Publications by authors named "Akbar M"

An electrophysiological study was performed using chloral hydrate-anesthetized rats to determine whether tandospirone, a 5-HT1A agonist, affects neuronal activities of the medial vestibular nucleus (MVN), since serotonergic innervation and 5-HT1A receptors are present in this nucleus. Tandospirone applied microiontophoretically at a current of 20-60 nA caused an inhibition of tilt-induced firing of alpha-type neurons, which showed increased and decreased firing with lateral tilt ipsilateral and contralateral to the recording site, respectively, along with that of beta-type neurons which exhibited the reverse responses to ipsilateral and contralateral tilt stimulation. The inhibition was antagonized during simultaneous, iontophoretic application of WAY-100635 (20-60 nA), a 5-HT1A receptor antagonist, although WAY-100635 alone rarely affected spontaneous or tilt-induced firing in either type of neurons.

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The effect of polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (22:6n-3; DHA) and arachidonic acid (20:4n-6; AA), on apoptotic cell death was evaluated based on DNA fragmentation and caspase-3 activity induced by serum starvation using Neuro-2A and PC-12 cells. The presence of 20:4n-6 in the medium during serum starvation decreased DNA fragmentation and this initial protective effect was diminished with prolonged serum starvation. The observed protective effect of 20:4n-6 was not affected by the inhibitors of cyclooxygenase (COX) and lipoxygenase.

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Background: This study aimed to examine the association between clinicopathologic parameters and positive margins in women with ductal carcinoma in situ (DCIS) treated by breast-conserving surgery (BCS).

Methods: We retrospectively reviewed the clinical, radiologic, and pathologic data of 100 women who had undergone BCS for DCIS in our center.

Results: Sixty-seven percent of patients presented via breast screening and 55% of all cases were diagnosed preoperatively on fine needle aspiration cytology ([FNAC] ie, C5).

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Electrophysiological studies were performed to elucidate whether L-3,4-dihydroxyphenylalanine (L-DOPA) acted on hippocampal CA1 neurons, since this drug has been reported to act as a neurotransmitter in the hypothalamus and striatum. Hippocampal slices (450 microM thick) obtained from male Wistar rats (4-7 weeks of age) were placed in a bath (maintained at 30+/-1 degrees C) continuously perfused with artificial cerebrospinal fluid. The population spikes elicited by electrical stimuli applied to the Schaffer collateral/commissural fibers were recorded in the hippocampal CA1 region, using a glass micropipette filled with 3 M NaCl.

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In this paper evidence that supports a new role for melatonin as a negative endogenous regulator of cytosolic phospholipase A(2) (cPLA(2)) is presented. When rat pineal glands were incubated in culture, time-dependent release of arachidonic acid (AA) was observed, which was significantly inhibited by a known 85-kDa cPLA(2) inhibitor, methyl arachidonyl fluorophosphonate. Co-incubation with melatonin inhibited the AA release in a concentration-dependent manner, and this decrease was accompanied by a reduction of cPLA(2) protein and mRNA expression.

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Enrichment of Neuro 2A cells with docosahexaenoic acid (22:6n-3) decreased apoptotic cell death induced by serum starvation as evidenced by the reduced DNA fragmentation and caspase-3 activity. The protective effect of 22:6n-3 became evident only after at least 24 h of enrichment before serum starvation and was potentiated as a function of the enrichment period. During enrichment 22:6n-3 incorporated into phosphatidylserine (PS) steadily, resulting in a significant increase in the total PS content.

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Background/aims: Landmines have long been used in conventional warfare. These are antipersonnel mines which continue to injure people long after a ceasefire without differentiating between friend or foe, soldier or civilian, women or children. This study focuses on Afghan non-combatants engaged in mine clearing operations in Afghanistan in the aftermath of the Russo-Afghan war.

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Pancreatic beta cells respond to changes in blood glucose by secreting insulin and increasing insulin synthesis. To identify genes used in these responses, we have carried out expression profiling of beta cells exposed to high (25 mM) or low (5.5 mM) glucose by using oligonucleotide microarrays.

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Hyperpolarizing large-conductance, Ca(2+)-activated K(+) channels (BK) are important modulators of vascular smooth muscle and endothelial cell function. In vascular smooth muscle cells, BK are composed of pore-forming alpha subunits and modulatory beta subunits. However, expression, composition, and function of BK subunits in endothelium have not been studied so far.

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We describe a six generation Saudi kindred, with a recessive hereditary motor and sensory neuropathy (HMSN). Four individuals were affected including two children (a boy and a girl) and a 23-year-old man. The fourth (a female) died at the age of 14 years.

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Sigma receptors in the central nervous system have been considered to play an important role in the modulation of mental diseases and memory/learning. However, the physiological function of sigma receptors still remains unknown. To elucidate physiological functions of the sigma receptors in modulation of neuronal activities, the effects of OPC-24439 (a sigma receptor ligand) on neuronal activities in hippocampal slices were studied with electrophysiological methods.

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Major biochemical activities of the pineal gland include melatonin biosynthesis and 12-lipoxygenation. In this paper, we provide evidence in vivo that melatonin regulates 12-lipoxygenation via 12-lipoxygenase (LOX) expression. The relationship between these two biochemical activities was established by monitoring levels of endogenous melatonin and a 12-LOX metabolite, 12-hydroxyeicosatetraenoic acid (12-HETE), in the rat pineal gland both during the light-dark cycle and after isoproterenol injection using GC/MS with negative ion chemical ionization.

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Glutamate, the principal excitatory neurotransmitter in the brain, acts on three families of ionotropic receptor--AMPA (alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid), kainate and NMDA (N-methyl-D-aspartate) receptors and three families of metabotropic receptor (Group I: mGlu1 and mGlu5; Group II: mGlu2 and mGlu3; Group III: mGlu4, mGlu6, mGlu7 and mGlu8). Glutamate is removed from the synaptic cleft and the extracellular space by Na+-dependent transporters (GLAST/EAAT1, GLT/EAAT2, EAAC/EAAT3, EAAT4, EAAT5). In rodents, genetic manipulations relating to the expression or function of glutamate receptor proteins can induce epilepsy syndromes or raise seizure threshold.

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1. Growth patterns of the whole body, eviscerated carcases, breast muscle, leg and thigh muscles and abdominal fat pads were compared in 4 lines (Lines A, B, C, and D) of male ducks selected for market weight (n = 1305) using growth curve analysis, allometric growth analysis and repeated measure analysis. At 49 d of age, Line A was heaviest, followed by Line B, Line C and Line D.

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Objective: To study the effect of decline in blood pressure on mortality in patients with spontaneous intracerebral hemorrhage (ICH).

Design: Retrospective chart review.

Setting: University-affiliated teaching hospital.

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We report on two brothers (the product of first-degree consanguineous marriage; aged 15 and 12 years) who presented with severe hypotonia at birth, proximal muscle weakness associated with delayed motor milestones but normal cognitive function. Investigations (at 4 years of age) revealed mildly elevated serum creatine kinase (CK) levels (300 and 824 IU/l; N < or = 210). Muscle biopsies showed minimal change myopathy, no neurogenic atrophy but remarkable type-1 fibre predominance (up to 85.

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We performed a retrospective multicenter chart review to compare the efficacy and tolerance of plasma exchange (PE) and intravenous immunoglobulin (i.v.Ig) in treatment of 54 episodes of myasthenic crisis.

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The genetically epilepsy-prone rat is an animal model of inherited generalised tonic-clonic epilepsy that shows abnormal susceptibility to audiogenic seizures and a lowered threshold to a variety of seizure-inducing stimuli. Recent studies suggest a crucial role for glutamate and GABA transporters in epileptogenesis and seizure propagation. The present study examines the levels of expression of the messenger RNAs encoding the glial and neuronal glutamate transporters, GLT-1 and EAAC-1, and the neuronal GABA transporter, GAT-1, in paired male genetically epileptic-prone rats and Sprague Dawley control rats using the technique of in situ hybridization.

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Objective: To determine the association between human immunodeficiency virus (HIV) infection and stroke among young persons.

Design: Retrospective case-control study.

Setting: Large, inner-city public hospital.

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Congenital muscular dystrophy (CMD) is a group of clinically and genetically heterogeneous disorders inherited in an autosomal recessive mode. The alpha2-chain of laminin-2 (previously called merosin) has been shown by immunohistochemical and genetic analyses to be implicated in the pathogenesis of the 'classic' form of CMD. In the 'merosin-deficient' subgroup, which represents about half of the cases, more definite evidence of the involvement of the laminin alpha2-chain has recently been reported with the identification of mutations in the gene encoding the alpha2-chain of laminin 2 (LAMA2) in CMD patients.

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In situ hybridization techniques and quantitative western blotting were used to study the expression of the glial glutamate transporter GLT-1 and GLAST in the brains of normal (implanted, non-kindled) and fully kindled rats. Wistar rats were implanted with stimulating electrodes in the basolateral amygdala, and killed 28 days after the stimulated group had shown stage 5 seizures on five occasions. The brains were processed for in situ hybridization of messenger RNA for GLT-1 using 35S-labelled oligonucleotide probes or digoxigenin-labelled riboprobes.

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Background And Purpose: Numerous case series have proposed a relationship between "crack" cocaine use and stroke. We performed a retrospective case control study at a large inner-city public hospital to determine the relationship between crack use and stroke among young persons.

Methods: We reviewed records of all patients aged 20 to 39 years with a diagnosis of stroke, and of controls selected from patients with noncocaine-related diagnoses, admitted from January 1990 through June 1994.

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Exogenous sphingosine 1-phosphate (S1P) stimulated hydrogen peroxide (H2O2) generation in association with an increase in intracellular Ca2+ concentration in FRTL-5 thyroid cells. S1P also induced inositol phosphate production, reflecting activation of phospholipase C (PLC) in the cells. These three S1P-induced events were inhibited partially by pertussis toxin (PTX) and markedly by U73122, a PLC inhibitor, and were conversely potentiated by N6-(L-2-phenylisopropyl)adenosine, an A1-adenosine receptor agonist.

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Kindling is a well documented model of acquired focal epilepsy and synaptic plasticity in the nervous system. Previous biochemical studies have indicated an increase in mGluR-mediated phosphoinositide hydrolysis in the amygdala or hippocampus of fully kindled animals. In this study we have used in situ hybridisation techniques to examine the mRNA expression of group I metabotropic glutamate receptors (mGluR1 and mGluR5 both linked to phosphoinositide hydrolysis) in the hippocampus of amygdala-kindled animals sacrificed 24 h, 7 days or 28 days following the last electrically evoked stage 5 seizure, and in implanted non-stimulated control rats.

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