The spike glycoprotein of the new coronavirus 2019-nCoV contains a furin-like cleavage site absent in CoV of the same clade

In 2019, a new coronavirus (2019-nCoV) infecting Humans has emerged in Wuhan, China. Its genome has been sequenced and the genomic information promptly released. Despite a high similarity with the genome sequence of SARS-CoV and SARS-like CoVs, we identified a peculiar furin-like cleavage site in the Spike protein of the 2019-nCoV, lacking in the other SARS-like CoVs. In this article, we discuss the possible functional consequences of this cleavage site in the viral cycle, pathogenicity and its potential implication in the development of antivirals.

•

The genomic sequence of 2019-nCoV indicates that the virus clusters with betacoronaviruses of lineage b.

•

2019-nCoV S-protein sequence has a specific furin-like cleavage site absent in lineage b CoV including SARS-CoV sequences.

•

The furin-like cleavage site in the S-protein of 2019-nCoV may have implications for the viral life cycle and pathogenicity.

•

Campaigns to develop anti-2019-nCoV therapeutics should include the evaluation of furin inhibitors.

Association of subgingival colonization of Candida albicans and other yeasts with severity of chronic periodontitis

BACKGROUND AND OBJECTIVE

The aim of this study is to analyze the relationship between the subgingival colonization by Candida albicans and other yeasts with the severity of chronic periodontitis (CP).

MATERIAL AND METHODS

After sample size calculation, 40 patients with CP and 20 healthy subjects (HS) were included in the study. Cases of slight-moderate (MCP, n = 23) and severe CP (SCP, n = 17) were defined according to the Centers for Disease Control/American Association of Periodontology classification. Subgingival samples were acquired using sterile paper-points from the sulcus or the deepest periodontal pocket of each healthy and subject with CP, respectively, and were cultured aerobically on three selective media. Yeast colonies that grew on the surface of plates were later identified by biochemical reactions. Statistical tests were used to analyze the association between subgingival yeast colonization (number of yeast-positive individuals and colony forming units (CFU) per subject) and periodontal disease status, considering statistical significance when P < 0.05.

RESULTS

Although several yeast species were found (C. parapisilosis, Rhodotorula sp., C. dubliniensis and C. tropicalis), only C. albicans was present in all the patients with yeast-positive CP. Twelve patients (30%) with CP presented yeasts in the subgingival biofilm while only three patients (15%) in the HS group were positive for these microorganisms. No statistical difference was found between the CP and HS groups (P = 0.084). However, when the CP group was divided on the basis of severity, statistical differences were observed between the SCP and MCP groups (47% vs. 17%, P = 0.043), and between the SCP and HS groups (47% vs. 15%, P = 0.033). No statistical difference was observed between the MCP and HS groups (17% vs. 15%, P = 0.832). High densities of yeasts were found only in patients with MCP and SCP (mean and range 61.25 (0-100) CFU/plate and mean and range 51 (0-101) CFU/plate, respectively).

CONCLUSION

In this group of patients, subgingival colonization of some yeasts, especially C. albicans, was associated with the severity of CP.

An intervention study of the effects of calcium intake on faecal fat excretion, energy metabolism and adipose tissue mRNA expression of lipid-metabolism related proteins

CONTEXT

In various observational studies, an inverse relation between calcium intake and body weight has been observed. A possible explanation could be an increased calcium excretion through the faeces caused by an increased dietary calcium intake.

OBJECTIVE

To examine whether an increased calcium intake could lead to changes in faecal fat and energy excretion.

DESIGN

Four different isocaloric diets with various calcium contents (400, 1200 and 2500 mg from dairy and 1200 mg from calcium carbonate (1200S)) were administered in a crossover design for 7 days each.

SUBJECTS

Five healthy men and five healthy women (age=28+/-2, body mass index=24.1+/-0.4, body fat%=25.6+/-2.4) were recruited by local announcement.

MEASUREMENTS

At the end of every intervention period, faecal samples were collected for determination of fat, energy and calcium content, blood samples were obtained for determination of relevant blood parameters; and fat samples were obtained for measurement of the mRNA expression. Furthermore, resting energy expenditure and fat oxidation were measured with the ventilated-hood technique.

RESULTS

We observed a non-significant 56% increase in fat excretion (P=0.159) on the 2500 mg diet, compared to the 400 mg diet. The 2500 mg diet significantly reduced the expression of fatty acid synthase (FAS) mRNA (P<0.05) and the calcium content of the diets significantly affected calcium excretion. Furthermore, we saw a significant decrease of serum triglycerides on the 1200S diet (P<0.05).

CONCLUSION

In this study, we observed a trend towards a higher fat excretion on the high-calcium diet, but this difference failed to reach statistical significance. It is possible that the relatively high protein content of the experimental diets increased calcium absorption from the intestine, thus decreasing the amount of calcium available for binding to fat and eliminating possible effects of dietary calcium on fat excretion. Furthermore, we observed decreases in FAS mRNA expression and serum triglycerides as a result of a high calcium intake.

Prevalence and impact of symptoms suggestive of gastroesophageal reflux disease

Few studies have focused on the impact of gastroesophageal reflux disease on general health and on work absenteeism. Our aim was to evaluate the prevalence and severity of symptoms suggestive of gastroesophageal reflux disease in two samples of Italian employees. We interviewed 424 subjects of S. Matteo Hospital staff and 344 subjects of the Military Factory of Pavia regarding the frequency and severity of heartburn and acid regurgitation during the last 12 months. Subjects were specifically asked whether symptoms interfered with the quality of work activities or determined work absenteeism. In all, 91% of eligible subjects responded. The prevalence rate per 100 of any heartburn or regurgitation experienced at least monthly was 21. This value increased to 45% taking into consideration symptoms experienced occasionally. Mild or moderate symptoms were more frequent than severe symptoms (P < 0.001). Only 2.6% of subjects answered that symptoms have a negative influence on the quality of their work. No work absenteeism was recorded. The study confirms that typical gastroesophageal reflux symptoms are common conditions, but mainly of mild or moderate degree.

Glucagon-like peptide 1 receptor activation regulates cocaine actions and dopamine homeostasis in the lateral septum by decreasing arachidonic acid levels

Agonism of the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) has been effective at treating aspects of addictive behavior for a number of abused substances, including cocaine. However, the molecular mechanisms and brain circuits underlying the therapeutic effects of GLP-1R signaling on cocaine actions remain elusive. Recent evidence has revealed that endogenous signaling at the GLP-1R within the forebrain lateral septum (LS) acts to reduce cocaine-induced locomotion and cocaine conditioned place preference, both considered dopamine (DA)-associated behaviors. DA terminals project from the ventral tegmental area to the LS and express the DA transporter (DAT). Cocaine acts by altering DA bioavailability by targeting the DAT. Therefore, GLP-1R signaling might exert effects on DAT to account for its regulation of cocaine-induced behaviors. We show that the GLP-1R is highly expressed within the LS. GLP-1, in LS slices, significantly enhances DAT surface expression and DAT function. Exenatide (Ex-4), a long-lasting synthetic analog of GLP-1 abolished cocaine-induced elevation of DA. Interestingly, acute administration of Ex-4 reduces septal expression of the retrograde messenger 2-arachidonylglycerol (2-AG), as well as a product of its presynaptic degradation, arachidonic acid (AA). Notably, AA reduces septal DAT function pointing to AA as a novel regulator of central DA homeostasis. We further show that AA oxidation product γ-ketoaldehyde (γ-KA) forms adducts with the DAT and reduces DAT plasma membrane expression and function. These results support a mechanism in which postsynaptic septal GLP-1R activation regulates 2-AG levels to alter presynaptic DA homeostasis and cocaine actions through AA.

The anti-schistosomal drug praziquantel is an adenosine antagonist

The mechanism of action of praziquantel (PZQ), the drug of choice against schistosomiasis, is still unclear. Since exposure of schistosomes to the drug is associated with calcium influx and muscular contraction, calcium channels have been suggested as the target, although direct combination of PZQ with their subunits was never demonstrated. We report a hitherto unknown effect of PZQ, namely the inhibition of nucleoside uptake, as observed in living worms using radio-isotope labelled adenosine and uridine. This effect is clearly seen in schistosomes but is absent in mammalian cells in culture. Moreover it is a specific pharmacological effect seen exclusively with the active levo-R(-)stereo isomer of the drug, and is shared by at least one benzodiazepine having antischistosomal activity. This novel effect acquires significance given that schistosomes cannot synthesize purine nucleosides de novo. A possible relationship between this novel effect and the known action of PZQ on calcium channels is discussed, since adenosine is known to bind to specific receptors and to behave as an indirect antagonist of calcium release in mammalian cells. If calcium channels were correlated with adenosine receptors also in schistosomes, as they are in mammals, this would support the hypothesis that PZQ-induced calcium influx may be correlated to adenosine receptor blockade.

Ultrasound-guided aspiration of endometriomas: possible applications and limitations

OBJECTIVES

To evaluate the role of needle aspiration in the management of endometriomas.

DESIGN

Retrospective evaluation of the activity of the section of interventional ultrasound in a single tertiary care institution.

SETTING

Department of Obstetrics and Gynecology, Ospedale S. Gerardo, Monza, University of Milan, Italy.

PATIENTS

Two hundred nine premenopausal patients underwent aspiration for diagnostic purpose (n = 166), for relief of symptoms (n = 25), or with therapeutic intent (n = 18).

RESULTS

Adequate material was obtained by all punctures. Early complications (self-limiting vagal symptoms or pain) occurred in eight cases. Short-term complications consisted of acute abdominal pain in three cases and infection in one. Three women required surgical treatment of the complication. At first examination after aspiration, persistence of the cyst was observed in all but four cases, including all cases who had undergone therapeutic aspiration. Nine patients reported relief of symptoms but six other patients referred onset or worsening of pelvic discomfort after aspiration.

CONCLUSIONS

Ultrasound-guided aspiration of endometriomas is feasible. The transvaginal route reduces early complication but implies a risk of infection of 1.3%. However, drainage alone is ineffective as a therapeutic procedure and the applications of aspiration of endometriomas appear limited to some cases with diagnostic intent.

Role of puncture and aspiration in expectant management of simple ovarian cysts: a randomised study

OBJECTIVES

To assess the potential of expectant management for simple ovarian cysts diagnosed by transabdominal or transvaginal ultrasonography. To compare the results of needle aspiration with those achieved with simple observation.

DESIGN

Randomised trial.

SETTING

Hospital department of obstetrics and gynaecology.

SUBJECTS

278 women with simple cysts randomly allocated to simple observation (143) or ultrasound guided fine needle aspiration (135) between 1990 and 1994.

MAIN OUTCOME MEASURES

Resolution of cyst or development of malignancy.

RESULTS

After six months 269 were available for follow up. The rate of resolution was 46% (59/128) with aspiration and 44.6% (63/141) with observation. Only the diameter of the cyst (P < 0.0001) was a significant independent prognostic factor for resolution in a multivariate analysis. Age and treatment had no significant effect. One woman was subsequently found to have borderline malignant changes on histopathological examination. Her cyst was detected by transabdominal ultrasonography.

CONCLUSIONS

Expectant management for up to six months does not cause risks for the patients and allows spontaneous resolution in over a third of cases, avoiding the costs and risks of unnecessary surgery. Aspiration does not provide better results than simple observation.

B-vitamins intake, DNA-methylation of One Carbon Metabolism and homocysteine pathway genes and myocardial infarction risk: the EPICOR study

BACKGROUND AND AIMS

Several epidemiological studies highlighted the association between folate and B-vitamins low intake and cardiovascular diseases (CVD) risk. Contrasting results were reported on the relationship between folate intake and DNA-methylation. Folate and B-vitamins may modulate DNA-methylation of specific enzymes which are included in the One-Carbon Metabolism (OCM) and in the homocysteine (Hcy) pathways. The aim of the study was to evaluate whether DNA-methylation profiles of OCM and Hcy genes could modulate the myocardial infarction (MI) risk conferred by a low B-vitamins intake.

METHODS AND RESULTS

Study sample (206 MI cases and 206 matched controls) is a case-control study nested in the prospective EPIC cohort. Methylation levels of 33 candidate genes where extracted by the whole epigenome analysis (Illumina-HumanMethylation450K-BeadChip). We identified three differentially methylated regions in males (TCN2 promoter, CBS 5'UTR, AMT gene-body) and two in females (PON1 gene-body, CBS 5'UTR), each of them characterized by an increased methylation in cases. Functional in silico analysis suggested a decreased expression in cases. A Recursively Partitioned Mixture Model cluster algorithm identified distinct methylation profiles associated to different MI risk: high-risk vs. low-risk methylation profile groups, OR = 3.49, p = 1.87 × 10(-)(4) and OR = 3.94, p = 0.0317 in males and females respectively (multivariate logistic regression adjusted for classical CVD risk factors). Moreover, a general inverse relationship between B-vitamins intake and DNA-methylation of the candidate genes was observed.

CONCLUSIONS

Our findings support the hypothesis that DNA-methylation patterns in specific regions of OCM and Hcy pathways genes may modulate the CVD risk conferred by folate and B-vitamins low intake.

Early and short-term complications after US-guided puncture of gynecologic lesions: evaluation after 1,000 consecutive cases

PURPOSE

To ascertain the complication rate associated with ultrasound (US)-guided puncture of gynecologic lesions.

MATERIALS AND METHODS

Between 1986 and 1992, 878 transabdominal and 122 transvaginal US-guided punctures of gynecologic lesions were performed in 893 patients. Most of the procedures were performed in adnexal cysts (n = 838); the rest, in solid tumors (n = 66), mixed tumors (n = 56), or lymphoceles, abscesses, or fluid collections (n = 40). No anesthesia or antibiotic prophylaxis was routinely used.

RESULTS

No life-threatening complication was recorded. Early complications (defined as complications that occurred within 24 hours after puncture) were recorded in 31 patients and consisted mainly of transient vagal symptoms or pain. Short-term complications (within 5 days after puncture) were recorded in 10 patients, six of whom required surgery.

CONCLUSION

US-guided puncture of gynecologic lesions is safe in selected patients. Complication rates depend on the type of lesion and are very high in dermoid cysts, which should not be punctured, and extremely low in serous cysts, solid tumors, and mixed tumors.

Drugs of abuse modulate the phosphorylation of ARPP-21, a cyclic AMP-regulated phosphoprotein enriched in the basal ganglia

ARPP-21 is a cyclic AMP-regulated phosphoprotein of M(r) 21 kDa that is enriched in the cell bodies and terminals of medium-sized spiny neurons in the basal ganglia. Using a new phosphorylation state-specific antibody selective for the detection of ARPP-21 phosphorylated on Ser(55), we have demonstrated that activation of dopamine D1 receptors increased the level of ARPP-21 phosphorylation in mouse striatal slices. Conversely, activation of D2 receptors caused a large decrease in ARPP-21 phosphorylation. Treatment of mice with either methamphetamine or cocaine resulted in increased ARPP-21 phosphorylation in vivo. Studies using specific inhibitors of protein phosphatases and experiments in mice bearing a targeted deletion of the gene for DARPP-32, a dopamine-activated inhibitor of protein phosphatase-1, indicated that protein phosphatase-2A is primarily responsible for dephosphorylation of ARPP-21 in mouse striatum. These results demonstrate that phosphorylation and dephosphorylation of ARPP-21 are tightly regulated in the striatum. We speculate that ARPP-21 might mediate some of the physiologic effects of dopamine and certain drugs of abuse in the basal ganglia.

Lymphocyte proliferation assays as potential biomarkers for toxicant exposures

Recently there has been interest in developing assays that can be used as indicators (biomarkers) of exposure to toxic agents. We have been exploring the potential utility of three lymphocyte proliferation assays [the responses of B lymphocytes to the mitogen lipopolysaccharide (LPS), the responses of T lymphocytes to the mitogen concanavalin A (ConA), and the responses of T lymphocytes to antigenic stimuli in a mixed lymphocyte culture (MLC) assay] as biomarkers of toxicant exposure. Studies were initiated to assess the applicability and specificity of these assays and to investigate the mechanisms by which toxicants alter lymphocyte proliferation. All studies were performed using cells isolated from Fischer 344 rats. To assess applicability, mitogen assays were performed using in vitro exposures to eight different toxicants: hydroquinone, benzoquinone, Aroclor 1254, styrene oxide, and the salts of mercury, cadmium, chromate, and nickel. In vitro concentrations spanned five orders of magnitude (100 to 0.01 mg/l). At the lowest concentration tested, all eight compounds induced changes in at least one mitogen assay, indicating that these assays may be applicable to a wide range of toxicants. Variations of the ConA and MLC assays were used to test for specificity. In both assays, splenocytes taken from rats exposed in vivo to either chromate or to cadmium responded differently when the cells were cocultured with exogenously added chromate or cadmium ions, indicating that it may be possible to detect exposure to a specific toxicant by performing modified lymphocyte proliferation assays. In the mechanistic studies, splenocytes from cadmium and chromate-treated rats altered the ConA-induced proliferation of cocultured syngeneic cells. In addition, the antigenicity of splenocytes isolated from cadmium-treated rats was enhanced when these cells were used as stimulators for allogeneic splenocytes. The results of these studies indicate that lymphocyte proliferation assays may be useful for detecting exposure to a wide range of toxicants and that variations of these assays may be useful for implementing immunologically based tests for detecting exposures to specific chemicals.

The effect of alendronate (Fosamax) and implant surface on bone integration and remodeling in a canine model

Patients at high risk for osteoporosis and its associated morbidity, including postmenopausal women, are being pharmacologically managed to stabilize and improve bone mass. Alendronate sodium (Fosamax) is a commonly used antiresorptive agent effective in osteopenic women for reducing bone resorption, increasing bone density, and decreasing fracture incidence. With the increased incidence of alendronate-treated women who are undergoing hip replacement or fracture repair by prosthesis placement, data are needed to predict how alendronate affects host bone integration with uncemented surfaces. The aim of this study was to determine the effect of alendronate on new bone formation and attachment to implant surfaces in a normal and simulated estrogen-deficient, calcium-deficient canine model, using an implantable bone growth chamber. Alendronate did not affect host bone integration to surfaces commonly used in uncemented total joint arthroplasty, but there were significant differences dependent solely on the type of surface.

Structural insights into the multi-determinant aggregation of TDP-43 in motor neuron-like cells

TDP-43 is aggregated in patients with ALS and FLTD through mechanisms still incompletely understood. Since aggregation in the cytosol is most probably responsible for the delocalization and loss of proper RNA-binding function of TDP-43 in the nucleus, interception of the formation of aggregates may represent a useful therapeutic option. In this study, we investigated the relative importance of the N-terminal and C-terminal moieties of TDP-43 in the aggregation process and the weight of each of the six cysteine residues in determining unfolding and aggregation of the different domains. We report that cytoplasmic inclusions formed by WT and mutant TDP-43 in motor neuron-like NSC34 cells are redox-sensitive only in part, and contain at least two components, i.e. oligomers and large aggregates, that are made of different molecular species. The two N-terminal cysteine residues contribute to the seeding for the first step in oligomerization, which is then accomplished by mechanisms depending on the four cysteines in the RNA-recognition motifs. Cysteine-independent large aggregates contain unfolded isoforms of the protein, held together by unspecific hydrophobic interactions. Interestingly, truncated isoforms are entrapped exclusively in oligomers. Ab initio modeling of TDP-43 structure, molecular dynamics and molecular docking analysis indicate a differential accessibility of cysteine residues that contributes to aggregation propensity. We propose a model of TDP-43 aggregation involving cysteine-dependent and cysteine-independent stages that may constitute a starting point to devise strategies counteracting the formation of inclusions in TDP-43 proteinopathies.

Molecular cloning of Schistosoma mansoni calcineurin subunits and immunolocalization to the excretory system

In order to explain the schistosomicidal effect of cyclosporin A, the hypothesis was advanced that the drug, complexed with cyclophilin, inhibits the phosphatase activity of parasite calcineurin (CN), with mechanisms similar to those operating in its immunosuppressive action. As a preparatory step to the testing of this hypothesis, we report the molecular cloning of both CN subunits in Schistosoma mansoni. The catalytic (A) subunit has a predicted sequence of 607 amino acids and shows substantial similarity to other cloned CNs, except for the carboxy-terminal end that is highly divergent. The regulatory (B) subunit consists of 169 amino acids that are 86% identical to those of the human counterpart and, from its anomalous electrophoretic mobility, it appears to be myristoylated. The results of Southern blotting experiments are compatible with the existence of multiple genes for CNA and a single gene for CNB. Western blots showed that both subunits are present at all stages of the parasite life cycle and can be detected both in the soluble and in the membrane fraction. Immunofluorescence confocal microscopy revealed a striking concentration of the anti-CNA reactivity in 6-8 discrete spots in the schistosomula and in distinct spots along the body of the adult parasite, corresponding to the expected localization of flame cells. Both patterns were confirmed by a perfect co-localization of the anti-CNA signal with that of a previously characterized anti-flame cell monoclonal antibody. The preferential confinement of schistosome CN to the protonephridial system suggests that the enzyme in the parasite may fulfil similar functions to those performed in mammalian kidneys.

Stage-specific expression of a Schistosoma mansoni polypeptide similar to the vertebrate regulatory protein stathmin

The ubiquitous vertebrate protein stathmin is expressed and phosphorylated in response to a variety of external and internal signals. Stathmin, in turn, controls cell growth and differentiation through its capacity to regulate microtubule assembly dynamics. This is the first report on the molecular cloning and characterization of a stathmin-like protein (SmSLP) in an invertebrate, the human blood fluke Schistosoma mansoni. SmSLP is first synthesized at high levels in the intermediate molluscan host and completely disappears 48 h after penetration into the mammalian host. The protein is preferentially iodinated in intact immature parasites using the Bolton-Hunter reagent, can be quantitatively extracted in high salt buffers, and remains soluble after boiling. Native SmSLP was partially sequenced, and its complete structure was derived from the cloning and sequencing of its cDNA. The sequence is up to 26% identical to vertebrate stathmin sequences and contains two potential phosphorylation sites. Native SmSLP is indeed phosphorylated because phosphatase digestion shifts its mobility in electrofocusing gels. SmSLP associates with tubulin, as suggested by immune co-precipitation results. In vitro experiments demonstrated that SmSLP inhibits tubulin assembly and causes the depolymerization of preassembled microtubules, thus probably fulfilling regulatory roles in critical steps of schistosome development.

Characterization of a Schistosoma mansoni cDNA encoding a B-like cyclophilin and its expression in Escherichia coli

A cDNA encoding a Schistosoma mansoni cyclophilin (SmCyP) has been cloned by polymerase chain reaction amplification using degenerate oligonucleotides based on known conserved cyclophilin (CyP) sequences and by screening an expression cDNA library. The cDNA sequence encodes a 21.5-kDa protein, which shares 59% sequence identity with human CyP B. The SmCyP protein was expressed in Escherichia coli with a hexahistidine affinity tag at its amino terminus and antibodies to the purified (His6)-SmCyP fusion protein were raised in a rabbit. Fractionation of parasite material followed by immunoblot analysis revealed that schistosome CyP is a soluble protein. The N-terminus of the predicted protein contains a hydrophobic region, suggestive of a signal sequence. Accordingly, a recombinant SmCyP protein, lacking the first 23 amino acids was found to share the same gel electrophoretic mobility as the parasite-derived CyP protein, suggesting cleavage of a leader sequence. Hybridization of genomic DNA to a full-length cDNA probe indicates that the SmCyP gene is present as a single copy. Immunohistological experiments in conjunction with confocal scanning laser microscopy and immune electron microscopy show that SmCyP is present in abundance in the adult worm as well as in the schistosomula. The function of CyP in the schistosome is presently unclear, but since its ligand, cyclosporin A, has antischistosomal activity, its function is expected to be a vital one.

Association between pulmonary embolism and COVID-19 severe pneumonia: Experience from two centers in the core of the infection Italian peak

Purpose

Pulmonary embolism (PE) in COVID-19 patients can play a key role in precipitating clinical conditions. We aimed to evaluate PE distribution on CTA and to investigate any possible association with D-dimer (DD), pulmonary stage of disease and prognosis.

Method

COVID-19 patients of two affiliated Hospitals, undergone a CTA examination for PE suspicion, were retrospectively enrolled. Comorbidities, laboratory tests and clinical outcomes (hospitalization, discharge, death) were assessed. A parenchymal stage (early, progressive, peak, absorption) for lung involvement was assigned.

Results

A cohort of 114 patients (mean age 61 years; 26.3 % females) with severe COVID-19 pneumonia were evaluated. At last follow-up 25 (21.9 %) were hospitalized, 72 (63.2 %) discharged, 17 (14.9 %) dead. Eighty-eight patients (77.2 %) had at least one comorbidity, being cardiovascular ones the most frequent (44.7 %). CTA revealed PE in 65 patients (57 %), with concomitant pulmonary trunk and/or main arteries involvement in 16.9 %. PE defects were ubiquitous in 18.5 % of cases. The predominant parenchymal stages were the progressive (24.6 %) and peak (67.7 %). DD levels showed a significant correlation with PE occurrence and extent in pulmonary branches, despite anticoagulant therapies; trend of correlation with pulmonary stages was also noted.

Conclusions

PE is a frequent complication in severe COVID-19 patients, particularly during central parenchymal stages and despite ongoing anticoagulant therapy. CTA and DD levels play a crucial role in the assessment of suspected PE, despite anticoagulant therapies, along with proper information about lung involvement extent.

Cat-scratch disease in Northern Italy: atypical clinical manifestations in humans and prevalence of Bartonella infection in cats

In this paper, we report an investigation on cat-scratch disease (CSD) in Northern Italy. Seventy-four cases of CSD were diagnosed at the San Matteo hospital, Pavia, during the period 2005-2010. Of these 74 patients, 18 (24.3 %) reported atypical clinical manifestations such as ocular papillitis, maculopapular eruptions, vertebral infection, pulmonary infiltrates, and granulomatous hepatitis. Contact with cats was documented for 61 patients (82.4 %), while cat-related trauma was reported for 49 patients (66.2 %). We subsequently investigated the presence of Bartonella infection in cats belonging to the above patients and in other domestic and stray cats from three provinces of Northern Italy. Among the 27 domestic cats tested, nine of the 11 belonging to the CSD patients and two of the remaining 16 were infected by B. henselae (81.8 % vs. 12.5 %). Out of over 1,300 stray cats examined, 23.1 % were seropositive for B. henselae; after culturing and genotyping, 17 % were found to be infected by B. henselae (15.5 %) or B. clarridgeiae (1.5 %).

Immune function assays as indicators of chromate exposure

The potential immunomodulatory effects of chromium were investigated using a series of in vitro and in vivo studies. Chromium (as K2CrO4) in concentrations spanning five orders of magnitude was added in vitro to T-lymphocyte (concanavalin A) and B-lymphocyte (liposaccharide) mitogen cultures and was found to inhibit T-lymphocyte responses at all concentrations tested and to inhibit B-lymphocyte responses at all but the lowest concentration tested (0.01 mg/L). When the same concentrations of chromium were employed in mixed lymphocyte cultures, antigen-induced thymidine uptake was inhibited at the highest concentrations (100 mg/L-1 mg/L), enhanced at 0.1 mg/L, and equal to control values at lower concentrations. Splenocytes isolated from rats exposed to K2CrO4 in drinking water exhibited enhanced responses to T- and B-lymphocyte mitogens. The addition of 0.1 mg/L of chromium to a mixed lymphocyte culture containing splenocytes taken from chromium-exposed rats increased by 5-fold the uptake of thymidine by these cells. These increased responses of cells from chromium-exposed rats may indicate chromium-induced sensitization and may possibly be used as a biological marker for chromium exposure.

Crack characterization using guided circumferential waves

This paper examines the propagation of guided circumferential waves in a hollow isotropic cylinder that contains a crack, with the goal of using these guided waves to both locate and size the crack. The crack is sized using a modified Auld's formula, which relates the crack's length to a reflected energy coefficient. The crack is then located by operating on the backscattered signal with a time-frequency digital signal processing (DSP) technique, and then comparing these results to those obtained if the cylinder is perfect. The guided circumferential waves are generated with a commercial finite element method (FEM) code. One objective of this work is to demonstrate the effectiveness of using sophisticated DSP techniques to describe the effect of scattering on dispersive waves, showing it is possible to characterize cracks systematically and accurately by quantifying this scattering effect. The results show that the need for high frequency signals to detect small cracks is significantly decreased by using these techniques.

[Rehabilitation after sports injuries. Current concepts and data]

Sports injuries and their treatment have become increasingly more important in recent years due to the leisure behaviour of our society. Besides the aspects of acute care and medical treatment there often remains the question of optimal rehabilitative care and return to sports. Overall, the correct early planning of rehabilitation has a great influence on the prognosis of sports injuries and the date of resumption of sporting activities. One of the key aspects to consider is the phase-dependent course of rehabilitation with appropriate therapy focus. A multidisciplinary and interdisciplinary, phase-dependent, individual treatment plan that also complies with the biopsychosocial background of the athlete must be created for this purpose. Increasingly relevant is also the sport psychological support during all phases of rehabilitation, including the use of cognitive behavioral therapy. Before an athlete returns to sports and competition, objectified sport-specific criteria must be met.

Relationship between structure and neutralizing activity of rabbit tetanus antibodies elicited by acellular and whole-cell pertussis DTP vaccines

Symmetric and asymmetric IgGs having different neutralizing capacity are synthesized in variable proportions by the same clones during the course of immune response. The neutralizing activity of tetanus antibodies was studied in rabbits vaccinated with acellular (DTPa) or whole-cell pertussis (DTPw) vaccines. Symmetric and asymmetric F(ab)'2 fragments from the IgG fraction of the peak serum pools from each group of rabbits were purified by concanavalin A chromatography and measured by ELISA. After the third vaccine dose the asymmetric antibody percentage for DTPw (40%) was twice that for DTPa (20%). The neutralizing activity of asymmetric antibodies was roughly sixfold lower than symmetric ones. When antibody values titrated by ELISA approach minimal protective level, the proportion of symmetric antibodies with high toxin neutralizing activity acquires crucial importance.