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The aim of this study was to investigate the dose-related effects of dichlorvos inhalation on electrophysiological alterations of diaphragm and phrenic nerve and the changes in the histologic structure of respiratory system. This study was performed on 33 rats divided into 5 groups, inhaling 1, 2, 5, 10, and 15 microg/L of dichlorvos, respectively. Electrodiagnostic investigations of diaphragm and phrenic nerve were made before and after inhalations. Aspiration samples were taken from lungs to evaluate the presence of infection agents. The airways, lungs, and diaphragms were dissected out for histologic investigation. Rats exposed to a low concentration of dichlorvos (1-5 microg/L) showed no symptoms of intoxication, but exposure to higher doses (10-15 microg/L) induced dyspnea in several animals. Lower doses of dichlorvos revealed no electromyographic changes on diaphragm, whereas higher doses revealed a clear neuropathic involvement. Delayed phrenic nerve motor conduction velocity was noted for each group (p.05). Morphologic changes on the tracheal epithelium, hyperplasia, thickening of the blood-air barrier, degeneration in alveoli, and ductus alveolaris were seen in histopathologic investigation. In conclusion, the acute inhalation of dichlorvos caused clear evidence of neuropathic involvement of the diaphragm and the phrenic nerve. Also, toxic pneumonitis and injury to the tracheal epithelial were noticed.

Myringosclerosis (MyS) is a common sequela of acute and chronic otitis media and ventilation tube treatment of serous otitis media. We aimed to study the effect of topical administration of N -acetylcysteine (NAC) on MyS by assessment of otomicroscopic evaluation, lipid peroxidation and nitric oxide (NO) (nitrite/nitrate) levels in experimental myringotomized rat tympanic membrane. Thirty adult rats were used and the upper posterior quadrant of the tympanic membranes of rats was myringotomized. Thereafter, they were divided into four groups. Group I received no treatment, group II was treated with saline, groups III and IV were treated with topical NAC (0.1 ml of 6 and 12 mg ml(-1), respectively). The levels of nitrite/nitrate and malondialdehyde (MDA) were measured in serum samples. In the otomicroscopic evaluation, non-treated and saline treated ears (controls) showed extensive occurrence of myringosclerotic plaques. Groups III and IV showed fewer occurrences of sclerotic plaques. There was no significant difference between groups III and IV regarding the development of MyS. The development of myringosclerotic lesion was found to be significantly different between NAC treated groups (III and IV) and the control groups (I and II). The levels of nitrite/nitrate of both groups III and IV were significantly lower than the control groups. The levels of MDA of these groups were also significantly lower than the control group. The relationship between groups III and IV was not statistically significant for the levels of nitrite/nitrate and MDA. We conclude that the topical treatment of NAC reduces the levels of MDA and NO products in rats. These results suggest that topical NAC application may be useful for the prevention of MyS.

Objective: Theeffectsofanimmunosuppressiveagent,mycophenolate mofetil (MM), were investigated and compared with those of methylprednisolone (MP) and dexamethasone (DXM) on the traumatic nerve function. Study Design: This is a randomized controlled animal study. Materials and Methods: This experimental study was performed on 84 male Wistar albino rats. The rats were assigned to 12 groups each consisting of 7 animals. The groups were formed according to application of normal-dose DXM (group 1A-B), high-dose MP (group 2A-B), normal-dose MP (group 3A-B), MM (group 4A-B), and MM with high-dose MP combination therapies (group VA-B). Right sciatic nerve dissection was performed, and compound muscle action potential thresholds were recorded. The nerve was traumatized with the compression of a Jeweller forceps for 20 seconds. Posttraumatic thresholds were also recorded. The compound muscle action potential thresholds were recorded in the first and fourth weeks for the assigned groups. Then, the nerve was transected and prepared for electron microscopic and histopathologic examinations. Nitric oxide and malondialdehyde assessments were performed on both tissue and blood samples. Results: Only the MM and MP+MM groups had satisfactory electron microscopic findings and were about to reach the tissue characteristics of the control animals. Despite the electrophysiologic recovery, the DXM group was found to have poor electron microscopic scoring. Conclusions: Mycophenolate mofetil has been found to be beneficial in the treatment of traumatic nerve paralysis. Although a complementary investigation is needed, this immunosuppressive agent may be an alternative to corticosteroids for the selected cases where steroid therapy is contraindicated.

Pott’s puffy tumor is a rare clinical entity described as osteomyelitis of the frontal bone associated with subperiosteal abscess. The causative factors and treatment modalities are discussed in light of the literature.

This study was designed to investigate the effects of bipolar and mononopolar electrocauterization on peripheral nerve tissue. The comparison on the deleterious effects of the different cautery modalities and the importance of probe tip placement are evaluated using electrophysiological, electron microscopic and biochemical assessment parameters. Ninety-eight male Wistar albino rats, each weighing 250–275 g, were randomly divided into 14 groups. Each group consisted of seven animals. Monopolar and bipolar electrocautery were performed at 15 watts. The application was performed either directly on the nerve or 1 mm lateral to the longitudinal axis of the nerve for ‘near the nerve groups’, respectively. The electrophysiological findings showed that the mean amplitudes were at the lowest value in the first day for all the groups. At the end of the 3rd week, we recognised that the electrophysiological recovery continued. Electron microscopic evaluation showed myelin disruption in all groups. Myelin disruption of healthy neurons was at the highest level in the 1st day of application in accordance with the electrophysiological findings. Biochemical evaluation revealed statistical significance between the control and the two of the ‘near the nerve groups’ (GIII and GV) for NO (nitrite and nitrate) serum level. The data of the present study might suggest that electrocautery, independent of the type and form of application, may result in significant damage in histological and electrophysological basis. Although the relative proportions cannot be ascertained, the time course of recovery suggests that both axon and myelin damage have occurred. The probable electrocautery damage may be of substantial importance for the situation that the nerves are displaced by tumor masses or atypical neural traces.

Background and objectives: The cerebellar tonsillar herniation occurring in Chiari malformation Type I (CMI) mainly results from overcrowding of a normally developing hindbrain within a primary small posterior cranial fossa (PCF) due to an anomaly in the embryological development of the occipital bone. In the present study, the lengths of PCF parameters were studied in adult CMI patients. Patients and methods: The authors retrospectively examined 15 adult patients with CMI. Multiple measurements were made on magnetic resonance images (MRIs). The results were compared with the findings in 25 controls and 30 dry skulls. Results: Length of the neural structures did not significantly differ between the CMI and the control groups. The average length of the basiocciput was significantly shorter in the CMI group as compared with the control group. The mean length of the supraocciput was significantly shorter and the average diameter of the foramen magnum was significantly longer in the CMI group when compared to the control group and dry skulls. Conclusions: The morphometric data suggest that, in CMI, a hypoplastic occipital bone, possibly due to the paraxial mesodermal defect of the parachordal plate, causes overcrowding in PCF, which contains the normally developed neural structures.

Myasthenia gravis (MG) is an autoimmune neuromuscular disease. Although most MG cases do not have accompanying malignant disease, patients with thymoma may have an increased risk for secondary malignancy. The reason MG patients are prone to developing cancer is not very well known. Salivary gland tumors account for approximately 3% of head and neck tumors, and approximately 80% of these occur in the parotid gland. Mucoepidermoid carcinoma is the most common malignant tumor of the parotid gland. MG may be associated with squamous cell carcinoma of the head and neck. We present a patient with MG who developed parotid gland mucoepidermoid carcinoma. MG patients with parotid gland cancer have not been previously reported. We also discuss the possible mechanisms of tumor development in an MG patient.

The study investigates the effect of airway instrumentation on the histopathology of the intestine, contribution of bacterial translocation, and whether oxygen supplementation may counteract the possible detrimental effects of this procedure.Fifty-five Wistar rats were assigned to 3 groups. Group 1 served as control. Groups 2 and 3 underwent airway instrumentation. In addition, group 3 received oxygen supplementation during the procedure. Arterial blood gases were measured after the procedure. Samples of mesenteric lymph nodes ileum, cecum, spleen, liver, and blood were harvested for determination of bacterial growth after 24 hours. Ileum was evaluated histologically.In group 2, the rats presented a decrease in oxygen saturation (90% +/- 0.3%, P.0001), hypoxemia (PaO2, 73 +/- 1.5 mm Hg; P.0001), and respiratory acidosis (pH 7.27 +/- 0.01; PaCO2, 48 +/- 1.5 mm Hg; P.0001) after airway instrumentation. These rats also showed evidence of intestinal injury (P.0001) and bacterial translocation to mesenteric lymph nodes in 10 of 20 rats compared with 0 of 15 in the controls (P = .004). In group 3, oxygen supplementation provided normal arterial blood gas parameters, and led to minimal histologic changes and bacterial translocation in only 1 of 20 rats, compared with group 2 (P.0001 and P = .005, respectively).The study suggests that oxygen supplementation during airway instrumentation prevents hypoxemia, intestinal damage, and bacterial translocation.

Inverted papilloma (IP) of the nasal cavity and paranasal sinuses is an uncommon pathology, especially in the pediatric population. We present a pediatric case of recurrent IP in the left nasal cavity. The physical examination of a 9-year-old girl revealed a polypoid mass filling the middle meatus in the left nasal cavity. Purulent secretion and adenoid vegetation obstructing the choanea were also noted. Coronal and axial maxillo-facial computed tomography demonstrated a mass in the nasal cavity, enlarging the left middle meatus. We discussed the imaging findings and treatment of IP and concluded that it should have been included in the differential diagnosis of nasal mass lesions in the pediatric population.

Summary Objective To assess the relation between mastoid size and attic blockage in COME patients treated with ventilation tube insertion and prognosis regarding tympanometric compliance and computed tomography findings of temporal bones. Material and methods Twenty-four ears of 15 patients with chronic otitis media with effusion were selected prospectively. The ages of patients were between 5 and 13 years old and eight of them were females. All patient received medical treatment for 10 days. Ventilation tubes were inserted with or without adenoidectomy or adenotonsillectomy to the unimproved patients. Postoperative compliances were measured on first day, first week, and first month and the tympanometric results were compared each one with others and with mastoid pneumatization degree using computerized tomographic findings. Results The hearing thresholds were between 23 and 43 dB in left ears and between 22 and 45 dB in right ears. Mastoid pneumatization and aditus were normal and open in three (12.6%); sclerotic and open in eight (33.3%); sclerotic and blocked in 13 patients (54.1%), when the temporal bones assessed by computerized tomography. The mean compliance values of patients elevated postoperatively in regard with time and this increase was significant. There was a significant statistical relation between mastoid pneumatization and compliance of the ears. Conclusion Tympanometric assessment may be considered as a valuable and cost-effective method rather than CT in the evaluation of aditus blockage and residual soft tissue of the tympanomastoid region.

Congenital masses are the most common non-inflammatory neck lesions in children. Although usually present at birth, they can appear at any age. Dermoid cysts are benign lesions of congenital origin usually presenting as a midline neck mass. They rarely appear in the lateral region of the neck. Lateral cervical dermoid cyst is presented as a rare, unusual case, and differential diagnosis and management are discussed in light of recent literature.

Objective: To determine the effect of alprostadil on the ischemia–reperfusion (I/R) injury of the sciatic nerve in rats. Materials and methods: Pre-reperfusion administration of alprostadil (0.05 μg kg−1) was assessed in the I/R injury model of the rat sciatic nerve. In this model, blood samples were investigated for the I/R injury markers namely malondialdehyde (MDA), an indicator of lipid peroxidation, and nitrite/nitrate levels, products of nitric oxide (NO) metabolism. Results: A significant decrease in MDA, and increase in NO levels were observed in the groups which received alprostadil before reperfusion, when compared to their corresponding untreated controls (I/R only) at all time intervals (P=0.0001). There was a statistically significant difference in both MDA, and NO levels between certain time intervals. There was no statistical linear correlation between MDA and NO levels. Conclusion: Alprostadil may be suggested as a protective anti-inflammatory and a vasodilator pharmacological agent for I/R injury in peripheral nerves. Also, measurements of NO and MDA may be complementary to the generally accepted evaluation parameters of I/R injury including electromyography and nerve histopathology.

Intramuscular benign lipoma commonly is found on the extremities, but is extremely rare in the head and neck region. Intramuscular type lipomas arise between the muscle fibers and pass through the intermuscular septa, infiltrating the surrounding tissue. A 29-year-old male patient presented with the complaint of a painless and slowly growing lateral neck mass on the left side. Physical examination revealed a 4x5-cm mass adjacent to the sternocleidomastoid (SCM) muscle. CT examination revealed a lobulated, well-circumscribed 5.5x2.5-cm diameter mass with adipose tissue signal density inside the SCM muscle. The surgical exploration of the mass was done under general anesthesia, and it was excised totally. Recurrence was not seen in the 3-year follow-up. This rare entity should be considered in the differential diagnosis of intramuscularly located neck masses. Complete removal of the tumor can only succeed if planned and performed after a thorough preoperative clinical and radiological assessment in order to prevent recurrences.

In this retrospective study, the computed tomography (CT) archives of paranasal sinus examinations were reviewed and three cases of antroliths are presented. The archivesof paranasal sinus CT studies of 1957 patients (1023 females, 934 males, mean age 36.5 years) were surveyed. CT studies were performed using 3 mm collimation and interval in the coronal, axial or both coronal and axial planes.Three out of 1957 patients demonstrated antroliths, all in the left maxillary sinus. Associated sinusitis was detected in all three patients. Only one patient was operated. The chemical analysis of the antrolith revealed it to be a calcium oxalate stone. All the relevant literatureis reviewed and only 25 other cases of true antrolithiasis were encountered. The clinical and radiological features of antroliths,as well as differential diagnosis were discussed.Antrolithiasis should be considered in any case of sinusitis, that does not respond to appropriate medical therapy.

Objective: This study investigates the effect of bronchoscopy on intestinal mucosal barrier function and its association with intestinal nitric oxide production. Methods: 30 rats were used. The study group (n=15) underwent rigid bronchoscopy. At 24 h following bronchoscopy, ileal nitrite/nitrate levels were evaluated. The ileum was also examined for mucosal damage, and graded according Chiu's histologic injury scale. Results: In the bronchoscopy group, the ileal nitrite/nitrate levels were significantly higher than those of controls (398.5±85.1 and 44.5±6.6 nmol/g tissue, respectively, P=0.001). In the bronchoscopy group, the mucosal damage was significant, compared with those of controls (mean ranks, 22.8 and 8.2, P

Corticosteroids are shown to have deleterious effects on wound healing for various tissues. Arginine metabolism and nitric oxide (NO) synthesis play an important role in many aspects of inflammation and wound healing. The study was designed to evaluate the relationship of dexamethasone impaired healing of tracheal anastomoses to NO metabolism and lipid peroxidation. Forty-two adult Wistar rats were randomly divided into five groups. The animals underwent tracheal transection and primary anastomoses. The groups were assigned as follows: Group I (GI) (sham, N =6); Group II (GII) (control, N =6); Group III (GIII), dexamethasone, 0.1 mg kg −1 per day, intramuscularly for a week ( N =10); Group IV (GIV), dexamethasone, 1 mg kg −1 per day, intramuscularly for a week ( N =10); Group V (GV), dexamethasone, 6 mg kg −1 intramuscularly as a single dose ( N =10). After 7 days, bursting pressure was used to evaluate anastomotic healing. Serum nitrite/nitrate and malondialdehyde (MDA) levels were measured as an index of NO synthesis and lipid peroxidation, respectively. The bursting pressure significantly decreased in GIII and GIV when compared to the control group. The difference between GIII and GIV was also statistically significant. Nitrite/nitrate and MDA levels of GIII were found to be significantly higher than the control group. Also, the difference was found to be statistically significant between GIII and GIV in regard to nitrite/nitrate levels. The present study demonstrates that daily administration of dexamethasone for a week inhibits NO synthesis in a dose-dependent manner on tracheal anastomotic healing. Besides the generally accepted evaluation parameters including bursting pressure and hydoxyproline content; NO and MDA levels may be helpful in the assessment of wound healing especially for the investigation of impairment mechanism.

Hypothesis To understand cochlear dysfunction and the recovery pattern of the cochlea after acute electrical injury. Background The cochlea is believed to be more vulnerable to direct current than to alternating current. However, the damage-and frequency-specific recovery characteristics of the cochlea have not been well described. Methods Baseline distortion product otoacoustic emission measurements were taken via transtympanic electrodes from 19 guinea pigs. A 20-Hz alternating current and a positive direct current, both at a 1,000-microA intensity, were applied to 9 and 10 animals, respectively. The measurements were repeated immediately after the application of current and after 10 days. Comparisons were made for both groups individually in signal-to-noise ratios obtained before and immediately after, immediately and 10 days after, and before and 10 days after the application of electrical current. Results Alternating and direct currents caused a significant depression in signal-to-noise ratio immediately after the application. However, 10 days later, the mean signal-to-noise ratio in the animals subjected to alternating current came significantly close to the baseline value, particularly between the frequencies of 2,211 and 3,717 Hz. By contrast, the mean signal-to-noise ratio in the animals subjected to direct current remained significantly depressed throughout all frequencies except for 2,211 Hz. Conclusion Baseline distortion product otoacoustic emission measurements enabled cochlear function to be monitored in a frequency-specific manner after electrical injury. The functional damages were quantitatively close to each other for both types of currents at a given intensity. Nevertheless, recovery was more apparent in the animals exposed to alternating current than in those exposed to direct current. Recovery was also better in the midfrequency region than in higher frequencies. It is hypothesized that the reason for the difference in recovery in both groups was the net charge left by direct current.

The diagnosis of solitary plasma cell neoplasm is based on clinical, radiological and laboratory findings and it can be accepted as the precursor lesion of multiple myeloma as spread of disease occurs in 30-50% of affected patients. However, solitary plasmacytoma of the temporal bone is a rare pathology. We present an interesting case of plasmacytoma of the temporal bone which was controlled by a combination of surgery and radiotherapy.

PubMedID: 9740996 Salivary duct carcinoma (SDC) is an uncommon and highly aggressive neoplasm that reveals histopathologic features resembling infiltrating duct carcinoma of the breast and prostate. SDC arising on the basis of preexisting pleomorphic adenoma (PA) is very rare. This report describes the fine-needle aspiration (FNA) cytology of a case of SDC ex PA. FNA smears were cellular with cells with large, pleomorphic nuclei, some prominent nucleoli, and finely vacuolated cytoplasm. The neoplastic cells were forming groups, sheets, and papillary structures and a cribriform pattern was present in some sheets. Mitotic figures were frequently seen. Necrosis was prominent in the background. Histologic sections of the tumor revealed areas of comedo carcinoma, papillary carcinoma, and infiltrative carcinoma as well as multiple foci of PA. The presence of a cribriform pattern, tumor cells resembling breast ductal carcinoma cells, and a necrotic background are helpful features for an accurate cytodiagnosis of SDC.