Potential Cardiologic Protective Effects of Acetylcholinesterase Inhibitors in Patients With Mild to Moderate Dementia

In patients with mild to moderate dementia, acetylcholinesterase inhibitors (AChE-I) are used to improve cognitive functions, but bradycardia, conduction abnormalities, and hypotension are possible side effects because of the peripheral muscarinic M2 receptor stimulation. This study aimed to evaluate the main cardiologic clinical outcomes in patients with dementia who are on AChE-I. In this retrospective, monocentric, observational cohort study, 2 groups were considered: (1) patients with dementia because of the typical and atypical forms of Alzheimer disease treated with AChE-I and (2) cognitively unimpaired, matched control group. The primary end point was a composite of cardiovascular death, nonfatal acute myocardial infarction, myocardial revascularization, occurrence of stroke and/or transient ischemic attacks, and hospitalization for heart failure occurring during a mean of 3.1 years of follow-up. The secondary end points were each individual component of the primary end point, total mortality, noncardiovascular death, and incidence of pacemaker implant. Each group included 221 patients who were homogeneous in terms of age, gender, and main cardiovascular risk factors. Major adverse cardiovascular events occurred in 24 patients with dementia (2.1 per 100 patient-years) compared with 56 in control group (5.0 per 100 patient-years), p = 0.036. Even if not significant, the difference was mainly driven by myocardial revascularization (3.2% vs 6.8%) and hospitalization for heart failure (4.5% vs 14.5%). As expected, noncardiovascular mortality was significantly higher in the treatment group (13.6% vs 2.7% p = 0.006). No significant difference between the groups was observed in terms of other secondary outcomes. In conclusion, in patients with dementia, the use of AChE-I may be protective for cardiovascular outcomes, especially in reducing heart failure hospitalization and myocardial revascularization.

Clinical Performance of Complete-Arch Implant- Supported Rehabilitations Using Monolithic Lithium Disilicate Restorations Bonded to CAD/CAM Titanium and Zirconia Frameworks up to 5 Years

This clinical study evaluated the survival of monolithic lithium disilicate (ML) (IPS Emax, Ivoclar Vivadent) restorations bonded to complete-arch CAD/CAM made titanium or zirconia frameworks. Between August 2007 and December 2009, 15 patients (7 female, 8 male; mean age: 56.8 years old) received 30 implant-supported screw-retained rehabilitations with ML restorations cemented to CAD/CAM made titanium (T) (n=6) or zirconia (Z) frameworks (n=24) adhesively (Multilink Automix, RelyX Unicem) and followed up until December 2015. The evaluation protocol involved technical failures (chipping, debonding or fracture of crown/framework, screw loosening), Californian Dental Association (CDA) quality criteria (Romeo: Excellent; Sierra: Acceptable; Tango: Retrievable; Victor: Not acceptable) and biological failures (mucositis, peri-implantitis). Mean observation time was 60.3 months. No implants were lost, and all the prostheses were in situ. Four mechanical failures occurred in the form of minor chipping (n=3 in ML-Z, n=1 in ML-T) and major fracture in ML crown (n=1 in ML-Z). Romeo scores (N=370) decreased until final observation (N=347) and 23 Sierra scores were given to the restorations. Mucositis was observed in 3 patients and peri-implantitis in one patient. Complete-arch implant-borne FDPs made of monolithic lithium disilicate bonded to titanium or zirconia frameworks could be a promising alternative.

Mid- and long-term atrio-ventricular mechanics in children after recovery from asymptomatic or mildly symptomatic SARS-CoV-2 infection

Background

Clinical manifestations of children's coronavirus disease-2019 (COVID-19) were initially considered less severe compared with adult patients. However, there is now increasing evidence of a “long-tail” of COVID-19 related symptoms lasting for several months after recovery from the acute infection. Long COVID-19-related symptoms and mechanisms are poorly characterized and understood, with several phenotypes reported, often driven by long-term tissue damage (such as lung, heart and brain) and pathological inflammation due to viral persistence and/or immune deregulation.

Purpose

The objective of this study was to evaluate atrio-ventricular mechanics, by means of two-dimensional speckle-tracking echocardiography, in previously healthy children recovered from asymptomatic or mildly symptomatic severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in a long-term follow-up.

Methods

We analysed a cohort of 157 paediatric patients, mean age 7±4 years, who had a confirmed diagnosis of SARS-CoV-2 infection and were asymptomatic or mildly symptomatic for COVID-19. Patients underwent standard transthoracic echocardiogram and speckle tracking echocardiographic study 148±68 days after diagnosis. One hundred seven age, sex, and body surface area comparable healthy subjects were used as control group.

Results

Left ventricular ejection fraction was within normal limits in postCOVID-19 cases and CTRL with no significant differences between the two groups (postCOVID-19: 65.6±4% vs CTRL: 65.0±5%, p=0.182).

Left ventricular (LV) global longitudinal strain (postCOVID-19: −20.5±2.9%; CTRL: −21.8±1.7%; p<0.001) was significantly reduced in cases compared with CTRLs. An amount of 11 (7%) postCOVID-19 cases showed impaired GLS values < −17% and 95 subjects (60%) presented with a strain lower than −16% in more than 2 segments. These subjects did not show any difference regarding symptoms or serological findings. Moreover, GLS was significantly reduced in children with disease's onset during the second wave of COVID-19 pandemic, compared with those during the first wave (second wave: −20.2±2.6%; first wave: −21.2±3.4%; p=0.048). Finally, peak left atrial systolic strain was within the normal range in the postCOVID-19 group with no significant differences compared to CTRL (postCOVID-19: 49.1±12%; CTRL: 49.5±18%).

Conclusions

SARS-CoV-2 infection may affect left ventricular deformation in children despite an asymptomatic or only mildly symptomatic acute illness. Our data show an amount of 60% of children, recovering from asymptomatic or mildly symptomatic COVID-19, with still mild subclinical systolic cardiac impairment in the mid- and long-term follow-up after the infection. This subtle impairment was seen to be worse in children recovering from the second wave of COVID-19 compared to the first one.

A follow-up is needed to verify the reversibility of these alterations and their impact on long-term outcomes.

Funding Acknowledgement

Type of funding sources: None.

P154 EVOLUTION OF ECHOCARDIOGRAPHIC AND CARDIAC MRI ABNORMALITIES DURING FOLLOW–UP IN PATIENTS WITH PREVIOUS MIS–C DIAGNOSIS

Background

Cardiovascular manifestations in the acute phase of MIS–C are frequent. However, there is lacking evidence regarding late cardiological follow–up of this cohort of patients. The aim of our study was to describe the early and late cardiac abnormalities in patients with MIS–C, assessed by standard echocardiography (TTE), speckle tracking echocardiography (STE), and cardiac MRI (CMR).

Materials and Methods

32 consecutive patients with confirmed MIS–C diagnosis were enrolled in this study. Clinical, laboratory and microbiological data were collected for all patients. At disease onset, all children underwent standard transthoracic echocardiography, STE with analysis of left ventricle global longitudinal strain (GLS) and 23 (75%) of them performed CMR. Patients underwent complete cardiological evaluation, including echocardiography and STE at two months (T1) and six months (T2) after diagnosis. CMR was repeated at six months after diagnosis.

Results

Mean age was 8.25±4years (range 1.3–17.7). Cardiovascular symptoms were present in 45.8% of cases. Thirteen children (40.6%) shared Kawasaki Disease–like symptoms, and 5 (15.6%) needed ICU admission. All patients showed an hyperinflammatory state. Tn–I was elevated in 20 (62.5%) and BNP in 28 (87.5%) patients. Median time to STE evaluation was 7 days and to CMR 18 days since fever onset. Mean LVEF at baseline was 58.8±10% with 10 patients (31%) below 55%. STE showed reduced mean LV GLS (–17.4±4%). Coronary dilation was observed in 9 (28,1%) patients. On CMR, LGE with nonischemic pattern was evident in 8/23 patients (35%). Median time to T1 and T2 evaluation was respectively 48.5 and 207 days. Follow–up data showed statistically significant improvement in left ventricular systolic function compared to acute phase. LVEF improved rapidly at T1 (62.5 ± 7.5 vs. 58.8±10.6%, p value 0.044) with only three patients (10%) below ≤ 55% at T1 and one patient (4%) at T2. LV GLS remained impaired at T1 (–17.2 ± 2.7 vs.–17.4 ± 4, p value 0.71), and significantly improved at T2 (–19±2.6% vs. –17.4±4%, p value 0.009). LV GLS was impaired (&gt;–18%) in 53% of patients at baseline and T1, while only 13% showed LV GLS reduction at T2. CMR, performed 6 months after diagnosis, showed LGE persistence in 33.4% of cases.

Conclusions

Even though, early cardiac involvement significantly improves during follow–up, subclinical myocardial damage seems to be still detectable 6 months follow up in one third of MIS–C patients.

Exercise stress echocardiography in paediatric and adolescent patients

Funding Acknowledgements

Type of funding sources: None.

INTRODUCTION

Exercise stress echocardiography (ESE) is still underused in paediatric patients, and very little data is available for congenital heart diseases (CHDs).

PURPOSE

To describe the current application of ESE in our Paediatric Cardiology Departments.

METHODS

Data from patients who underwent ESE in our Centres, including baseline and under stress symptoms, vital parameters, ECG, and echocardiograms were retrospectively analyzed and compared, as well as clinical management plans formulated based on ESEs results.

RESULTS

Forty-five patients from Centre 1 (median age 16 years), including 87% of patients with CHDs, and 20 patients from Centre 2 (median age 11 years), mainly tested to rule out myocardial ischemia, were included. Among patients from Centre 1, 28 had previously been treated surgically, 6 percutaneously and 11 were under follow-up. Indications for ESE/patients’ native diagnosis are illustrated in the picture.

Centre 1: Exercise was maximal in 17 patients, with 2 of them having symptoms at the peak of exercise. It was stopped beforehand in 28 patients because of dyspnea (3) and muscle fatigue (25). No arrhythmia was detected. ESE was considered as positive in 14 patients; after that, 3 patients underwent percutaneous interventions, 2 underwent cardiac surgery, 3 received indication for cardiac catheterization, 4 for advanced cardiac imaging and 2 for exercise restriction and medical therapy.

Centre 2: Fifteen patients (75%) completed the exercise, and none of them developed symptoms. In the remaining 25%, exercise was stopped because of muscle exhaustion. No arrhythmia was detected, and all the ESEs were negative.

Comparing the cohorts, no significant differences in terms of ejection fraction were noticed at rest and under stress. Patients in cohort 1 were older (p = 0,002), they achieved lower average maximal heart rate (p = 0,0001), performed less lasting exercise (p = 0,05) and ESE was maximal less frequently (p = 0,005). Lastly, they had significant changes in clinical decisions (p = 0,004).

CONCLUSIONS

ESE is a feasible and promising technique in paediatric cardiology, particularly in children with congenital heart diseases, and could influence significantly clinical management plans. Abstract Figure.

OUP accepted manuscript

Aims

Methods and results

Conclusion

Exercise stress echocardiography in children and teenagers with congenital heart diseases

Background

Exercise Stress Echocardiography (ESE) is currently applied to paediatric patients mainly to detect myocardial ischemia and few data is available for congenital heart diseases (CHDs).

Purpose

The aim of this study is to describe the current application of ESE in our Departments.

Methods

Data from patients who underwent ESE in our two centres were retrospectively analysed, as well as clinical management plans formulated based on ESEs results.

Results

Fifty-five patients (median age 15 years) were included. Among them, 19 had been previously treated surgically, 6 percutaneously and 30 were under follow-up.

Indications for ESE were: hypertension and/or evaluation of aortic arch gradient in patients treated surgically (5) or percutaneously (1) for aortic coarctation (ACo); aortic/subaortic gradient in bicuspid aortic valve (BAV) after balloon valvuloplasty (4), Ross (1), or under follow up (1); right ventricular and pulmonary valve function in Tetralogy of Fallot (3) and after percutaneous treatment of pulmonary atresia (1); atrio-ventricular valves gradient (1 for tricuspid dysplasia and 1 for left cor triatriatum); single ventricle function (1); pulmonary artery gradient (2) and myocardial ischemia (6) after Arterial Switch; rule out myocardial ischemia in coronary anomalies (4), chest pain (9), Kawasaki disease (KD 9), syncope (1) and in patients with ectopic beats under exercise (2); rule out dynamic obstruction in hypertrophic cardiomyopathy (HCM, 3).

The exercise was maximal in 28 patients, with 2 of them having symptoms at the peak of exercise. In the other patients, peak heart rate ranged from 52% to 84% of targeted values. Mean exercise duration and reached Watts were 10 minutes and 112, respectively. Reasons for ending exercise were muscle fatigue in 25 patients and dyspnoea in 2 patients. No arrhythmia was detected.

Clinical management changed in 10 of patients after ESE (20%), all having CHDs. Three patients underwent percutaneous interventions; 1 aortic balloon valvuloplasty, 1 stent dilation and 1 pulmonary valve replacement; 2 underwent surgery (1 aortic valve replacement and 1 subaortic membrane resection), 4 underwent further imaging including cardiac computed tomography (1), cardiac magnetic resonance (2) and cardiac catheterization (1); 1 received indication for restriction from intense physical activities.

Conclusions

ESE has an important clinical role in patients with congenital heart diseases, impacting clinical management.

Funding Acknowledgement

Type of funding sources: None. Indications for ESEChangements in clinical management

Left ventricle longitudinal strain alterations in asymptomatic or mildly symptomatic pediatric patients with recent SARS-CoV-2 infection

Funding Acknowledgements

Type of funding sources: None.

Background

Evidence suggests that clinical manifestations of children’s COVID-19 may be less severe. However, it has been described the pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) which resembles other inflammatory conditions (i.e. Kawasaki disease). Patients affected by PIMS-TS showed cardiac involvement with myocardial injury, reduced left ventricle systolic function and coronary artery abnormalities. Little is known regarding cardiac involvement in pediatric patients with asymptomatic or mildly symptomatic SARS-CoV-2 infection.

Methods

We analyzed 23 pediatric patients (13males, 56%) with diagnosis of SARS-CoV-2 infection based on PCR analysis of nasopharingeal swab (NPS), and asymptomatic or only mildly symptomatic for COVID-19. Patients underwent standard transthoracic echocardiogram (TTE) within 2-3 month from diagnosis and after negative NPS for SARS-CoV-2. We performed offline analysis with GE EchoPAC software to measure global longitudinal strain (GLS) of the LV using 2D speckle tracking imaging. Therefore, we compared the results with a matched group of 23 controls (13males, 56%).

Results

Cases and controls were similar regarding age (5.9 ± 4.1years vs. 6.4 ± 4.4 years, p = 0.63), body surface area (0.98 ± 0.3m2 vs. 0.8 ± 0.4m2, p = 0.17), LV FS (37.9 ± 5.9% vs. 36.4 ± 8.3%, p = 0.74) and LV biplane EF (63.9 ± 5.2% vs. 66.4 ± 5.3%, p = 0.11). GLS analysis showed significant strain reduction of the LV mid-wall segments and of the basal anterior, posterior and septal inferior segments among cases compared to controls. Furthermore, in the case group there were 7 subjects (30%) with a strain below 16.5% in at least 3 segments.

Conclusion

SARS-CoV-2 infection may affect LV deformation in asymptomatic or only mildly symptomatic children, showing a peculiar pattern with lower longitudinal strain in all mid-wall segments of LV compared to control subjects. The clinical significance of this findings is unclear and follow-up is needed to verify the reversibility of this alterations.

Gut T cell-independent IgA responses to commensal bacteria require engagement of the TACI receptor on B cells

The gut mounts secretory immunoglobulin A (SIgA) responses to commensal bacteria through nonredundant T cell-dependent (TD) and T cell-independent (TI) pathways that promote the establishment of mutualistic host-microbiota interactions. SIgAs from the TD pathway target penetrant bacteria, and their induction requires engagement of CD40 on B cells by CD40 ligand on T follicular helper cells. In contrast, SIgAs from the TI pathway bind a larger spectrum of bacteria, but the mechanism underpinning their production remains elusive. Here, we show that the intestinal TI pathway required CD40-independent B cell-activating signals from TACI, a receptor for the innate CD40 ligand-like factors BAFF and APRIL. TACI-induced SIgA responses targeted a fraction of the gut microbiota without shaping its overall composition. Of note, TACI was dispensable for TD induction of IgA in gut-associated lymphoid organs. Thus, BAFF/APRIL signals acting on TACI orchestrate commensal bacteria-specific SIgA responses through an intestinal TI program.

Reliability of Chair-side Monolithic CAD-CAM Generated Lithium Disilicate Single Crowns with Knife- Edge Finish Line: Up to 5-Year Retrospective Analysis of Clinical Performance

This clinical study evaluated the survival of monolithic lithium disilicate (MLD) single crowns. Between January-2010 and January-2015, 87 patients received 122 MLD (IPS e.max CAD) single crowns on natural teeth with knife-edge finish lines that were adhesively bonded (Maxcem Elite). MLD single crowns (N=122) were bonded on 60 molars (maxilla:35, mandible:25), 53 premolars (maxilla:27, mandible:26), 4 canines (maxilla:2, mandible:2), 3 laterals and 2 centrals (maxilla). One crown fracture, one retention loss and one endodontic complication were experienced (survival rate: 97.5%). MLD single crowns could be safely indicated on teeth with knife-edge preparations.

Responsive population dynamics and wide seeding into the duodenal lamina propria of transglutaminase-2-specific plasma cells in celiac disease

A hallmark of celiac disease is autoantibodies to transglutaminase 2 (TG2). By visualizing TG2-specific antibodies by antigen staining of affected gut tissue, we identified TG2-specific plasma cells in the lamina propria as well as antibodies in the subepithelial layer, inside the epithelium, and at the brush border. The frequency of TG2-specific plasma cells were found not to correlate with serum antibody titers, suggesting that antibody production at other sites may contribute to serum antibody levels. Upon commencement of a gluten-free diet, the frequency of TG2-specific plasma cells in the lesion dropped dramatically within 6 months, yet some cells remained. The frequency of TG2-specific plasma cells in the celiac lesion is thus dynamically regulated in response to gluten exposure. Laser microdissection of plasma cell patches, followed by antibody gene sequencing, demonstrated that clonal cells were seeded in distinct areas of the mucosa. This was confirmed by immunoglobulin heavy chain repertoire analysis of plasma cells isolated from individual biopsies of two untreated patients, both for TG2-specific and non-TG2-specific cells. Our results shed new light on the processes underlying the B-cell response in celiac disease, and the approach of staining for antigen-specific antibodies should be applicable to other antibody-mediated diseases.

The success of indirect restorations in posterior teeth: a systematic review of the literature

AIM

Aim of the study was to evaluate the long-term reliability and effectiveness of inlays and onlays in ceramic and composite material, examining scientific studies published from 2004 to 2013. The results of this review were analyzed and compared with the important literature review proposed by Manhart in 2004.

METHODS

With this review it was possible to analyze a total sample of 5858 Class I and II restorations, made in the posterior region: 5295 ceramic and 563 composite restorations in 2377 patients. Works were evaluated using USPHS, modified USPHS and CDA criteria after a mean observation period of 5.4 years (5.9 years for ceramic restorations, 2.6 for composite restorations).

RESULTS

The arithmetic average of success was 94%, higher in ceramic restorations (94.9%) than composite materials (91.1%). The weighted average success rate was 95.3%, 92.8% for composite restorations and 96.3% for ceramic ones. The highest rates of success were found in ceramic restorations notwithstanding the longer observation period.

CONCLUSION

Indirect restorations have a low failure rate and they prove to be an excellent choice in the treatment of both class I and II lesions. During the last 6 years, the parameters related to these restorations have improved, with a 4% increase of success.

Polymerization degree and cementation methods of two different self-adhesive luting cements used for glass fiber postcementation

AIM

Aim of this study was to evaluate two different luting cements and how their clinical procedures influence the postcementation quality.

METHODS

Thirty-six freshly extracted mono-radicular teeth (N.=18) were treated endodontically and randomly divided into two groups. Posts were cemented respectively with two different self adhesive luting cements: Group A - RelyX Unicem (3M Espe) and Group B - Multilink Sprint (Ivoclar-Vivadent) following the manufacturers' instructions. Teeth were then thermocycled according to protocol ISO/TR 11405 and were immersed 24 hours in 2% methylene-blue solution. Each tooth was sectioned by a diamond-coated saw (Isomet-Buhler) from CEJ to apex. Each slice was examined for the presence or absence of gutta-percha remnants, voids, bubbles, dye infiltration degree and polymerization grade of the luting agent. Findings were evidenced by stereoscopic microscopy (30x) and Micro-Raman spectroscopy. Mann-Whitney and ANOVA statistical analyses were performed for all results.

RESULTS

No statistical significances were evidenced for gutta-percha presence, dye infiltration and polymerization degree. Voids were present mostly in Group B and bubbles in Group A. Both differences were statistically significant.

CONCLUSION

Materials and protocols for glass fiber posts cementation are fundamental for the clinical success. Self adhesive luting cements, if used correctly, could be an acceptable and quick luting agent for postcementation.

A combination therapy to treat second-degree anti-Ro/La-related congenital heart block. A strategy to avoid stable third-degree heart block?

While mainly based on the use of fluorinated steroids, there is no standard management of anti-Ro/La-related congenital heart block (CHB). This is a report concerning two consecutive cases of anti-Ro/La-related second-degree block treated with betamethasone (4 mg/day), weekly plasmapheresis, and intravenous immunoglobulins (IVIGs; 1 g/kg) administered every 15 days, a therapy that was begun shortly after CHB was detected and continued until delivery. The newborns were also treated with IVIG (1 g/kg) soon after birth and continued fortnightly until the anti-Ro/La antibody levels became undetectable. In both cases second-degree AV block reverted to a stable sinus rhythm with a first-degree atrioventricular (AV) block. Moreover, there was no recurrence of CHB when therapy was suspended, as confirmed by a 29 month and an eight month follow-up, respectively.

Indirect resin composite restorations: evaluation of polymerization of luting agents by means of micro-Raman spectrophotometry

AIM

The degree of conversion of a luting composite cement influences its clinical performance. Aim of the study was to evaluate the degree of conversion of 4 different composite cements by means of micro Raman spectrophotometry.

METHODS

Forty-four cylindrical onlays of different and defined thickness (1, 2, 3, 4 mm) were built using a custom made template. The onlays were made in composite material (Signum, Heraeus; shade A 3,5) and cemented onto a glass plate with different luting materials: dual curing (Variolink II, Calibra) and light curing (Venus flow, Tetric flow). The lamp tip was shielded in order to have the light reach the cement only through the onlay. Samples were divided into 12 groups (N.=3), differing in onlay thickness and luting material. Each sample was examined in three spots by a micro-Raman spectrophotometer (Dilor Hr-Labram). The conversion degree was evaluated by analyzing the variations in intensity of the 1638 cm(-1) aliphatic peak (C=C), characteristic of all Bis-GMA containing materials, related to the invariant 1608 cm(-1) (C-C of the aromatic ring).

RESULTS

All materials show good polymerisation results below 1 mm and 2 mm onlays. Below onlays thicker than 3 mm a constant degree of conversion throughout the surface of samples could not be found: spots with satisfactory polymerisation and spots with insufficient polymerisation were found.

CONCLUSIONS

Onlay thickness has a key role in cement conversion. The thicker the onlay, the less predictable the conversion.

A New Miniaturised Optical System for Chemical Species Spectroscopic Detection Based on a Scanning Integrated Mach–Zehnder Microinterferometer on LiNbO3

Absorption or emission spectroscopy is a powerful tool for detecting chemical compounds, diluted in fluid media: the sensitivity of this technique depends on the optical path of the source radiation, on the spectral window used for analysis and on the spectrometer performances. In this view, we designed and produced the first prototypes of an integrated scanning Fourier Transform Microinterferometer with Mach-Zehnder geometry, by using MEOS (Micro Electro Optical Systems) technologies. The microdevice, obtained by fabricating integrated optical waveguides on LiNbO(3) (LN) crystals, is electrically driven, without moving parts, by exploiting the electrooptical properties of the material. The microdevice operates the Fourier Transform of the input radiation spectral distribution, which can be reconstructed starting from the output signal by means of Fast Fourier Transform (FFT) techniques. The microinterferometer weights few grams, the power consumption is of a few mW and, in principle, can operate in the LN transmittance range (0.36-4.5 microm). The microinterferometer performances were preliminary tested in the (0.4-1.7 microm) spectral window. In the Visible region (0.4-0.7 mum) this microsystem demonstrated a spectral resolution suitable for detecting the characteristic lines of the solar spectrum together with the absorption bands of common gases present in Earth's atmosphere. In a further experiment we tested its performances for gas trace detection by using a calibrated NO(2) optical gas cell, showing the possibility to reveal up to 10 ppb, when suitable optical paths are used. Finally, colorimetry tests for the titration of an organic dye (E131) in alcohol solution are presented.

Measurement of the D(s)+ lifetime

A high statistics measurement of the D(s)+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, D(s)+ --> phi(1020)pi+ and D(s)+ -->K*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5(stat) +/- 5.1(syst) fs using 8961 +/- 105 D(s)+ --> phi(1020)pi+ and 4680 +/- 90 D(s)+ --> K*(892)0K+ decays. This is a significant improvement over the present world average.

A 24-month survey on root canal treatment performed by NiTi engine driven files and warm gutta-percha filling associated system

AIM

Techniques based on NiTi engine driven files for shaping and warm gutta percha for obturing the root canal space are becoming more and more popular. Aim of this paper is to evaluate, by a clinical longitudinal study, the type of sealing and the outcome of endodontic treatment, performed by new Profile and Thermafil technique, in teeth with or without periapical lesions.

METHODS

A total of 122 teeth in 64 patients were consecutively enrolled in the study; 63 teeth had normal periapical status (Group A) and 59 teeth had periapical lesion (Group B). Endodontic therapy was carried out by Profile .04 and Profile .06 NiTi engine driven files and the obturation was made by Thermafil, a filling technique based on heated gutta-percha surrounding a plastic carrier. The type of sealing was evaluated by a score (A best - D worst) and the type of healing was classified as complete, incomplete and failure according to previous published data. The radiographical outcome of the teeth was evaluated by independent observers after 24 months. Data were analysed by non parametric statistics.

RESULTS

At the end of the study, 115 teeth (59 group A and 56 group B) were examined. The quality of sealing was evaluated and some differences were reported comparing different types of teeth. The radiographic outcome was evaluated and 94.9% showed to be completely healed in group A and 48.2% in group B (p=0.0001).

CONCLUSION

The technique based on NiTi engine driven files and Thermafil heated gutta-percha has shown, after 24 months, results which were comparable to other root canal shaping and filling methods.

Dysregulation of CD30+ T cells by leukemia impairs isotype switching in normal B cells

Chronic lymphocytic leukemia (CLL) is associated with impaired immunoglobulin (Ig) class-switching from IgM to IgG and IgA, a defect that leads to recurrent infections. When activated in the presence of leukemic CLL B cells, T cells rapidly up-regulate CD30 through an OX40 ligand and interleukin 4 (IL-4)-dependent mechanism. These leukemia-induced CD30+ T cells inhibit CD40 ligand (CD40L)-mediated S mu-->S gamma and S mu-->S alpha class-switch DNA recombination (CSR) by engaging CD30 ligand (CD30L), a molecule that interferes with the assembly of the CD40-tumor necrosis factor receptor-associated factor (TRAF) complex in nonmalignant IgD+ B cells. In addition, engagement of T cell CD30 by CD30L on neoplastic CLL B cells down-regulates the CD3-induced expression of CD40L. These findings indicate that, in CLL, abnormal CD30-CD30L interaction impairs IgG and IgA production by interfering with the CD40-mediated differentiation of nonmalignant B cells.

Ongoing hypermutation in the Ig V(D)J gene segments and c-myc proto-oncogene of an AIDS lymphoma segregates with neoplastic B cells at different sites: implications for clonal evolution

To investigate the role of somatic Ig hypermutation in the evolution of AIDS-associated B cell lymphomas, we analyzed the Ig V(D)J and c-myc genes expressed by neoplastic B cells in two extranodal sites, testis and orbit, and clonally related cells in the bone marrow. Testis and orbit B cells expressed differentially mutated but collinear V(H)DJ(H), V kappa J kappa and c-myc gene sequences. Shared mutations accounted for 10.2%, 8.4%, and 4.3% of the overall V(H)DJ(H), V kappa J kappa, and c-myc gene sequences. Tumor-site specific V(H)DJ(H), V kappa J kappa, and c-myc mutations were comparable in frequency, and a single point-mutation gave rise to an EcoRI site in the testis c-myc DNA. Both shared and tumor site-specific V(H)DJ(H), V kappa J kappa, and c-myc mutations displayed predominance of transitions over transversions. The "neoplastic" V(H)DJ(H) sequence was expressed by about 10(-5) cells in the bone marrow, and contained two of the three orbital, but none of the testicular V(H)DJ(H) mutations. The nature and distribution of the Ig V(D)J mutations found in the kappa chain suggested a selection by antigen in testis and orbit. Our data suggest that, in AIDS-associated B cell lymphomas, the Ig hypermutation machinery targets V(H)DJ(H), V kappa J kappa, and c-myc genes with comparable efficiency and modalities.

The 24-hour rhythm of blood pressure differs from that of leg hemodynamics in orthotopic heart transplant recipients

BACKGROUND

This study was aimed at investigating whether a circadian rhythm of peripheral resistance exists in patients with orthotopic cardiac transplantation (OCT) and whether it parallels that of blood pressure (BP).

METHODS

BP and leg flow and resistance (plethysmography) were monitored for 24 hours in 13 denervated OCT recipients and 13 control patients with native heart, matched for casual blood pressure.

RESULTS

On the basis of BP trend, control patients showed a BP reduction during sleep, whereas OCT recipients did not. Leg resistance was significantly lower and leg flow significantly higher during sleep than during waking in all patients, and the extent of the nocturnal decrease was similar in the two categories.

CONCLUSIONS

The decrease in leg resistance in patients confined to bed for 24 hours is caused by peripheral mechanisms and does not depend on the autonomic control of the heart. The nocturnal decline in BP depends, on the contrary, on cardiac control and is lost in patients with denervated heart.

B cell receptor engagement and T cell contact induce Bcl-6 somatic hypermutation in human B cells: identity with Ig hypermutation

The human bcl-6 proto-oncogene has been found to be mutated in both neoplastic and normal B cells. We used CL-01 cells, our monoclonal model of germinal center differentiation, and normal human B cells to explore the induction requirements and the modalities of bcl-6 hypermutation. As we have previously shown, CL-01 cells are IgM+ IgD+ and effectively mutate the expressed Ig VHDJH and V lambda J lambda genes and switch to IgG, IgA, and IgE upon B cell receptor engagement and contact with CD4+ T cells through CD40:CD154 and CD80:CD28 coengagement. In this paper we showed that the same stimuli induce somatic hypermutation of bcl-6 in CL-01 and normal IgM+ IgD+ B cells. bcl-6 hypermutation was not accompanied by translocation of this proto-oncogene or hypermutation of the beta-actin gene, and it did mimic Ig hypermutation. It was associated with transcription initiation, in that it targeted the first exon and a 696-bp sequence immediately downstream (approximately 0.6 kb) of the transcription initiation site while sparing further downstream (approximately 2.5 kb) and upstream (approximately 0.1 kb) areas. bcl-6 hypermutation displayed an overall rate of 2.2 x 10-4 changes/base/cell division with characteristic nucleotide preferences and showed strand polarity. These findings show that B cell receptor engagement promotes hypermutation in genes other than Ig, and suggest that cis-regulating elements similar to those of the Ig locus exist in bcl-6.

Engagement of CD153 (CD30 ligand) by CD30+ T cells inhibits class switch DNA recombination and antibody production in human IgD+ IgM+ B cells

CD153 (CD30 ligand) is a member of the TNF ligand/cytokine family expressed on the surface of human B cells. Upon exposure to IL-4, a critical Ig class switch-inducing cytokine, Ag-activated T cells express CD30, the CD153 receptor. The observation that dysregulated IgG, IgA, and/or IgE production is often associated with up-regulation of T cell CD30 prompted us to test the hypothesis that engagement of B cell CD153 by T cell CD30 modulates Ig class switching. In this study, we show that IgD+ IgM+ B cells up-regulate CD153 in the presence of CD154 (CD40 ligand), IL-4, and B cell Ag receptor engagement. In these cells, CD153 engagement by an agonistic anti-CD153 mAb or T cell CD30 inhibits S mu-->Sgamma, Smu-->Salpha, and S mu-->Sepsilon class switch DNA recombination (CSR). This inhibition is associated with decreased TNFR-associated factor-2 binding to CD40, decreased NF-kappaB binding to the CD40-responsive element of the Cgamma3 promoter, decreased Igamma3-Cgamma3 germline gene transcription, and decreased expression of Ku70, Ku80, DNA protein kinase, switch-associated protein-70, and Msh2 CSR-associated transcripts. In addition, CD153 engagement inhibits IgG, IgA, and IgE production, and this effect is associated with reduced levels of B lymphocyte maturation protein-1 transcripts, and increased binding of B cell-specific activation protein to the Ig 3' enhancer. These findings suggest that CD30+ T cells modulate CSR as well as IgG, IgA, and IgE production by inducing reverse signaling through B cell CD153.

Circulating thrombopoietin in reactive conditions behaves like an acute phase reactant

In a recent study we found elevated thrombopoietin (TPO) levels along with a trend toward correlation between serum TPO and some acute phase reactants (APR) in patients with reactive thrombocytosis. In order to further clarify the behaviour of TPO in reactive conditions and to highlight the eventual drawbacks of serum TPO (sTPO) against plasma TPO (pTPO) measurements, serial measurements were made of sTPO, pTPO, interleukin (IL)-6, C-reactive protein (CRP), fibrinogen (FBG), and erythrocyte sedimentation rate (ESR) in 12 patients before and at the 3rd, 7th, 14th, 45th day after hip replacement surgery. Platelet count, sTPO and pTPO were also measured in 30 healthy donors. As expected sTPO were significantly higher than pTPO levels (approximately 30% on average) both in controls (P < 0.00001) and in patients (P < 0.00001). Overall a very good correlation (r = 0.975, P < 0.00001) was found between serum and plasma TPO, whereas no correlation was found between platelet count and the sTPO/pTPO ratio indicating that the difference between sTPO and pTPO is independent from platelet count. So both serum and plasma seem to be suitable samples for TPO measurement if it is taken into account that sTPO are about 30% higher than pTPO. All the parameters we measured in our patients increased during the post-surgery period and returned to the basal value at the 45th day. pTPO levels peaked at the 3rd day, preceding by 11 days the peak in platelet count. A significant correlation was found between pTPO and ESR (P = 0.012), pTPO and FBG (P = 0.044), pTPO and CRP (P = 0.033), and a nearly significant correlation between pTPO and IL-6 (P = 0. 054). These results indicate that, in the course of reactive conditions, an early rise in TPO precedes and probably induces a later increase in platelet count. Moreover, the significant correlations along with the similarity in the chronological variations between TPO and some APRs suggest that TPO behave like an APR.

The evolutionarily conserved sequence upstream of the human Ig heavy chain S gamma 3 region is an inducible promoter: synergistic activation by CD40 ligand and IL-4 via cooperative NF-kappa B and STAT-6 binding sites

Germline C gamma gene transcription is a crucial event in the process that leads to switch DNA recombination to IgG, but its regulation in the human is poorly understood. We took advantage of our monoclonal model of germinal center B cell differentiation, IgM+ IgD+ CL-01 cells, to define the role of the I gamma 3 evolutionarily conserved sequence (ECS) in the germline transcriptional activation of the human C gamma 3 gene. The I gamma 3 ECS lies upstream of the major I gamma 3 transcription initiation site and displays more than 90% identity with the corresponding human I gamma 1, I gamma 2, and I gamma 4 regions. Reporter luciferase gene vectors containing the human gamma 3 ECS were used to transfect CL-01 cells, which have been shown to undergo Smu-->S gamma 3 DNA recombination, upon engagement of CD40 by CD40 ligand (CD40L) and exposure to IL-4. In these transfected CL-01 cells, CD40:CD40L engagement and exposure to IL-4 synergistically induced gamma 3 ECS-dependent luciferase reporter gene activation. Targeted mutational analysis demonstrated that a tandem NF-kappa B/Rel binding motif is critical for the gamma 3 ECS responsiveness to both CD40L and IL-4, while a STAT-6-binding site is additionally required for IL-4 inducibility. Electrophoretic mobility shift assays showed that p50/p65/c-Rel and STAT-6 are effectively induced by CD40L and IL-4, respectively, and bind to specific DNA motifs within the ECS. These partially overlapping CD40L and IL-4 responsive elements are functionally cooperative as the disruption of one of them prevents synergistic promoter activation. Thus, the gamma 3 ECS is an inducible promoter containing cis elements that critically mediate CD40L and IL-4-triggered transcriptional activation of the human C gamma 3 gene.

CD40 engagement triggers switching to IgA1 and IgA2 in human B cells through induction of endogenous TGF-beta: evidence for TGF-beta but not IL-10-dependent direct S mu-->S alpha and sequential S mu-->S gamma, S gamma-->S alpha DNA recombination

IgA are major effectors of antimicrobial defense in the respiratory and digestive tracts. We have analyzed the requirements for and the modalities of switching to IgA using our recently identified monoclonal model of human germinal center differentiation, CL-01 B cells. CL-01 cells bear surface IgM (sIgM) and sIgD and switch to all seven downstream isotypes in response to physiologic stimuli. In these cells, CD40 engagement by CD40 ligand induces production of endogenous TGF-beta and IL-10, expression of germline Ialpha1-Calpha1 and Ialpha2-Calpha2 transcripts, mature VHDJH-Calpha1 and VHDJH-Calpha2 transcripts, and IgA secretion. These events are associated with not only direct Smu-->Salpha, but also sequential Smu-->Sgamma, Sgamma-->Salpha DNA recombination, and are ablated by neutralizing anti-TGF-beta but not IL-10 Ab, and indicating that TGF-beta, not IL-10, is a crucial mediator of the transcriptional activation and recombination of human Calpha1 and Calpha2 genes. Our findings in CL-01 cells were reproduced in freshly isolated naive sIgM+ sIgD+ B lymphocytes. Thus, engagement of CD40, in the absence of other (known) stimuli, is sufficient to effectively induce switching to IgA in human B cells. This is effected by direct and sequential DNA recombination events, which are both dependent upon endogenous TGF-beta secreted by the CD40L-induced B cells.

Lack of intraclonal diversification in Ig heavy and light chain V region genes expressed by CD5+IgM+ chronic lymphocytic leukemia B cells: a multiple time point analysis

To analyze the modalities of clonal expansion of chronic lymphocytic leukemia (CLL) cells, we sequenced at multiple time points the V(D)J genes expressed by CD5+IgM+CLL B cells in three patients. All three V(D)J gene sequences were found to be point mutated. The mutation frequency in the Ig VH (3.96 x 10(-2) and 2.41 x 10(-2) change/bp) and Vkappa and Vlambda (6.67 x 10(-2) and 1.74 x 10(-2) change/bp) genes of two CLLs (1.19 and 1.32, respectively) was similar, and higher than that in the corresponding gene segments of the third CLL (1.69; 3.4 x 10(-3) and 6.67 x 10(-3) change/bp). In all three CLLs, there was no preferential representation of nucleotide changes yielding amino acid replacement (R mutations), nor was there any preferential segregation of R mutations within the Ig V gene complementarity-determining regions. In all three CLLs, the somatic mutations were all identical in multiple Ig VHDJH transcripts at any given time point, and were all conserved at multiple time points throughout a 2-yr period. The lack of concentration of R mutations in the complementarity-determining regions and the lack of intraclonal heterogeneity suggest that Ag may no longer be able to play a significant role in the clonal expansion of these cells. This conclusion would be strengthened further by the germline configuration of the bcl-1 and bcl-2 proto-oncogenes that are translocated in neoplastic B cells that display significant traces of intraclonal diversification and Ag-dependent selection, such as B-prolymphocytic leukemia and low grade follicular non-Hodgkin lymphoma.

Retinal vascular network architecture in low-birth-weight men

BACKGROUND

Low birth weight is associated with hypertension and increased cardiovascular mortality, but the mechanism of this association is not known. Hypertension is accompanied by abnormalities of the microvasculature including rarefaction.

OBJECTIVE

To test the hypothesis that low birth weight is associated with an alteration in microvascular architecture.

DESIGN

A stratified random sample of 100 men aged 64-74 years was selected from a cohort of men whose birth weights were known. They were of relatively high or low birth weight ('high' > or = 3700 g, 'low' < or = 3200 g) and high or low systolic blood pressure (high > or = 160 mmHg, low < or = 140 mmHg).

METHODS

Retinal arteriolar geometry was defined in terms of arteriolar bifurcation angles and junction exponents (a measure of the relative diameters of parent and daughter vessels), measured from photographic diapositives using operator-directed image analysis.

RESULTS

Members of low-birth-weight groups had significantly narrower bifurcation angles than did members of high-birth-weight groups (74 +/- 1 degree versus 78 +/- 1 degree, P= 0.017 by analysis of variance). There was no significant difference between angles in members of groups with high and low blood pressures. Neither birth weight nor blood pressure grouping affected junction exponents.

CONCLUSIONS

Narrower bifurcation angles are associated with increased circulatory energy costs and may be related to a lower than normal microvascular density. Our finding of differences in retinal microvascular architecture might reflect a persistent alteration in vascular architecture as a result of an impairment of foetal development and could provide a mechanistic link between low birth weight and subsequently increased cardiovascular risk.