Effect of multiscale PCA de-noising on EMG signal classification for diagnosis of neuromuscular disorders

Different approaches have been applied for quantitative analysis of EMG signals. This study introduces the effect of Multiscale Principal Component Analysis (MSPCA) denoising method in ElectroMyoGram (EMG) signal classification. The effect of the MSPCA denoising method discussed on EMG signal classification. In addition, effect of Multiple Single Classification (MUSIC) feature extraction method presented and compared for the classification of EMG signals. The results were accomplished on the basis of EMG signal data to classify into normal, ALS or myopathic. Furthermore, total accuracy of classifiers such as k-Nearest Neighbor (k-NN), Artificial Neural Network (ANN) and Support Vector Machines (SVMs) were discussed. Significant results were found by using MSPCA denoising method. The comparisons between the developed classifiers were based on a number of scalar performances such as sensitivity, specificity, accuracy, F-measure and area under ROC curve (AUC). The results show that MSPCA de-noising has considerably increased the accuracy as compared to EMG data without MSPCA de-noising.     

Anti‐erosive effects of fluoride and phytosphingosine: an in vitro study

A selection of commercially available products containing stannous fluoride (SnF₂)/sodium fluoride (NaF), SnF₂/amorphous calcium phosphate (ACP), SnF₂/NaF/ACP, tin (Sn)/fluorine (F)/chitosan were compared with phytosphingosine (PHS) with respect to their anti‐erosive properties in vitro. One‐hundred and twenty bovine enamel specimens were immersed in the respective product slurries for 2 min, twice daily. The formulations were diluted with either remineralization solution or artificial saliva. After each treatment, an erosive challenge was performed for 10 min, twice daily, using citric acid, pH 3.4. The specimens were stored in remineralization solution or artificial saliva until the next treatment‐erosion challenge. After 10 d, tissue loss was determined using profilometry. Enamel softening was determined through surface microhardness measurements. Tissue‐loss values (measured in μm and expressed as mean ± SD) for PHS, SnF₂/NaF, SnF₂/ACP, SnF₂/ACP/NaF, and Sn/F/chitosan treatment groups and for the negative‐control group, were, respectively, 35.6 ± 2.8, 15.8 ± 1.8, 22.1 ± 2.0, 22.9 ± 1.8, 16.2 ± 1.2, and 51.2 ± 4.4 in the presence of remineralization solution and 31.7 ± 3.3, 15.6 ± 2.9, 16.5 ± 2.7, 16.8 ± 2.1, 13.1 ± 3.0, and 50.7 ± 2.8 in the presence of artificial saliva. There were no significant differences in surface microhardness measurements between the treatment groups. In conclusion, PHS resulted in a significant reduction of tissue loss compared with the negative control, but in comparison, the toothpastes containing Sn²⁺ and F^? ions were significantly more effective compared with PHS.     

Left ventricular remodeling and aortic distensibility in elite power athletes

The aim of this study was to determine left ventricular (LV) morphology and aortic function in power athletes and to compare them with normal subjects. Thirty-two elite male wrestlers and 15 age-matched healthy male controls were included. All subjects underwent echocardiographic examination. Measurements included LV cavity dimension at systole and diastole, wall thickness, diastolic parameters, and aortic diameter, 3cm above aortic valve, at systole and diastole. Left ventricular mass and mass index were found to be higher in the athletes than in control subjects. The aortic distensibility index was found to be reduced in the athletes compared with controls (2.53 ± 0.91 vs 3.94 ± 1.77cm²dyne^–1 10^–6, P = 0.003), while the aortic stiffness index was significantly higher in the athletes than in controls (9.12 ± 3.23 vs 6.65 ± 2.35, P = 0.02). However, LV end-systolic wall stress was lower in the athletes than in controls. Furthermore, transmitral early (E) and late (A) peak velocity, peak velocity of the myocardial systolic wave (S _m), and early (E _m) and atrial (A _m) diastolic waves at the inferior wall were higher in the athletes than in controls. Reduced aortic distensibility in elite power athletes may be one of the cardiovascular adaptation factors which affect LV hypertrophy.     

False Aneurysm of the Hepatic Artery after Laparoscopic Cholecystectomy

Purpose: A rare complication of laparoscopic cholecystectomy is defined: iatrogenic injuries to hepatic artery system which may evolve to pseudoaneurysms in the late postoperative period. This rare phenomenon may be overlooked and pose a challenge to surgeons.

Material and methods: We will describe three cases with iatrogenic pseudoaneurysms after laparoscopic cholecystectomy.

The onset of symptoms and the course of the disease was not uniform. Diagnosis was made after a considerable delay. In the first case, a small, uncomplicated extrahepatic pseudoaneurysm was successfully treated with coil embolization. The second patient who had an intrahepatic pseudoaneurysm with multiple injuries to the common bile duct and portal vein, did not survive despite surgical and endovascular interventions. In the latter, surgical treatment for a large pseudoa-neurysm that had ruptured into the liver parenchyma was successfully conducted.

Review of the literature reveals fifty-four more cholecystectomy-related pseudoaneurysms. The site of injury was the right hepatic artery in 61% of the cases and the presenting symptom was upper gastrointestinal bleeding (haemobilia) in two-third of the patients. Embolization was performed in 82% of the cases, and surgery was undertaken in the remaining 18%.

Conclusion: Pseudoaneurysm is an uncommon complication of laparoscopic cholecystectomy. Prompt attention is necessary since the lesion has a high risk of rupture. Embolization is the first line of treatment and surgery is reserved for more complex injuries and cases with life-threatening rupture of the aneurysm.     

A Surgical Approach to Anogenital Buschke Loewenstein Tumours (Giant Condyloma Acuminata)

Background: Condyloma acuminata are anogenital warts caused by human papillomavirus (HPV). Neglected giant peri-anal condyloma acuminata (Buschke Loewenstein Tumours) require major surgical procedures. This report reflects our experience concerning the aggressive surgical approach to this rarely presented type of condyloma acuminata.

Methods: The medical records of five patients, who had been surgically treated following the diagnosis of giant perianal condyloma acuminata between April, 1996 and September, 2003 were reviewed and evaluated retrospectively. Full thickness tumour and skin excisions were performed followed by delayed split thickness skin graftings in all patients. Results: Five patients (3 men, 2 women) who suffered from giant condyloma acuminata lesions obliterating the anal canal were evaluated. The mean age was 36.5 years (range: 24–52). All patients underwent total surgical excisions. The wounds were left open for secondary healing, and following a mean time period of 35 days, split thickness skin graftings were performed. The histopathologic examinations of the specimens of these five patients did not reveal any malignant transformations. No recurrences were detected at the end of a mean follow-up period of 22 months and all patients were considered to be disease-free at the end of their long-term 5-year follow-up periods.

Conclusions: Peri-anal condyloma acuminatum is usually a benign disease, but may grow locally to an excessive extent, developing into a Buschke Loewenstein Tumour, and may cause serious peri-anal hygiene problems. Even though the incidence of malignant transformation is rare, there is always a risk of this complication occurring. Transmission of the disease to other sexual partners is another point of concern. Therefore, this disease must be treated aggressively with total surgical excision. The results of our surgical treatment methods are satisfactory.