An experimentally representative in-silico protocol for dynamical studies of lyophilised and weakly hydrated amorphous proteins

Characterization of biopolymers in both dry and weakly hydrated amorphous states has implications for the pharmaceutical industry since it provides understanding of the effect of lyophilisation on stability and biological activity. Atomistic Molecular Dynamics (MD) simulations probe structural and dynamical features related to system functionality. However, while simulations in homogenous aqueous environments are routine, dehydrated model assemblies are a challenge with systems investigated in-silico needing careful consideration; simulated systems potentially differing markedly despite seemingly negligible changes in procedure. Here we propose an in-silico protocol to model proteins in lyophilised and weakly hydrated amorphous states that is both more experimentally representative and routinely applicable. Since the outputs from MD align directly with those accessed by neutron scattering, the efficacy of the simulation protocol proposed is shown by validating against experimental neutron data for apoferritin and insulin. This work also highlights that without cooperative experimental and simulative data, development of simulative procedures using MD alone would prove most challenging.

RAPP-containing arrest peptides induce translational stalling by short circuiting the ribosomal peptidyltransferase activity

Arrest peptides containing RAPP (ArgAlaProPro) motifs have been discovered in both Gram-positive and Gram-negative bacteria, where they are thought to regulate expression of important protein localization machinery components. Here we determine cryo-EM structures of ribosomes stalled on RAPP arrest motifs in both Bacillus subtilis and Escherichia coli. Together with molecular dynamics simulations, our structures reveal that the RAPP motifs allow full accommodation of the A-site tRNA, but prevent the subsequent peptide bond from forming. Our data support a model where the RAP in the P-site interacts and stabilizes a single hydrogen atom on the Pro-tRNA in the A-site, thereby preventing an optimal geometry for the nucleophilic attack required for peptide bond formation to occur. This mechanism to short circuit the ribosomal peptidyltransferase activity is likely to operate for the majority of other RAPP-like arrest peptides found across diverse bacterial phylogenies.

The SecM arrest peptide traps a pre-peptide bond formation state of the ribosome

Nascent polypeptide chains can induce translational stalling to regulate gene expression. This is exemplified by the E. coli secretion monitor (SecM) arrest peptide that induces translational stalling to regulate expression of the downstream encoded SecA, an ATPase that co-operates with the SecYEG translocon to facilitate insertion of proteins into or through the cytoplasmic membrane. Here we present the structure of a ribosome stalled during translation of the full-length E. coli SecM arrest peptide at 2.0 Å resolution. The structure reveals that SecM arrests translation by stabilizing the Pro-tRNA in the A-site, but in a manner that prevents peptide bond formation with the SecM-peptidyl-tRNA in the P-site. By employing molecular dynamic simulations, we also provide insight into how a pulling force on the SecM nascent chain can relieve the SecM-mediated translation arrest. Collectively, the mechanisms determined here for SecM arrest and relief are also likely to be applicable for a variety of other arrest peptides that regulate components of the protein localization machinery identified across a wide range of bacteria lineages.

Simulation of Complex Biomolecular Systems: The Ribosome Challenge

Large biomolecular systems are at the heart of many essential cellular processes. The dynamics and energetics of an increasing number of these systems are being studied by computer simulations. Pushing the limits of length- and timescales that can be accessed by current hard- and software has expanded the ability to describe biomolecules at different levels of detail. We focus in this review on the ribosome, which exemplifies the close interplay between experiment and various simulation approaches, as a particularly challenging and prototypic nanomachine that is pivotal to cellular biology due to its central role in translation. We sketch widely used simulation methods and demonstrate how the combination of simulations and experiments advances our understanding of the function of the translation apparatus based on fundamental physics. Expected final online publication date for the Annual Review of Biophysics, Volume 52 is May 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Motibot: the Virtual Coach for healthy coping intervention in diabetes

Introduction

Virtual coaches (VCs) can support people with Diabetes Mellitus (DM) by motivating them to better manage their health. Few VCs were aimed at providing psychosocial support. In this regard, motivation is a pivotal construct in diabetes self-management as it allows adults with DM to adhere to the clinical recommendations.

Objectives

The present study aimed to develop a VC able to motivate adults with DM to adopt and acquire healthier coping strategies, to decrease symptoms of depression, anxiety, perceived stress, and diabetes-related emotional distress, while also improving their well-being.

Methods

A total of 12 adults with DM (M=27.91 years; SD=9.82) interacted with a VC, called Motibot using Telegram for an overall duration of 12 sessions. Participants completed a battery of instruments at pre-, post-intervention and follow-up.

Results

highlighted a decrease in anxiety, and depression symptoms between pre-, post-intervention and follow-up, as also showed by the results that emerged through the text mining. Motibot was perceived as motivating and encouraging in the adoption of appropriate coping strategies, such as mindfulness practices. Motibot was also perceived as trustworthy, reflective, and stimulating in its dialogical interaction. Indeed, adults felt involved in the interaction with Motibot, thereby showing an overall perception of a better quality of life, in the absence of diabetes distress.

Conclusions

This study sheds light on the importance of VCs in health care for people with DM for psychosocial support. This is the first experimental study on the matter, and thus, further iterations of the intervention are needed using a larger sample size.

Disclosure

No significant relationships.

Poor mobilization of autologous CD34+ peripheral blood stem cells in haematology patients undergoing autologous stem cell transplantation is associated with the presence of variants in genes implicated in clonal haematopoiesis of indeterminant potential

Clonal haematopoiesis of indeterminant potential (CHIP) increases in frequency with age. The effect of CHIP on the mobilization of autologous CD34+ peripheral blood stem cells (PBSC) has not been reported. This study uses a DNA-based targeted candidate gene approach to identify the presence of somatic mutations in ASXL1, DNMT3A, JAK2, SF3B1, TET2 and TP53 in CD34+ haematopoietic progenitor cell-apheresis products of 96 patients who undergo PBSC mobilization for autologous stem cell transplantation (ASCT). Variants were identified in a significantly greater proportion of patients who experience poor CD34+ PBSC mobilization. A DNA-based targeted candidate gene array is able to predict poor CD34+ PBSC mobilization and may be deployed pre-emptively to minimize mobilization and graft failures.

Molecular detection of Leishmania (Sauroleishmania) tarentolae in human blood and Leishmania (Leishmania) infantum in Sergentomyia minuta: unexpected host-parasite contacts

The detection of atypical Kinetoplastida in vertebrate hosts and vectors might suggest unexpected host-parasite contacts. Aside to major vectors of Leishmania (Leishmania) infantum in Italy (e.g. Phlebotomus perniciosus and Phlebotomus perfiliewi), the sand fly fauna also includes Sergentomyia minuta, herpetophilic and proven vector of Leishmania (Sauroleishmania) tarentolae, in which records of blood meal on mammals and detection of L. infantum DNA are increasing. This study was conducted in Central Italy aiming to molecularly detect potential atypical Leishmania host-vector contacts. Detection of Leishmania spp. DNA was performed by polymerase chain reaction (SSU rRNA, ITS1 targets) on field-collected sand fly females (N = 344), blood samples from humans (N = 185) and dogs (N = 125). Blood meal identification was also performed on engorged sand flies. Leishmania spp. DNA was found in 13.1% sand flies, 3.7% humans and 14.4% dogs. Sequence analysis identified L. infantum in S. minuta (4.4%), P. perniciosus (9.1%), humans (2.2%) and dogs (14.4%). Leishmania tarentolae was detected in S. minuta (12.6%), P. perfiliewi (6.6%) and human (1.6%) samples. Of 28 S. minuta examined for blood meal, 3.6 and 21.4% scored positive for human and lizard DNA, respectively. These results indicate the importance of one-health approach to explore new potential routes of transmission of leishmaniasis involving S. minuta.

Effect of a health education intervention on intestinal parasitic infections in Bolivian children

Backgrounds

Intestinal parasitic infections (IPI) are a major health issue for children of low- and middle-income countries. Water, sanitation and hygiene (WASH) practices are crucial for preventing IPI. The aim of the study was to evaluate the effects of a school-based health education intervention on handwashing behavior and IPI prevalence in children

Methods

This is a randomized intervention trial in 8 primary schools in rural communities over the course of 3 school years; preliminary results from the first two years of the trial are here presented. Schools were randomly selected and assigned in a 1:1 ratio to intervention or control (no intervention) groups. For each school year, the intervention included 14 school-based educational sessions and 2 skit events, involving children aged 8-12 years. Knowledge, attitude and practice questionnaire and handwashing at key events was assessed at the beginning and end of each school year. IPI prevalence was assessed with repeated cross-sectional parasitology surveys 12 months apart, involving a minimum of 50 children for each school

Results

At baseline, no significant differences between intervention and control schools were present in the proportion of children who washed their hands at key events (7.2% vs 9.3%, p = 0.28), in IPI (79.4% vs 75.3%, p = 0.3) and multiple parasitic infections (MPI) prevalences (47.6 vs. 38.6; p = 0.051). At the end of the second year, the percentage of children who washed their hands at key events was significantly higher in the intervention schools (75.4% vs 12.1%, p < 0.001), and the prevalence of IPI and MPI in the intervention schools were respectively about 25% and 15% lower than in the control schools (respectively, 42.9% vs 67.8%, p < 0.001; 16.1% vs 31.6%, p < 0.001)

Conclusions

A school-based health education intervention could achieve significant changes in hand-washing behaviors and reduction in the prevalence of IPI in children. The third year survey results are needed to confirm these findings

Key messages

An health education intervention on water, sanitation and hygiene (WASH) practices can reduce the risk of IPI infection in children. An health education intervention on water, sanitation and hygiene (WASH) practices could be configured as a sustainable long-term approach to intestinal parasitic infections control in children.

Fatty acid synthase and adenosine monophosphate-activated protein kinase regulate cell survival and drug sensitivity in diffuse large B-cell lymphoma

Fatty acid synthesis is crucial in supporting the survival and proliferation of multiple forms of cancer. The high metabolic demands of fatty acid synthesis are regulated by the AMP-activated kinase and activity of the fatty acid synthase enzyme. In this study, the roles of these enzymes in diffuse large B-cell lymphoma (DLBCL) were investigated by genetic knock-down and pharmacological activation of AMP-activated kinase by metformin, and selective inhibition of fatty acid synthase using the novel drug Fasnall. We observed distinct heterogeneity and adaptive plasticity of lipid metabolism in a panel of DLBCL cell lines and demonstrate the therapeutic potential of inhibiting fatty acid synthesis in a subset of DLBCL cells. The translational relevance of these in vitro data is supported by the strong correlation between AMP-activated protein kinase expression in primary DLBCL samples and disease relapse. Inhibition of fatty acid synthase with Fasnall may represent a therapeutic option for DLBCL that preferentially subverts to de novo fatty acid synthesis.

Understanding the Synergy of NKp46 and Co-Activating Signals in Various NK Cell Subpopulations: Paving the Way for More Successful NK-Cell-Based Immunotherapy

The NK cell population is characterized by distinct NK cell subsets that respond differently to the various activating stimuli. For this reason, the determination of the optimal cytotoxic activation of the different NK cell subsets can be a crucial aspect to be exploited to counter cancer cells in oncologic patients. To evaluate how the triggering of different combination of activating receptors can affect the cytotoxic responses of different NK cell subsets, we developed a microbead-based degranulation assay. By using this new assay, we were able to detect CD107a⁺ degranulating NK cells even within the less cytotoxic subsets (i.e., resting CD56^bright and unlicensed CD56^dim NK cells), thus demonstrating its high sensitivity. Interestingly, signals delivered by the co-engagement of NKp46 with 2B4, but not with CD2 or DNAM-1, strongly cooperate to enhance degranulation on both licensed and unlicensed CD56^dim NK cells. Of note, 2B4 is known to bind CD48 hematopoietic antigen, therefore this observation may provide the rationale why CD56^dim subset expansion correlates with successful hematopoietic stem cell transplantation mediated by alloreactive NK cells against host T, DC and leukemic cells, while sparing host non-hematopoietic tissues and graft versus host disease. The assay further confirms that activation of LFA-1 on NK cells leads to their granule polarization, even if, in some cases, this also takes to an inhibition of NK cell degranulation, suggesting that LFA-1 engagement by ICAMs on target cells may differently affect NK cell response. Finally, we observed that NK cells undergo a time-dependent spontaneous (cytokine-independent) activation after blood withdrawal, an aspect that may strongly bias the evaluation of the resting NK cell response. Altogether our data may pave the way to develop new NK cell activation and expansion strategies that target the highly cytotoxic CD56^dim NK cells and can be feasible and useful for cancer and viral infection treatment.

Understanding the Synergy of NKp46 and Co-Activating Signals in Various NK Cell Subpopulations: Paving the Way for More Successful NK-Cell-Based Immunotherapy

The NK cell population is characterized by distinct NK cell subsets that respond differently to the various activating stimuli. For this reason, the determination of the optimal cytotoxic activation of the different NK cell subsets can be a crucial aspect to be exploited to counter cancer cells in oncologic patients. To evaluate how the triggering of different combination of activating receptors can affect the cytotoxic responses of different NK cell subsets, we developed a microbead-based degranulation assay. By using this new assay, we were able to detect CD107a⁺ degranulating NK cells even within the less cytotoxic subsets (i.e., resting CD56^bright and unlicensed CD56^dim NK cells), thus demonstrating its high sensitivity. Interestingly, signals delivered by the co-engagement of NKp46 with 2B4, but not with CD2 or DNAM-1, strongly cooperate to enhance degranulation on both licensed and unlicensed CD56^dim NK cells. Of note, 2B4 is known to bind CD48 hematopoietic antigen, therefore this observation may provide the rationale why CD56^dim subset expansion correlates with successful hematopoietic stem cell transplantation mediated by alloreactive NK cells against host T, DC and leukemic cells, while sparing host non-hematopoietic tissues and graft versus host disease. The assay further confirms that activation of LFA-1 on NK cells leads to their granule polarization, even if, in some cases, this also takes to an inhibition of NK cell degranulation, suggesting that LFA-1 engagement by ICAMs on target cells may differently affect NK cell response. Finally, we observed that NK cells undergo a time-dependent spontaneous (cytokine-independent) activation after blood withdrawal, an aspect that may strongly bias the evaluation of the resting NK cell response. Altogether our data may pave the way to develop new NK cell activation and expansion strategies that target the highly cytotoxic CD56^dim NK cells and can be feasible and useful for cancer and viral infection treatment.

The tumour microenvironment is immuno-tolerogenic and a principal determinant of patient outcome in EBV-positive diffuse large B-cell lymphoma

OBJECTIVE

Epstein-Barr virus-positive diffuse large B-cell lymphoma (EBV^-pos DLBCL) is a recently identified entity. Data regarding outcome to frontline immuno-chemotherapy are conflicting. Although the prognostic impact of the tumour microenvironment (TME) in EBV^-neg DLBCL is well-established, it remains untested whether the TME influences survival in EBV^-pos DLBCL. There are no data with new digital gene expression technologies that simultaneously interrogate the virus, B cells and the tumour microenvironment (TME).

METHODS

We used the NanoString™ platform in a population-based cohort of 433 patients to establish if the technology could detect EBV in the tumour biopsies and to investigate the influence that EBV has on the complex tumour microenvironment of DLBCL.

RESULTS

Incidence of EBV^-pos DLBCL was 6.9% with 5-year survival of 65% vs 82% in EBV^-neg DLBCL (P = 0.018). EBV^-pos tissues had similar expression of T-cell genes compared to EBV^-neg DLBCL but higher levels of the antigen-presenting molecule B2M. This was countered by elevated PD-L1, PD-L2, LAG3 and TIM3 immune checkpoints and a higher CD163/CD68 "M2" macrophage score.

CONCLUSION

In EBV^-pos DLBCL, the TME is immuno-tolerogenic and may explain the poor outcomes seen in this subtype of DLBCL.

Dirofilaria repens Infection Mimicking Lung Melanoma Metastasis

We describe a rare case of Dirofilaria repens infection presenting as peripheral lung nodules and mimicking a metastatic focus from a previously diagnosed cutaneous melanoma. To avoid invasive investigations before arriving at the correct diagnosis, dirofilariasis should be included as a part of the diagnostic process in subjects with lung nodules who live in (or have traveled to) endemic regions.

Receptor homodimerization plays a critical role in a novel dominant negative P2RY12 variant identified in a family with severe bleeding

Essentials Three dominant variants for the autosomal recessive bleeding disorder type-8 have been described. To date, there has been no phenotype/genotype correlation explaining their dominant transmission. Proline plays an important role in P2Y12R ligand binding and signaling defects. P2Y12R homodimer formation is critical for the receptor function and signaling.

SUMMARY

Background Although inherited platelet disorders are still underdiagnosed worldwide, advances in molecular techniques are improving disease diagnosis and patient management. Objective To identify and characterize the mechanism underlying the bleeding phenotype in a Caucasian family with an autosomal dominant P2RY12 variant. Methods Full blood counts, platelet aggregometry, flow cytometry and western blotting were performed before next-generation sequencing (NGS). Detailed molecular analysis of the identified variant of the P2Y12 receptor (P2Y12R) was subsequently performed in mammalian cells overexpressing receptor constructs. Results All three referred individuals had markedly impaired ADP-induced platelet aggregation with primary wave only, despite normal total and surface P2Y12R expression. By NGS, a single P2RY12:c.G794C substitution (p.R265P) was identified in all affected individuals, and this was confirmed by Sanger sequencing. Mammalian cell experiments with the R265P-P2Y12R variant showed normal receptor surface expression versus wild-type (WT) P2Y12R. Agonist-stimulated R265P-P2Y12R function (both signaling and surface receptor loss) was reduced versus WT P2Y12R. Critically, R265P-P2Y12R acted in a dominant negative manner, with agonist-stimulated WT P2Y12R activity being reduced by variant coexpression, suggesting dramatic loss of WT homodimers. Importantly, platelet P2RY12 cDNA cloning and sequencing in two affected individuals also revealed three-fold mutant mRNA overexpression, decreasing even further the likelihood of WT homodimer formation. R265 located within extracellular loop 3 (EL3) is one of four residues that are important for receptor functional integrity, maintaining the binding pocket conformation and allowing rotation following ligand binding. Conclusion This novel dominant negative variant confirms the important role of R265 in EL3 in the functional integrity of P2Y12R, and suggests that pathologic heterodimer formation may underlie this family bleeding phenotype.

Mean platelet diameter measurements to classify inherited thrombocytopenias

INTRODUCTION

Mean platelet volume (MPV) assists the differential diagnosis of inherited thrombocytopenia (IT) but lacks standardisation and varies between automated analysers. Classification of IT based on mean platelet diameter (MPD) has been proposed by an international collaborative study but has not been validated.

METHODS

To assess the applicability of MPD to classify forms of IT, digital images of blood films from patients with established genetic causes for IT were generated, and the MPD measured (ZEISS Axio-scanner and Image J software) by a blinded reviewer. Comparison was made to the proposed classification system.

RESULTS

Mean platelet volume was measured in thrombocytopenia with different genetic aetiologies, bilallelic BSS (bBSS) (n = 1), monoallelic BSS (mBSS) (n = 2), MYH9-related disorders (MYH9-RD) (n = 11), GFI1B-related thrombocytopenia (RT) (n = 15), FLI1-RT (n = 2), TUBB1-RT (n = 3), ITGA2B/ITGB3-RT (n = 1), RUNX1-RT (n = 2) and controls (n = 54). bBSS and 82% of MYH9-RD samples had MPD >4 μm which correlated with "IT with giant platelets." Only 55% of samples expected in the "large platelet group" had MPD meeting the classification cut-off (MPD >3.2 μm). FLI1-RT MPD were significantly larger than expected whilst ITGA2B/ITGB3-RT MPD were smaller than proposed. MPD in FPD/AML were "normal."

CONCLUSION

Platelet MPD measurements are a useful guide to classify IT, but the time taken to record measurements may limit clinical applicability.

Thrombocytopenia and CD34 expression is decoupled from α-granule deficiency with mutation of the first growth factor-independent 1B zinc finger

Essentials The phenotypes of different growth factor-independent 1B (GFI1B) variants are not established. GFI1B variants produce heterogeneous clinical phenotypes dependent on the site of mutation. Mutation of the first non-DNA-binding zinc-finger causes a mild platelet and clinical phenotype. GFI1B regulates the CD34 promoter; platelet CD34 expression is an indicator of GFI1B mutation.

SUMMARY

Background Mutation of the growth factor-independent 1B (GFI1B) fifth DNA-binding zinc-finger domain causes macrothrombocytopenia and α-granule deficiency leading to clinical bleeding. The phenotypes associated with GFI1B variants disrupting non-DNA-binding zinc-fingers remain uncharacterized. Objectives To determine the functional and phenotypic consequences of GFI1B variants disrupting non-DNA-binding zinc-finger domains. Methods The GFI1B C168F variant and a novel GFI1B c.2520 + 1_2520 + 8delGTGGGCAC splice variant were identified in four unrelated families. Phenotypic features, DNA-binding properties and transcriptional effects were determined and compared with those in individuals with a GFI1B H294 fs mutation of the fifth DNA-binding zinc-finger. Patient-specific induced pluripotent stem cell (iPSC)-derived megakaryocytes were generated to facilitate disease modeling. Results The DNA-binding GFI1B variant C168F, which is predicted to disrupt the first non-DNA-binding zinc-finger domain, is associated with macrothrombocytopenia without α-granule deficiency or bleeding symptoms. A GFI1B splice variant, c.2520 + 1_2520 + 8delGTGGGCAC, which generates a short GFI1B isoform that lacks non-DNA-binding zinc-fingers 1 and 2, is associated with increased platelet CD34 expression only, without quantitative or morphologic platelet abnormalities. GFI1B represses the CD34 promoter, and this repression is attenuated by different GFI1B zinc-finger mutations, suggesting that deregulation of CD34 expression occurs at a direct transcriptional level. Patient-specific iPSC-derived megakaryocytes phenocopy these observations. Conclusions Disruption of GFI1B non-DNA-binding zinc-finger 1 is associated with mild to moderate thrombocytopenia without α-granule deficiency or bleeding symptomatology, indicating that the site of GFI1B mutation has important phenotypic implications. Platelet CD34 expression appears to be a common feature of perturbed GFI1B function, and may have diagnostic utility.

Murine thymic NK cells are distinct from ILC1s and have unique transcription factor requirements

Group 1 innate lymphoid cells include natural killer (NK) cells and ILC1s, which mediate the response to intracellular pathogens. Thymic NK (tNK) cells were described with hybrid features of immature NK cells and ILC1 but whether these cells are related to NK cells or ILC1 has not been fully investigated. We report that murine tNK cells expressed the NK-cell associated transcription factor EOMES and developed independent of the essential ILC1 factor TBET, confirming their placement within the NK lineage. Moreover, tNK cells resemble NK cells rather than ILC1 in their requirements for the E protein transcription factor inhibitor ID2. We provide further insight into the mechanisms governing tNK-cell development by showing that the transcription factor ETS1 prevented tNK cell acquisition of the conventional NK-cell maturation markers CD11b and KLRG1. Our data reveal few ILC1 in the thymus and clarify the identity and developmental requirements of tNK cells.

Monitoring game-based motor rehabilitation of patients at home for better plans of care and quality of life

This paper describes the biomedical, remote monitoring infrastructure developed and currently tested in the EU REHAB@HOME project to support home rehabilitation of the upper extremity of persons post-stroke and in persons with other neurological disorders, such as Multiple Sclerosis patients, in order to track their progress over therapy and improve their Quality of Life. The paper will specifically focus on describing the initial testing of the tele-rehabilitation system's components for patients' biomedical monitoring over therapy, which support the delivery and monitoring of more personalized, engaging plans of care by rehabilitation centers and services.

Sonographic evaluation of the lower uterine segment thickness in women with a single previous Cesarean section

AIM

The aim of this paper was to evaluate the lower uterine segment (LUS) thickness through transvaginal sonography in late preterm and full term pregnancies with a single previous Cesarean section, to correlate the obtained LUS measurements with intraoperative observations, and to identify a predictive cut-off value in order to select the best candidates for a vaginal birth after Cesarean delivery (VBAC).

METHODS

Two hundred and fourteen women with a single previous Cesarean section who had an ultrasound measurement of the LUS thickness (stratified in S1, S2 and S3) in pregnancy were enrolled. The outcome of interest was the visual finding of a thin uterine scar at the time of the iterative Cesarean section. Linear regression was used to correlate the LUS thickness with gestational age (GA). A ROC curve has been used to determine the detection rate (DR) and the risk of each actual value of LUS thickness versus a thin uterine scar (outcome of interest).

RESULTS

The LUS thickness was correlated with the gestational age (R2=0.034, P-value =0.005). The DR as estimated by ROC curves to detect a translucent lower uterine segment (S3) was 94.1% at a false positive rate (FPR) of 20%. The correspondent cut-off value was 1.8 mm. Finally a likelihood ratio (LR) of observing S3 was estimated. At the quoted cut-off of 1.8 mm the LR was 3. As demonstrated, for a segment of 1 mm the LR was instead about 13.

CONCLUSION

The obtained values lead us to the conclusion that a thickness less than 1.8 mm can be reasonably considered a valid cut-off value to identify patients with a higher risk of thin uterine scar.

NOTCH1 mutations in +12 chronic lymphocytic leukemia (CLL) confer an unfavorable prognosis, induce a distinctive transcriptional profiling and refine the intermediate prognosis of +12 CLL

Trisomy 12, the third most frequent chromosomal aberration in chronic lymphocytic leukemia (CLL), confers an intermediate prognosis. In our cohort of 104 untreated patients carrying +12, NOTCH1 mutations occurred in 24% of cases and were associated to unmutated IGHV genes (P=0.003) and +12 as a sole cytogenetic abnormality (P=0.008). NOTCH1 mutations in +12 CLL associated with an approximately 2.4 fold increase in the risk of death, a significant shortening of survival (P<0.01) and proved to be an independent predictor of survival in multivariate analysis. Analogous to +12 CLL with TP53 disruption or del(11q), NOTCH1 mutations in +12 CLL conferred a significantly worse survival compared to that of +12 CLL with del(13q) or +12 only. The overrepresentation of cell cycle/proliferation related genes of +12 CLL with NOTCH1 mutations suggests the biological contribution of NOTCH1 mutations to determine a poor outcome. NOTCH1 mutations refine the intermediate prognosis of +12 CLL.

New insights into the epidemiology of bovine piroplasmoses in Italy

Few studies have been published on bovine piroplasmoses in Italy, and therefore a clear picture of the epidemiology of these infections is difficult to obtain. Vertebrate and invertebrate hosts in Central and Northern Regions of Italy were investigated in 2005 and 2006, when microscopy, molecular tools and serological tests were applied to 468 blood samples drawn from cattle in order to evaluate the presence of these protozoa and identify possible risk factors. Ticks were also collected, identified and analyzed by molecular techniques. Microscopy identified 6.5% of the animals as positive, whereas PCR detected piroplasm DNA in 21.6%. BLAST analysis showed 67 amplicons (17.0%) referable to the Theileria sergenti/buffeli/orientalis group, 17 (4.3%) to Theileria annae, and 1 to Babesia divergens. Serology evidenced a prevalence of 45.4% for Babesia bovis, 17.4% for Babesia bigemina, and 34.9% for B. divergens. The 127 collected ticks were identified as belonging to 5 species, mostly represented by Rhipicephalus bursa, Hyalomma marginatum and Ixodes ricinus. Molecular analyses evidenced the presence of B. bovis and B. bigemina, in 3 and 5 ticks, respectively. Our findings suggest that different species of piroplasms are circulating in bovine populations in Central and Northern Italy, and provide new insights into the complex epidemiology of bovine piroplasmoses in Italy.

Subcutaneous dirofilariosis in South-East Serbia--case report

Human dirofilariosis is a relatively rare infection caused by filarial worms of the genus Dirofilaria. We herein report the first case of human subcutaneous dirofilariosis in the southeastern part of Serbia. A complete alive nematode was removed from a nodule in the periorbital region of a 50-year-old woman. The nematode was morphologically identified as a D. repens-like immature female. The diagnosis was confirmed with molecular methods. The patient was probably infected in the South-East Serbia as she had not travelled abroad, nor in other parts of Serbia such as Vojvodina, recently identified as a hyperendemic area for D. repens infection of dogs.

Bilateral cleft lip and palate without premaxillary protrusion is associated with lethal aneuploidies

OBJECTIVE

To investigate the clinical implications of two categories of fetal bilateral cleft lip and palate (BCLP): with premaxillary protrusion and with a flattened profile.

METHODS

This was a retrospective study of fetuses with a prenatal diagnosis of BCLP at the Department of Obstetrics and Gynecology of the University of Bologna in the period 1991-2005.

RESULTS

BCLP was diagnosed prenatally in 14 cases (mean gestational age at diagnosis, 21 (range, 12-36) weeks). In nine of these, there was a premaxillary pseudomass; in the remaining five, the profile was flat. Associated structural and/or chromosomal anomalies were found in two of the nine with a premaxillary pseudomass and in all five of those with a flat profile (P = 0.02). All fetuses with a flat profile had aneuploidies (three trisomy 18, one trisomy 13, one trisomy 8 mosaic), as did one of the nine with a premaxillary pseudomass. Eight of the pregnancies were terminated, including three of those with a premaxillary pseudomass and all five of those without. All continuing pregnancies resulted in live births, although one neonate affected by Krabbe's disease died shortly after birth.

CONCLUSIONS

Our findings suggest that a third of cases of BCLP diagnosed in utero have a flat profile and these are at high risk of lethal aneuploidies.

Canine piroplasmosis in Italy: epidemiological aspects in vertebrate and invertebrate hosts

In Italy, canine piroplasmosis is believed to be widespread, but few data are available on its presence in most areas. In 2005 and 2006, vertebrate and invertebrate hosts were investigated in Central and Northern Regions of the Country. Microscopy on blood smears, molecular tools and serological tests were applied to 420 blood samples collected from dogs, in order to evaluate the presence of these protozoa and to identify possible risk factors. Moreover, ticks were analyzed by molecular techniques. Microscopy identified as positive 2.8% of the animals, all from Central Italy, and PCR detected 'piroplasm' DNA in 6.0%. Serology evidenced a mean prevalence of 34.0% with a decreasing trend from Central to Northern areas. The 507 collected ticks were identified as belonging to 8 species, mostly represented by Rhipicephalus sanguineus (n=376) and Ixodes ricinus (n=58). Molecular analyses evidenced the presence of babesial parasites (Babesia canis canis, B. canis vogeli, B. microti-like) in 25 (4.9%) of them; in Rh. sanguineus there was also demonstration of the vertical transmission of B. canis canis. Statistical analysis identified 'kennel' as risk factor for Babesia infection. Our findings evidenced that different species of piroplasms potentially infectious for dogs are circulating in Italy, and that epidemiological aspects of these infections are more complex than expected. Vector importance of both Rh. sanguineus and I. ricinus is hypothesized, but further investigation is needed.

Occurrence of the G3 Indian buffalo strain of Echinococcus granulosus in cattle

During a survey carried out to define the occurrence of Echinococcus granulosus in cattle bred in the province of Rieti (Central Italy), molecular diagnostics (PCR amplification and sequencing of a partial region of the mitochondrial CO1 gene) showed that 6/10 positive bovines harboured hydatid cysts (No.=16) genetically identical (95.8-100%) to the Indian buffalo genotype G3. As far the location of the 16 cysts, 11 of them were found in the lungs of three animals, whereas 5 cysts were in the liver of three parasitized hosts. The occurrence of genotype G3 in 60% of parasitized bovines living in an area never studied before provides more definite evidence about the existence of the strain in this region, and proves that cattle have to be considered a non-accidental host.

Aedes albopictus and Culex pipiens implicated as natural vectors of Dirofilaria repens in central Italy

To identify the natural vectors of Dirofilaria repens Railliet et Henry, entomological samplings were carried out in four sites within the Lazio region, foci of canine subcutaneous dirofilariasis. Collections were made in 2002-2003 by means of dog-baited and miniature Centers for Disease Control and Prevention traps as well as on humans. Microscopy identified 1576 attracted mosquito females as belonging to six species, but molecular diagnostics detected filarial DNA only in Culex pipiens L. and Aedes albopictus (Skuse, 1894). Dirofilaria immitis Leidy DNA, D. repens DNA, or both were found in the head and thorax of both mosquitoes. The simultaneous presence of vectors showing diurnal and nocturnal activity patterns is of concern for animal and human health. The finding of D. immitis DNA in mosquitoes in areas where only D. repens was been recovered in dogs also demonstrates that this filarial parasite circulates among carnivores (wild or domesticated pets).

Prospective evaluation of the risk of pre-eclampsia using logistic regression analysis

OBJECTIVES

To calculate the risk of developing pre-eclampsia (PET) in a consecutive series of low-risk women at 18-24 weeks' gestation, using recently published logistic regression models.

METHODS

This was a prospective study, with complete follow-up, in a consecutive series of unselected low-risk singleton pregnancies. Uterine artery pulsatility index as well as a combination of maternal factors were recorded at 18-24 weeks' gestation. The distribution of the estimated risks for the 16 PET patients was compared with that obtained for 136 women who had a normal pregnancy, as assessed by routine testing. A receiver-operating characteristics (ROC) curve was plotted to evaluate the detection rate at fixed false-positive rates (FPRs) of 5%, 10% and 20% and the corresponding odds cut-offs.

RESULTS

Just 1/16 (6.2%) women with PET developed the disease before the 34(th) week of gestation. Using the 'All PET' logistic regression model, for 16 PET cases the overall median odds was 1 : 1454, higher compared with that of 1 : 41635 estimated for controls. Using the 'PET >or= 34 weeks' model, the median odds of the 15 women who developed PET late was 1 : 3405, compared with 1 : 40785 for controls. In the case of PET before 34 weeks, the risk was 1 : 426373 vs. 1 : 4159823126 estimated for controls ('PET < 34 weeks' model). Detection rates for the All PET model were 18%, 50% and 62% at a FPR of 5%, 10% and 20%, respectively. For the PET >or= 34 weeks model these detection rates were 6%, 46% and 60%, respectively.

CONCLUSION

Even though the individual odds estimation is too low to represent the real risk of PET, the recently published logistic regression models detected more than 60% of PET at a FPR of 20% for both All PET and PET >or= 34 weeks models. Using these models in clinical practice does not seem to give any significant improvement over Doppler alone in the prediction of PET, but the use of a PET-specific odds instead of an actual Doppler value alone seems to be useful for clinical management.

Natural vectors of dirofilariasis in rural and urban areas of the Tuscan region, central Italy

Entomological investigations by means of dog- and human-baited traps were carried out in summers 2000-2002 in urban and rural areas of the Tuscan region in central Italy. The aim of the study was to define the mosquito species involved in the transmission of Dirofilaria nematodes and to assess the risk that their presence might represent for animal and human health. Nocturnal fieldwork on host-seeking activity and feeding preferences was followed by microscopic identification of the mosquito species attracted and by molecular identification of Dirofilaria parasites in mosquitoes. In total, 3,611 mosquito females belonging to 12 species, largely represented by Culex pipiens L. and Aedes caspius (Pallas), were caught. Some females of each species collected fed on the dogs, indicating their possible role as an intermediate host, but filarial DNA was found only in Cx. pipiens, Anopheles maculipennis s.l. (Meigen), and Coquillettidia richiardii (Ficalbi). In rural environments, the DNA evidence indicated the presence of infective larvae of Dirofilaria immitis, whereas in urban areas, infective larvae of Dirofilaria repens were present. The role of Cx. pipiens as a vector for heartworm disease and subcutaneous infections in natural and artificial environments was confirmed, whereas Ae. caspius seemed refractory to the infection. The different role of the collected species is discussed. The vector competence of An. maculipennis and Cq. richiardii needs further investigation, because the importance of these species poorly represented, and the role of species such as Aedes albopictus (Skuse), characterized by a dominant diurnal activity pattern, has to be evaluated.

Screening of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial ''Italung-CT''

PURPOSE

To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as ''Italung-CT''.

MATERIALS AND METHODS

Sixty (47 males and 13 females, mean age 64+/-4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project.

RESULTS

and Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5 mm in diameter in 20 subjects, 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as a pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma.

CONCLUSIONS

The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the ''Italung CT'' trial which has just begun.

Investigation of the effects of copper ions on protein aggregation using a model system

Protein aggregation is a notable feature of various human disorders, including Parkinson's disease, Alzheimer's disease and many others systemic amyloidoses. An increasing number of observations in vitro suggest that transition metals are able to accelerate the aggregation process of several proteins found in pathological deposits, e.g. alpha-synuclein, amyloid beta (Abeta) peptide, beta(2)-microglobulin and fragments of the prion protein. Here we report the effects of metal ions on the aggregation rate of human muscle acylphosphatase, a suitable model system for aggregation studies in vitro. Among the different species tested, Cu(2+) produced the most remarkable acceleration of aggregation, the rate of the process being 2.5-fold higher in the presence of 0.1 mM metal concentration. Data reported in the literature suggest the possible role played by histidine residues or negatively charged clusters present in the amino acid sequence in Cu(2+)-mediated aggregation of pathological proteins. Acylphosphatase does not contain histidine residues and is a basic protein. A number of histidine-containing mutational variants of acylphosphatase were produced to evaluate the importance of histidine in the aggregation process. The Cu(2+)-induced acceleration of aggregation was not significantly altered in the protein variants. The different aggregation rates shown by each variant were entirely explained by the changes of hydrophobicity or propensity to form a beta structure introduced by the point mutation. The effect of Cu(2+) on acylphosphatase aggregation cannot therefore be attributed to the specific factors usually invoked in the aggregation of pathological proteins. The effect, rather, seems to be a general related to the chemistry of the polypeptide backbone and could represent an additional deleterious factor resulting from the alteration of the homeostasis of metal ions in cells.

Aedes albopictus is a natural vector of Dirofilaria immitis in Italy

Investigations were carried out in Padova town (Veneto region, NE Italy) to define the actual role of Aedes albopictus in the natural transmission of Dirofilaria nematodes, and to assess the risk that its presence might represent for veterinary and medical health. During summer 2000-2002 daytime captures of human-attracted mosquitoes were carried out in three areas of the town. The presence of filarial parasites in mosquitoes was evaluated by PCR, and sequencing confirmed species assessment. DNA extraction was performed separately on pools of the insect abdomen and thorax-head, to discriminate between Dirofilaria infected/infective specimens. A total of 2721 mosquitoes were caught and A. albopictus was the most abundant species (2534). Filarial DNA was found in 27.5% (19/69) of the abdomen pools formed with mosquitoes collected in summer 2000, and in 11.1% (16/144) and 4.9% (6/123) thorax-head pools coming from samplings 2001 and 2002, respectively. Filarial DNA was belonging to D. immitis and all studied areas harboured infective specimens. These results prove A. albopictus as natural vector of D. immitis in Italy. Moreover, they support the hypothesis that the presence of the mosquito could affect the transmission pattern of canine heartworm disease in urban environment and, considering the aggressive anthropophylic behaviour of the species (30-48 bites/h) proven in Padova town, could enhance the circulation of filarial nematodes from animals to humans.

First finding of Dirofilaria repens in a natural population of Aedes albopictus

The invasive mosquito Aedes albopictus (Skuse) (Diptera: Culicidae) has become widespread in Italy during the past decade. Also Italy has foci of canine filariasis caused by Dirofilaria (Spirurida: Onchocercidae), due to subcutaneous D. repens Railliet & Henry as well as the dog heartworm D. immitis (Leidy) transmitted by various vector mosquitoes (Diptera: Culicidae). In 2002, at Fiumicino, west of Rome (Lazio Region), 17% of dogs were found to have D. repens microfilariae in peripheral blood. To evaluate the role of Ae. albopictus as a vector of Dirofilaria in this area, female mosquitoes were collected daily, June-October 2002, landing on dog or human bait in a rural house at Focene. Mosquitoes were maintained at 27 degrees C and 70% RH for 6 days, to allow development or purging of filaria larvae, then identified and frozen for subsequent molecular assay with filaria-specific ribosomal S2-S16 primers. To distinguish specimens harbouring infective L3 Dirofilaria larvae, DNA was extracted separately from the mosquito abdomen and head-thorax. Dirofilaria species were identified by sequencing, confirmed by polymerase chain reaction of positive specimens using primers specific for D. immitis and D. repens. Dirofilaria DNA was detected in 3/154 (2%) of Ae. albopictus females examined: D. repens DNA in head-thorax and abdomen of one collected 27th July; D. immitis in the abdomen of one collected 24th September; DNA of both D. immitis and D. repens in the head-thorax of one collected 11th October 2002. Thus Ae. albopictus is a potential vector of both Dirofilarias in Italy, representing risks for veterinary and human health.

Sonography of pregnancies with first-trimester bleeding and a small intrauterine gestational sac without a demonstrable embryo

OBJECTIVE

This was a prospective observational cohort study to evaluate the outcome and prognostic criteria of pregnancies with first-trimester bleeding and a gestational sac <or=16 mm without a demonstrable embryo.

METHODS

Criteria for admission into the study included: (1) first-trimester bleeding; (2) a transvaginal scan performed upon admission demonstrating a single intrauterine gestational sac with a mean diameter <or=16 mm and without a demonstrable embryo. The outcome variable was miscarriage, defined as pregnancy loss prior to 22 weeks. The following explanatory variables were considered: maternal age, menstrual age, size of the gestational sac, presence or absence of the yolk sac and subchorionic hematoma, and beta-human chorionic gonadotropin levels. The relationship of these variables with pregnancy failure was analyzed by stepwise logistic regression.

RESULTS

Of 50 patients, 32 (64%) underwent miscarriage. The receiver-operating characteristics (ROC) curve of the size of the gestational sac demonstrated a high level of statistical significance (area under the ROC curve 0.9080, P < 0.000001) and stepwise logistic regression revealed that this was the only variable independently correlated with the subsequent occurrence of miscarriage.

DISCUSSION

It is commonly accepted that in pregnant patients with first-trimester bleeding, demonstration by transvaginal ultrasound of an intrauterine gestational sac <or=16 mm without an embryo may be compatible with a viable pregnancy. Our results suggest that in general this finding is associated with a poor outcome, with miscarriage occurring in two-thirds of patients. When the sac is small for gestational age, the risk of miscarriage is greatly increased. In the present series, a gestational sac diameter less than -1.34 standard deviations of the mean was associated with pregnancy failure in over 90% of cases.

Transabdominal sonography of the cavum septum pellucidum in normal fetuses in the second and third trimesters of pregnancy

OBJECTIVES

To assess the visualization rate and size of the cavum septum pellucidum (CSP) by transabdominal sonography in normal fetuses throughout pregnancy.

METHODS

The CSP was prospectively researched and measured using an axial transventricular plane in 286 consecutive uncomplicated singleton pregnancies between 15 and 41 weeks of gestation.

RESULTS

The CSP was seen in 40% of cases at 15 weeks, 82% at 16-17 weeks, 100% at 18-37 weeks and 79% at 38-41 weeks. Compared to biparietal diameter (BPD), the visualization rate was 33% between 31 and 32 mm, 45% between 33 and 34 mm, 84% between 35 and 43 mm, 100% between 44 and 88 mm and 86% between 89 and 99 mm. Mean CSP width was 5.3 +/- 1.7 mm (range 2-9 mm). The CSP width increased with gestational age and BPD but with a slight decrease around term.

CONCLUSIONS

In normal fetuses the CSP should always be visualized between 18 and 37 weeks, or with a BPD of 44-88 mm. Failure to observe the CSP in this interval, or possibly the presence of a large CSP, may indicate abnormal cerebral development and warrant further investigation. Conversely, absence of the CSP prior to 18 weeks, or later than 37 weeks, is a normal finding.