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Biomedical subjects

I Aydoğdu

Publications and source records attributed to I Aydoğdu.

10 recordsLinked to original sources
PubMed2004

Changes in the perioral muscle responses to cortical TMS induced by decrease of sensory input and electrical stimulation to lower facial region.

OBJECTIVE: To determine the changes in the motor cortex due to repetitive electrical stimulation and cutaneous anesthesia in lower facial region. METHODS: A total of 11 subjects participated in the study of repetitive electrical stimulation, and 10 other subjects in the study of lower facial anesthesia. Facial nerve root and face associated cortical MEPs by transcranial magnetic stimulation (eight-shaped coil) were recorded from perioral muscles pre- and post- electrical stimulation and lower facial anesthesia. Cheek near to the corner of the mouth was transcutaneously stimulated by bipolar surface electrode giving repetitive electrical shocks at 5 Hz. Five percent lidocain/prilocain local anesthetic cream was applied to left or right lip-cheek region. RESULTS: There was no significant change in perioral MEP responses after 10-30 min of 5 Hz electrical stimulation. We found a significant increase of amplitude in cortical MEP recordings during lower facial anesthesia especially in cases of cortical magnetic stimulations ipsilateral and contralateral to the anaesthetized side and in perioral recordings contralateral to the anaesthetized side. CONCLUSIONS: The present study demonstrates that topical anesthesia to the lower facial region leads to cortical modulation and fast plastic changes in both hemispheres that are directed to the normal side.

Adult↗
PubMed2001

The effect of head and neck positions on oropharyngeal swallowing: a clinical and electrophysiologic study.

OBJECTIVES: To determine the clinical usefulness of an electrophysiologic method for evaluating dysphagia and to identify the effects of various head and neck positions on oropharyngeal swallowing. DESIGN: Experimental, with control group. SETTING: An electromyography laboratory. PARTICIPANTS: Patients with neurogenic dysphagia (n = 51) and healthy controls (n = 24). Patients were divided into 2 groups: those patients with unilateral lower cranial lesions (n = 9) and those without laterality in the function of the oropharyngeal muscles (n = 42). INTERVENTIONS: Subjects were instructed to swallow doses of water, gradually increasing in quantity from 1 to 25 mL under 5 conditions: neutral, chin up, chin tucked, head rotated right, and head rotated left. MAIN OUTCOME MEASURES: Change in dysphagia limit through specified head and neck postures. Oropharyngeal swallowing was evaluated by laryngeal movements that were detected by a piezoelectric sensor and electromyography of the submental muscle complex. Laryngeal sensor signals occurring within 8 seconds of a swallow were accepted as a sign of the dysphagia limit. RESULTS: In the control group, dysphagia limit did not change significantly with changes in head and neck postures, except for the chin-up posture (p <.05) in which piecemeal deglutition occurred when subjects swallowed volumes less than 20 mL. Dysphagia limit improved significantly (p <.05) in 67% of the patients with unilateral lower cranial lesions when the head was rotated toward the paretic side. In dysphagic patients with bilateral symptoms, a significant (p <.01) improvement in dysphagia limit occurred in 50% of patients in chin-tuck position, but in the chin-up position, 55% of the patients experienced a significant (p <.01) decrease in dysphagia limit. CONCLUSION: The electrophysiologic method of measuring dysphagia limit confirms neurogenic dysphagia and its severity in the neutral head position. Changes in head and neck positions do not significantly alter dysphagia limit in unimpaired subjects except for the chin-up position. Although the results obtained were not compared with other techniques (eg, videofluoroscopy), this simple electrophysiologic method for describing dysphagia limit may have a place in the evaluation of dysphagia and its variability in various head and neck positions.

Adolescent↗
PubMed2000

The electromyographic behavior of the thyroarytenoid muscle during swallowing.

The electromyographic (EMG) behavior of the laryngeal adductors (e.g., the thyroarytenoid [TA] muscle) during swallowing has been scarcely studied. However, the detailed analysis of TA muscle is important to understand the physiology of swallowing. We investigated 14 healthy adult subjects. Activation of the TA laryngeal adductor muscle was compared with the mechanically measured laryngeal up-down movement and with the onset of excitation of laryngeal elevators, such as submental (SM) muscles, during swallowing. The laryngeal adductor of TA and laryngeal elevators of SM muscles were electromyographically (integrated/rectified) recorded. The vertical laryngeal movements during swallowing were recorded using a piezoelectric sensor. The EMG behavior of the TA muscle revealed three different activities during swallowing. The basic activity was stable; it almost started with the upward movement of larynx and after the SM-EMG onset. A fore-burst was recorded just before the upward movement of the larynx and a late-burst appeared just after the downward movement. The fore-burst was proposed to be related with oral-laryngeal reflexes, and the late-burst could be a rebound activity after a short expiration of swallowing, while the basic activity is accepted to be a part of activity of central-pattern generator of swallowing program.

Adult↗
PubMed1997

Use of high-dose chemotherapy plus granulocyte colony-stimulating factor for the salvage of refractory or resistant-relapse lymphoma patients without stem cell support.

The combination of cyclophosphamide (CY) and etoposide is synergistic, spares bone marrow stem cells and can be given repeatedly in high doses without stem cell support. Thirteen patients with non-Hodgkin's lymphoma (n = 8) or Hodgkin's disease (n = 5), received high-dose chemotherapy (HDC). Median age was 32 years (24-52). Male to female ratio was 10:3. All the patients were in advanced-stage. Karnofsky score prior to HDC was 60% (range 40-90). Six patients showed primary refractoriness and 7 had resistant relapse. HDC consisted of CY 1,500 mg/m2/day and etoposide 300 mg/m2/day, both for 4 days. rhG-CSF was started 24 h after the last dose of chemotherapy as a continuous intravenous infusion at a dose of 0.01 mg/kg/day and stopped when the leukocyte count reached 1 x 10(9)/1 on 3 consecutive days. Overall, 69% (9/13) of patients responded to HDC. Four achieved CR and 5 achieved PR. Two of the patients showed disease progression. The other 2 died during the early period of HDC. Neutrophil and platelet recovery after HDC were 8 (6-16) and 10 (4-14) days, respectively. The major nonhematological toxicities were nausea-vomiting (100%) and diarrhea (61%). The median follow-up was 204 (7-600) days. Two patients relapsed 48 and 185 days after HDC. Eight patients are still alive, 7 progression free. The progression-free survival is 220 (40-285) days. In conclusion, HDC + granulocyte colony-stimulating factor (G-CSF), without stem cell support seems to be promising in refractory or resistant relapse lymphoma patients bringing the need for randomized studies to show the cost effectiveness of HDC + G-CSF compared to HDC + autologous stem cell support.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Effects of bolus volume on oropharyngeal swallowing: an electrophysiologic study in man.

OBJECTIVE: Different variables of oropharyngeal swallowing change in response to bolus volume and consistency as determined by manometric/videofluoroscopic studies. But the subject is debatable especially from the physiologic point of view. No electrophysiologic studies are available on human subjects. METHODS: The effects of bolus volume and viscosity on different variables of oropharyngeal swallowing were investigated using electrophysiologic methods. Mechanical upward and downward laryngeal movements and submental electromyographic (SM-EMG) activity of the laryngeal elevator muscles were recorded during dry and 3-, 10-, and 20-ml water swallowing in 14 normal subjects. Cricopharyngeus (CP) muscle was investigated during 3- and 10-ml water swallowing in 10 normal subjects. Semisolid and liquid swallowing were compared in eight normal subjects. RESULTS: The total duration of SM-EMG, time necessary for larynx elevation, CP-EMG pause related with upper esophageal sphincter opening and swallowing variability (jitter) all increased significantly with increasing bolus volume. Laryngeal superior relocation time and CP-EMG pause were shorter for semisolid swallowing compared with swallowing the same amount of liquid. CONCLUSION: The duration of SM-EMG activity, laryngeal upward-downward movements, and CP-EMG pause are affected by sensory inputs such as volume and viscosity of the bolus swallowed. The results indicate that sensory input modifies the central swallowing pattern although basic events remain the same in normal human subjects.

Adolescent↗
PubMed1996

Middle latency auditory evoked potentials (MLAEPs) in (MS).

Middle latency auditory evoked potentials (MLAEPs) were studied in 30 definite multiple sclerosis (MS) patients in addition to brain-stem auditory evoked potentials (BAEPs). BAEP abnormalities were detected in 18 (60%) patients. MLAEPs were abnormal in 22 (73%) of them. In 15 patients BAEPs and MLAEPs were both abnormal. MLAEPs were found abnormal in 7 of the 12 patients with normal BAEPs. In 18 patients with abnormal BAEPs only 3 had normal MLAEPs. MLAEPs abnormalities are consistent with a rostral auditory pathway involvement. Therefore, they can be used in combination with BAEPs to examine the whole auditory system to improve the sensitivity.

Adolescent↗
PubMed1996

Piecemeal deglutition and dysphagia limit in normal subjects and in patients with swallowing disorders.

OBJECTIVE: Before the advanced evaluation of deglutition and selection of a treatment method, objective screening methods are necessary for patients with dysphagia. In this study a new electroclinical test was established to evaluate patients with dysphagia. METHODS: This test is based on determining piecemeal deglutition; which is a physiological phenomenon occurring when a bolus of a large volume is divided into two or more parts which are swallowed successively. The combined electrophysiological and mechanical method used to record laryngeal movements detected by a piezoelectric transducer, and activities of the related submental integrated EMG (SM-EMG)-and sometimes the cricopharyngeal muscle of the upper oesophageal sphincter (CP-EMG)-were performed during swallowing. Thirty normal subjects and 66 patients with overt dysphagia of neurogenic origin were investigated after detailed clinical evaluation. Twenty patients with a potential risk of dysphagia, but who were normal clinically at the time of investigation, were also evaluated to determine the specificity of the test. All subjects were instructed to swallow doses of water, gradually increasing in quantity from 1 ml to 20 ml, and any recurrence of the signals related to swallowing within the eight seconds was accepted as a sign of dysphagia limit. RESULTS: In normal subjects as well as in the patients without dysphagia, piecemeal deglutition was never seen with less than 20 ml water. This volume was therefore accepted as the lower limit of piecemeal deglutition. In patients with dysphagia, dysphagia limits were significantly lower than those of normal subjects. CONCLUSION: The method is a highly specific and sensitive test for the objective evaluation of oropharyngeal dysphagia even in patients with suspected dysphagia of neurogenic origin. It can also be safely and simply applied in any EMG laboratory.

Adult↗
PubMed1995

An electrophysiological investigation of deglutition in man.

This article describes a combined electrophysiological and mechanical method used to measure laryngeal movements and related submental EMG activity during swallowing. The mechanical upward and downward movements of the larynx were detected using a piezoelectric sensor while the submental integrated EMG (SM-EMG) was recorded. Measurements were performed in 29 human subjects. The interval between the onsets of the two sensor signal deflections was used as a measure of the time the larynx remained in its superior position during swallowing. In 10 subjects, the cricopharyngeus muscle (CP) of the upper esophageal spinchter showed a continuous tonic EMG activity except during swallowing. All the parameters measured were influenced by the type and volume of the bolus material. The method presented in this study proved its usefulness in the study of the physiology of deglutition as well as in its objective clinical evaluation in patients with dysphagia.

Adult↗
PubMed1994

Peripheral T cell receptors alpha beta and gamma delta in patients with Hodgkin's lymphoma.

Antigen recognition by T cells is determined by an antigen specific T cell receptor (TCR). Two heterodimeric TCR structures associated with CD3 have been defined: TCR alpha beta and TCR gamma delta. TCR alpha beta and its function are well described but the role of TCR gamma delta in normal and lymphoproliferative disorders is not well established. In newly diagnosed or relapsed/refractory Hodgkin's disease (HD), a disease associated with defective T cell functions and increased sIL-2R, we determined levels of seven TCR alpha beta variable regions [beta V5(a), beta V5(b), beta V6(a), beta V12(a), alpha beta V(a), alpha V2(a)] and TCR gamma delta by using monoclonal antibodies (MCA). TCR gamma delta levels did not show any difference, but several variable regions of the TCR alpha beta differed when groups are compared with each other and the control group.

Adolescent↗