Jul
02
2009
0

Cytogenotoxicity induced by PBDE-47 combined with PCB153 treatment in SH-SY5Y cells.

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are important recalcitrant halogenated compounds that have been regarded as major environmental pollutants. Recently, their concurrent appearance in the environment and humans and their structural and toxicological profile similarities have sparked interest in the potential toxicologic consequences of their coexposure. The aim of the current study was to evaluate the cytogenotoxic effects induced by 2,2′,4,4′-tetrabromodiphenyl ether (PBDE-47) combined with 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB153) treatment in human neuroblastoma cells (SH-SY5Y) in vitro. SH-SY5Y cells were exposed to different concentrations of PBDE-47 (0, 2, 4, 8 muM) with or without PCB153 (5 muM) for 24 h. Thereafter, the cell viability, DNA damage, chromosomal abnormalities, and DNA-protein crosslinks (DPC) were determined. The results show that PBDE-47 and PCB153 alone and in combination induce DNA damage, with an increase in the frequency of micronuclei (MN) and DPC formation with increasing PBDE-47 concentration. In cells coexposed to PBDE-47 and PCB153, the cell viability significantly decreased while the MN frequency, DNA damage and DPC formation were all obviously increased compared to those of cells treated with the corresponding concentrations of PBDE-47 or PCB153 alone. Factorial analysis suggests that there were interactions between PBDE-47 and PCB153. The results imply that PBDE-47 interacts with PCB153 to inhibit cell viability and induce DNA damage, DPC formation, and chromosome abnormalities. (c) 2009 Wiley Periodicals, Inc. Environ Toxicol, 2009.

Written by admin in: Ischemic Brain Damage |
Jul
02
2009
0

Motor abnormalities in premanifest persons with Huntington’s disease: The PREDICT-HD study.

The PREDICT-HD study seeks to identify clinical and biological markers of Huntington’s disease in premanifest individuals who have undergone predictive genetic testing. We compared baseline motor data between gene-expansion carriers (cases) and nongene-expansion carriers (controls) using t-tests and Chi-square. Cases were categorized as near, mid, or far from diagnosis using a CAG-based formula. Striatal volumes were calculated using volumetric magnetic resonance imaging measurements. Multiple linear regression associated total motor score, motor domains, and individual motor items with estimated diagnosis and striatal volumes. Elevated total motor scores at baseline were associated with higher genetic probability of disease diagnosis in the near future (partial R(2) 0.14, P < 0.0001) and smaller striatal volumes (partial R(2) 0.15, P < 0.0001). Nearly all motor domain scores showed greater abnormality with increasing proximity to diagnosis, although bradykinesia and chorea were most highly associated with diagnostic immediacy. Among individual motor items, worse scores on finger tapping, tandem gait, Luria, saccade initiation, and chorea show unique association with diagnosis probability. Even in this premanifest population, subtle motor abnormalities were associated with a higher probability of disease diagnosis and smaller striatal volumes. Longitudinal assessment will help inform whether motor items will be useful measures in preventive clinical trials. (c) 2009 Movement Disorder Society.

Written by admin in: Ischemic Brain Damage |
Jul
02
2009
0

Norepinephrine and cardiovascular responses to maximal exercise in Parkinson’s disease on and off medication.

The aim of this experiment is to understand how Parkinson’s disease (PD) medication affects the autonomic responses of individuals during an acute exercise stress test. Fourteen people with PD and fifteen healthy individuals age-matched between 50 and 80 years performed a modified Bruce protocol. Subjects with PD performed the test once off medication (PD-off) and then 1 week later on medication (PD-on). Heart rate (HR), blood pressure (BP), VO(2), and norepinephrine (NE) levels were taken at rest and at peak exercise. At peak exercise HR, BP, and NE values for the PD-on and PD-off group were all significantly lower than healthy controls, regardless of whether subjects were on their medication. Autonomic abnormalities during exercise in this population appear to be disease manifested and not impactedby medications used to treat PD. We can assume, both on and off medication, this population will show markedly lower BP, HR, and NE responses. (c) 2009 Movement Disorder Society.

Written by admin in: Ischemic Brain Damage |
Jul
01
2009
0

Amiodarone induced liver cirrhosis. Report of two cases.

Amiodarone is used commonly in patients with cardiac diseases. Common side effects include thyroid dysfunction and hepatic abnormalities. However, recently there has been concern for developing liver cirrhosis secondary to amiodarone therapy. We present two cases of liver cirrhosis in patients taking amiodarone. Their clinical presentation as well as histological features are discussed in detail.

Written by admin in: Ischemic Brain Damage |
Jul
01
2009
0

Assessing gastrointestinal symptoms and perception, quality of life, motility, and autonomic neuropathy in clinical studies.

Imprecise characterization of complaints of the upper and lower gastrointestinal (GI) tract puts patients at risks of either a delayed diagnosis or misdiagnosis and contributes to an increase in the overall direct and indirect costs of the health system. The current scenario in the case of functional GI diseases originates from at least two conditions: frequency of diseases and bothersome symptoms with an impact on the quality of life (QoL). To make a correct diagnosis is therefore almost mandatory. Once a positive diagnosis of functional involvement of the GI tract is made, the correct diagnosis assessment includes the study of symptom characteristics, entity and perception, detection of abnormal patterns of GI motor-function (gallblader and gastric emptying, oro-cecal and colonic transit, etc.), potential involvement of the autonomic nervous system (sympathetic, parasympathetic), and overall impact of such abnormalities on the QoL and psychological profiles. Results of these tests can be variable, depending on the type and intensity of the illness. In the present review, the state-of-the-art methods for correct assessment of several factors regarding the onset, perpetuation and outcome of functional GI diseases are discussed.

Written by admin in: Ischemic Brain Damage |
Jul
01
2009
0

Incomplete posterior circle of willis: a risk factor for migraine?

BACKGROUND: Migraine is associated with vascular risk factors and white matter abnormalities (WMA). Cerebral hypoperfusion is known to be one mechanism underlying WMA and a few studies have shown that an incomplete circle of Willis (CW) may predispose to cerebral hypoperfusion. This study assessed the relationship between the morphologic characteristics of the CW and migraine. METHODS: This case-control study was carried out in the Amiens University Hospital. Patients undergoing 3-dimensional time of flight magnetic resonance angiography of the CW from January 1 to June 30, 2006 were included (n = 124). A definitive diagnosis of migraine was established in 47 patients: 23 (48.9%) experienced migraine without aura and 24 (51.1%) migraine with aura. The remaining 77 patients with other neurologic disorders constituted the control group. The posterior CW was graded as complete when both posterior communicating arteries and the P1 segments of the posterior cerebral artery were present on visual examination and incomplete when one of these vessels was missing (interobserver agreement: K(total) = 0.746). RESULTS: Incomplete posterior CW was significantly more common in migraineurs than in the control group (49% vs 18%; P < .001). On multivariate analysis, incomplete posterior CW was the sole independent factor associated with migraine (OR: 6.5; 95% CI: 2.6-16.2; P < .001). No difference was found between migraineurs with and without aura. CONCLUSIONS: Despite some methodological limitations, our results showed that incomplete posterior CW was associated with migraine.

Written by admin in: Ischemic Brain Damage |
Jul
01
2009
0

2-D DIGE analysis implicates cytoskeletal abnormalities in psychiatric disease.

The mechanisms underlying white matter changes in psychiatric disease are not known. We aimed to characterise the differential protein expression in deep white matter from the dorsolateral prefrontal cortex from 35 schizophrenia, 35 bipolar disorder, and 35 control subjects, from the Stanley Array Collection. We used 2-D DIGE to profile for protein expression changes in the brain. We found 70 protein spots to be significantly differentially expressed between disease and control subjects (ANCOVA, p<0.05), 46 of which were subsequently identified by LC-MS/MS. The proteins identified included novel disease candidates as well as proteins that have previously been reported as abnormal in schizophrenia, thus reinforcing their association with the disease. Furthermore, we confirmed the direction of change for three proteins using ELISA, namely neurofilament-light, amphiphysin II, and Rab-GDP-alpha, in a subset of the Stanley Array Collection. In addition, altered expression of neurofilament-light, amphiphysin II, and Rab-GDP-alpha was not observed in the cortex of mice chronically treated with haloperidol, making it less likely that these alterations are a consequence of neuroleptic medication. The data presented here strongly suggest disruption of the cytoskeleton and its associated signal transduction proteins in schizophrenia, and to a lesser extent in bipolar disorder.

Written by admin in: Ischemic Brain Damage |
Jul
01
2009
0

Association of DRD3 and GRIN2B with impulse control and related behaviors in Parkinson’s disease.

We aimed to assess whether allelic variants of dopamine receptor, glutamate receptor, and serotonin transporter genes are associated with the appearance of impulse control and related behaviors (ICRB) in Parkinson’s disease (PD) with dopamine replacement therapy (DRT). We surveyed ICRB in consecutive Korean patients with PD who were treated with stable DRT using modified Minnesota Impulsive Disorders Interview over a period of 4 months. In the 404 patients who completed the interview and the 559 Korean healthy normal controls, genotyping was performed for variants of the DRD3 p.S9G, DRD2 Taq1A, GRIN2B c.366C>G, c.2664C>T and c.-200T>G, and the promoter region of the serotonin transporter gene (5-HTTLPR). Behavioral abnormalities suggestive of ICRB including compulsive buying, gambling, sexual behavior and eating, and punding, were present in 14.4% of the patients. Variants of DRD2 and 5-HTTLPR were not associated with the risk of developing ICRB. However, the AA genotype of DRD3 p.S9G and the CC genotype of GRIN2B c.366C>G were more frequent in patients with ICRB than in nonaffected patients (odds ratio [OR] = 2.21, P = 0.0094; and 2.14, P = 0.0087, after adjusting for age and sex). After controlling for clinical variables in the multivariate analysis, carriage of either AA genotype of DRD3 or CC genotype of GRIN2B was identified as an independent risk factor for ICRB (adjusted OR: 2.57, P = 0.0087). Variants of DRD3 p.S9G and GRIN2B c.366C>G may be associated with the appearance of ICRB in PD. (c) 2009 Movement Disorder Society.

Written by admin in: Ischemic Brain Damage |
Jun
28
2009
0

Oxidative stress in SEPN1-related myopathy: From pathophysiology to treatment.

OBJECTIVE: Mutations of the selenoprotein N gene (SEPN1) cause SEPN1-related myopathy (SEPN1-RM), a novel early-onset muscle disorder formerly divided into four different nosological categories. Selenoprotein N (SelN) is the only selenoprotein involved in a genetic disease; its function being unknown, no treatment is available for this potentially lethal disorder. Our objective was to clarify the role of SelN and the pathophysiology of SEPN1-RM to identify therapeutic targets. METHODS: We established and analyzed an ex vivo model of SelN deficiency using fibroblast and myoblast primary cultures from patients with null SEPN1 mutations. DCFH assay, OxyBlot, Western blot, Fura-2, and cell survival studies were performed to measure intracellular oxidant activity, oxidative stress markers, calcium handling, and response to exogenous treatments. RESULTS: SelN-depleted cells showed oxidative/nitrosative stress manifested by increased intracellular oxidant activity (reactive oxygen species and nitric oxide) and/or excessive oxidation of proteins, including the contractile proteins actin and myosin heavy chain II in myotubes. SelN-devoid myotubes showed also Ca(2+) homeostasis abnormalities suggesting dysfunction of the redox-sensor Ca(2+) channel ryanodine receptor type 1. Furthermore, absence of SelN was associated with abnormal susceptibility to H(2)O(2)-induced oxidative stress, demonstrated by increased cell death. This cell phenotype was restored by pretreatment with the antioxidant N-acetylcysteine. INTERPRETATION: SelN plays a key role in redox homeostasis and human cell protection against oxidative stress. Oxidative/nitrosative stress is a primary pathogenic mechanism in SEPN1-RM, which can be effectively targeted ex vivo by antioxidants. These findings pave the way to SEPN1-RM treatment, which would represent a first specific pharmacological treatment for a congenital myopathy. Ann Neurol 2009;65:677-686.

Written by admin in: Ischemic Brain Damage |
Jun
28
2009
0

Is reflex sympathetic dystrophy/complex regional pain syndrome type I a small-fiber neuropathy?

Neurologist S. Weir Mitchell first described “causalgia” following wartime nerve injury, with its persistent distal limb burning pain, swelling, and abnormal skin color, temperature, and sweating. Similar post-traumatic symptoms were later identified in patients without overt nerve injuries after trauma. This was labeled reflex sympathetic dystrophy (RSD; now complex regional pain syndrome type I [CRPS-I]). The pathophysiology of symptoms is unknown and treatment options are limited. We propose that persistent RSD/CRPS-I is a post-traumatic neuralgia associated with distal degeneration of small-diameter peripheral axons. Small-fiber lesions are easily missed on examination and are undetected by standard electrophysiological testing. Most CRPS features-spreading pain and skin hypersensitivity, vasomotor instability, osteopenia, edema, and abnormal sweating-are explicable by small-fiber dysfunction. Small fibers sense pain and temperature but also regulate tissue function through neuroeffector actions. Indeed, small-fiber-predominant polyneuropathies cause CRPS-like abnormalities, and pathological studies of nerves from chronic CRPS-I patients confirm small-fiber-predominant pathology. Small distal nerve injuries in rodents reproduce many CRPS features, further supporting this hypothesis. CRPS symptoms likely reflect combined effects of axonal degeneration and plasticity, inappropriate firing and neurosecretion by residual axons, and denervation supersensitivity. The resulting tissue edema, hypoxia, and secondary central nervous system changes can exacerbate symptoms and perpetuate pathology. Restoring the interest of neurologists in RSD/CRPS should improve patient care and broaden our knowledge of small-fiber functions. Ann Neurol 2009;65:629-638.

Written by admin in: Ischemic Brain Damage |

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