α-Synuclein-induced mitochondrial dysfunction in isolated preparation and intact cells: implications in the pathogenesis of Parkinson's disease

This study has shown that purified recombinant human α-synuclein (20 μM) causes membrane depolarization and loss of phosphorylation capacity of isolated purified rat brain mitochondria by activating permeability transition pore complex. In intact SHSY5Y (human neuroblastoma cell line) cells, lactacystin (5 μM), a proteasomal inhibitor, causes an accumulation of α-synuclein with concomitant mitochondrial dysfunction and cell death. The effects of lactacystin on intact SHSY5Y cells are, however, prevented by knocking down α-synuclein expression by specific siRNA. Furthermore, in wild-type (non-transfected) SHSY5Y cells, the effects of lactacystin on mitochondrial function and cell viability are also prevented by cyclosporin A (1 μM) which blocks the activity of the mitochondrial permeability transition pore. Likewise, in wild-type SHSY5Y cells, typical mitochondrial poison like antimycin A (50 nM) produces loss of cell viability comparable to that of lactacystin (5 μM). These data, in combination with those from isolated brain mitochondria, strongly suggest that intracellularly accumulated α-synuclein can interact with mitochondria in intact SHSY5Y cells causing dysfunction of the organelle which drives the cell death under our experimental conditions. The results have clear implications in the pathogenesis of sporadic Parkinson's disease. α-Synuclein is shown to cause mitochondrial impairment through interaction with permeability transition pore complex in isolated preparations. Intracellular accumulation of α-synuclein in SHSY5Y cells following proteasomal inhibition leads to mitochondrial impairment and cell death which could be prevented by knocking down α-synuclein gene. The results link mitochondrial dysfunction and α-synuclein accumulation, two key pathogenic mechanisms of Parkinson's disease, in a common damage pathway.

The predictive value of the clinical features of malignancy in cases of preoperative follicular thyroid neoplasia

AIM

It is generally impossible to make a distinction between benign and malign with a cytopathological examination using a fine needle aspiration biopsy (FNAB) in follicular lesions of the thyroid gland. This is the reason why lesions are frequently reported as follicular neoplasia (FN). Our study aims to examine the predictive value of carcinoma detection of different clinical features in cases with determined FN with FNAB.

METHODS

Clinical and histopathological data of a total of 116 patients (26 male, 90 female) subjected to surgery because of thyroid gland pathology with FN between March 1997 and December 2011 were retrospectively examined in two different centers.

RESULTS

Results of the histopathological examinations were reported as: carcinoma in 33 (28.4%) cases (18 [54.5%] cases with papillary thyroid cancer, 11 [33.3%] cases with follicular thyroid cancer and 4 [12.1%] cases with papillary thyroid cancer follicular variant), as follicular adenoma (FA) in 32 (27.6%) patients and as a benign colloidal nodule in 51 (43.9%) patients. No statistical significance was determined between advanced age, male sex, solid single nodule, increased nodule diameter, hypoactive nodule existence and malignancy (P>0.05).

CONCLUSION

Malignancy was found in 28.4% cases with FN detected as a result of FNAB in our study series, a ratio which is significantly higher than that reported in the literature. We think that the characteristics of the patient and the tumor are not effective in diagnosing cancer. In the case of the existence of bilateral thyroid pathology, the surgical therapy option should be bilateral total thyroidectomy due to such a high ratio of cancer occurrence.

Effectiveness of temozolomide treatment used at the same time with radiotherapy and adjuvant temozolomide; concomitant therapy of glioblastoma multiforme: multivariate analysis and other prognostic factors

AIM

Prognostic factors which affect treatment results of glioblastoma multiforme (GBM; WHO Grade IV) patients has been investigated in many researches. For these patients determination of prognostic factors helps generating multimodal therapy protocols. For this purpose, in the Baskent University Medical School, Neurosurgery Clinic, Adana Medical Research Center, specific characteristics of GBM patients who have surgery retrospectively investigated and factors which affect prognosis has been determined.

METHODS

Between January 2005 and January 2009, 59 patients (25 female, 34 male) who have GBM have been evaluated retrospectively. Mean follow-up period was 27.4 (+/-17.3) months. Headache (66.1%) was the most seen symptom. Time of diagnosis was 1-2 months for most of the patients (54.2%). Fifty-nine patients had 67 operations totally. Preoperative Karnofski Performance Scale (KPS) was >or=70 for 43 operations, <or=70 for 24 operations. Frontal lobe was the most involved part of the tumor,and biggest tumor has the diameter of 4.8 (+/-1.42) cm. Forty gross total resection, 26 subtotal resection and 1 lobectomy were performed. Postoperatively for 41 operations KPS>or=70, for 26 operations KPS<or=70. After surgery 44 patients had radiation therapy (RT). Eighteen patients had only adjuvant RT, 26 patients had temozolomide (TMZ) treatment used at the same time with RT combination therapy (CombT with TMZ) and 6 cures adjuvant TMZ concomitant therapy (ConcT with TMZ). Median survival and prognostic factors of 42 GBM patients was calculated with multivariable and univariable analysis.

RESULTS

Median survival was 8 (+/-1.5) months for patients who died. One year survival was 83.3% and two-year survival 16.7%. After treatment, relapse occurred in 12 patient at the site of the tumor and these patients had been reoperated. After univariate statistical analysis preoperative KPS was >or=70 (P=0.0000) , postoperative KPS 2 was >or=70 (P=0.0000), type of tumor resection (P=0.00002), multiple operations (P=0.001), adjuvant RT (P=0.0000) and ConcT with adjuvant TMZ (P=0.0000) were all positive prognostic factors which extend the survival. After multivariate analysis, post operative KPS was >or=70 (P=0.003; OR:0.89; % 95 CI:0.83-0.96), type of resection (P=0.055; OR:0.37; % 95 CI:0.13-0.12) and multiple operations (P=0.042; OR:2.65; % 95 CI:1.03-6.82) were independent prognostic factors.

CONCLUSION

When independent prognostic factors were examined ,median survival found out 7.8 months longer fort he patients whose postoperative KPS were >or=70, 5.7 months longer for the patients who had radical resection, 6.6 months longer for the patients who had multiple operations. Although patients who had ConcT with adjuvant TMZ had 1.7 months longer survival compared to patients who had only adjuvant RT, it was not determined as an independent prognostic factor.

Paraparesis following straining accompanied by spontaneous thoracolumbar spinal epidural hematoma: a case report

Spontaneous spinal epidural hematoma (SSEH) is a rare disease that requires emergency surgical intervention because it can cause serious and permanent neurological damage. Its etiology is related to coagulopathy, vascular malformation, hypertension, neoplasms, infections and idiopathic causes. It is frequently observed in the cervicothoracic and thoracolumbar regions. Inadequate spinal vascularization of the thoracolumbar junction increases the risk of spinal infarcts in lesions in this region. Therefore, prompt and effective surgical intervention is critical in patients with a thoracolumbar SSEH. We conclude that prognosis would be better than it is if patients with complete neurological damage were to undergo spinal decompression within the first 36 hours, and patients with incomplete neurological damage were operated on in the first 48 hours. We report a 71-year-old female patient with a history of aspirin use who developed paraparesis accompanied by SSEH following straining, and emphasize the importance of early surgical treatment.

Effects of sevoflurane and desflurane on cytokine response during tympanoplasty surgery

BACKGROUND

This study was devised to compare the effects of sevoflurane and desflurane anaesthesia on the cytokine response.

METHODS

Sixty ASA I-II patients, scheduled for tympanoplasty, were randomly allocated to be anaesthetized with either sevoflurane or desflurane at maintenance inspiratory concentrations of 1-1.5 MAC of either agent. Blood samples were taken for plasma tumour necrosis factor alpha (TNFalpha), interleukin 1beta and interleukin-6 assay before induction of anaesthesia, before surgery, and at the end of surgery. Alveolar cells were obtained after induction of anaesthesia and at the end of surgery.

RESULTS

Plasma TNFalpha was greater with desflurane than sevoflurane both before surgery (45.1 +/- 3.5 pg ml(-1) for desflurane vs. 23.2 +/- 2.5 pg ml(-1) for sevoflurane, P < 0.01) and (62.0 +/- 5.3 pg ml(-1) vs. 35.5 +/- 4.6 pg ml(-1), P < 0.001). Interleukin 1beta was similarly greater with desflurane than sevoflurane before (39.3 +/- 4.0 pg ml(-1) vs. 17.4 +/- 3.0 pg ml(-1); P < 0.01) and after surgery (46.0 +/- 3.4 pg ml(-1) vs. 23.3 +/- 3.2 pg ml(-1), P < 0.001). There were similar results for interleukin 6 before (42.3 +/- 3.5 pg mls(-1). 29.0 +/- 2.6 pg ml(-1), P < 0.001) and after surgery (86.0 +/- 4.5 pg ml(-1) vs. 45.9 +/- 6.3 pg ml(-1), P < 0.001). Alveolar cell TNFalpha concentrations after surgery were also greater with desflurane than sevoflurane (96.3 +/- 12.4 pg ml(-1) vs. 64.8 +/- 10.1 pg ml(-1), P < 0.001), as were interleukin 1beta (75.4 +/- 6.2 pg ml(-1) vs. 32.0 +/- 8.3 pg ml(-1), P < 0.001) and interleukin 6 concentrations (540.1 +/- 65.3 pg ml(-1) vs. 363.6 +/- 29.2 pg ml(-1), P < 0.001).

CONCLUSION

Desflurane appears to cause a greater systemic and intrapulmonary pro-inflammatory response than sevoflurane during anaesthesia for ear surgery.

Intradural disc mimicking: a spinal tumor lesion

STUDY DESIGN

A case report of intradural disc hernia mimicking an intradural extramedullary spinal tumor lesion in radiological evaluation.

OBJECTIVE

To describe a lumbar intradural disc herniation with atypical radiological appearance and point out the role of contrast magnetic resonance imaging (MRI) of the lumbar spine.

SETTING

Turkey.

CASE REPORT

A 58-year-old man with suspected lumbar intradural mass and neurological involvement received L5 total laminectomy. L5 total laminectomy was performed, and on inspection dura was swollen and immobile. A longitudinal incision was made in the dura and an intradural-free disc fragment was removed. The patient's postoperative period was uneventful and he had full recovery in 3 months.

CONCLUSIONS

Lumbar intradural disc rupture must be considered in the differential diagnosis of mass lesions causing nerve root or cauda equina syndromes. Contrast-enhanced MRI scans are useful to differentiate a herniated disc from a disc space infection or tumor. This case demonstrates the role and the importance of contrast MRI in the diagnosis of intradural disc herniation.

Correlation of the relationships of brain-tumor interfaces, magnetic resonance imaging, and angiographic findings to predict cleavage of meningiomas

OBJECT

The authors examined the relationships of brain-tumor interfaces, specific magnetic resonance (MR) imaging features, and angiographic findings in meningiomas to predict tumor cleavage and difficulty of resection.

METHODS

Magnetic resonance imaging studies, angiographic data, operative reports, clinical data, and histopathological findings were examined retrospectively in this series, which included 126 patients with intracranial meningiomas who underwent operations in which microsurgical techniques were used. The authors have identified three kinds of brain-tumor interfaces characterized by various difficulties in microsurgical dissection: smooth type, intermediate type, and invasive type. The signal intensity on T1-weighted MR images was very similar regardless of the type of brain-tumor interface (p > 0.1). However, on T2-weighted images the different interfaces seemed to correlate very precisely with the signal intensity and the amount of peritumoral edema (p < 0.01), allowing the prediction of microsurgical effort required during surgery. On angiographic studies, the pial-cortical arterial supply was seen to participate almost equally with the meningeal-dural arterial supply in vascularizing the tumor in 57.9% of patients. Meningiomas demonstrating hypervascularization on angiography, particularly those fed by the pial-cortical arteries, exhibited significantly more severe edema compared with those supplied only from meningeal arteries (p < 0.01). Indeed, a positive correlation was found between the vascular supply from pial-cortical arteries and the type of cleavage (p < 0.05).

CONCLUSIONS

In this analysis the authors proved that there is a strong correlation between the amount of peritumoral edema, hyperintensity of the tumor on T2-weighted images, cortical penetration, vascular supply from pial-cortical arteries, and cleavage of the meningioma. Therefore, the consequent difficulty of microsurgical dissection can be predicted preoperatively by analyzing MR imaging and angiographic studies.