Study of Cytotoxic Properties of an Experimental Preparation with Features of a Dental Infiltrant

Microinvasive dentistry is based on the treatment of early carious lesions with the use of dental infiltrants. The commercially available Icon dental infiltrant does not contain any bacteriostatic component. An experimental preparation enriched with the missing component was synthesised. The aim of this study was to evaluate the cytotoxicity of the experimental preparation. Mouse fibroblasts of the L-929 lineage were used for the in vitro study. Cell morphology and viability were assessed. In the cytotoxicity analysis, it was shown that the experimental preparation (42.8 ± 10.3) after 24 h at two-fold dilution showed similar cytotoxicity to Icon (42.7 ± 8.8) (p > 0.05), while at four-fold dilution experimental preparation (46.7 ± 3.1), it was less toxic than Icon (34.2 ± 3.1) (p < 0.05). The experimental preparation has the potential to provide an alternative to the Icon commercial preparation. Further research is needed to evaluate the cytotoxicity of the experimental preparation over a longer period of time.     

Electrophysiologic Effects of Endothelin Receptor–A Blockade in Patients with Coronary Artery Disease

Selective endothelin receptor-A antagonists are a promising new treatment in patients with heart failure and/or pulmonary hypertension. Animal studies have suggested that these agents may have additional cardiac electrophysiologic actions, however, no data exist in man. We examined the effects of acute endothelin receptor-A blockade on the sinus node, the atrioventricular node and on the ventricular myocardium, in patients with single-vessel coronary artery disease and preserved left ventricular function. The selective endothelin receptor-A antagonist BQ-123 was administered by the intracoronary route, in order to achieve maximum local cardiac effects.After endothelin receptor-A blockade, QT interval increased from 373 ± 30 msec (mean ± SD) to 395 ± 20 msec (p < 0.01) and QTc interval increased from 394 ± 36 msec to 421 ± 28 msec (p < 0.01). QT-dispersion, calculated from 12-lead ECG, decreased from 40 ± 18 msec to 24 ± 8 msec (p < 0.01) and QTc-dispersion decreased from 44 ± 20 msec to 26 ± 9 msec (p < 0.05). These changes were evident only after infusion in the left, but not in the right coronary artery. No effect was found on the sinus node, the atrioventricular node, or the ventricular effective refractory periods.We conclude that selective endothelin receptor A blockade lengthens ventricular repolarization and decreases its inhomogeneity. Further studies are needed to evaluate possible antiarrhythmic actions of this class of agent.     

Elevated levels of leukotriene B4 and leukotriene E4 in bronchoalveolar lavage fluid from patients with scleroderma lung disease

OBJECTIVE: The leukotrienes are a family of arachidonic acid-derived lipid mediators with proinflammatory and profibrotic properties. The aim of this study was to analyze the role of leukotriene B(4) (LTB(4)) and LTE(4) in the pathogenesis of scleroderma lung disease (SLD). METHODS: Nineteen systemic sclerosis (SSc) patients with SLD, 11 SSc patients without SLD, and 10 healthy controls were studied. Bronchoalveolar lavage (BAL) fluid was obtained during routine bronchoscopy of the right middle lobe in all study subjects. Levels of LTB(4) and LTE(4) were measured using enzyme immunoassay kits. RESULTS: Levels of LTB(4) and LTE(4) were significantly higher in SSc patients with SLD (251 +/- 170 pg/ml and 479 +/- 301 pg/ml, respectively), than those in patients without SLD (114 +/- 86 and 159 +/- 149 pg/ml) and those in normal controls (86 +/- 49 and 110 +/- 67 pg/ml). In the total group of patients with SSc, levels of both leukotrienes correlated positively with the total number of cells in the BAL fluid and correlated negatively with the forced vital capacity. After intravenous pulse therapy with cyclophosphamide in 6 patients, there was a significant reduction in the concentration of LTB(4) (from 380 +/- 196 pg/ml to 155 +/- 123 pg/ml) but no significant difference in the levels of LTE(4) (from 697 +/- 325 pg/ml to 418 +/- 140 pg/ml). CONCLUSION: Our findings show that LTB(4) and LTE(4) levels are elevated in SSc patients with SLD and correlate with parameters of inflammation in the lungs. These results indicate that leukotrienes may contribute to the pathogenesis of SLD and may represent a new therapeutic target.     

Seasonal Changes in Platelet Activity in Pollen-Induced Seasonal Allergic Rhinitis and Asthma

Background. Previously we reported that patients sensitized to pollen-allergens who had seasonal allergic rhinitis and seasonal asthma may show increased plasma levels of platelet activation markers during grass pollen season. Objective. To find out whether the pattern of platelet activity measured by plasma PF-4 level in the same group of patients changed off-season compared with the pollen season as well as in comparison with healthy control subjects. Methods. Off-pollen season, plasma PF-4 level was determined by enzyme-linked immunosorbent assay (ELISA) in 16 grass pollen allergic patients who had seasonal allergic rhinitis and seasonal asthmatic symptoms (none of them had any history of allergic diseases outside the season) and in 29 healthy nonatopic subjects. Results. Plasma PF-4 level in the patients off–pollen season was significantly lower as compared with the season and did not differ significantly as compared to the healthy subjects. Conclusions. This observation taken along with our previous results indicates that patients with seasonal allergic rhinitis and asthma symptoms may have an increased circulating platelet activation, yet this phenomenon disappears in the asymptomatic period of the disease. This might indicate that platelet activation within the systemic circulation is an important factor in the development of seasonal allergic airway inflammation.     

Quantitative ultrasound measurements at hand phalanges in children and adolescents: a longitudinal study

The purpose of this longitudinal study was to characterize changes in quantitative ultrasound (QUS) values over a 1-y period in healthy boys and girls aged 7 to 12 y at baseline and assess the relation between the increase in anthropometric parameters and amplitude dependent speed of sound (Ad-SoS). A total of 269 children completed the study (139 girls and 130 boys). Ultrasound measurements were performed with a DBM Sonic 1200 device (IGEA, Carpi, Italy), which measures the Ad-SoS, m/s. Girls had significantly higher QUS values than boys at first and second measurements (p < 0.01 and p < 0.00001, respectively). Both girls and boys experienced statistically significant increases in Ad-SoS and all anthropometric parameters over a 1-y period. When the studied group was divided into age groups by year, the differences in QUS values between genders were significant only for 11 and 12 y groups at baseline (p < 0.02 and p < 0.01, respectively) and second visit (p < 0.00001 and p < 0.001, respectively). Stepwise regression analyses models with Ad-SoS at baseline and after 1 y as dependent variables showed a strong correlation between Ad-SoS and Tanner stage in girls but not in boys. In the entire survey group, only 21.5% of the boys and 41% of the girls experienced increases in Ad-SoS more than least significant change. This article suggests that QUS measurements allow the investigation of longitudinal changes and give reliable information about skeletal status in a manner similar to other methods.     

Dose‐dependent effects of sildenafil on post‐ischaemic left ventricular function in the rat isolated heart

Objectives Sildenafil may be beneficial during myocardial ischaemia/reperfusion, but this effect may be dose‐dependent, accounting for previous conflicting results. We have explored the effects of two acute and one chronic administration regimen on left ventricular function. Methods The study was conducted on 36 Wistar rats (290 ± 7 g). Sildenafil was administered 30 min before ischaemia at a low (0.7 mg/kg, n= 8) or high (1.4 mg/kg, n= 8)dosage. The chronic treatment arm (n= 8) consisted of two daily injections of sildenafil (0.7 mg/kg) for three weeks. The control group was formed by 12 rats. Ischaemic contracture, post‐ischaemic recovery and hypercontracture were measured in isolated, Langendorff‐perfused preparations. Key findings Ischaemic contracture tended to be lower after high‐dose sildenafil, while remaining unchanged after low‐dose or chronic sildenafil administration. Compared with controls (62.9 ± 2.0% of baseline developed pressure), post‐ischaemic recovery was higher (P= 0.0069) after low dose (75.1 ± 2.4%), unchanged (P= 0.13) after high dose (69.1 ± 2.1%), but lower (P < 0.001) after chronic (42.9 ± 4.5%) sildenafil administration. Compared with controls (71.8 ± 3.9 mmHg), hypercontracture was higher (P= 0.0052) after chronic sildenafil administration (89.5 ± 4.1 mmHg), but similar after acute low dose (65.7 ± 3.3 mmHg, P= 0.33) or high dose (67.1 ± 4.7 mmHg, P= 0.43). Conclusions The effects of sildenafil after ischaemia/reperfusion were strongly dose‐dependent. Beneficial actions on left ventricular function were evident after acute pretreatment with a low dosage, but were lost after doubling the dose. Chronic sildenafil administration deteriorated left ventricular function during ischaemia and reperfusion.     

Baseline platelet size is increased in patients with acute coronary syndromes developing early stent thrombosis and predicts future residual platelet reactivity. A case-control study

Introduction

Pre-procedural predictors of early stent thrombosis (ST) and future response to platelet inhibitors are in demand. We sought to evaluate the impact of baseline platelet indices on the occurrence of early ST and future residual platelet reactivity.

Materials and methods

Hundred and eight patients with acute coronary syndromes (ACS) in whom stents were implanted were included: 36 consecutive ST cases and 72 matched controls. Platelet indices assessed with flow cytometry before stent implantation were retrieved from the department's data base. Residual platelet reactivity specific to aspirin (aspirin reaction units-ARU) and clopidogrel (P2Y12 reaction units-PRU) was assessed prospectively with VerifyNow^® under dual antiplatelet treatment.

Results

Platelet size reported as mean platelet volume (MPV) or proportion of large platelets (LPLT) was significantly higher in ST cases compared with controls (10.4, 95% confidence intervals [CI], 10.1-10.8 vs. 9.7, CI, 9.5-9.9, P = 0.0004 and 35.8, CI, 34.2-37.3 vs. 33.3, CI, 32.2-34.3, P = 0.007, respectively). Dual aspirin and clopidogrel poor-responsiveness was diagnosed significantly more often in ST cases than in controls (19.6% vs. 1.4%, P = 0.004), whereas no difference was observed for single aspirin or clopidogrel poor-responsiveness. A strong correlation was found between MPV and both, ARU (r = 0.66, P < 0.0001) and PRU (r = 0.55, P < 0.0001). Similarly, higher LPLT was associated with higher ARU (r = 0.47, P < 0.0001) and PRU (r = 0.38, P = 0.0001).

Conclusions

Baseline platelet size is increased in patients with ACS developing early ST and correlates with future residual platelet reactivity under aspirin and clopidogrel therapy. Dual but not isolated aspirin or clopidogrel poor-responsiveness appears to be associated with early ST.     

Results of Destandau microendoscopic lumbar discectomy

BACKGROUND AND PURPOSE: Endoscopic methods are increasingly used in spine surgery, including the operative treatment of lumbar disc herniation. In this study we present a clinical series of 45 patients with lumbar disc prolapse who were operated on endoscopically with ENDOSPINE instrumentation (Karl STORZ GmbH and Co. KG), using the Destandau technique. MATERIAL AND METHODS: Between 2005 and 2006 endoscopy was used in 76 operations of lumbar disc prolapse and in 45 patients the entire procedure was performed endoscopically. All procedures were carried out from a posterior approach using a 4 mm Hopkins 0 degrees -telescope placed in the working insert equipped with channels for suction tube, operative instruments and nerve root retractor. The outcome was assessed using modified McNab criteria both directly and three months (in 35 patients) postoperatively. RESULTS: Good to excellent outcome was achieved in 89% of patients, which is consistent with results reported by experienced authors and comparable with results of "classic" microdiscectomy. Five patients reported no improvement and 3 of them were subsequently reoperated using the open surgical approach. In 3 patients the dural sac was lacerated but none of the tears exceed a few millimetres in length and they were not associated with neural injury. They were easily repaired endoscopically with a patch of "Tachocomb" tissue sealant. CONCLUSIONS: Destandau microendoscopic discectomy (MED) is a novel, safe and effective method that minimizes invasiveness of the surgical approach. Results achieved with this method are comparable to those achieved with "classic" microdiscectomy.