Does a decannulation protocol exist in COVID-19 patients? The importance of working in a multiprofessional team

As a Covid Hub in Emilia Romagna, we have experienced an increasing number of tracheostomized patients, prompting us to develop a standardized decannulation protocol for COVID-19 ARDS patients. Currently, there are no guidelines or protocols for decannulation in this population, and few studies have investigated the early outcomes of tracheostomy in COVID-19 patients, with no detailed analysis of the decannulation process. We recognized the importance of mutual reliance among our team members and the significant achievements we made compared to previous decannulation methods. Through the optimization of the decannulation process, we identified a clear, safe, and repeatable method based on clinical best practice and literature evidence. We decided to implement an existing standardized decannulation protocol, which was originally designed for severe brain-damaged patients, due to the growing number of COVID-19 patients with tracheostomy. This protocol was designed for daily practice and aimed to provide a uniform approach to using devices like fenestrated cannulas, speaking valves, and capping. The results of our implementation include:expanding the applicability of the protocol beyond severe brain-damaged patients to different populations and settings (in this case, patients subjected to a long period of sedation and invasive ventilation)early activation of speech therapy to facilitate weaning from the cannula and recovery of physiological swallowing and phonationearly activation of otolaryngologist evaluation to identify organic problems related to prolonged intubation, tracheostomy, and ventilation and address proper speech therapy treatmentactivation of more fluid and effective management paths for decannulation with a multiprofessional team.

Promotion of mental health in young adults via mobile phone app: study protocol of the ECoWeB (emotional competence for well-being in Young adults) cohort multiple randomised trials

BACKGROUND

Promoting well-being and preventing poor mental health in young people is a major global priority. Building emotional competence (EC) skills via a mobile app may be an effective, scalable and acceptable way to do this. However, few large-scale controlled trials have examined the efficacy of mobile apps in promoting mental health in young people; none have tailored the app to individual profiles.

METHOD/DESIGN

The Emotional Competence for Well-Being in Young Adults cohort multiple randomised controlled trial (cmRCT) involves a longitudinal prospective cohort to examine well-being, mental health and EC in 16-22 year olds across 12 months. Within the cohort, eligible participants are entered to either the PREVENT trial (if selected EC scores at baseline within worst-performing quartile) or to the PROMOTE trial (if selected EC scores not within worst-performing quartile). In both trials, participants are randomised (i) to continue with usual practice, repeated assessments and a self-monitoring app; (ii) to additionally receive generic cognitive-behavioural therapy self-help in app; (iii) to additionally receive personalised EC self-help in app. In total, 2142 participants aged 16 to 22 years, with no current or past history of major depression, bipolar disorder or psychosis will be recruited across UK, Germany, Spain, and Belgium. Assessments take place at baseline (pre-randomisation), 1, 3 and 12 months post-randomisation. Primary endpoint and outcome for PREVENT is level of depression symptoms on the Patient Health Questionnaire-9 at 3 months; primary endpoint and outcome for PROMOTE is emotional well-being assessed on the Warwick-Edinburgh Mental Wellbeing Scale at 3 months. Depressive symptoms, anxiety, well-being, health-related quality of life, functioning and cost-effectiveness are secondary outcomes. Compliance, adverse events and potentially mediating variables will be carefully monitored.

CONCLUSIONS

The trial aims to provide a better understanding of the causal role of learning EC skills using interventions delivered via mobile phone apps with respect to promoting well-being and preventing poor mental health in young people. This knowledge will be used to develop and disseminate innovative evidence-based, feasible, and effective Mobile-health public health strategies for preventing poor mental health and promoting well-being.

TRIAL REGISTRATION

ClinicalTrials.gov ( www.clinicaltrials.org ). Number of identification: NCT04148508 November 2019.

Microvascular reconstruction two years after subtotal glossectomy: Is it worth it?

We ought to report an unusual case of a 49-year-old patient who underwent delayed reconstruction of the oral cavity defect, with an anterolateral thigh flap, two years after surgical demolition and adjuvant chemo-radiotherapy. At the end of oncologic treatment, he could not eat through oral route and presented evident speech articulation difficulties. After surgical reconstruction, swallowing assessment showed an improvement of swallowing with no gross signs of airways inhalation. His understandability of speech improved as well. Delayed reconstruction by a microvascular free flap with exclusive functional rehabilitation intent is feasible and may have satisfactory functional outcomes.

Ecological momentary assessment for chronic pain in fibromyalgia using a smartphone: a randomized crossover study

BACKGROUND

Daily diaries are a useful way of measuring fluctuations in pain-related symptoms. However, traditional diaries do not assure the gathering of data in real time, not solving the problem of retrospective assessment. Ecological momentary assessment (EMA) by means of electronic diaries helps to improve repeated assessment. However, it is important to test its feasibility in specific populations in order to reach a wider number of people who could benefit from these procedures.

METHODS

The present study compares the compliance and acceptability of an electronic diary running on a smartphone using a crossover design for a sample with a specific pain condition, fibromyalgia and low familiarity with technology. Forty-seven participants were randomly assigned to one of two conditions: (1) paper diary - smartphone diary and (2) smartphone diary - paper diary, using each assessment method for 1 week.

RESULTS

The findings of this study showed that the smartphone diary made it possible to gather more accurate and complete ratings. Besides, this method was well accepted by a sample of patients with fibromyalgia referred by a public hospital, with an important proportion of participants with low level of education and low familiarity with technology.

CONCLUSIONS

The findings of this study support the use of smartphones for EMA even in specific populations with a specific pain condition, fibromyalgia and with low familiarity with technology. These methods could help clinicians and researchers to gather more accurate ratings of relevant pain-related variables even in populations with low familiarity with technology.

In vitro genotoxic and cytotoxic effects of ivermectin and its formulation ivomec on Chinese hamster ovary (CHOK1) cells

The effects of ivermectin (IVM) and its commercial formulation ivomec (IVM 1.0%) were studied on Chinese hamster ovary (CHO(K1)) cells by several genotoxicity [sister chromatid exchange (SCE) and single cell gel electrophoresis (SCGE)] and cytotoxicity [cell-cycle progression (CCP), mitotic index (MI), proliferative replication index (PRI), 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and neutral red (NR)] bioassays within the 1.0-250 microg/ml concentration-range. While IVM and ivomec did not modified SCE frequencies, they induced DNA-strand breaks revealed by SCGE. An enhancement of slightly damaged cells and a decrease in undamaged cells were observed in IVM-treated cultures with 5.0-50.0 microg/ml. In ivomec((R))-treated cells, while an increase in slightly damaged cells was induced with 5.0-50.0 microg/ml, the damaged and undamaged cells increased and decreased only with 50.0 microg/ml. Both compounds exerted a delay in CCP and a reduction in PRI when 25.0 microg/ml was employed whereas cytotoxicity was observed at higher concentration than 50.0 microg/ml. No MI alteration was observed with 1.0-10.0 and 1.0-5.0 microg/ml of IVM and ivomec, respectively. A concentration-related trend to an increase in MI was achieved within 1.0-10.0 microg/ml. An increase in the MI was induced in 10.0 microg/ml ivomec-treated cultures. A marked reduction of about 89% and 62% in regard to controls was observed with 25.0 microg/ml of IVM and ivomec, respectively. NR and MTT assays revealed a cell growth inhibition when 0.25-250.0 microg/ml of both compounds was employed. The results highlighted that IVM and ivomec exert both genotoxicity and cytotoxicity in mammalian cells in vitro, at least in CHO(K1) cells.

Interactions between ephrin-B and metabotropic glutamate 1 receptors in brain tissue and cultured neurons

We examined the interaction between ephrins and metabotropic glutamate (mGlu) receptors in the developing brain and cultured neurons. EphrinB2 coimmunoprecipitated with mGlu1a receptors, in all of the brain regions examined, and with mGlu5 receptors in the corpus striatum. In striatal slices, activation of ephrinB2 by a clustered form of its target receptor, EphB1, amplified the mGlu receptor-mediated stimulation of polyphosphoinositide (PI) hydrolysis. This effect was abolished in slices treated with mGlu1 or NMDA receptor antagonists but was not affected by pharmacological blockade of mGlu5 receptors. An interaction among ephrinB2, mGlu1 receptor, and NMDA was supported by the following observations: (1) the NR1 subunit of NMDA receptors coimmunoprecipitated with mGlu1a receptors and ephrinB2 in striatal lysates; (2) clustered EphB1 amplified excitatory amino acid-stimulated PI hydrolysis in cultured granule cells grown under conditions that favored the expression of mGlu1a receptors; and (3) clustered EphB1 amplified the enhancing effect of mGlu receptor agonists on NMDA toxicity in cortical cultures, and its action was sensitive to mGlu1 receptor antagonists. Finally, fluorescence resonance energy transfer and coclustering analysis in human embryonic kidney 293 cells excluded a physical interaction between ephrinB2 and mGlu1a (or mGlu5 receptors). A functional interaction between ephrinB and mGlu1 receptors, which likely involves adaptor or scaffolding proteins, might have an important role in the regulation of developmental plasticity.

Nine years' experience of telecardiology in primary care

The ITMS telecardiology network started in April 1995. Over nine years, about 7000 peripheral medical users (mainly general practitioners), who were experienced in using transtelephonic electrocardiography and who were spread throughout Italy, conducted teleconsultations with the Telecardiology Centre. A total of 106,942 patients were evaluated. Teleconsultation was carried out for non-cardiac symptoms or routine control for 30,444 patients (28%) and for symptoms suggestive of heart disease for 76,498 (72%). After teleconsultation, 61,908 patients (58%) were reported to have no heart disease, 27,947 patients (26%) had their drug dose adjusted and remained at home, 11,503 patients (11%) were sent to their cardiologist for further investigations and 5584 patients (5%) were urgently hospitalized. Among the hospitalized patients, the echocardiogram demonstrated an ST-elevation coronary syndrome in 1785 patients (32%), a non-ST-elevation coronary syndrome in 2236 (40%) and a life-threatening arrhythmia in 1354 (24%). Telecardiology improves the decision making of general practitioners, avoids unnecessary hospitalizations, reduces the time before treatment in cardiac emergencies, rationalizes health-care costs and promotes home care.

Left ventricular myocardial mass determination by contrast enhanced colour Doppler compared with magnetic resonance imaging

OBJECTIVE

To assess the feasibility of using contrast enhanced colour Doppler echocardiography to determine left ventricular (LV) mass and to compare its accuracy with LV mass obtained by magnetic resonance imaging (MRI).

METHODS

Images were acquired in the short axis plane of the heart, derived from coronal and sagittal scout views and double oblique angulation. The LV mass was calculated by two methods: Simpson's rule and the area-length method. Levovist (Schering AG, Berlin, Germany) 2.5 g was given by slow intravenous bolus or infusion over about 45 seconds for contrast imaging. LV images were captured in the apical two chamber, four chamber, and three chamber views. Each contrast harmonic colour Doppler image was converted to a cavity-only image by simple image mathematics.

RESULTS

27 (77.1%) of the patients (mean (SD) age 66.2 (8.9) years) were men. There was a mean (SD) interval of 6.6 (8.6) days (range 0-27 days) between echocardiography and MRI. The mean (SD) LV mass determined by MRI Simpson's rule method was 171.0 (52.4) g (range 105.1-318.7 g). The mean LV mass (SD) determined by the echocardiographic Simpson's rule method was 178.2 (47.0) g (range 112.6-307.6 g). The mean (SD) MRI area-length LV mass was 187.3 (64.5) g (range 109.0-393.6 g). The linear regression correlation between LV mass determined by MRI Simpson's and echocardiographic Simpson's methods was excellent (y = 1.022x, R2 = 0.986) with a mean (SD) difference of 7.20 (20.9) g. The linear regression correlation between the MRI area-length LV mass and MRI Simpson's LV mass was excellent (y = 1.101x, R2 = 0.989) with a mean (SD) difference of 16.3 (22.3) g.

CONCLUSIONS

LV mass may be obtained reliably by contrast enhanced colour Doppler and two dimensional echocardiography. The contrast Doppler method accurately determines LV mass with excellent agreement with the MRI technique.

The role of telecardiology in supporting the decision-making process of general practitioners during the management of patients with suspected cardiac events

We studied the role of telecardiology in reducing unnecessary hospital admissions of patients with suspected life-threatening cardiac events (CEs), evaluated by general practitioners (GPs). Over one month, 456 consecutive patients (mean age 65 years, SD 19) complaining of typical (10%) or atypical (42%) chest pain, palpitations (19%), dyspnoea (19%) or syncope (10%) were enrolled. Before teleconsultation, the GPs recorded their own opinion (based on clinical evaluation only) about the presence of a CE. Following transmission of the electrocardiogram (ECG), this opinion was compared with that of the cardiologist. In total there was agreement between the GP and cardiologist about the presence of a CE in 316 of the patients (69%) and disagreement in 140 patients (31%). This represents a specificity and sensitivity of the GPs' diagnosis of 76% and 47%, respectively. For 84 of 134 patients judged as having a CE by the GP, telecardiology avoided hospitalization; on the other hand, telecardiology identified a CE in 56 of 322 patients judged as not having a CE by the GP. Telecardiology is a useful tool with which to reduce unnecessary hospitalizations in patients with suspected life-threatening CEs.

Cor triatriatum sinistrum and persistent left superior vena cava: an original association

Cor triatriatum sinistrum is a rare congenital heart disease usually diagnosed in symptomatic children. Symptoms depend on the degree of obstruction to pulmonary venous return with pulmonary hypertension and other associated abnormalities. Persistent left superior vena cava is quite a common congenital heart disease (about 0.5% in healthy populations). It should be suspected every time a dilated coronary sinus is detected at the echo examination. Transthoracic and transoesophageal examinations visualize the site and the size of the fibrous membrane as well as the degree of obstruction, and allow the evaluation of pulmonary pressures that are very important clues for prognosis and therapy. This case report describes the clinical signs and the diagnostic ultrasound findings evaluated in comparison with magnetic resonance imaging, a well-defined gold standard in heart disease of this uncommon congenital association.

MR evaluation of coronary stents with navigator echo and breath-hold cine gradient-echo techniques

The aim of this study was to evaluate coronary artery stents with MR. Thirty-eight patients underwent MR imaging 48.1 +/- 6.6 days (range 38-60 days) after placement of 47 coronary stents of 11 different types, using navigator echo (NE) and cine gradient-echo (GE) techniques. For both sequences the low signal artifact was used to localize the stent, whereas the flow-related high signal before and distal to the stent was considered as a patency sign. Exercise electrocardiographic test (EET) had been performed 1-7 days before MR. No adverse event with possible relation to the MR examination was observed. All the stents were recognized as signal void with GE, and all but one with NE. Of the 2 patients with positive EET, the first one, with a stent on the left anterior descending coronary artery, presented low signal distal to the stent at both MR sequences, suggesting dysfunction [60% stenosis at conventional coronary angiography (CCA)]; the second one, with two sequential stents on the right coronary artery, presented lack of signal distal to the stents at both MR sequences, suggesting occlusion (97% stenosis at CCA). For the 44 remaining stents in 36 patients with negative EET, MR high signal before and distal to the stent suggested patency at both sequences. MR seems to be a safe and promising technique for non-invasive evaluation of coronary stents.

Long-term follow-up of right ventricular monomorphic extrasystoles

OBJECTIVES

The purpose of this study was to verify in a long-term follow-up whether frequent monomorphic right ventricle extrasystoles may progress to arrhythmogenic right ventricular dysplasia (ARVD).

BACKGROUND

Frequent monomorphic right ventricle extrasystoles are generally considered benign. However, in patients with this pattern, cardiac magnetic resonance (MR) has recently shown anatomical and functional abnormalities of the right ventricle.

METHODS

Sixty-one patients who had been classified by noninvasive examinations as having frequent idiopathic right ventricle ectopy were contacted after 15 +/- 2 years (12 to 20) and submitted to clinical examination, electrocardiogram (ECG), Holter monitoring, stress test, signal averaged ECG, echocardiography and, in 11 patients, cardiac MR. The primary end point was to ascertain the presence of cases of sudden death or progression to ARVD.

RESULTS

At the end of the follow-up, 55 patients were alive; six died, none of sudden death; eight stated to be well but refused further examinations. The 47 patients examined had normal ECG; in 24 patients (51%), extrasystoles were no longer present at Holter monitoring; late potentials were present in up to 15% of the patients; the right ventricle was normal at echocardiography. In 8 of 11 patients (73%), cardiac MR showed focal fatty replacement and other abnormalities of the right ventricle.

CONCLUSIONS

In this long-term follow-up study, no patient died of sudden death nor developed ARVD; two-thirds of the patients were asymptomatic, and, in half of the patients, ectopy had disappeared. Focal fatty replacement in the right ventricle was present in most.

The role played by the group A streptococcal negative regulator Nra on bacterial interactions with epithelial cells

Group A streptococci (GAS) specifically attach to and internalize into human epithelial host cells. In some GAS isolates, fibronectin-binding proteins were identified as being responsible for these virulence traits. In the present study, the previously identified global negative regulator Nra was shown to control the binding of soluble fibronectin probably via regulation of protein F2 and/or SfbII expression in the serotype M49 strain 591. According to results from a conventional invasion assay based on the recovery of viable intracellular bacteria, the increased fibronectin binding did not affect bacterial adherence to HEp-2 epithelial cells, but was associated with a reduction in the internalization rates. However, when examined by confocal and electron microscopy techniques, the nra-mutant bacteria were shown to exhibit higher adherence and internalization rates than the corresponding wild type. The mutant bacteria escaped from the phagocytic vacuoles much faster, promoting consistent morphological changes which resulted in severe host cell damage. The apoptotic and lytic processes observed in nra-mutant infected host cells were correlated with an increased expression of the genes encoding superantigen SpeA, the cysteine protease SpeB, and streptolysin S in the nra-mutant bacteria. Adherence and internalization rates of a nra/speB-double mutant at wild-type levels indicated that the altered speB expression in the nra mutant contributed to the observed changes in both processes. The Nra-dependent effects on bacterial virulence were confined to infections carried out with stationary growth phase bacteria. In conclusion, the obtained results demonstrated that the global GAS regulator Nra modulates virulence genes, which are involved in host cell damage. Thus, by helping to achieve a critical balance of virulence factor expression that avoids the injury of target cells, Nra may facilitate GAS persistence in a safe intracellular niche.

Co-operative binding of human fibronectin to Sfbl protein triggers streptococcal invasion into respiratory epithelial cells

Streptococcal fibronectin binding protein I (SfbI) mediates adherence to and invasion of Streptococcus pyogenes into human epithelial cells. In this study, we analysed the binding activity of distinct domains of SfbI protein towards its ligand, the extracellular matrix component fibronectin, as well as the biological implication of the binding events during the infection process. By using purified recombinant SfbI derivatives as well as in vivo expressed SfbI domains on the surface of heterologous organism Streptococcus gordonii, we were able to dissociate the two major streptococcal target domains on the human fibronectin molecule. The SfbI repeat region exclusively bound to the 30 kDa N-terminal fragment of fibronectin, whereas the SfbI spacer region exclusively bound to the 45 kDa collagen-binding fragment of fibronectin. In the case of native surface-expressed SfbI protein, an induced fit mode of bacteria-fibronectin interaction was identified. We demonstrate that binding of the 30 kDa fibronectin fragment to the repeat region of SfbI protein co-operatively activates the adjacent SfbI spacer domain to bind the 45 kDa fibronectin fragment. The biological consequence arising from this novel mode of fibronectin targeting was analysed in eukaryotic cell invasion assays. The repeat region of SfbI protein is mediating adherence and constitutes a prerequisite for subsequent invasion, whereas the SfbI spacer domain efficiently triggers the invasion process of streptococci into the eukaryotic cell. Thus, we were able to dissect bacterial adhesion from invasion by manipulating one protein. SfbI protein therefore represents a highly evolved prokaryotic molecule that exploits the host factor fibronectin not only for extracellular targeting but also for its subsequent activation that leads to efficient cellular invasion.

Value of navigator echo magnetic resonance angiography in detecting occlusion/patency of arterial and venous, single and sequential coronary bypass grafts

Aim of our work was to validate magnetic resonance angiography (MRA) in detecting occlusion/patency of coronary artery bypass grafts. Twenty patients with previous history of bypass surgery and recurrent episodes of chest pain were enrolled. Two patients could not be studied (claustrophobia, erratic breathing). Thus, 18 patients with 51 bypasses were examined using a navigator echo sequence: 21 arterial grafts (six sequential) and 30 saphenous vein grafts (five sequential). All patients had undergone contrast conventional angiography 3-15 days before MRA. The magnetic resonance (MR) data set was analyzed by two independent readers blinded to the results of conventional angiography (occlusion of 12 of 51 grafts). At magnetic resonance, two bypasses of the posterior descending artery, patent at conventional angiography, could not be visualized because of imaging slab malpositioning. Interobserver concordance was 96% (47/49). Magnetic resonance and conventional angiography provided identical answers in 47 out of 49 (96%) of the examined grafts. Eleven out of 12 occluded grafts and 36 out of 37 patent grafts were correctly identified with MR. As far as occlusion is concerned, the sensitivity of MR was 91%, the specificity 97%. To summarize, a 30 min outpatient MR examination is highly reliable in determining occlusion/patency of arterial and venous, single and sequential bypasses.

Coronary aneurysms and stenosis detected with magnetic resonance coronary angiography in a patient with Kawasaki disease

Coronary artery abnormalities in Kawasaki syndrome develop in about 15-25% of young patients, mostly as aneurysms. In the long-term evolution of coronary artery disease thrombotic occlusion of aneurysms, premature atherosclerosis, and stenosis, are observed. Magnetic resonance is an emerging modality in the angiographic assessment of coronary arteries. The authors report a case of coronary artery aneurysms and stenosis in a 26-year-old patient with Kawasaki disease detected by magnetic resonance coronary angiography and confirmed by conventional coronary angiography.

Adipose replacement and wall motion abnormalities in right ventricle arrhythmias: evaluation by MR imaging. Retrospective evaluation on 124 patients

We reevaluated the magnetic resonance (MR) examinations of 38 healthy volunteers (control group, CG) and of 124 patients with RV arrhythmia with left bundle branch block (LBBB) morphology: 45 with episodes of RV sustained tachycardia and of polymorphic RV premature beats (RVST-PPB group); 36 with only RV outflow tract sustained or not sustained tachycardia (RVOTT group); 43 with RV monomorphic premature beats (RVMPB group). All the examinations were reevaluated in a blinded fashion for detecting myocardial adipose replacement (AR) and wall bulges or aneurysms. In RVST-PPB patients, no AR was observed in 9%; 1 RV region involvement, 0%; 2 regions, 4%; > or = 3 regions, 87%; left ventricle (LV), 15%. RVOTT patients: 28%, 53%, 14%, 5%, and 0% [corrected], respectively. RVMPB patients: 33%, 46%, 19%, 2%, and 0% [corrected], respectively. In CG, AR was observed in 11% (in RV outflow tract), RV bulges were detected in 75% [corrected] of RVST-PPB, 39% of RVOTT, and 14% of RVMPB patients, none of the CG; RV aneurysms in 33% of RVST-PPB patients, none of RVOTT patients, RVMBP patients, and CG. A significant difference among groups for RV and LV AR as well as RV bulges and aneurysms was found (p < 0.0001). In the direct comparisons, significant differences were found for: disease duration (RVST-PPB vs. RVMPB, p = 0.0396); RV AR (all the patients groups vs. CG, RVST-PPB vs. RVOTT or RVMPB, p < 0.0001); RV aneurysms (RVST-PPB vs. CG, RVST-PPB vs. RVOTT or RVMPB, p < 0.0002); bulges (all comparisons, p < 0.0174). AR is confirmed as a structural substrate in RV arrhythmias. Number and extension of MR abnormalities are correlated to different degrees of RV arrhythmias.

Two distinct pathways for the invasion of Streptococcus pyogenes in non-phagocytic cells

Adherence to and invasion of epithelial cells represent important pathogenic mechanisms of Streptococcus pyogenes. A fibronectin-binding surface protein of S. pyogenes, Sfbl protein, has been implicated in both adherence and invasion processes. Invasion of Sfbl-containing strains has been suspected to be responsible for the failure of antibiotics treatment to eradicate S. pyogenes. In this study, we tested the adherence and invasion properties of two well-characterized clinical isolates: A40, which expresses Sfbl; and A8, which is Sfbl negative and is unable to bind fibronectin. In strain A40, Sfbl was the main factor required for attachment and invasion by using fibronectin as a bridging molecule and the alpha5beta1 integrin as cellular receptor. The uptake process was characterized by the generation of large membrane invaginations at the bacteria-cell interface without evidence of actin recruitment or cellular injury. A40 cells were located in phagosomes and, only 24 h after infection, a consistent part of the bacterial population reached the cytoplasm. In contrast, uptake of strain A8 required major rearrangements of cytoskeletal proteins underneath attached bacteria. In A8, a proteinaceous moiety was involved, which does not interact with alpha5beta1 or need any known bridging molecule. Bacterial attachment stimulated elongation and massive recruitment of neighbouring microvilli, which fused to surround streptococcal chains. They led to the generation of large pseudopod-like structures, which engulfed bacteria that were rapidly released and replicated in the cytoplasm. The identification of two completely different uptake pathways reported here provided further evidence regarding the diversity of S. pyogenes isolates and might contribute towards understanding the pathogenesis and persistence of S. pyogenes.

Magnetic resonance imaging of athlete's heart: myocardial mass, left ventricular function, and cross-sectional area of the coronary arteries

To evaluate left ventricular myocardial mass and function as well as ostial coronary artery cross-sectional area in endurance athletes, an athlete group of 12 highly trained rowers and a control group of 12 sedentary healthy subjects underwent MR examination. An ECG-gated breath-hold cine gradient-echo sequence was used to calculate myocardial mass, end-diastolic and end-systolic volumes, stroke volume, and cardiac output, all related to body surface area, as well as ejection fraction. A 3D fat-saturated ECG- and respiratory-triggered navigator echo sequence was used to evaluate coronary arteries: left main (LM), left anterior descending (LAD), left circumflex (LCx), and right coronary artery (RCA). Cross-sectional area was calculated and divided for body surface area. Myocardial mass was found significantly larger in athlete group than in control group (p = 0.0078), the same being for end-diastolic volume (p = 0.0078), stroke volume (p = 0.0055), LM (p = 0.0066) and LAD (p = 0.0129). No significant difference was found for all the remaining parameters. Significant correlation with myocardial mass was found for LM (p < 0.001) and LAD (p = 0.0340), not for LCx and RCA. Magnetic resonance imaging is a useful tool in evaluating the myocardial hypertrophy and function of athlete's heart. Magnetic resonance angiography is a valuable noninvasive method to visualize the correlated cross-sectional area increase of the left coronary artery system.

Three-dimensional, navigator-echo MR coronary angiography in detecting stenoses of the major epicardial vessels, with conventional coronary angiography as the standard of reference

PURPOSE

To test three-dimensional (3D), navigator-echo magnetic resonance (MR) coronary angiography in detecting stenoses of the coronary arteries.

MATERIALS AND METHODS

Forty-two patients (age range, 50-79 years) underwent MR coronary angiography (1.5 T). A navigator-echo sequence was used. Two or three 15% overlapped transverse slabs were acquired. Data were analyzed by readers blinded to conventional coronary angiographic results. On conventional coronary angiograms, coronary arterial stenoses of 50% or greater narrowing were considered significant. On MR coronary angiograms, the major coronary vessels were subdivided into proximal (within 5 cm) and distal (beyond 5 cm) segments, except for the left main vessel. Stenoses of 50% or greater were identified on reformatted multiplanar MR coronary angiograms.

RESULTS

Three MR coronary angiographic examinations were aborted because of patient claustrophobia; 39 of 39 left main, 117 of 117 proximal, and 78 of 117 distal segments were visualized. MR coronary angiography showed a sensitivity of 82% (95% CI: 73%, 91%) and a specificity of 89% (95% CI: 85%, 94%) in overall stenoses identification, of 90% (95% CI: 81%, 99%) and 90% (95% CI: 83%, 96%) for proximal segments, and of 68% (95% CI: 50%, 86%) and 81% (95% CI: 71%, 92%) for distal segments, respectively.

CONCLUSION

Navigator-echo, 3D MR coronary angiography is a promising sequence for assessing coronary arterial stenoses, but further improvements are required for distal segments.

Fc-mediated nonspecific binding between fibronectin-binding protein I of Streptococcus pyogenes and human immunoglobulins

Fibronectin-binding protein I (SfbI) from Streptococcus pyogenes plays a key role in bacterial adhesion to, and invasion of, eukaryotic cells. In addition, SfbI exhibits a considerable potential as mucosal adjuvant and can trigger polyclonal activation of B cells. Here, we report that SfbI is also capable of binding human IgG in a nonimmune fashion. SfbI was reactive with IgG1, IgG2, IgG3, and IgG4 isotypes (type IIo IgG-binding profile). The affinity constant (Kd) of the SfbI-IgG interaction was in the range of 1-2 x 10(-5) M. Further studies demonstrated that the SfbI binding was mediated by the Fc component of the IgG molecule. Experiments performed using purified recombinant proteins spanning different domains of SfbI showed that the IgG-binding activity was restricted to the fibronectin-binding domains, and in particular to the fibronectin-binding repeats. Finally, the presence of recombinant SfbI resulted in an impairment of both phagocytosis of IgG-coated RBCs and Ab-dependent cell cytotoxicity by macrophages. These results demonstrated for the first time that, in addition to its major role during the colonization process, SfbI may also favor bacterial immune evasion after the onset of the infection by interfering with host clearance mechanisms.

Protective immune response against Streptococcus pyogenes in mice after intranasal vaccination with the fibronectin-binding protein SfbI

Despite the significant impact on human health of Streptococcus pyogenes, an efficacious vaccine has not yet been developed. Here, the potential as a vaccine candidate of a major streptococcal adhesin, the fibronectin-binding protein SfbI, was evaluated. Intranasal immunization of mice with either SfbI alone or coupled to cholera toxin B subunit (CTB) triggered efficient SfbI-specific humoral (mainly IgG) and lung mucosal (14% of total IgA) responses. CTB-immunized control mice were not protected against challenge with S. pyogenes (90%-100% lethality), whereas SfbI-vaccinated animals showed 80% and 90% protection against homologous and heterologous challenge, respectively. Multiple areas of consolidation with diffused cellular infiltrates (macrophages and neutrophils) were observed in lungs from control mice; the histologic structure was preserved in SfbI-vaccinated animals, which occasionally presented focal infiltrates confined to the perivascular, peribronchial, and subpleural areas. These results suggest that SfbI is a promising candidate for inclusion in acellular vaccines against S. pyogenes.

Streptococcal invasion

The genus Streptococcus consists of large number of species many of which are pathogenic to humans and animals. Although streptococci have long been considered as extracellular pathogens, they are capable of causing serious invasive infections such as necrotizing fasciitis and meningitis. Streptococcal invasion, therefore, has been a focus of many studies in recent years. Streptococci are efficiently internalized by nonprofessional phagocytes and the current research interest has shifted to determine the role of this invasion in the natural infection process. Moreover, characterization of bacterial and eukaryotic components involved in the uptake process might be useful in developing new strategies for combating streptococcal infections.

Magnetic resonance spectroscopy of ischemic heart disease

An overview of the basic knowledge necessary to understand the procedure of Magnetic Resonance Spectroscopy of the myocardium and its most significant applications in the study of ischemic heart disease, is presented, with reference to the personal experience. The chemical shift phenomenon, the main techniques of spectroscopic localization and the general aspects of myocardial 31P and 1H Magnetic Resonance Spectroscopy, including proton decoupling and magnetization transfer, are illustrated. Postprocessing techniques before and after Fourier transform are mentioned. 31P Magnetic Resonance Spectroscopy allows the noninvasive assessment of the metabolism of high energy phosphates, PCr/ATP ratio in particular, in the in vivo myocardial tissue with significant applications in the diagnostic approach to ischemic patients with the support of provocative tests (dobutamine). 1H Magnetic Resonance Spectroscopy allows similar evaluations based on the peak of total creatinine.

Magnetic resonance assessment of coronary artery bypass grafts

The increasingly widespread use of myocardial revascularization by aortocoronary bypass grafts and the frequent need for their angiographic control require noninvasive imaging procedures able to provide reliable information on their performance. After an overview of angiography as gold standard and the different imaging procedures of aortocoronary bypass grafts alternative to MRI, echocardiography, nuclear cardiology, X-ray or electron beam ultrafast CT, main MRI procedures for the study of aortocoronary bypass, are illustrated together with the results of the personal experience as those of navigator echo technique provided with cardiac and respiratory synchronization (91% sensitivity for aortocoronary bypass occlusion and 97% specificity for patency). In the near future, hardware and software refinements, intravascular contrast media and the application to aortocoronary bypass grafts of flowmetric techniques of phase-velocity mapping will enable the evaluation of bypass stenosis and distal coronary arteries as well as a complete functional graft assessment.

Invasion and survival of Streptococcus pyogenes in eukaryotic cells correlates with the source of the clinical isolates

The invasiveness of 96 group A streptococci (GAS) isolates (56 from throat or skin and 40 from blood) were analyzed. GAS invasion strongly correlated with the source of the isolates, whereas no correlation was observed with the Vir type. Isolates from throat or skin exhibited the highest invasion efficiency (57% were between 0.1% and 10%). In contrast, 77.5% of the blood isolates were noninvasive (efficiency <0.01%) and only 7.5% exhibited rates comparable to those of throat or skin isolates (>0.1%). Immunofluorescence studies of 34 selected isolates showed that attachment and invasion are strain-related. Although isolates with high invasiveness usually exhibit high attachment, isolates that showed high attachment and no invasion or poor attachment and efficient internalization were identified. The ability of GAS to invade and survive within eukaryotic cells may provide bacteria a sure niche, in which they are protected against host defense mechanisms or antimicrobial agents favoring their local persistence.

The fibronectin-binding protein of Streptococcus pyogenes, SfbI, is involved in the internalization of group A streptococci by epithelial cells

Streptococcus pyogenes organisms (group A streptococci) are considered to be highly adhesive extracellular pathogens. However, it has recently been reported that S. pyogenes has the capacity to efficiently invade eukaryotic cells. In this study, we demonstrate that the interaction of S. pyogenes fibronectin-binding protein (SfbI) with fibronectin on nonphagocytic HEp-2 cells triggers bacterial internalization. Blocking of the SfbI adhesin by either antibodies against the whole protein or antibodies against the fibronectin-binding domains of SfbI, as well as pretreatment of HEp-2 cells with purified SfbI protein, prevents both S. pyogenes attachment and internalization. Inert latex beads precoated with the purified SfbI protein are ingested by eukaryotic cells, demonstrating that SfbI is per se enough to trigger the internalization process. Experiments performed with a recombinant SfbI domain encompassing the two fibronectin-binding regions of the SfbI molecule demonstrated that these binding regions are essential and sufficient to activate uptake by HEp-2 cells. These results demonstrate that the fibronectin-binding protein SfbI is involved in both S. pyogenes' attachment to and ingestion by HEp-2 cells and contribute to elucidation of the underlying molecular events leading to eukaryotic cell invasion by S. pyogenes.

Bacteria involved in the blockage of biliary stents and their susceptibility to antibacterial agents

Endoscopically inserted stents are used for the palliation of obstructive jaundice, but infections and blockage of these stents by biliary sludge and bacterial biofilm may develop, presenting major complications. To analyze which bacteria are involved in this process, 25 biliary stents were examined. Eighty-one microorganisms were isolated: 59 gram-negative bacteria (54 Enterobacteriaceae and 5 Pseudomonas aeruginosa), 19 gram-positive bacteria (all Enterococcus spp.), and 3 Candida albicans. The Enterobacteriaceae were sensitive to netilmicin (100%), imipenem (98%), ciprofloxacin (96%), cefotaxime (69%), and piperacillin (57%), whereas Enterococcus spp. were sensitive to imipenem (79%), piperacillin (75%), ciprofloxacin (63%), and ampicillin (58%). The unpredictable aetiology and high rates of antibiotic resistance suggest that bacteriological monitoring is mandatory to avoid treatment failures in these patients.

Right ventricular dysplasia as a generalized cardiomyopathy? findings on magnetic resonance imaging

The aim of our study was to define cardiac morphological and functional abnormalities of right ventricular dysplasia by magnetic resonance imaging. Twenty-two healthy volunteers (age, 37.7 +/- 14.2 years) free of cardiac or respiratory diseases (group I) and 12 patients (age, 41.9 +/- 15.8 years) with clinical, electrophysiological and cineangiographic diagnosis of right ventricular dysplasia (group II) underwent magnetic resonance imaging at 0.2 Tesla. End-diastolic diameter, trabecular disarray and segmental wall motion abnormalities were evaluated for the right ventricle as were adipose replacement and fractional shortening for both ventricles. The right ventricular end-diastolic diameter was significantly enlarged in group II (P = 0.0023). Right ventricular trabecular disarray was mild in two group I subjects, and moderate in seven and massive in five group II patients. Right ventricular systolic bulges were found in seven group II patients, aneurysms in five. Excellent agreement was found between magnetic resonance imaging and cineangiography for bulges, aneurysms and tricuspid regurgitation (P < 0.0001). On spin-echo images, signal hyperintensities, due to adipose replacement, were found in 44 cardiac regions in group II: right ventricular outflow tract (12), sub-tricuspid posterobasal region (8), right ventricular apex (9), right ventricular anterior wall (6), interventricular septum (4), left ventricular lateral wall (4), left ventricular apex (1). Significant signal-to-noise ratio differences were found between group II abnormal areas and group I myocardial tissue for the right (P < 0.0001) and left ventricles (P = 0.0006). Fractional shortening in the right and left ventricles were significantly reduced in group II (P = 0.0002 and P = 0.00016, respectively). Magnetic resonance imaging can be considered a very useful diagnostic tool for the detection of features typical of right ventricular dysplesia, such as adipose replacement, trabecular disarray, bulges and aneurysms and provides useful information about cardiac function and regional wall motion. It indicates that left ventricular involvement occurs in a significant fraction of patients, and suggests that right ventricular dysplasia may be a generalized cardiomyopathy.

[Retrospective study of 135 cases of lung neoplasms diagnosed between 1983 and 1993]

The authors expose the results of a retrospective study concerning 135 cases of neoplasia diagnosed by their Department between 1983 and 1993. The patients' age, their sex, their consume of tobacco, their survival from the moment of the diagnosis have been considered in the study. Likewise the clinical instrumental researches and their reliability, the different incidence of the examined pathology in the first and in the second part of the period considered. It is emerged from the collected data, that also in our territory there is an increasing tendency in the incidence of lung neoplasia, a generally short survival after the diagnosis, a strong prevalence of smokers among those people affected from the disease, the difficulty of an early diagnosis due to scarce specificity of the commonest symptoms. The final auspicious is that a more incisive diligence in prevention and significant progresses in clinical pharmacological research may determine a notable reduction of the incidence of such a dramatic pathology.

The coronary subclavian steal syndrome: an uncommon sequel to internal mammary-coronary artery bypass surgery

Coronary subclavian steal syndrome is a possible sequel in patients who have undergone myocardial revascularization with an internal mammary artery. We report a case of this syndrome in a 67-years-old man. In 1990 he underwent a quadruple bypass: aorta-obtuse margin, aorta-right coronary (two sequential), internal artery mammary-descending coronary artery. Three months later he started to have angina pectoris. In April 1992 an aortic arch angiography and a coronary angiography were performed. The examination showed an occlusion of the left subclavian artery at its origin. The artery was opacified countercurrently by the left vertebral artery but the left mammary artery was not opacified. Left coronary angiography showed a very severe disease of left anterior descending coronary artery and retrograde flow through the anastomosis in the left mammary artery. The patient underwent a left common carotid-subclavian artery bypass operation using a 6 mm vascutex graft. Eighteen months later the patient is doing well without angina pectoris and with very little alteration of the perfusion in the left frontal lobe observed by SPECT neuroimaging with a lipophilic tracer (99mTc-HMPAO). We think that the coronary-subclavian steal syndrome can be treated successfully with low risk by means of common carotid-subclavian artery bypass.

[The role of stabilometry in assessing the correlations between craniomandibular disorders and equilibrium disorders]

We examined three groups: 29 patients suffering from balance disorders and craniomandibular disorders but from vestibular disease; 21 patients suffering from balance disorders, craniomandibular disorders and vestibular disease; 26 patients suffering from craniomandibular disorders but not from vestibular disease or balance disorders. All cases were examined by the odontologist and otoneurologist and tested by computerized stabilometry; they were reexamined after six months of therapy by an occlusal stabilization splint. The static analysis of the results show a significative reduction of the postural oscillations in all patients.

[The use of computer-assisted stabilometry in the diagnosis of craniomandibular disorders]

The aim of this study was to evaluate the influence of the cervical region and the stomatognathic system on the balance control. We examined 35 healthy subjects and 201 balance disorder patients; of the 201 patients 60 suffered also from craniomandibular disorders (CMD) and 40 from cervical rachis disease. All cases were tested by computerized stabilometry executed in Romberg position: with closed eyes, retroflexed head and two cotton roles between the dental arches. The results show that cervical rachis disease and stomatognathic dysfunction have a significative influence on the balance control; however, this influence is smaller than that of vestibular disease; moreover, the computer stabilometry allows to measure the degree of ascending or descending correlation between the posture and stomatognathic system.

[Heart involvement in thymic neoformations: the role of magnetic resonance tomography. Experience in 3 cases]

Three paracardiac masses (1 thymic cyst, 2 thymomas) were studied by magnetic resonance imaging (MRI) using spin-echo, multi-echo, and gradient-echo sequences (cine-MR). MRI showed: a pedunculate cystic lesion, typical for thymic origin, in Case 1; cardiac and pulmonary infiltration, and 3 intracardiac metastases, in Case 2; cardiovascular compression but not infiltration, in Case 3. In 3/3 cases MRI was superior to transthoracic echocardiography (TTE), and in 2/2 MRI was superior to computed tomography (CT), not performed in Case 2 (allergy to contrast agents). MRI may be considered the most important technique to evaluate cardiovascular involvement by thymic neoplasms. MRI should be performed after TTE and makes CT unnecessary.

MRI in hypertrophic cardiomyopathy: a morphofunctional study

OBJECTIVE

We compared MRI with two-dimensional echocardiography (2dE) and Doppler echocardiography to determine the diagnostic role of MRI in hypertrophic cardiomyopathy (HCM).

MATERIALS AND METHODS

Twenty-three patients with 2dE diagnosis of HCM were examined with MRI; 12 of 23 patients were also studied by color (cDE) and continuous wave (cwDE) Doppler echocardiography. Morphologic information and diastolic heart wall thickness were obtained by SE sequences; functional study was performed by gradient echo sequences (cine MR).

RESULTS

The correlation between MR, SE sequences and 2dE was better for septal (r = 0.930, p < 0.01) than for posterolateral (r = 0.739, p < 0.01) wall thickness. The assessment of the distribution of the hypertrophy was changed by MR in five cases. Cine MR functional study showed a systolic subaortic signal void (dynamic obstruction) in 12 of 22 patients and a systolic left atrial signal void (mitral regurgitation) in 17 of 22. Systolic wall thickening was studied by cine MR and 2dE in 11 patients: A good correlation was found for septum (0.01 < p < 0.05) and a poor one for posterolateral wall (p > 0.05). The cine MR and cDE turbulence duration in the left ventricle and atrium showed excellent correlation (p < 0.01). Good agreement was found between the duration of subaortic turbulence (cine MR or cDE) and the pressure gradient (cwDE) (p < 0.01 and 0.01 < p < 0.05, respectively) and between cine MR and cDE semiquantitative estimate of the mitral regurgitation (p < 0.01). In all patients with subaortic MR signal void studied with cwDE, a pressure gradient was present.

CONCLUSION

Magnetic resonance imaging can play an important role in the diagnosis of HCM after 2dE-DE.