The scar: the wind in the perfect storm-insights into the mysterious living tissue originating ventricular arrhythmias.

BACKGROUND: Arrhythmic death is very common among patients with structural heart disease, and it is estimated that in European countries, 1 per 1000 inhabitants yearly dies for sudden cardiac death (SCD), mainly as a result of ventricular arrhythmias (VA). The scar is the result of cardiac remodelling process that occurs in several cardiomyopathies, both ischemic and non-ischemic, and is considered the perfect substrate for re-entrant and non-re-entrant arrhythmias. METHODS: Our aim was to review published evidence on the histological and electrophysiological properties of myocardial scar and to review the central role of cardiac magnetic resonance (CMR) in assessing ventricular arrhythmias substrate and its potential implication in risk stratification of SCD. RESULTS: Scarring process affects both structural and electrical myocardial properties and paves the background for enhanced arrhythmogenicity. Non-uniform anisotropic conduction, gap junctions remodelling, source to sink mismatch and refractoriness dispersion are some of the underlining mechanisms contributing to arrhythmic potential of the scar. All these mechanisms lead to the initiation and maintenance of VA. CMR has a crucial role in the evaluation of patients suffering from VA, as it is considered the gold standard imaging test for scar characterization. Mounting evidences support the use of CMR not only for the definition of gross scar features, as size, localization and transmurality, but also for the identification of possible conducting channels suitable of discrete ablation. Moreover, several studies call out the CMR-based scar characterization as a stratification tool useful in selecting patients at risk of SCD and amenable to implantable cardioverter-defibrillator (ICD) implantation. CONCLUSIONS: Scar represents the substrate of ventricular arrhythmias. CMR, defining scar presence and its features, may be a useful tool for guiding ablation procedures and for identifying patients at risk of SCD amenable to ICD therapy.

Sella turcica and craniofacial morphology in patients with palatally displaced canines: a retrospective study.

BACKGROUND: The aim of the study was to evaluate the sella and craniofacial morphological features in growing patients with palatally displaced canines compared to controls. MATERIALS AND METHODS: Twenty-two subjects with palatally displaced canines were retrospectively selected and compared to 22 controls matched for age and gender. Lateral cephalograms were collected and sagittal and vertical cephalometric variables were measured, together with sella interclinoid distance, sella depth, and sella diameter. The independent samples T-test or Mann-Whitney U-test were used to compare all the variables between the two groups. A Pearson correlation was computed for the craniofacial and sella variables that differed significantly (p < 0.05) between the groups. RESULTS: Patients with palatally displaced canines showed a smaller interclinoid distance and a greater SNA angle than control subjects. The interclinoid distance and the SNA angle were negatively correlated (-0.52, p = 0.017) in the experimental group. CONCLUSIONS: Growing patients with palatally displaced canines had smaller sella interclinoid distances and a greater SNA angle than control subjects.

Differentiation of steroidogenic cells in the developing adrenal gland of Testudo hermanni Gmelin, 1789 (chelonian reptiles).

The aim of this study was to investigate the development and differentiation of steroidogenic cells in the embryonic adrenal gland of Testudo hermanni using histological, histochemical, immunohistochemical and ultrastructural methods. The 26 developmental stages were divided into three periods: early (stages 1-18, up to 20 days of incubation), intermediate (stages 19-22, incubation days 21-35) and advanced (stages 23-26, from incubation day 36 to hatching). A small presumptive bud of steroidogenic cells was visible at the end of the early period, protruding into the coelom from the lateral wall of intermediate mesoderm. Ultrastructural characteristics suggested that young and scarcely differentiated cells could already be able to perform steroidogenic activity: lipid droplets, large amount of SER and RER, small rounded mitochondria with variously shaped cristae and dense matrix. The cell membrane showed microvilli and coated pits. During the intermediate period, the interrenal bud deepened into the haemopoietic tissue, close to the mesonephros and the newly formed metanephros. The ultrastructural, immunohistochemical and immunocytochemical characteristics pointed to enhanced steroidogenic activity. The contact with both kidney types (mesonephros and metanephros) continued in the advanced period, and chromaffin cells were also extensively mixed with steroidogenic cells. This is a peculiar feature of chelonian adrenal gland, in comparison with that of other reptiles. The variable cytological characteristics of embryonic steroidogenic cells in the advanced period suggest a four-phase cycle of steroidogenic activity.

Immunosuppressive therapy in virus-negative inflammatory cardiomyopathy.

While there is general agreement on the favorable impact of immunosuppression in eosinophilic, granulomatous, giant cell and lymphocytic myocarditis and with inflammatory myocardial disease associated with connective tissue disorders or with rejection of a transplanted heart, its therapeutic role in the treatment of lymphocytic inflammatory cardiomyopathy (ICM) is still debated. Previous retrospective studies reported a relevant (≥ 10% left ventricular ejection fraction) clinical benefit in 90% of patients with virus-negative ICM and no cardiac impairment in 85% of patients with virus-positive ICM following immunosuppression. Some studies identified cardiomyocyte HLA up-regulation as an additional indicator of ICM susceptibility to immunosuppressive therapy. Recently in a single-center randomized prospective double-blind trial using a combination of prednisone (1 mg/kg per day for 4 weeks followed by 0.33 mg/kg per day for 5 months) and azathioprine (2 mg/kg per day for 6 months) in addition to supportive treatment in 85 virus-negative ICM patients, a significant improvement of left ventricular ejection fraction and a significant reduction of left ventricular dimensions in 88% of 43 treated patients was reported when compared to 42 patients receiving placebo who showed a cardiac impairment initially in 83% of cases (TIMIC study). These data confirm the efficacy of immunosuppression in virus-negative ICM. The lack of response in 12% of cases suggests that the missing response might be due to the presence of viruses which were not screened for or to mechanisms of damage and inflammation not susceptible to immunosuppression. The recovery of cardiac function in responders to immunosuppression was associated with the inhibition of cardiomyocyte death, an increase of cell proliferation and with newly synthesized contractile material.

Morphology and ultrastructure of the pronephros of Testudo hermanni Gmelin, 1789 (chelonian reptiles).

The aim of this study was to investigate the morphology and ultrastructure of the pronephros of Testudo hermanni as observed in the earlier part of its development. This paired structure appears during renal ontogenesis and originates from the first somites localised in the cephalic part of the embryo. The first pronephric evidence is noted at stage 12. The kidney is composed of large glomeruli that are devoid of a capsule and protrude into the coelomic cavity. A ciliated nephrostome provides access to short renal tubules, lined with a well-developed brush border. Two nephric ducts on the lateral sides of the embryo are connected to the tubules. The cytological characteristics of the pronephric structure suggest that it might be functional, at least in the first part of development. The pronephros of Testudo hermanni regresses after a short time around stage 18, while the mesonephros is already well differentiated. Its plesiomorphic characteristics, similar to those observed in amphibians, might be related to the phyletic position of chelonians within the reptiles.

Effect of the Enveloppe Linguale Nocturne on atypical swallowing: surface electromyography and computerised postural test evaluation.

AIM: Swallowing is a neuromuscular mechanism regulated by many nervous reflex arcs. Persistence of child swallowing at the end of dental eruption is called atypical swallowing (AS). This condition is related to a dysfunction of vertical maxillary growth called open bite. The authors treated this malocclusion with the Enveloppe Linguale Nocturne (ELN), or tongue positioner, created by Dr. Bonnet. The aim of this work is to evaluate the effect of ELN on swallowing and the postural variation obtained by its use. MATERIALS AND METHODS: Seven patients affected by AS were evaluated. Surface Electromyography (sEMG) testing was performed on each patient with different tongue positions, and swallowing was evaluated with and without the ELN. A surface Electromyograph (Biopack) with 8 channels was used (4 channels for the right muscles and 4 for the left) on 4 groups of muscles: temporals, masseters (MM), submental (SUB) and sternocleidmastoids. On each patient a postural test using a computerised Postural test (Lizard) was also performed. Statistical analysis was done using the Graph pad Instat 3 both for sEMG activity and for computerised postural analysis. RESULTS: All seven subjects had different results in the sEMG and footrest tests. The sEMG test results indicated that muscle activation and swallowing duration varied greatly with the use of ELN, with a reduction of time of swallow act (p = 0.002) and variation in contraction of muscles. Mean MM activation was higher without ELN than in tests performed with the appliance (p = 0.002). Mean SUB activation was higher with than without ELN (p = 0.0033). ELN has a therapeutic effect on posture too. Computerised postural test without device showed in all patients an alteration of barycentre as well as an elevated oscillatory record (A mmq; V mms). With ELN footrest kilogram difference (p = 0.0110), Oscillatory Area (P = 0.0102) and velocity of oscillation (P = 0.0102) presented a great reduction in respect to patients record without ELN. CONCLUSION: With ELN the tongue reaches the physiologic position during the swallowing and it is possible to have a low dental contact without tongue interference. ELN has no dental retention or contact. For this reason sEMG swallowing test shows that ELN induces a Mm activation reduction compared to swallowing test without ELN (P = 0.002) and an increase of SUB activation (P = 0.0033). In the same way with ELN there is a significant reduction of time of swallowing (c.f. oral phase) (P = 0.002). Patients with ELN changed their posture with a complete modification of barycentre (Footrest unbalancing kg P = 0.0110), oscillatory movement area (Footrest Area difference P = 0.0102), and oscillatory Velocity (Footrest Velocity oscillation difference P = 0.0102). These data suggest that this appliance has a function in the rehabilitation of atypical swallowing. ELN produces a physiologic neuromuscular mechanism that induces the correction of tongue position.

Immunohistochemical localization of oestrogen receptor alpha in the various cell categories of chick embryo ovary.

The immunohistochemical (IHC) localization of oestrogen receptor alpha (ERα) was studied in the developing left ovary of 14.5-day-old chick embryos. The study was focused in particular on distinguishing in cortex and medulla the different cell categories that proved positive to the reaction, in order to gain further understanding of gonadal cell interactions during ovarian development. Immunostained cells were observed in both the cortex and medulla, but the reactivity for ERα was discontinuous, probably due to variable cell requirements. In the cortex, positivity was observed in cells of the ovarian surface epithelium, in germ cells and in prefollicular cells. In the medulla, positivity was found in the following cell categories: interstitial cells, poorly differentiated somatic cord cells, including those delimiting lacunae, germ cells and their accompanying cells of epithelial origin. Furthermore, the IHC results showed that the intracellular localization of the antigen was cytoplasmic, nuclear, or both. The significance of ERα presence and intracellular localization was discussed in relation and as supplementary to previous research by various Authors. In particular, as regards the unusual cytoplasmic immunoreactivity, a gradual shift of ERα localization from cytoplasmic to nuclear during the embryonic period is suggested.

Clinical and computerized evaluation in study of temporo-mandibular joint intracapsular disease.

AIM: In this work authors show a diagnostic criteria in study of TMID: neuro occlusal clinical evaluation (NOE), T-Scan 2 system and surface electromyography (sEMG). METHODS: Nine patients 25-30 years old with TMID problem and 9 healthy group control have been selected and examined. On each patients it has been performed NOE, T-Scan and sEMG test. NOE has been calculated on each patient photos lateral mandibular excursion angle called: masticatory functional angle (AFM). T-Scan System is a computerized occlusal analyzer that provide in-depth understanding of the overall balance of the occlusion. At the same time of T-Scan record sEMG tests, in resting position and in maximum clench, have been performed. RESULTS: In healthy control there were no AFM difference. In no healthy group there were difference between the two AFM greater than 6 degrees. T-Scan COF showed how in healthy group control there was never a difference of COF greater than 5%. In no healthy group the difference were greater than 5% P<0.05. T-scan showed difference of time force in maximum intercuspidation (MIFT) in healthy respect TMID patients. In healthy patients MIFT was higher than TMID patients P<0.05. sEMG test showed in non healthy group a great asymmetrical activation of masseter (MM). MM activation were greater on side affected by joint sound than the balance side P<0.001. sEMG show how in TMID patients maximum masseter activation is always lower than maximum masseter activation of healthy subjects P<0.001. CONCLUSION: Neuro occlusal clinical evaluation (NOE) in TMID patients is supported by instrumental evaluation.

Impaired left ventricular energy metabolism in patients with hypertrophic cardiomyopathy is related to the extension of fibrosis at delayed gadolinium-enhanced magnetic resonance imaging.

OBJECTIVE: Areas of intramyocardial late enhancement (LE) at delayed enhanced magnetic resonance imaging (DE-MRI) and reduction of myocardial phosphocreatine (PCr)/ATP-ratio at phosphorus magnetic resonance spectroscopy ((31)P-MRS) are both reported in hypertrophic cardiomyopathy (HCM) and indicate areas of increased interstitial myocardial space with fibrosis and impairment of myocardial energy metabolism, respectively. We sought to ascertain whether in HCM patients the abnormal features of left ventricular (LV) interstitial space revealed by DE-MRI correlated with impaired LV energy metabolism shown at (31)P-MRS. METHODS: 19 patients with HCM proved by histological analysis of multiple endomyocardial biopsies and with normal coronary arteries, underwent cardiac MRI including DE-MRI and (31)P-MRS. DE-MRI for detection and quantification of late enhancement (LE) and (31)P-MRS to assess the myocardial PCr/ATP-ratio were performed by means of a 1.5-T magnet. 19 healthy subjects, matched for gender and age were studied by (31)P-MRS as control group. RESULTS: LE areas in the LV wall were found in 17 out of 19 patients with an extension ranging from 0.8% to 19.5% of the LV-mass (mean value 7.6% (SD 5.6%). The PCr/ATP-ratio was lower in HCM patients than in control subjects (2.18 (0.41) vs 2.41 (0.30); p<0.05). LE% and PCr/ATP-ratio were inversely related (R = -0.57; p<0.05) and LE% was the stronger predictor of PCr/ATP-ratio by multivariate analysis. CONCLUSIONS: This study demonstrated that the known alteration of the PCr/ATP-ratio observed in HCM patients is correlated with the presence of fibrotic areas in the myocardium of the left ventricle.

Alterations of energy metabolism and glutathione levels of HL-60 cells induced by methacrylates present in composite resins.

OBJECTIVES: Methacrylic compounds such as 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA) and bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate (Bis-GMA) are largely present in auto- or photopolymerizable composite resins. Since the polymerization reaction is never complete, these molecules are released into the oral cavity tissues and biological fluids where they could cause local adverse effects. The aim of this work was to verify the hypothesis that the biological effects of HEMA, TEGDMA and Bis-GMA - at a non-cytotoxic concentration - depend on the interaction with mitochondria and exert consequent alterations of energy metabolism, GSH levels and the related pathways in human promyelocytic cell line (HL-60). METHODS: The biological effects of methacrylic monomers were determined by analyzing the following parameters: GSH concentration, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione reductase (GR) activity, oxygen and glucose consumption and lactate production along with cell differentiation and proliferation. RESULTS: All monomers induced both cellular differentiation and decrease in oxygen consumption. Cells treated with TEGDMA and Bis-GMA showed a significant enhancement of glucose consumption and lactate production. TEGDMA and HEMA induced GSH depletion stimulating G6PDH and GR activity. CONCLUSIONS: All the monomers under study affect the metabolism of HL-60 cells and show differentiating activity. Since alterations in cellular metabolism occurred at compound concentrations well below cytotoxic levels, the changes in energy metabolism and glutathione redox balance could be considered as potential mechanisms for inducing clinical and sub-clinical adverse effects and thus providing useful parameters when testing biocompatibility of dental materials.

In vitro comparison of the cytotoxicity of two orthodontic composite resins.

AIM: Several studies have reported that dental resin-based materials release substances with biological activity: for this reason in this study we evaluated the in vitro cytopathic effects of a self-curing and a light-curing orthodontic composite resins by a cytotoxicity test. METHODS: The cytotoxic potential of specimens, prepared according to the manufacturer instructions, was evaluated using the thiazolyl blue tetrazolium bromide (MTT) assay on the mouse fibroblast cell line (3T3 Swiss) with 2 cells-material contact systems: the 24 h extracts method and the indirect toxicity method. RESULTS: The results obtained in this study elicit a close agreement between the 2 procedures; from the data obtained in the reported experimental conditions, it was possible to establish that the examined chemical-cured material is more cytotoxic than the light-cured one. CONCLUSIONS: From a clinical point of view, the photo-polymerizable resins are undoubtedly more useful in the daily practice, because of the larger precision of the bonding obtainable by the greater period available for setting the brackets before their lock. The results obtained in this study, even considering the limits of the in vitro tests, represent a further favourable feature of the light-curing composite resins. However, further investigations about the influence of polymerization methods of the materials on the biological effects are suggested to contribute to the determination of the best clinical operative conditions.

Immunosuppressive treatment of chronic non-viral myocarditis.

Inflammatory cardiomyopathy defined as myocarditis associated with cardiac dysfunction, represents a main cause of heart failure. Despite the improvement of diagnostic techniques, a specific standardized treatment of myocarditis is not yet available. The immunohistochemical detection of myocardial HLA up-regulation has been demonstrated useful in the identification of a sub-group of autoimmune inflammatory dilated cardiomyopathy (DCM) in part susceptible to immunosuppression. Recently, in a retrospective study, we defined the virologic and immunologic profile of responders and non-responders to immunosuppressive therapy of active lymphocytic myocarditis and chronic heart failure in patients who had failed to benefit from conventional supportive treatment. Non-responders were characterized by high prevalence (85%) of viral genomes in the myocardium and no detectable cardiac autoantibodies in the serum. Conversely, 90% of responders were positive for autoantibodies, while only 3 (15%) of them presented viral particles at PCR analysis on frozen endomyocardial tissue. With regard to the type of virus involved in non-responders, enterovirus, adenovirus, or their combination was associated with the worst clinical outcome. Hepatitis C virus (HCV) was the only viral agent of our series associated with detectable cardiac autoantibodies, suggesting a relevant immunomediated mechanism of damage by HCV and explaining the relief of myocardial inflammation after immunosuppressive treatment. The assessment of virologic and immunologic features of patients with biopsy-proven inflammatory cardiomyopathy may allow us to identify a specific treatment leading to recovery of cardiac function.

Transanal rectocele repair using EndoGIA: short-term results of a prospective study.

BACKGROUND: The surgical treatment of symptomatic rectocele may be carried out by means of endorectal techniques. Results depend on a correct etiologic evaluation of associated diseases. We report the preliminary results of an original endorectal technique applied to selected patients. METHODS: Fifteen women (median age, 57 years; range, 38-73 years) underwent transanal rectocele resection by a 60 mm endo-GIA and subsequent plication of the anterior rectal wall. All patients had a primary isolated anterior medium sublevator rectocele with obstructed defecation symptoms. They were prospectively evaluated by questionnaire, defecation diary, clinical examination, defecography and anal manometry were performed preoperatively. All patients had less than three weekly bowel motions. Postoperative follow-up included clinical examination and symptoms questionnaire with defecation diary at one week, one month and three months; defecography was performed at three months. RESULTS: The time required to repair the rectocele was approximately 20 min. The mean time spent in hospital after the operation was 37 h. Postoperative pain was low or moderate in all cases, one patient had acute urinary retention, 11 had minor rectal bleeding, and 5 had temporary urgency. Abolition of excessive straining, feeling of incomplete evacuation, enemas and self-digitations was achieved in all patients; stool frequency at three months was 7 per week in 10 patients, 5-6 per week in 3 patients and 4-6 in 2 patients (p<0.001). Defecography at three months did not show any rectocele recurrence. CONCLUSIONS: Transanal rectocele repair with linear stapler applied in selected patients is safe and easy to perform. Short-term results are safisfactory. Complete investigations of impaired defecation and selection of patients are needed to achieve satisfactory results.

[Biomechanical aspects of the space gaining therapy according to Cetlin]. / Aspetti biomeccanici nella terapia di recupero di spazio secondo Cetlin.

The non extraction technique according to N. Cetlin for the treatment of crowded and protrusive dentitions in class I and class II malocclusions is assessed. The intent of this article is to outline the approach to non extraction treatment with the following major clinical objectives: 1) space gaining in both maxillary and mandibular arches; 2) anchorage preservation throughout treatment and 3) intrusion of the maxillary incisors.

Retinol-induced apoptosis in larval pancreas of Bufo bufo.

Tadpoles of Bufo bufo at the end of premetamorphosis were exposed to the action of retinol diluted in the rearing water at two concentrations: 20 and 40 microM, for 48 h. Assuming that retinol causes growth suppression by cell death induction, the TUNEL reaction for the detection of apoptotic cells was performed on paraffin sections of pancreas. The results showed that retinol induced a significant dose-dependent increase of number of apoptotic cells with respect to controls, in which apoptosis was scarce. Electron microscopic observations of treated specimens showed that the effects of retinol mostly occurred on exocrine cells: condensed crescent-shaped nuclear chromatin, dark cytoplasm with long projections; conversely, mitochondria and endoplasmic reticulum appeared unaffected.

Programmed cell death in the pancreas of Bufo bufo during metamorphosis.

Programmed cell death or apoptosis occurred in anuran amphibian larval pancreas as a remodelling agent, and was responsible for the reduction of the gland volume during metamorphosis. Apoptotic cells were recognisable by their morphological characteristics and could be immunocytochemically detected by means of the TUNEL reaction, which evidenced nuclear DNA fragmentation. During the last stages of prometamorphosis, that is in the period of hindlimb differentiation, only a few TUNEL positive cells occurred, whereas they increased at the beginning of metamorphic climax, that is at forelimb emergence and during tail regression. Under the electron microscope, the typical morphological characteristics of apoptosis were observed: decrease in size, and the presence of wide intercellular spaces and nuclei with dense chromatin masses arranged in crescents. The fragmentation of these cells produced the so-called 'apoptotic bodies': portions of cytoplasm lined by a membrane, containing nuclear fragments and cytoplasmic organites. Dead cell elimination is hypothesised to occur by phagocytic ingestion.

Inflammatory left ventricular microaneurysms as a cause of apparently idiopathic ventricular tachyarrhythmias.

BACKGROUND: We sought to investigate the arrhythmogenic role, incidence, treatment, and prognosis of inflammatory left ventricular (LV) microaneurysms in patients with apparently idiopathic ventricular tachyarrhythmias. Methods and Results-- We studied 156 consecutive patients (71 men, 85 women; mean age, 44.1+/-11.8 years) with severe ventricular arrhythmias and normal 2D echo cardiac parameters by coronary and ventricular angiography, biventricular endomyocardial biopsy, and electrophysiological study. Polymerase chain reaction was used to detect genomic sequences of enterovirus, adenovirus, Epstein Barr virus, cytomegalovirus, herpes simplex viruses, influenza A and B viruses, and hepatitis C virus in frozen endomyocardial samples. Of these patients, 15 (9.6%) showed angiographic evidence of single or multiple LV microaneurysms. All 15 patients had recurrent episodes of ventricular tachycardia with right bundle-branch block morphology, and the arrhythmias originated within or close to the aneurysms in those patients (n=6) undergoing ventricular mapping. A lymphocytic myocarditis was observed in LV biopsies of all patients and in the right ventricles of 3 patients. Polymerase chain reaction analysis was performed in 12 and viral genomes were found in 5 (42%): hepatitis C virus in 2, enterovirus in 2, and influenza virus A in 1. The patients were treated with antiarrhythmics, and cardiac function was preserved for the next 47+/-39.5 months of follow-up. No major clinical event was registered, and arrhythmias were successfully treated by antiarrhythmics. CONCLUSIONS: Inflammatory LV microaneurysms, often of viral origin, are a consistent cause of apparently idiopathic ventricular arrhythmias. Their prognosis so far has been benign, and aggressive therapeutic strategies have been unnecessary.