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SUMMARYα-Synuclein (α-Syn) aggregation and amyloid formation is directly linked with Parkinson’s disease (PD) pathogenesis. However, the early events involved in this process remain unclear. Here, using in vitro reconstitution and cellular model, we show that liquid-liquid phase separation (LLPS) of α-Syn precedes its aggregation. In particular, in vitro generated α-Syn liquid-like droplets eventually undergo a liquid-to-solid transition and form amyloid-hydrogel containing oligomers and fibrillar species. Factors known to aggravate α-Syn aggregation such as low pH, phosphomimic substitution, and familial PD mutation also promote α-Syn LLPS and its subsequent maturation. We further demonstrate α-Syn liquid droplet formation in cells, under oxidative stress. These cellular α-Syn droplets eventually transform into perinuclear aggresomes, the process regulated by microtubules. The present work provides detailed insights into the phase separation behavior of natively unstructured α-Syn and its conversion to a disease-associated aggregated state, which is highly relevant in PD pathogenesis.

Background The diagnosis of temporomandibular disorders (TMDs), specifically TMD myalgia, can be challenging. Although the anatomy of the jaw muscles has been extensively characterized, a structural difference in TMD-myalgia individuals has never been demonstrated. Tendons are a highly specialized tissue with a predominately mechanical function. Collagen fibrils, the main contributor to tendon mechanical properties, begin macroscopic failure at 8% to 10% strain. The characterization of tendon/muscle abnormalities in individuals with chronic, painful TMD myalgia will lay the groundwork for utilizing noninvasive magnetic resonance imaging (MRI) for screening and objective monitoring of patients with TMD myalgia. A structural marker unique to TMD myalgia will aid in its diagnosis and treatment. Objective(s) This study aimed to determine differences in the tendon/muscle volume ratio of the temporalis muscle in patients with TMD myalgia compared with age-/gender-matched controls without facial pain. Study Design This was a retrospective, observational study of the temporalis muscle and tendon on MRI images. The comparison between groups was based on a voxel-based morphometry of anatomic T1-weighted MRI images and analyzed for differences in the tendon/muscle volume ratio. The study included at least 14 patients per group to detect a 5% difference in tendon/muscle volume ratio. An intraclass correlation coefficient was used to evaluate the intrarater test–retest reliability. General linear models were used to test whether the outcome measures (muscle/tendon volume, muscle/tendon T1 signal intensity, tendon/muscle ratio) are different between groups. Results Our pilot data demonstrated similar muscle volumes but significantly smaller tendon volumes and signal intensity when comparing patients with TMD myalgia with healthy controls (P Discussion/Conclusions Preliminary data suggest that chronic TMD myalgia may be associated with structural abnormalities of the temporalis tendon. Should the temporalis tendon/muscle volume ratio prove to be a reliable marker, this metric may be used to evaluate different treatment modalities in a noninvasive manner.

Autoregulation of blood flow is essential for the preservation of organ function to ensure continuous supply of oxygen and essential nutrients and removal of metabolic waste. This is achieved by controlling the diameter of muscular arteries and arterioles that exhibit a myogenic response to changes in arterial blood pressure, nerve activity and tissue metabolism. Large-conductance voltage and Ca(2+)-dependent K(+) channels (BK channels), expressed exclusively in smooth muscle cells (SMCs) in the vascular wall of healthy arteries, play a critical role in regulating the myogenic response. Activation of BK channels by intracellular, local, and transient ryanodine receptor-mediated "Ca(2+) sparks," provides a hyperpolarizing influence on the SMC membrane potential thereby decreasing the activity of voltage-dependent Ca(2+) channels and limiting Ca(2+) influx to promote SMC relaxation and vasodilation. The BK channel α subunit, a large tetrameric protein with each monomer consisting of seven-transmembrane domains, a long intracellular C-terminal tail and an extracellular N-terminus, associates with the β1 and γ subunits in vascular SMCs. The BK channel is regulated by factors originating within the SMC or from the endothelium, perivascular nerves and circulating blood, that significantly alter channel gating properties, Ca(2+) sensitivity and expression of the α and/or β1 subunit. The BK channel thus serves as a central receiving dock that relays the effects of the changes in several such concomitant autocrine and paracrine factors and influences cardiovascular health. This chapter describes the primary mechanism of regulation of myogenic response by BK channels and the alterations to this mechanism wrought by different vasoactive mediators.

Aggregation of alpha-Synuclein (alpha-Syn) into amyloid fibrils is known to be associated with the pathogenesis of Parkinson's disease (PD). Several missense mutations of the a-Syn gene have been associated with rare, early onset familial forms of PD. Despite several studies done so far, the local/residue-level structure and dynamics of alpha-Syn in its soluble and aggregated fibril form and how these are affected by the familial PD associated mutations are still not clearly understood. Here, we review studies performed by our group as well as other research groups, where time-resolved fluorescence spectroscopy has been used to understand the site-specific structure and dynamics of alpha-Syn under physiological conditions as well as under conditions that alter the aggregation properties of the protein such as low pH, high temperature, presence of membrane mimics and familial PD associated mutations. These studies have provided important insights into the critical structural properties of alpha-Syn that may govern its aggregation. The review also highlights time-resolved fluorescence as a promising tool to study the critical conformational transitions associated with early oligomerization of alpha-Syn, which are otherwise not accessible using other commonly used techniques such as thioflavin T (ThT) binding assay.

Polychlorinated biphenyls (PCBs) comprise a ubiquitous class of toxic substances associated with carcinogenic and tumor-promoting effects as well as neurotoxic properties. Reactive oxygen species, which is produced from PCBs, alters blood–brain barrier (BBB) integrity, which is paralleled by cytoskeletal rearrangements and redistribution and disappearance of tight junction proteins (TJPs) like claudin-5 and occludin. Quercetin, a potent antioxidant present in onion and other vegetables, appears to protect brain cells against oxidative stress, a tissue-damaging process associated with Alzheimer’s and other neurodegenerative disorders. The aim of this study is to analyze the role of quercetin on oxidative stress markers and transcription of transmembrane and cytoplasmic accessory TJPs on cerebrum, cerebellum and hippocampus of female rats exposed to PCBs. Rats were divided into the following four groups. Group I: received only vehicle (corn oil) intraperitoneally (i.p.); group II: received Aroclor 1254 at a dose of 2 mg/kg body weight (bwt)/day (i.p); group III: received Aroclor 1254 (i.p.) and simultaneously quercetin 50 mg/kg bwt/day through gavage and group IV: received quercetin alone gavage. From the experiment, the levels of hydrogen peroxide, lipid peroxidation and thiobarbituric acid reactive substances were observed to increase significantly in cerebrum, cerebellum and hippocampus as 50%, 25% and 20%, respectively, after exposure to PCB, and the messenger RNA expression of TJP in rats exposed to PCBs is decreased and is retrieved to the normal level simultaneously in quercetin-treated rats. Hence, quercetin can be used as a preventive medicine to PCBs exposure and prevents neurodegenerative disorders.

The aim is to study the effect of Tartrazine (E102) - synthetic food colour - on the antioxidant status of testis of Wistar rats. Twelve male Wistar rats were grouped into 2 groups of six each - Control and Tartrazine-treated groups. Control group was orally administered with water alone while the experimental group was orally administered with tartrazine dissolved in water. The treatment was carried out for 60 days and the activities of antioxidant enzymes - superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) and the levels of their cofactors were subsequently determined in the testis, along with histological studies. Activities of the 4 enzymes showed a common decrease with corresponding alterations in their cofactor levels. The colour orally administered to the experimental animals probably would have generated reactive oxygen species (ROS) and H2O2, thereby disrupting the enzymatic antioxidant defense of their testes. Tartrazine is capable of producing free radicals, which in turn cause damage to the cellular compartment system of rat testis.

The protective role of lycopene against various toxicants on various organs and its association with decreased oxidative stress seems to be well established. Sertoli cell function in the adult testis determines daily sperm production. Increasing evidence suggests that environmental pollutants including polychlorinated biphenyls (PCBs) are male infertility, which is associated with oxidative stress. Hence, the present study was designed to find out whether PCBs disrupt Sertoli cell function by inducing oxidative stress or endocrine disruption? Whether lycopene attenuates PCBs-induced disruption in Sertoli cells or not? Adult male rats were divided into four (vehicle control, lycopene, PCBs and PCBs + lycopene treated) groups. After the experimental period (30 days), the animals were decapitated for the blood collection and testes were removed for the isolation of Sertoli cells. In PCBs exposure, serum hormones (FSH, testosterone and estradiol), Sertoli cellular receptors (FSHR and AR) were significantly decreased whereas oxidative stress markers (H 2 O 2 and LPO) and ER-s expression in Sertoli cells were significantly increased. Sertoli cell functional proteins such as connexin 43, transferrin and androgen-binding protein expressions and the level of lactate were significantly decreased. However, simultaneous supplementation of lycopene to PCBs-exposed rats significantly decreased the endocrine disruption and oxidative stress in Sertoli cells. The findings point out that lycopene protects the Sertoli cell function by preventing PCBs-induced oxidative stress and endocrine disruption.

Prostate cancer is a leading cause of death among the aging men. Surgical or radiotherapy is effective when the cancer is confined to the prostate gland but once the cancer spreads beyond the pelvis even chemotherapy and hormonal ablation therapy fails in curing this disease. Our previous studies have shown that diallyl disulfide (DADS) induces cell cycle arrest and also induces apoptosis in PC-3 cells. And now the present study is focused to see whether there is an activation of caspase cascade pathway. Hence, in the present study the apoptotic effect of DADS is studied by Western blot analysis of caspase-3, -9, -10 and Bcl-2, Bad, and Bax protein. The Apoptotic cells were assessed by Hoechst 33342 staining with 25 and 40 microM concentrations of DADS for 24 h. The results have shown that DADS at 25 and 40 microM concentrations has induced the activation of caspases. There is a significant increase in the expression of caspases (3, 9, and 10). The proapoptotic protein Bax has significantly increased at 40 microM of DADS treatment and there is significant increase of Bad protein at both the concentration. Bcl-2 protein has significantly decreased in DADS treated cells. Therefore, the present investigation serves as evidence that DADS may be a therapeutic drug in the treatment of prostate cancer.

The central role of collagen as the major structural fibrous protein in the mammalian extracellular matrix has motivated a significant effort toward the determi- nation of its mechanical properties at all levels, ranging from single monomers and long-chain polymers to a structural element within a biological tissue. However, the stabiliza- tion of collagen against collagenolytic degradation finds sig- nificance in biomedical and industrial applications. Tannins are plant-derived polyphenols that have the ability to inhibit the collagenase activity at minimum concentration. The in- hibitory effect of wattle (Acacia mollissima) and myrobalan (Terminalia chebula) on the action of collagenase against colla- gen was probed in this study. The kinetics of the inhibition of collagenase by wattle and myrobalan was deduced from the extent of hydrolysis of 2-furanacryloyl-L-leucyl-glycyl- L-prolyl-L-alanine. Both wattle and myrobalan tannin exhib- ited competitive modes of inhibition against collagenase. Circular dichroism studies of collagenase on treatment with wattle and myrobalan revealed changes in the secondary structure of collagenase. These results suggest that the tan- nins of A. mollissima and T. chebula extracts facilitated colla- gen stabilization through collagenase inhibition. 2007

Inhibitory effect of green tea polyphenols viz., catechin and epigallocatechin gallate (EGCG) on the action of collagenase against collagen has been probed in this study. Catechin and EGCG treated collagen exhibited 56 and 95% resistance, respectively, against collagenolytic hydrolysis by collagenase. Whereas direct interaction of catechin and EGCG with collagenase exhibited 70 and 88% inhibition, respectively, to collagenolytic activity of collagenase against collagen and the inhibition was found to be concentration dependent. The kinetics of inhibition of collagenase by catechin and EGCG has been deduced from the extent of hydrolysis of (2-furanacryloyl-L-leucyl-glycyl-L-prolyl-L-alanine), FALGPA. Both catechin and EGCG exhibited competitive mode of inhibition against collagenase. The change in the secondary structure of collagenase on treatment with catechin and EGCG has been monitored using circular dichroism spectropolarimeter. CD spectral studies showed significant changes in the secondary structure of collagenase on treatment with higher concentration of catechin and EGCG. Higher inhibition of EGCG compared to catechin has been attributed to the ability of EGCG to exhibit better hydrogen bonding and hydrophobic interaction with collagenase.

Various epidemiological survey suggests that the central nervous system is the target for many environmental contaminants. One among them is Aroclor 1254, a mixture of polychlorinated biphenyls (PCBs) which explore a spectrum of biochemical and neurotoxic responses in humans and laboratory animals. Learning and motor coordination deficits are the profound effects of PCBs which may be related to cerebral dysfunction. The aim of the study is to elicit the protective effect of melatonin (Mel), a potent, blood brain permeable antioxidant against the effect of Aroclor 1254 on the signaling of glutamate-principal excitatory neurotransmitter and brain derived neurotrophic factor (BDNF) in the cerebral cortex of adult rats which plays a key role in brain functions. Adult male Wistar rats were grouped into four and treated intraperitonealy (i.p) Group I with corn oil (Control), Group II with PCBs (2 mg/kg/bwt), Group III with PCBs + Mel (2 mg/kg/bwt + 5 mg/kg/bwt) and Group IV with Mel (5 mg/kg/bwt). The protein expression of glutamate signaling molecules and mRNA expressions of GLAST, BDNF signaling molecules were analyzed. The results suggest that simultaneous melatonin treatment significantly attenuated the NMDA receptor mediated glutamate excitotoxicity and protects the inhibition of BDNF signaling caused by PCBs exposure in cerebral cortex of adult male rats. Schematic pathway illustrating the proposed mechanism by which melatonin protects against A1254 mediated glutamate induced neurodegeneration in the cerebral cortex of adult male rats. PCBs induced neurodegeneration is caused by the overactivation of NMDAR, followed by the activation of voltage dependent calcium channels leading to the increase in intracellular Ca(2+) that stimulates calpain. Calpain inturn inhibits the PKA α and neurtrophin BDNF, its receptor and downstream signaling MAPK pathway leading to neurodegeneration. Melatonin had scavenged the ROS produced by PCBS and decreased the NMDAR expression which inturn protected the cells from neurodegeneration.

Polychlorinated biphenyls (PCBs) are widespread persistent environmental contaminants that display a complex spectrum of toxicological properties, including neurotoxicity. Studies have shown that PCBs increase oxidative stress in brain, leading to apoptosis. The progressive loss of neurons in cerebral cortex and cerebellum, leads to various neurodegenerative diseases. Hence the present study is designed to determine PCBs toxicity toward neuronal cells and whether it could be inhibited by potent antioxidant melatonin. Four groups of adult male Wistar rats were treated for 30 days with corn oil, PCBs, PCBs+Mel and Melatonin, respectively. After treatment period the rats were euthanized and the brain was dissected to isolate cerebral cortex and cerebellum. The neuronal cells alone were then separated from the isolated brain regions, to detect the mRNA levels of apoptotic and neurofilament gene, a neuronal specific marker. Our results suggests that PCBs induces apoptosis in neuronal cells which is subsided by the anti apoptotic effect of melatonin.

Urokinase-type plasminogen activator (uPA) is a serine protease that is involved in cancer progression, especially invasion and metastasis including prostate cancer. uPA activation is mediated by transactivation of uPAR and epidermal growth factor receptor (EGF-R) in prostate cancer progression. Prostate cancer (PC-3) cells have highly invasive capacity and they express uPA and uPAR gene. PC-3 cells are treated with quercetin, which inhibits invasion and migration of PC-3 cells. Quercetin downregulates uPA, uPAR and EGF, EGF-R mRNA expressions. Quercetin inhibits cell survival factor β-catenin, NF-κB and also proliferative signalling molecules such as p-EGF-R, N-Ras, Raf-1, c.Fos c.Jun and p-c.Jun protein expressions. But quercetin increased p38 mitogen-activated protein kinase protein expression. Our results suggest that quercetin inhibit migration and invasion of prostate cancer cells. It shows the value for treatment of invasive and metastasis type of prostate cancer.

The antitumour activity of the methanolic extract of Glinus lotoides (MGL) has been evaluated against Dalton's ascitic lymphoma (DAL) in Swiss albino mice. A significant enhancement of mean survival time of tumour bearing mice and peritoneal cell count in normal mice was observed with respect to the control group. When these MGL treated animals underwent i.p. inoculation with DAL cells, tumour cell growth was found to be inhibited. After 14 d of inoculation, MGL is able to reverse the changes in the haemotological parameters, protein and packed cellular volume consequent to tumour inoculation.

A 52 year old man with hypertension and diabetes mellitus presented with sudden onset of binocular diplopia on looking to the left side, right facial weakness, and epiphora in the right eye. Ocular motor examination revealed combination of right gaze paresis and right internuclear ophthalmoplegia suggestive of horizontal one-and-a-half syndrome (fig 1A–C). Vertical ocular movements from the primary position were normal (fig 1D, E). In addition, he also had right lower motor neurone facial weakness …

A 60 year old man with hypertension and diabetes mellitus sought neurological consultation for sudden onset of numbness over the left side of body. On examination, he was conscious and had dysarthria. Right lingual paresis was observed on tongue protrusion (fig 1A). The other neurological findings included left lemniscal sensory impairment and mild left haemiparesis without facial involvement (fig 1B). The presence of crossed neurological …

Thalamic disequilibrium syndrome (TDS) refers to unsteady stance and gait resulting from unilateral thalamic lesion. Posterolateral thalamic involvement may result in disequilibrium with minimal motor or sensory deficit.1 However, this entity has received less attention in comparison with thalamic sensory, movement, and ataxic disorders. The transient nature of TDS underscores its importance for the prevention of falls in neurorehabilitation. The current report highlights development of TDS due to right thalamic hemorrhage after thrombolytic therapy for acute myocardial infarction. A 65-year-old man underwent thrombolytic therapy for acute anterior wall myocardial infarction with streptokinase followed by heparin and oral antiplatelet agents. When he tried to move 3 days later, he could not stand or walk unassisted. On assisted standing, he had truncal instability with axial lateropulsion to the left. He also required assistance for sitting up in bed. Neurologically he had normal visual fields, cranial nerve function (especially ocular movements), muscle power, and …

A 3 year old female child, born of consanguineous parentage and full term normal delivery, developed psychomotor regression. When examined one year later, she exhibited no tracking of visual or auditory stimuli and optic fundi revealed mild pallor. She could produce no meaningful speech. She had drooling of saliva from the mouth, bilateral pyramidal signs, and …