Impact of oxidative stress on lung diseases

Reactive oxygen species (ROS) are products of normal cellular metabolism and are known to act as second messengers. Under physiological conditions, ROS participate in maintenance of cellular 'redox homeostasis' in order to protect cells against oxidative stress through various redox-regulatory mechanisms. Overproduction of ROS, most frequently due to excessive stimulation of either reduced nicotinamide adenine dinucleotide phosphate by cytokines or the mitochondrial electron transport chain and xanthine oxidase, results in oxidative stress. Oxidative stress is a deleterious process that leads to lung damage and consequently to various disease states. Knowledge of the mechanisms of ROS regulation could lead to the pharmacological manipulation of antioxidants in lung inflammation and injury.     

The outcome of cementless total hip arthroplasty in haemophilic hip arthropathy

Summary.  Total hip arthroplasty (THA) in haemophilic arthropathy is reported to be less successful than in non-haemophilic indications. Although preliminary results are encouraging, the survival and functional outcome of cementless THA in haemophilia are not known. The aim of this study was to analyse mid-term results of cementless THA in haemophilia. Twenty-seven consecutive cementless THAs with 23 patients performed between June 1995 and June 2003 were reviewed. Mean age at time of operation was 36 years and mean follow-up period was 92 months (range, 60–156). Radiographic assessment was done for fixation of components, loosening, osteolysis, wear and bone responses around the implants. The factor requirements, amount of transfusion and complications associated with bleeding were studied. The mean preoperative Harris hip score changed from 57 to 95.9 at the latest follow-up. The survival at mean follow-up was 95.2%. One patient with osteolysis around acetabular cup was re-operated with bone-grafting and change of polyethylene liner. One loose cup was revised with a cemented cup. All other components were deemed stable at the latest follow-up. A standardized management protocol and dedicated team approach comprising of haematologist, physicians, physical therapist, nurses and coordinators is needed for excellent results. The present retrospective study shows that the functional results of cementless THA in haemophilia are satisfactory as it happens in osteoarthritic patients according to the current literature, mainly the younger. Thus, taking into account that the majority of haemophilia patients requiring a THA are relatively young, cementless THA is currently recommended.     

Skin barrier function recovery after diamond microdermabrasion

Microdermabrasion is a popular method for facial rejuvenation and is performed worldwide. Despite its extensive usage, there are few publications on skin barrier change after microdermabrasion and none concerning diamond microdermabrasion. Our object was to see changes in transepidermal water loss (TEWL), hydration and erythema of the face following diamond microdermabrasion. Twenty-eight patients were included in this spilt face study. TEWL, stratum corneum hydration and the degree of erythema were measured from the right and left sides of the face (forehead and cheek) at baseline. One side of the face was treated with diamond microdermabrasion and the other side was left untreated. Measurements were taken right after the procedure and repeated at set time intervals. Diamond microdermabrasion was associated with a statistically significant increase in TEWL immediately after the procedure and at 24 h. However, on day 2, levels of TEWL were back to baseline. An increase in hydration and erythema was observed right after microdermabrasion, but both returned to baseline on day 1. The results show that skin barrier function of the forehead and cheek recovers within 2 days of diamond microdermabrasion. Diamond microdermabrasion performed on a weekly basis, as presently done, is expected to allow sufficient time for the damaged skin to recover its barrier function in most parts of the face.     

Antiarrhythmic Effects of VVI Pacing at Physiologic Rates: A Crossover Controlled Evaluation

Ventricular pacing can prevent bradycardia-dependent ventricular ectopic activity (VEA) and is helpful in some cases of drug-refractory venfricuiar tachycardia (VT). This study is a prospective evaluation of VVI pacing for the control of VEA not related to underlying bradycardia, drug side-effects, or prolonged QT interval syndromes. Twenty-nine patients undergoing serial electrophysioiogic-pharmacoiogic testing for VT control were studied. Eighteen of these patients (12 men; meon age = 60.1) both completed ihe protocol and had sufficient VEA for analysis. Coronary disease was present in 13 patients, cardiomyopathy in two patients, and one patient each had myocarditis, mitral valve prolapse, and no structural heart disease. Ambulatory (Holter) monitor recordings during VVI pacing were compared with control recordings made in the absence of pacing, VVI pacing rates were 10–15 bpm above the mean daily heart rate (mean = 92 bpm; range = 63–110). Hours from paced recordings were paired with hours from control (prior to analysis) according to time of day to reduce the effects of spontaneous variability in VEA frequency. Overall, VVI pacing reduced ventricular premature complexes (VPGs) 26% from 331 to 245/hour (p < 0.001). During pacing, couplets (pairs, successive VPGs) were reduced from 6.95 to 1.03/hour (p < 0.000001) and VT (≥3 successive VPCs) from 0.89 to 0.045 episodes/hour (p < 0.003). Of 13 patients with couplets, 11 had ≥50% reduction and five had ≥90% reduction. Baseline VT was eliminated in four out of nine patients during pacing. Pacing did not increase VEA significantly in any patient. In this group of patients, reduction of VEA by VVI pacing was significant and was comparable to pharmacologic interventions. Higher forms of VEA fcouplets and VT) appeared to respond better than single VPCs. Further studies may define patients with VEA who can benefit from pacing     

Recombinant human epidermal growth factor treatment of radiation-induced severe oral mucositis in patients with head and neck malignancies

Mucositis of the oral cavity and pharynx is a major dose-limiting factor in the application of radiotherapy (RT) to patients with head and neck cancer. Therefore, we evaluated the wound healing effect of human recombinant epidermal growth factor (rhEGF) in head and neck cancer and lymphoma patients with irradiation (with or without combined chemotherapy-induced oral mucositis). Patients at Asan Medical Center who had undergone definitive RT of the head and neck region with or without combined chemotherapy and who had developed severe oral mucositis (higher than the Radiation Therapy Oncology Group grade 3) were treated with topical rhEGF twice daily for 7 days. The evaluation of response with regard to oral mucositis was performed 1 week later. Of the 11 treated patients, three had nasopharyngeal carcinoma, three had carcinoma of the oropharynx, two had carcinoma of the oral cavity, one had carcinoma of the hypopharynx and two had lymphoma of the head and neck. Six patients received RT only, and five patients received concurrent chemoradiotherapy. All patients showed improvements in their oral mucositis after topical treatment with rhEGF in that the Radiation Therapy Oncology Group grade was significantly decreased ( P  = 0.0000). This finding suggests that rhEGF is effective and safe for the treatment of radiation-induced mucositis. Further studies are needed to determine the optimal dosage and fractionation schedule.     

In vivo comparison of force development with various materials of implant-supported prostheses

Summary  The purpose of this study was to measure axial loading, generating bending moments on fibre reinforced composite (FRC) implant prostheses using strain-gauged customized abutment in vivo . Bending moments of conventional implant prosthetic material were also measured and the data were compared with those for FRC. Three unit fixed dental prostheses were made for two dental implant fixtures, which had been functioning properly for more than one year using Tescera^TM ATL^TM, porcelain fused to metal and gold as occlusal material. Three patients participated in this study; two patients had two implants on one side of the mandible and one had two implants on both sides of the mandible. Five sets of fixed dental prostheses were fabricated for each material and these were cemented with Temp-bond^® on strain-gauged customized abutments, which were screwed into the underlying implant fixtures. Axial loadings and bending moments were measured when a patient bit the experimental fixed dental prosthesis. anova and the Tukey HSD test (α = 0·05) were used for statistical analysis. There were no significant differences in normalized bending moments among the three different implant prosthetic materials. Within the limitations of this study, Tescera^TM ATL^TM generated bending moments similar to conventional implant prosthetic materials such as gold and porcelain.     

Effects of Electrocautery on Transvenous Lead Insulation Materials

Introduction: Insulation defects are a leading cause of transvenous lead failure. The purpose of this study was to determine the effects of electrocautery on transvenous lead insulation materials.
Methods: A preparation was done to simulate dissection of a transvenous lead from tissues. Radiofrequency energy was delivered using a standard cautery blade at outputs of 10, 20, and 30 W, for 3 and 6 seconds, using parallel and perpendicular blade orientations on leads with outermost insulations of silicone rubber, polyurethane, and silicone–polyurethane copolymer. Damage to each lead segment was classified after visual and microscopic analysis.
Results: Significant insulation damage occurred to almost all polyurethane leads. Full insulation breaches were observed with 30 W regardless of application duration with a parallel direction and with all power outputs with a perpendicular direction. Thermal insulation damage to copolymer insulation was similar to that of the polyurethane leads. In contrast, there was no thermal damage to silicone leads, regardless of the power output and duration of power delivery. However, mechanical insulation damage was observed to all silicone leads when at least 20 W was applied in a direction perpendicular to the lead.
Conclusions: Polyurethane (PU55D) and copolymer materials have low thermal stability and are highly susceptible to thermal damage during cautery. Implanting physicians should be aware of the lead insulation materials being used during implant procedures and their properties. The use of direct contact cautery on transvenous leads should be minimized to avoid damage to the lead, especially on leads with polyurethane or copolymer outer insulations.     

Pigmented nail with atypical melanocytic hyperplasia

We report two cases showing black discoloration of the thumb nail which were histologically found to be acral lentiginous melanoma (ALM) in situ. A pigmented subungual lesion is more frequently malignant than benign and it is generally believed that diagnosis of subungual melanoma during the radial-growth phase is very difficult. Our cases are particularly interesting because atypical melanocytic hyperplasia was confined to the epidermis despite the lesion being present for a long time.     

Nonsurgical Electrical Ablation of Tachycardias: Importance of Prior in Vitro Testing of Catheter Leads

Nonsurgical electrical ablation of tachycardia pathways or foci has been attempted or carried out using a variety of temporary pacing catheter leads. To determine the ability of such leads to withstand the high energies used in such procedures, 34 leads were suspended in saline, and subjected to repeated electrical shocks. Small (4 French) temporary pacing leads made by a variety of manufacturers tolerated multiple shocks up to 100 joules; above this level, failures became increasingly common, although usually the failure mode was benign with respect to patient care implications. Testing of 6, 7, and 8 French leads revealed considerable inter-and intra-manufacturer differences in the ability to withstand higher energy shocks, reflecting differences in materials and fabrication techniques. It is concluded that careful in vitro lead testing is required prior to using identical models in humans for arrhythmia ablation procedures.