Vibration analysis of structural elements using differential quadrature method

The method of differential quadrature is employed to analyze the free vibration of a cracked cantilever beam resting on elastic foundation. The beam is made of a functionally graded material and rests on a Winkler-Pasternak foundation. The crack action is simulated by a line spring model. Also, the differential quadrature method with a geometric mapping are applied to study the free vibration of irregular plates. The obtained results agreed with the previous studies in the literature. Further, a parametric study is introduced to investigate the effects of geometric and elastic characteristics of the problem on the natural frequencies

Prognostic value of telomerase and DNA ploidy in laryngeal carcinoma

Prognosis of carcinoma of the larynx is currently based on the morphologic analysis of the tumor extent, differentiation -grading and type of microscopic invasion. The DNA ploidy status and the cell proliferation activity may give complementary information about the prognosis. Telomerase may be used as a measure of tumor proliferation. The aim of this work is to investigate the probable application of telomerase as measure of cell immortalization as well as DNA ploidy as a measure of cell proliferation in prognosis of patients with laryngeal carcinoma. The work was carried out as a prospective observational study that included 35 patients with laryngeal carcinoma who were treated surgically at Ain Shams University Hospitals, Cairo, Egypt. Flowcytometric analysis and biochemical assay of telomerase, using human Telomerase Reverse Transcriptase [hTERT] mRNA assay by RT-PCR, in resected specimens were done. The proliferative indices in different parts of the tumor were found to be significantly different from each other, with those of tumor edges being the highest. The ploidy status at the edge of the tumor was significantly different between surviving and non-surviving patients, while the tumor core proliferative index was found to be significantly lower in patients without recurrence than those with recurrence. Agradient of telomerase levels was noticed. with levels from tumor cores being highest followed by tumor edges, resection margins and least levels in lymph nodes. Multivariate analysis showed hTERT levels in tumor edges to significantly affect survival. Both Flowcytometric parameters and telomerase activity may be useful as a prognostic factor for survival in patients with laryngeal carcinoma. Telomerase activity may be used for biologic demarcation for conservational laryngeal surgery, as well as a 'spectral' marker

Anatomical variations predisposing to pediatric sinusitis: a CT scan study

Sinusitis is a multifactorial disease. Anatomical variations and osteomeatal complex obstruction may be the major factors in predisposing to pediatric sinusitis. Other factors may include allergy, systemic diseases, stress, and genetic predisposition. This study aimed at defining the incidence of anatomical variations and dimensions of the lateral nasal wall structures and paranasal sinuses and their role in predisposing to pediatric sinusitis in Egyptian children. The study included CT scans [coronal sections] of nose and paranasal sinuses of 40 children, done at the radiology department of AinShams University Hospitals. These CT scans were carefully studied and classified into 2 groups. Group I [study group] involved CT scans with radiological signs of sinusitis of 25 Egyptian children [with a mean age = 9.34 yr. and SD= +/- 3.03], while group II [control group] involved CT scans of 15 normal children. We measured anatomical characters of the turbinates, maxillary sinus [height, width, slope of its roof to vertical plane and the level of its floor to the nasal floor], frontal sinus [development] and sphenoid sinus [height, width and development]. The results of measurements and variations of the previous anatomical structures were statistically analyzed comparing both groups to evaluate their significance in predisposing to pediatric sinusitis in Egyptian children. The results of the present study showed that the incidence of concha bullosa [in sinusitis group] was 24%, paradoxical and markedly edematous middle turbinate was also 24%, thin and rudimentary uncinate process [20%], the laterally curved uncinate process [16%], all of them were significantly higher in the study group [pediatric sinusitis] compared to the control group [sinusitis-free]. Also, a lower level of the maxillary sinus to the nasal floor [with mean value +/- 2mm] was found to be a statistically significant factor in predisposing to pediatric sinusitis in Egyptian children

Dental education in Egypt. What changes are needed?

Visualizing the future profiles of dental faculties, institutions through the next millennium and its impact on starting planning educational program that provide an outline life long learning and faculty development experience. There is a great need in dental education in Egypt for developing an education agenda and program that excel traditional practices to incorporate advancement in dental technology and education. The presentation will represent: How do we advance the research mission of academic dentistry using the information and the communication technology in distant education ? This paper will focus on how action is required to implement the changes for creating a new vision for dental education in Egypt through: 1-Designing learning experience. 2- Motivate faculty members to be better teacher. 3- Selecting new methods and techniques and materials for learning. 4- Skills in using a broad spectrum of technique e.g. presentation techniques and diagnostic technique for learning

Pharmacological and clinical comparative study between atracurium and cisatracurium

Cisatracuruim besylate is a new intermediate acting non depolarizing muscle relaxant. It is approximately three time more potent than atracurium as a neuromuscular blocking agent. The experimental study revealed that cisatracuruim produced dose dependent inhibition of muscle response to electrical stimulation of the sciatic nerve of anaesthetized cat, which was more potent than that produced by atracurium. Absence of contracture of frog's rectus abdominus after administration of both drugs indicate that depolarization could not be a mechanism of their paralyzing effect. Cisatracurium showed no effect on the blood pressure or heart rate of anaesthetized cat even in doses up to 4 mg / kg which is higher than the dose needed for neuromuscular blocking effect. In comparison, atracurium showed cardiovascular stability within the theraputic doses and even [6 x ED[95]] but with very high dose sever hypotension was produced both, cisatracurium and atracurium showed no effect on the myocardial contractility of isolated rabbite's heart. The comparative clinical study between atracurium and cisatracurium was done on 40 middle age adult patient ASA I and II undergoing elective surgery the patient classified into 2 groups [20 patient in each] group I received atracurium 0.5 mg / kg and Group II received cisatracurium 0.1 mg / kg. The onset time of cisatracurium was slightly longer than that for equipotent dose of atracurium [3.45 +/- 1.05] min versus [2.45 +/- 1.1] min respectively, the clinical effective duration of action, the recovery index and time of atracurium were similar to those of cisatracurium at equipotent dose. As regard to the cardiovascular system both cisatracurium and atracurium showed no significant changes in mean arterial blood pressure and heart rat at the equipotent dose. Cisatracurium is nondepolarizing muscle relaxant with intermediate duration of action, predictable recovery time and a constant pharmacodynamic profile which devoid of cardiovascular or histamin releasing effect and eliminated by non organ dependent hoffman elimination, so it is suitable drug to be introduced into clinical anaesthesia

Epidural anaesthesia in patients receiving prophylactic low molecular weight heparin [enoxaparin] during total hip replacement

This study was designed to determine the effect of LMWH as a prophylactic to reduce the prevalence of DVT after total hip replacement [THR] and to assess any haemorrhagic, soft tissue side effects or epidural haematoma after the use of LMWH. This study was carried out on 60 adult patients scheduled for total hip replacement under epidural anaesthesia. They were randomly classified into two groups: Group I [30 patients] received subcutaneous low molecular weight heparin [LMWH] enoxaparin 40 mg, 12 hour pre -operatively then after 12 h and 36 h postoperatively. Group II [30 patients] control group, did not receive enoxaparin. Haemorrhagic side effects were assessed by measurement of haemoglobine level, prothrombin time, partial thromboplastine time and platelets count, also we assessed blood loss and soft tissue complications as wound discharge and bruising of the leg. Both groups showed no significant difference in haemoglobin level and other blood laboratory tests in the pre -and postoperative period also there were no significant difference in haemorrhagic side effects or wound discharge but there was more bruising in the enoxaparin group, eight patients [13.3%] experienced minor neurologic complications or low back pain which was self limited and resolved with time. There were no manifestations of epidural haematoma leading to spinal cord compression. Proper patient selection, atraumatic technique, good monitoring, then administration of enoxaparin at least 12 hour before regional anaesthesia, removal of the catheter when the circulating LMWH is low after 10-12 hour from last injection and start the subsequent dose after 2 hours from removal of the catheter, should minimize the occurrence of epidural haematoma

Clinical efficacy of oral clonidine in anaesthetic practice

This study was done on 40 adult patients ASA physical status I and II subjected to an elective surgery. The effects of oral clonidine were investigated during general and spinal anesthesia. It was found that oral administration of clonidine as a premedication had significantly more sedation and less anxiety in patients undergoing general or spinal anesthesia. It also had advantageous hemodynamic effects resulted in a significant reduction of HR and ABP [SBP, DBP, MBP] in preinduction, postinduction and intra-operative measurement. Clonidine premedication attenuated the cardiovascular response to the stress of laryngoscopy and endotracheal intubation

Sevoflurane versus halothane for the incidence and type of arrhythmia during anaesthesia for adenotonsillectomy in children

This study was carried on 60 patients scheduled for adenotonsillectomy to compare the incidence and type of arrhythmia during sevoflurane or halothane anesthesia. All patients were premedicated with atropine 0.01-0.02 mg/kg im 30 minutes before induction of anesthesia, then received inhalation induction using nitrous oxide 50% in oxygen supplemented with either sevoflurane or halothane. Time to loss of eyelash reflex was more rapid with sevoflurane than halothane, although time to adequate anesthesia to allow the insertion of endotracheal tube was slower in sevoflurane group. The incidence of cardiac arrhythmia was higher during halothane [40%] than during sevoflurane anesthesia [20%] and the arrhythmia was more often ventricular in origin in the two groups

Damage control system surgical and anaesthetic roles

This study was conducted on 16 cases in AL ZAHRAA University Hospital from March 1997 to March 1998. All cases were presented with multiple injuries, usually head injury, orthopedic as well as abdominal organs involvement are combined. The majority of cases due to close [blunt] trauma 10 cases [62.5%], the patients were seen in a state of shock and the effect of urgent packing was evaluated in this study. It was considered good in 9 cases. The early mortality [either on the theater table or before re-operation to remove pack] occurred in 4 cases, while late death after removal of pack and definitive repair occurred in 3 cases. This high mortality rate [7 cases] 44% were attributed to the extensive tissue injury as well as age and chronic diseases

Comparison between mivacurium and atracurium in neuromuscular block and cardiovascular effects in patients receiving nitrous oxide - oxygen - halothane or nitrous oxide - oxygen - narcotic anaesthesia

This study was done on 60 patients of both sexes ASA I and II undergoing routine surgical operation in Al-Zahraa Hospital from March 1996 to March 1997, the study was undertaken to determine the neuromuscular block and cardiovascular effects of mivacurium in comparison with atracurium in 60 patients in two groups, each group 30 patients was subdivided into [a, b, c]. In group I, Halothane group [HAL] it was found that the mean onset for the low dose of mivacurium and that of atracurium were similar while the onset of high dose was much shorter, there was a highly significant difference between atracurium and both doses of mivacurium for the train of four [TOF] and the recovery index [RI]. In group II, [BAL] the balanced group there was no difference in the onset between both doses of mivacurium and that of atracurium, in comparison there was a highly significant difference between atracurium and the high dose of mivacurium in RI and TOF. Comparing group I and II halothane was found to potentiate the effect of mivacurium at neuromuscular junction with a high significant difference both at the low dose and at the high dose when compared with the balanced group. It was concluded that the spontaneous recovery from mivacurium induced neuromuscular block is very rapid and there is less need for neostigmine- atropine induced antagonism. The haemodynamic effects of mivacurium was also assessed, that the cardiovascular safety of mivacurium is proved by absence of clinically significant alteration from base line mean arterial pressure [MAP] and heart rate [HR] during bolus administration at doses up to 0.15 mg/kg. The cardiovascular effects of mivacurium may become evident after injection of larger doses. The present study revealed that mivacurium may be a useful nondepolarizing alternative to suxamethonium in elective procedures and in situation where rapid onset of action is not necessary. Due to its short duration of action and rapid recovery it is used as an adjunct to general anaesthesia, to facilitate tracheal intubation and provide skeletal muscle relaxation during surgery or mechanical ventilation for short procedures, and in situation where antagonism of residual neuromuscular block is considered undesirable

Burning mouth syndrome among Saudi subjects

This article represented 59 Saudi subjects complained from burning mouthsyndrome [BMS]. It is a condition characterized by a painful tongue or oralmucosa. The data were collected retrospectively over a period of four years[1988-1992], in subjects having only systemic diseases precipitating thecondition. BMS was common in anemic and diabetic subjects. The syndromedistribution was 37.3% and 30.5% respectively. It was less common inrheumatoid arthritis and psychiatric subjects [16.9% and 15.3%] respectively. In conclusion, the results helped in differential diagnosis of BMS. In caseof indecisive results obtained after excluding local and systemic factorspsychosis would be greatly considered

Diagnostic assessment of periodontal disease activity histometric changes in relation to microbial plaque levels before and after non-surgical therapy

Effective diagnosis and treatments of periodontal disease require accurate assessment of disease activity. This study was designed to assess the histometric and microbial changes in the active stage and in the quiescent stage after non-surgical therapy. A total of fifteen patients with 60 active sites were included. Activity was clinically evident by presence of pockets > 6 mm in depth and bleeding on probing. Plaque index [PI] and gingival index [GI], histometric analysis and ora test results were determined 4 weeks after scaling and root planning in comparison with the pre-treatment active state. Results showed improvement in all parameters after therapy. Clinical and histological parameters were sensitive in detecting disease activity while ora test showed variable sensitivity