influenza-like illnesses (ILIs).From July 2008 to June 2009, we collected respiratory specimens from patients who presented ILIs symptoms in public and private clinics in Antananarivo (the capital city of Madagascar). ILIs were defined as body temperature ≥38°C and cough and at least two of the following symptoms: sore throat, rhinorrhea, headache and muscular pain, for a maximum duration of 3 days. We screened these specimens using five multiplex real time Reverse Transcription and/or Polymerase Chain Reaction assays for detection of 14 respiratory viruses. We detected respiratory viruses in 235/313 (75.1%) samples. Overall influenza virus A (27.3%) was the most common virus followed by rhinovirus (24.8%), RSV (21.2%), adenovirus (6.1%), coronavirus OC43 (6.1%), influenza virus B (3.9%), parainfluenza virus-3 (2.9%), and parainfluenza virus-1 (2.3%). Co-infections occurred in 29.4% (69/235) of infected patients and rhinovirus was the most detected virus (27.5%). Children under 5 years were more likely to have one or more detectable virus associated with their ILI. In this age group, compared to those ≥5 years, the risk of detecting more than one virus was higher (OR = 1.9), as was the risk of detecting of RSV (OR = 10.1) and adenovirus (OR = 4.7). While rhinovirus and adenovirus infections occurred year round, RSV, influenza virus A and coronavirus OC43 had defined period of circulation.In our study, we found that respiratory viruses play an important role in ILIs in the Malagasy community, particularly in children under 5 years old. These data provide a better understanding of the viral etiology of outpatients with ILI and describe for the first time importance of these viruses in different age group and their period of circulation
Human Papillomaviruses and genital co-infections in gynaecological outpatients
<p>Abstract</p> <p>Background</p> <p>High grade HPV infections and persistence are the strongest risk factors for cervical cancer. Nevertheless other genital microorganisms may be involved in the progression of HPV associated lesions.</p> <p>Methods</p> <p>Cervical samples were collected to search for human Papillomavirus (HPV), bacteria and yeast infections in gynaecologic outpatients. HPV typing was carried out by PCR and sequencing on cervical brush specimens. <it>Chlamydia trachomatis </it>was identified by strand displacement amplification (SDA) and the other microorganisms were detected by conventional methods.</p> <p>Results</p> <p>In this cross-sectional study on 857 enrolled outpatients, statistical analyses revealed a significant association of HPV with <it>C. trachomatis </it>and <it>Ureaplasma urealyticum (</it>at high density) detection, whereas no correlation was found between HPV infection and bacterial vaginosis, <it>Streptococcus agalactiae</it>, yeasts, <it>Trichomonas vaginalis </it>and <it>U. urealyticum</it>. <it>Mycoplasma hominis </it>was isolated only in a few cases both in HPV positive and negative women and no patient was infected with <it>Neisseria gonorrhoeae</it>.</p> <p>Conclusion</p> <p>Although bacterial vaginosis was not significantly associated with HPV, it was more common among the HPV positive women. A significant association between HPV and <it>C. trachomatis </it>was found and interestingly also with <it>U. urealyticum </it>but only at a high colonization rate. These data suggest that it may be important to screen for the simultaneous presence of different microorganisms which may have synergistic pathological effects.</p
Clinical and neuroimaging correlates of antiphospholipid antibodies in multiple sclerosis: a preliminary study
<p>Abstract</p> <p>Background</p> <p>The presence of antiphospholipid antibodies (APLA) in multiple sclerosis (MS) patients has been reported frequently but no clear relationship between APLA and the clinical and neuroimaging features of MS have heretofore been shown. We assessed the clinical and neuroimaging features of MS patients with plasma APLA.</p> <p>Methods</p> <p>A consecutive cohort of 24 subjects with relapsing-remitting (RR) MS were studied of whom 7 were in remission (Rem) and 17 in exacerbation (Exc). All subjects were examined and underwent MRI of brain. Patients' plasma was tested by standard ELISA for the presence of both IgM and IgG antibodies using a panel of 6 targets: cardiolipin (CL), β2 glycoprotein I (β2GPI), Factor VII/VIIa (FVIIa), phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidylethanolamine (PE).</p> <p>Results</p> <p>In exacerbation up to 80% of MS subjects had elevated titers of IgM antibodies directed against the above antigens. However, in remission, less than half of MS patients had elevated titers of IgM antibodies against one or more of the above antigens. This difference was significant, p < 0.01, for all 6 target antigens. Interestingly, none of the MS patients had elevated plasma titers of IgG against any of the target antigens tested. Correlation analysis between MRI enhancing lesions and plasma levels of APLA revealed high correlation for aPC, aPS and aFVIIa (p ≤ 0.0065), a trend for aPE and aCL (p = 0.056), and no correlation for aβ2GP1. The strongest correlation was for aFVIIa, p = 0.0002.</p> <p>Conclusion</p> <p>The findings of this preliminary study show that increased APLA IgM is associated with exacerbations of MS. Currently, the significance of this association in pathogenesis of MS remains unknown. However, systematic longitudinal studies to measure APLA in larger cohorts of patients with relapsing-remitting MS, particularly before and after treatment with immunomodulatory agents, are needed to confirm these preliminary findings.</p
Cervical determinants of anal HPV infection and high-grade anal lesions in women: a collaborative pooled analysis
Cervical cancer screening might contribute to the prevention of anal cancer in women. We aimed to investigate if routine cervical cancer screening results-namely high-risk human papillomavirus (HPV) infection and cytohistopathology-predict anal HPV16 infection, anal high-grade squamous intraepithelial lesions (HSIL) and, hence, anal cancer.International Agency for Research on Cance
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