Large occipital nerve (Arnold’s nerve) schwannoma

A 37 year-old man who had a ten years history of remitting and intermittently severe neck pain with a suboccipital mass is presented. On initial neurological examination there was no abnormal finding except little mass in the posterior neck. Following physical examination radiological evaluation was requested. In sagittal pre (A) and postcontrast (B) T1W images the lesion in between cervical 2 and 3 spinal process (arrow). The lesion was well defined, encapsulated, heterogeneously enhanced in 2.5 x 2 cm size. There was no bony destruction but remodeling. On axial image the configuration and the location in the semispinalis capitis muscle was easily identified easily (C). The patient underwent operation and final pathologic and radiologic diagnosis was schwannoma with Antoni A cells which was originated from the greater occipital nerve

Can taraxacum officinale (dandelion) extract be an alternative of paracetamol in inflammatory and painful cases? an evaluation with regard to biochemical and reproductive parameters

The aim of this study was to investigate the usage of Taraxacum officinale extract (TOE) in inflammatory and painful cases as an alternative to paracetamol (PRC) through the assessment of biochemical and reproductive parameters. Totally, 30 male Sprague Dawley rats aged eight weeks old, were used in this study. The animals were obtained from Atatürk University Experimental Research and Application Centre and kept under standard laboratory conditions. Commercial pellet chow and fresh drinking water were available ad libitum. Rats were divided into five groups: Group I (n= 6); referred as control. Group II (n=6); referred as TOE150 (150 mg/kg). Group III (n=6); referred as TOE200 (200 mg/kg). Group IV (n=6); referred as TOE250 (250 mg/kg). Group V (n=6); referred as Paracetamol (PRC) (2 g/kg). The treatment was performed for consecutive 8 days. The animals were tranquilized and sacrificed on 9th day of study. Blood samples, cauda epididymal semen samples and testes tissues were collected. Routine semen examinations were performed and oxidative stress levels of testicular tissues were assayed. Reproductive organ weights [total testes weight (TTW) and total cauda epididymal weights (TCEW)] were recorded. Motility in TOE250 group was significantly higher when compared to the other groups (P<0.05). Velocity of sperm cells in PRC group was significantly lower when compared to the other groups (P<0.05). Dead sperm rate in control group was significantly higher when compared to the other groups (P<0.001). On the other hand, the lowest TCEW was in TOE150 group (P<0.05). There were no differences in terms of TTW among all groups. Malondialdehyde (MDA) level of PRC group was significantly higher than the treatment groups (P<0.05). Besides, glutathione peroxidase (GPx) levels of PRC group were lower than the other groups (P<0.001). Superoxide dismutase (SOD) level of PRC group was significantly lower than the treatment groups (P<0.001). The lowest catalase (CAT) level was in PRC group and the highest glutathione (GSH) level was in T200 group (P<0.001). In conclusion, it was observed that TOE could use as alternative of PRC and hence can be avoided from negative effects of PRC on biochemical and reproductive parameters

Applicability of current staging/categorization of α-synuclein pathology and their clinical relevance

In Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) α-synuclein (αS) pathology is seen that displays a predictable topographic distribution. There are two staging/categorization systems, i.e. Braak’s and McKeith’s, currently in use for the assessment of αS pathology. The aim of these diagnostic strategies in pathology is, in addition to assess the stage/severity of pathology, to assess the probabilities of the related clinical symptomatology i.e. dementia and extrapyramidal symptoms (EPS). Herein, we assessed the applicability of these two staging/categorization systems and the frequency of dementia and EPS in a cohort of 226 αS-positive-subjects. These subject were selected from a large autopsy sample (n = 1,720), irrespective of the clinical presentation, based on the detection of αS-immunoreactivity (IR) in one of the most vulnerable nuclei; in the dorsal motor nucleus of vagus, substantia nigra and basal forebrain. The frequency of αS-IR lesions in this large cohort was 14% (248 out of 1,720). If applicable, each of the 226 subjects with all required material available was assigned a neuropathological stage/category of PD/DLB and finally the neuropathological data was analyzed in relation to dementia and EPS. 83% of subjects showed a distribution pattern of αS-IR that was compatible with the current staging/categorization systems. Around 55% of subjects with widespread αS pathology (Braak’s PD stages 5–6) lacked clinical signs of dementia or EPS. Similarly, in respect to those subjects that fulfilled the McKeith criteria for diffuse neocortical category and displaying only mild concomitant Alzheimer’s disease-related pathology, only 48% were demented and 54% displayed EPS. It is noteworthy that some subjects (17%) deviated from the suggested caudo-rostral propagation suggesting alternative routes of progression, perhaps due to concomitant diseases and genetic predisposition. In conclusion, our results do indeed confirm that current staging/categorization systems can readily be applied to most of the subjects with αS pathology. However, finding that around half of the subjects with abundant αS pathology remain neurologically intact is intriguing and raises the question whether we do assess the actual disease process

The Free Energy Landscape of Small Molecule Unbinding

The spontaneous dissociation of six small ligands from the active site of FKBP (the FK506 binding protein) is investigated by explicit water molecular dynamics simulations and network analysis. The ligands have between four (dimethylsulphoxide) and eleven (5-diethylamino-2-pentanone) non-hydrogen atoms, and an affinity for FKBP ranging from 20 to 0.2 mM. The conformations of the FKBP/ligand complex saved along multiple trajectories (50 runs at 310 K for each ligand) are grouped according to a set of intermolecular distances into nodes of a network, and the direct transitions between them are the links. The network analysis reveals that the bound state consists of several subbasins, i.e., binding modes characterized by distinct intermolecular hydrogen bonds and hydrophobic contacts. The dissociation kinetics show a simple (i.e., single-exponential) time dependence because the unbinding barrier is much higher than the barriers between subbasins in the bound state. The unbinding transition state is made up of heterogeneous positions and orientations of the ligand in the FKBP active site, which correspond to multiple pathways of dissociation. For the six small ligands of FKBP, the weaker the binding affinity the closer to the bound state (along the intermolecular distance) are the transition state structures, which is a new manifestation of Hammond behavior. Experimental approaches to the study of fragment binding to proteins have limitations in temporal and spatial resolution. Our network analysis of the unbinding simulations of small inhibitors from an enzyme paints a clear picture of the free energy landscape (both thermodynamics and kinetics) of ligand unbinding

Relativistic K shell decay rates and fluorescence yields for Zn, Cd and Hg

In this work we use the multiconfiguration Dirac-Fock method to calculate the transition probabilities for all possible decay channels, radiative and radiationless, of a K shell vacancy in Zn, Cd and Hg atoms. The obtained transition probabilities are then used to calculate the corresponding fluorescence yields which are compared to existing theoretical, semi-empirical and experimental results