Evaluation of the Efficacy of Sildenafil Citrate Following Severe Head Trauma in an Experimental Rat Model.

AIM: To investigate the acute effects of sildenafil citrate in an experimental model of severe head trauma, and to compare it with the efficacy of mannitol, which is an osmotically active agent frequently used in clinical treatment of traumatic brain injury (TBI). MATERIAL AND METHODS: Twenty-eight Wistar-derived albino strain female rats were randomized into four groups comprising seven rats each. These groups were designated as follows: Group I: sham; Group II: TBI; Group III: TBI + mannitol (20% 1 gr/ kg, intraperitoneal); and Group IV: TBI + sildenafil citrate (10 mg/kg, intraperitoneal). Sections prepared following the tissue processing of samples obtained from the right prefrontal cortex and right hippocampal regions of the brains of sacrificed rats were histopathologically evaluated. Fractionator method via the Stereo Investigator software program (Micro Bright Field) was used to count the neurons. Pyknotic neuron count and pyknotic / total neuron count were compared between the groups. RESULTS: In the comparison of Group II and IV, pyknotic neuron count (prefrontal; group II: 116.00 ± 30.50, group IV: 80.00 ± 19.47) and pyknotic/ total neuron count (prefrontal; group II: 0,30 ± 0.08, group IV: 0.21 ± 0.02) were significantly lower in Group IV in both regions (p < 0.05). Similarly, in the comparison of Group II and III, the values in Group III were lower in both regions (p < 0.05). CONCLUSION: Sildenafil citrate decreases neuronal death in the acute phase and produces similar results with mannitol. Therefore, we believe that sildenafil citrate can be a useful adjunct or alternative agent for the clinical treatment of patients with acute TBI.

Stereological Evaluation of the Optic Nerve Volume in Alzheimer Disease.

Optic nerve damage occurs in Alzheimer disease (AD) related to the loss of the retinal ganglion cells that contribute fibers to the optic nerve and reduction of the density of axons of the optic nerve. In this study the authors evaluated optic nerve volume changes and the relation between the cerebrum and optic nerve volumes in AD patients. The study evaluated the volumetric measurements of optic nerve by applying the stereological method on magnetic resonance images (MRI). It included age-matched study and control groups, which were composed of 20 patients with probable AD and 20 healthy subjects, respectively. MRIs were analyzed by using the point-counting approach holding Cavalieri principle. There were statistically significant optic nerve volume reduction and cerebral atrophy in AD patients when compared with the age-matched control subjects (P = 0.013, P < 0.001, respectively) but there was no correlation between the optic nerve volume and cerebral volume in AD patients (r = 0.326, P = 0.160). There was a difference between optic nerve volumes of AD and control subjects. The stereological evaluation of optic nerve volume is of importance for both clinicians and anatomists and it can provide valuable information in the evaluation of morphological changes of AD in vivo.

Comparison of the Effects of 13-cis Retinoic Acid and Melatonin on the Viabilities of SH-SY5Y Neuroblastoma Cell Line.

OBJECTIVE: Neuroblastoma is one of common childhood tumors. Although its mortality is very high, there is no effective treatment yet. The aim of this project is to evaluate cytotoxic effects of melatonin (MLT) an endogen hormone and 13-cis retinoic acid (13-cis-RA) also named as isotretinoin an analogue of vitamin A on neuroblastoma SH-SY5Y cell line. METHODS: In this study, SH-SY5Y cell line was used. After cell culture, the cells were exposed to different doses of MLT and 13-cis-RA. 24 and 48 hours later. While the viabilities was estimated with MTT cell viability assay test, apoptotic indexes were calculated after staining with TUNEL based apoptosis kit. RESULTS: It was observed that MLT has very effective cytotoxic potential than 13-cis-RA on neuroblastoma cell line. At the same time, when MLT and 13-cis-RA were combined, this effect was potentiated. On the other hand, it was found that the effect of 13-cis-RA individually on neuroblastoma cells was very slight. CONCLUSION: We suggest that in the treatment of patient with neuroblastoma, MLT is very effective and also this effect can be augmented by combination with 13-cis-RA.

Effect of ligamenta flava hypertrophy on lumbar disc herniation with contralateral symptoms and signs: a clinical and morphometric study.

INTRODUCTION: The purpose of this study was to determine whether ligamentum flavum hypertrophy among disc herniated patients causes contralateral pain symptoms. For this reason we measured the thickness of the ligament in disc herniated patients with ipsilateral or contralateral symptoms. MATERIAL AND METHODS: Two hundred disc herniated patients with ipsilateral symptoms as group I were compared with five disc herniated patients with only contralateral symptoms as group II. Ligamenta flava thicknesses and spinal canal diameters of both groups were measured on magnetic resonance imaging (MRI) with a micro-caliper. RESULTS: Both groups underwent surgery only on the disc herniated side. The total thicknesses of the ligamenta flava in group II was thicker than in group I. There was no spinal stenosis in either group and no significance difference between the groups. Statistically significant differences were found for both ipsilateral and contralateral thickness of the ligament flava in both groups. We also compared thickness of the ligamenta flava for each level of disc herniation in group I; ligamenta flava hypertrophy was more common at L3-L4 and L4-L5 levels of vertebrae in females. CONCLUSIONS: Aetiology of contralateral sciatica among disc herniated patients may be related to hypertrophy of the ligamenta flava, especially on the opposite side. Surgical approaches of the disc herniated side alone may be sufficient for a good outcome.

Evaluation of cerebellar asymmetry in Alzheimer's disease: a stereological study.

OBJECTIVES: Alzheimer's disease (AD) is the most common cause of dementia and, as previous studies have indicated, degenerative changes in the cerebellum occur in AD. It is well known that the cerebellum does not have a symmetric morphology and some pathological disorders, such as schizophrenia, epilepsy, autism and alcoholism, can cause asymmetrical changes in the cerebellum. In this study, we aimed to evaluate whether or not patients with AD show cerebellar asymmetry. We also intended to depict the probable volumetric asymmetry by using a stereological technique. MATERIALS AND METHODS: The study evaluated the volumetric measurements of each cerebellar hemisphere by applying a stereological method to MR images. This age- and gender-matched study was composed of 15 patients with probable AD and 14 healthy subjects (controls). MR images were analyzed by using the point-counting approach, holding to Cavalieri's principle. RESULTS: Although there was significant cerebellar atrophy in AD patients, the study showed no statistically significant cerebellar asymmetry according to age and gender, both in the study and control groups (p > 0.05). CONCLUSIONS: There was no difference in cerebellar asymmetry associated with age and gender between the AD patients and control subjects. The stereological evaluation of cerebellar asymmetry correlating with gender is of importance to both clinicians and anatomists. The technique is simple, inexpensive, reliable and unbiased.

The premasseteric branch of facial artery: its importance for craniofacial surgery.

AIM: The masseter muscle is often exploited by craniofacial surgeons in transposition operations to correct facial palsy, benign masseteric hypertrophy; or neurectomy-induced atrophy of the muscle. A clear understanding of the course of the premasseteric branch of the facial artery and its relations with adjacent structures is essential in maneuvering the masseter muscle safely. In the present study the premasseteric branch was analyzed in details. MATERIAL AND METHODS: Neurovascular and anatomical features and relations of the premasseteric branch and its branches were evaluated according to location, origin, diameter, length and course by bilateral meticulous anatomic micro dissection under 4x loop magnification in formalin fixed 14 adult preserved cadavers. RESULTS: The premasseteric branch originated separately from the facial artery in all cases. The course of the branch was observed to the upper anterior border of the masseter muscle. The diameter of the premasseteric branch was 1.12 mm (mean) at the level of origin. The diameter of the premasseteric branch was larger than the facial artery in 3% of cases. The location of the branch was defined according to body of the mandible. Branches and anastomoses of the premasseteric branch were also represented. CONCLUSION: Anatomical data of the premasseteric branch will help craniofacial surgeons elevate flaps safely.

Stereological evaluation of the volume and volume fraction of intracranial structures in magnetic resonance images of patients with Alzheimer's disease.

In this study, we describe and adapt the relevant methods of magnetic resonance (MR) and stereology to estimate total brain volume (TBV), cerebral and cerebellar volume and their volume fractions within the brain. The study included 15 (8 males, 7 females) controls and 15 (8 males, 7 females) patients with Alzheimer's disease. The patients' MR images were obtained in both sagittal and axial planes. The volume and volume fraction of the total brain, cerebrum and cerebellum were determined on MR images using the point-counting approach of stereological methods. The volume fractions of the cerebrum to TBV and cerebellum to TBV in the control group were 66.38% and 67.87% in axial and sagittal planes, and 12.05% and 12.81% in axial and sagittal planes, respectively. The volume fractions of the cerebrum to TBV and cerebellum to TBV in the Alzheimer group were 52.40% and 56.26% in axial and sagittal planes, and 10.00% and 10.38% in axial and sagittal planes, respectively. The Alzheimer subjects showed significantly lower cerebral and cerebellar volume fraction to TBV than the control subjects (p<0.001). No significant difference was found in either group with regard to gender or planes (p>0.05). The present evaluation of TBV, cerebral and cerebellar volume and volume fractions can be done on any complete set of MR imaging, in which the plane scan distance and magnification factor are known, as they are in MRI. In conclusion, the cerebral and cerebellar to TBV volume fractions can be important tools in determining brain atrophy and can be estimated by the stereological method.

Stereological evaluation of volumetric asymmetry in healthy human cerebellum.

OBJECTIVES: Age-related volumetric differences in brain anatomy or volumetric brain analyses in many disorders are of interest. Delineating the normal anatomical cerebellar volume is of importance for both the anatomists and clinicians. In the present study, we aimed to evaluate the cerebellar volume using a stereological technique and to determine the possible volumetric asymmetry depending on age and gender. MATERIALS AND METHODS: Volumetric asymmetry of cerebellar hemispheres was evaluated using stereological method on the magnetic resonance images (MRI) of healthy male and female subjects. Randomly selected individuals (27 males, 27 females) aged between 10-86 years who have normal brain MRI were enclosed in the study. All the subjects were right handed. The individuals were divided into three groups according to age as 18-34 (young), 35-60 (middle aged) and 60-84 (elder) and their MRI images were analyzed. The data set were analyzed by two factor repeated measure analysis. RESULTS: Although the cerebellum was smaller between young and middle aged groups and also middle aged and elder groups, there were no any statistically significant differences between compared groups' mean (P > 0.05). There were not statistically differences according to sex and age groups (P > 0.05). CONCLUSIONS: There was no cerebellar asymmetry between compared groups. The stereological evaluation of cerebellar asymmetry in humans correlate with both gender and age groups is of importance for both clinicians and anatomists. The technique is simple, reliable, unbiased and inexpensive.