Sex Differences under Vitamin D Supplementation in an Animal Model of Progressive Multiple Sclerosis

A central role for vitamin D (VD) in immune modulation has recently been recognized linking VD insufficiency to autoimmune disorders that commonly exhibit sex-associated differences. Similar to other autoimmune diseases, there is a higher incidence of multiple sclerosis (MS) in women, but a poorer prognosis in men, often characterized by a more rapid progression. Although sex hormones are most likely involved, this phenomenon is still poorly understood. Oxidative stress, modulated by VD serum levels as well as sex hormones, may act as a contributing factor to demyelination and axonal damage in both MS and the corresponding preclinical models. In this study, we analyzed sex-associated differences and VD effects utilizing an animal model that recapitulates histopathological features of the progressive MS phase (PMS). In contrast to relapsing-remitting MS (RRMS), PMS has been poorly investigated in this context. Male (n = 50) and female (n = 46) Dark Agouti rats received either VD (400 IU per week; VD+) or standard rodent food without extra VD (VD-) from weaning onwards. Myelination, microglial activation, apoptotic cell death and neuronal viability were assessed using immunohistochemical markers in brain tissue. Additionally, we also used two different histological markers against oxidized lipids along with colorimetric methods to measure protective polyphenols (PP) and total antioxidative capacity (TAC) in serum. Neurofilament light chain serum levels (sNfL) were analyzed using single-molecule array (SIMOA) analysis. We found significant differences between female and male animals. Female rats exhibited a better TAC and higher amounts of PP. Additionally, females showed higher myelin preservation, lower microglial activation and better neuronal survival while showing more apoptotic cells than male rats. We even found a delay in reaching the peak of the disease in females. Overall, both sexes benefitted from VD supplementation, represented by significantly less cortical, neuroaxonal and oxidative damage. Unexpectedly, male rats had an even higher overall benefit, most likely due to differences in oxidative capacity and defense systems.

Foramen of Monro meningioma with atypical appearance: CT and conventional MR findings

Intraventricular meningiomas have often been reported; however, literature reveals very few cases localized within foramen of Monro. Herein we report a 57-year-old woman admitted with obstructive hydrocephalus-related symptoms. Strikingly, the lesion was completely calcified in CT and had no marked solid component on MRI. The lesion was completely removed by surgical resection with a transfrontal intraventricular approach. The resected mass was histopathologically diagnosed as meningioma. The patient's symptoms resolved immediately after the operation.

Spinal dural arteriovenous fistula in a case with lipomyelodysplasia

Coexistence of a spinal dural arteriovenous fistula within a dysraphic spinal lesion is a very rare situation. We report a 40-year-old man who presented with low back pain and progressive paraparesis. MR images showed an intradural high signal intensity mass at the L2-L3 level containing irregular signal void structures. Spinal angiography revealed extradural arteriovenous fistula with three connections, drained by a tortuous perimedullary vein.

Intracranial myeloid sarcoma: conventional and advanced MRI findings

Chloroma (myeloid or granulocytic sarcoma) is a rare type of tumour comprising immature granulocytic cells. It generally accompanies acute myeloid leukaemia and, rarely, other myeloproliferative disorders. When presenting as dural-based mass lesions, radiological differential diagnosis includes meningioma, metastasis and lymphoma. There is a limited number of descriptions of chloromas mimicking dural-based masses in the literature. We present preliminary diffusion-weighted MR, perfusion-weighted MR and MR spectroscopy findings of an intracranial myeloid sarcoma.

Focal increased cortical density in immediate postembolization CT scans of patients with intracranial aneurysms

BACKGROUND AND PURPOSE

Cortical hyperdensity was observed in the immediate postembolization CT scans of some patients with intracranial aneurysms following uneventful endovascular treatments. The clinical significance and possible underlying mechanism were evaluated.

MATERIAL AND METHODS

Ninety-three consecutive patients with a total of 100 intracranial aneurysms, treated by endosaccular packing, were studied. Seventy-four aneurysms were treated with balloon assistance, and the remaining aneurysms were treated without balloon assistance. All patients underwent cranial CT just before and immediately after the endovascular treatment. If the post-treatment CT showed any new finding, an immediate MR imaging and a repeat CT 4-6 hours after the initial posttreatment CT were performed. Several parameters were investigated related to the presence of cortical hyperdensity.

RESULTS

Cranial CT showed focal cortical hyperdensity following the treatment of 40/74 aneurysms (54%) with balloon remodeling and 9/26 aneurysms (34.6%) without balloon assistance. None of these patients were symptomatic, and cortical hyperdensity resolved in the repeat CT scans. A statistically significant relationship was observed between the presence of this finding and the total amount of contrast material, microcatheter time, number of balloon inflations, and total balloon inflation time.

CONCLUSION

Immediate postembolization CT may show focal cortical hyperdensity following uneventful endovascular aneurysm treatment, most likely caused by blood-brain barrier disruption resulting in accumulation of contrast medium. The hyperdensity was more frequent when balloon assistance was used but was also seen in the patients with no balloon use. It is important to differentiate this clinically insignificant finding from possible hemorrhage, which would affect patients' immediate postprocedural medical management.

Functional MRI in Patients with Intracranial Lesions near Language Areas

We aimed to depict Broca's area and Wernicke's area by word generation and sentence formation paradigms in patients with various intracranial lesions adjacent to language areas using functional MRI technique and to evaluate the ability of functional MRI to lateralize the hemispheric dominance for language. Twenty-three right-handed patients were included in this study. Lesions were classified as low-grade glioma (n=8), high-grade glioma (n=9), metastasis (n=1), meningioma (n=1), arteriovenous malformation (n=2) and mesial temporal sclerosis (n=2). We performed blood-oxygenated-level-dependant functional MRI using a 1.5-T unit. Word generation and sentence formation tasks were used to activate language areas. Language areas were defined as Brodmann 44, 45 (Broca's area) and Brodmann 22 area (Wernicke's area). Laterality index was used to show the dominant hemisphere. Two poorly cooperative patients showed no activation and were excluded from the study. Broca's area was localized in 21 patients (100 %). Wernicke's area, on the other hand, could only be localized in eight of the 21 patients (38 %).The left hemisphere was dominant in 86% of patients while atypical language lateralization (right or bilateral) was demonstrated in 14% of the patients. Bilateral activation areas were shown in 10% of those patients while right cerebral hemisphere was dominant in 4% of the patients. Word generation and sentence formation tasks are especially helpful in localizing Broca's area. Wernicke's area could also be demonstrated in some of the cases. Functional MRI can be used as an important and useful means of demonstrating language areas in patients with lesions adjacent to those areas and depicting the hemispheric dominance.

Morphologic and volumetric analysis of amygdala, hippocampus, fornix and mamillary body with MRI in patients with temporal lobe epilepsy

Our aim was to demonstrate lateralization morphometrically and volumetrically measuring the main limbic structures like hippocampus, amygdala, fornix and mamillary bodies in patients with temporal lobe epilepsy (TLE) and to establish the contribution of each anatomical structure to lateralizing the pathological site. Forty-two patients with complex partial seizures originating from the temporal lobe and 42 control healthy volunteers were included in the study. T2-weighted FSE sequences in axial and oblique coronal planes and T1-weighted SE sequences in the sagittal plane were used. A high-resolution IR sequence was used for the volumetric analysis of amygdala and hippocampus and for the measurement of fornix and mamillary body thickness. Intensity changes and atrophy of limbic structures were observed qualitatively and measurement of these structures was performed quantitatively. Student's t test and Mann-Whitney U-test were used for the statistical analysis. The p values <0.05 was taken as statistically significant. Ten out of 42 patients had intracranial masses and were excluded from the study. Qualitative analysis revealed atrophy in 84% and intensity increase in 60% of cases. Quantitative measurement demonstrated that control cases had a larger hippocampus than the patients ( p<0.001). There was unilateral hippocampal volume loss in 88% and bilateral volume loss in 13% of patients. There was no difference in the volume of amygdala between the groups ( p>0.05). According to the difference in the volumes of the right and left sides, there was unilateral atrophy in 34% of patients. Bilateral atrophy was not observed. There was a significant difference in fornix and mamillary bodies of the patients and control subjects ( p<0.005). In 62.5% of cases, there were abnormalities in the fornix with bilateral involvement in 13% of cases. Mamillary bodies were abnormal in 37% of patients with bilateral involvement in 15%. Lateralization was accomplished in 65% of the patients according to the percentage difference ratios of fornix and in 38% of the patients according to the mamillary bodies. It is important to demonstrate hippocampus atrophy in patients with TLE. In the decision of lateralization of the epileptic side, evaluation of the fornix could be a good and practical solution. However, hippocampal volumetry is an indispensable criterion in demonstrating hippocampal atrophy more accurately. Atrophy of the amygdala and thickness of mamillary bodies have the least importance for lateralization.

Table-moving contrast-enhanced magnetic resonance angiography in the evaluation of lower extremity peripheral arterial bypass grafts

The aim of this study was to investigate the utility of table-moving contrast-enhanced three-dimensional MR angiography in the evaluation of lower extremity peripheral arterial bypass grafts. Twenty-two lower extremity peripheral arterial grafts (13 autologous saphenous vein, 7 polytetrafluoroethylene and 2 Dacron) in 18 patients were evaluated. Preoperative diagnosis were occlusive arterial segments in 14 cases, 4 aneurysms in 2 cases (3 aneurysms in one case) and traumatic femoral artery injury in 2 cases. 1.5T superconductive magnet was used with torso-phase and whole body coil system on MRI examinations. Lower extremity peripheral arterial grafts were evaluated and anastomosis sites were classified into five groups as normal, insignificant stenosis (< 50%), significant stenosis (> 50%), occlusion and ectatic or aneurysmatic appearance. Contrast-enhanced MR angiography imaging of 66 segments of 22 graft patients were of high quality. No difficulties were confronted in the radiological evaluation of peripheral bypass grafts. Graft stenosis as detected in five grafts. Stenotic segments were at the proximal (n = 4) and distal (n = 3) anastomosis sites. Total occlusion was shown in three grafts. Ectasia or aneurysm was seen in only one graft. In lower extremity peripheral bypass graft patients, table-moving contrast enhanced MR angiography can be used in the evaluation and follow-up of the vascular lesions.

Glioblastoma multiforme with atypical diffusion-weighted MR findings

The aim of this study is to review the diffusion-weighted MRI findings of glioblastomas, to investigate those with atypical characteristics and to emphasise the reasons responsible for the atypical features on diffusion-weighted MR images. 48 cases of histologically proven glioblastomas were included in this study. In addition to conventional sequences of routine tumour protocol, diffusion-weighted MRI with spin-echo echo-planar sequence was performed. The cystic-necrotic components of the lesions, according to the conventional sequences, were determined on the diffusion-weighted MR images and were classified as typical or atypical. The presence of high signal intensity was accepted as an atypical feature while low signal intensity was accepted as typical. The apparent diffusion coefficient (ADC) values of the cystic components were calculated. The statistical significance of the typical and atypical glioblastomas was evaluated with the students t-test. In six of the cases apparent high signal intensity in diffusion weighted MR images was interpreted. In three cases the high signal intensity occupied all of the cystic component and in the other three most of the cystic component. The ADC values of the lesions varied between 0.86 x 10(-3) mm(2) s(-1) and 1.39 x 10(-3) mm(2) s(-1) (mean value 1.06+/-0.17 x 10(-3) mm(2) s(-1)). In 42 of the lesions the cystic-necrotic component demonstrated low signal intensity and the ADC values varied between 1.56 x 10(-3) mm(2) s(-1) and 3.32 x 10(-3) mm(2) s(-1) (mean value 2.36+/-0.46 x 10(-3) mm(2) s(-1)). The difference between ADC values of atypical and typical lesions was statistically significant (p<0.001). The vast majority of glioblastomas do not exhibit restricted diffusion in diffusion-weighted MRI, but some of them display homogeneous or heterogeneous high signal intensity and decrease of ADC values. Diffusion-weighted MRI alone is not helpful in the differentiation of malignant tumours from abscesses with low ADC values and similar conventional MRI findings.

Transient splenial lesion of corpus callosum associated with antiepileptic drug: conventional and diffusion-weighted magnetic resonance images

Transient focal lesions of splenium of corpus callosum can be seen as a component of many central nervous system diseases, including antiepileptic drug toxicity. The conventional magnetic resonance (MR) findings of the disease are characteristic and include ovoid lesions with high signal intensity at T2-weighted MRI. Limited information exists about the diffusion-weighted MRI characteristics of these lesions vanishing completely after a period of time. We examined the conventional, FLAIR, and diffusion-weighted MR images of a patient complaining of depressive mood and anxiety disorder after 1 year receiving antiepileptic medication.

Is there a role of free oxygen radicals in primary male osteoporosis?

OBJECTIVE

There is not enough evidence about the relationship between free radicals and male osteoporosis. In this study we investigated the role of free oxygen radicals and antioxidants on male osteoporosis in 31 male patients with primary osteoporosis and 21 subjects as controls.

METHODS

Bone mineral densities (BMD) of the lumbar and femoral neck region were evaluated using dual energy X-ray absorbsiometry. Serum malondialdehyde (MDA) and nitric oxide (NO) levels and superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured by analytical methods. In addition, serum osteocalcine and C telopeptide levels were determined to evaluate bone turnover MDA and NO levels and SOD activity were significantly increased (p < 0.05) in osteoporotic males.

RESULTS

There was a negative correlation between SOD and lumbar BMD levels (r= -0.328; p = 0.021). The same trend was observed between NO and lumbar BMD (r = -0.473; p = 0.001) and femoral neck BMD values (r = -0.540; p = 0.000). There was no significant correlation between free radical levels and bone turnover markers.

CONCLUSION

The data indicate an increase in free oxygen radical levels. As a result, antioxidant defenses would compromise in primary male osteoporotic patients. Therefore, it may be suggested that oxidative stress plays an important role in the pathophysiology of primary male osteoporosis.

High-grade and low-grade gliomas: differentiation by using perfusion MR imaging

AIM

Relative cerebral blood volume (rCBV) is a commonly used perfusion magnetic resonance imaging (MRI) technique for the evaluation of tumour grade. Relative cerebral blood flow (rCBF) has been less studied. The goal of our study was to determine the usefulness of these parameters in evaluating the histopathological grade of the cerebral gliomas.

METHODS

This study involved 33 patients (22 high-grade and 11 low-grade glioma cases). MRI was performed for all tumours by using a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence followed by conventional MRI. The rCBV and rCBF were calculated by deconvolution of an arterial input function. The rCBV and rCBF ratios of the lesions were obtained by dividing the values obtained from the normal white matter of the contralateral hemisphere. For statistical analysis Mann-Whitney testing was carried out. A p value of less than 0.05 indicated a statistically significant difference. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBV and rCBF ratios and grade of gliomas. Their cut-off value permitting discrimination was calculated. The correlation between rCBV and CBF ratios and glioma grade was assessed using Pearson correlation analysis.

RESULTS

In high-grade gliomas, rCBV and rCBF ratios were measured as 6.50+/-4.29 and 3.32+/-1.87 (mean+/-SD), respectively. In low-grade gliomas, rCBV and rCBF ratios were 1.69+/-0.51 and 1.16+/-0.38, respectively. The rCBV and rCBF ratios for high-grade gliomas were statistically different from those of low-grade gliomas (p < 0.001). The rCBV and CBF ratios were significantly matched with respect to grade, but difference between the two areas was not significant (ROC analysis, p > 0.05). The cut-off value was taken as 1.98 in the rCBV ratio and 1.25 in the rCBF ratio. There was a strong correlation between the rCBV and CBF ratios (Pearson correlation = 0.830, p < 0.05).

CONCLUSION

Perfusion MRI is useful in the preoperative assessment of the histopathologicalal grade of gliomas; the rCBF ratio in addition to the rCBV ratio can be incorporated in MR perfusion analysis for the evaluation.

No effect of GA-AS (904 nm) laser irradiation on the intact skin of the injured rat sciatic nerve

We evaluated the electrophysiological and histopathological effects of low-energy gallium arsenide (904 nm) laser irradiation on the intact skin injured rat sciatic nerve. Twenty-four male Wistar rats were divided into three groups ( n=8 each). At the level of proximal third of the femur the sciatic nerve was crushed bilaterally with an aneurysm clip (Aesculap FE 751, Tuttingen, Germany) for half a second. A gallium arsenide laser (wavelength 904 nm, pulse duration 220 ns, peak power per pulse 27 W, spot size 0.28 cm2, pulse repetition rate 16, 128 and 1000 Hz; total applied energy density 0.31, 2.48 and 19 J/cm2) was applied to the right sciatic nerve for 15 min daily at the same time on 7 consecutive days. The same procedure was performed on the left sciatic nerve of same animal, but without radiation emission, and this was accepted as control. Compound muscle action potentials were recorded from right and left sides in all three groups before surgery, just at the end of injury, at the 24th hour and on the 14th and 21st days of injury in all rats using a BIOPAC MP 100 Acquisition System Version 3.5.7 (Santa Barbara, USA). BIOPAC Acknowledge Analysis Software (ACK 100 W) was used to measure CMAP amplitude, area, proximal and distal latency, total duration and conduction velocity. Twenty-one days after injury, the rats were sacrificed. The sciatic nerves of the operated parts were harvested from the right and left sides. Histopathological evaluation was performed by light microscopy. Statistical evaluation was done using analysis of variance for two factors (right and left sides) repeated-measures (CMAP variables within groups) and the Tukey-Kramer Honestly Significant Difference test (CMAP variables between laser groups). The significance was set at p < 0.05. No statistically significant difference (p > 0.05) was found regarding the amplitude, area, duration and conduction velocity of CMAP for each applied dose (0.31, 2.48 and 19 J/cm2) on the irradiated (right) side and the control (left) side, or between irradiated groups. Twenty-one days after injury there were no qualitative differences in the morphological pattern of the regenerated nerve fibres in either irradiated (0.31, 2.48 and 19 J/cm2) or control nerves when evaluated by light microscopy. This study showed that low-energy GaAs irradiation did not have any effect on the injured rat sciatic nerve.