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Ameri A, Talebi AA, Beyarslan A, Kamali K, Rakhshani E. Study of the genus Bracon Fabricius, 1804 (Hymenoptera: Braconidae) of Southern Iran with description of a new species. Zootaxa 2014; 3754:353-80. [PMID: 24869696 DOI: 10.11646/zootaxa.3754.4.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Indexed: 11/04/2022]
Abstract
A survey on the genus Bracon Fabricius, 1804 was conducted in Hormozgan province, Southern Iran, during February 2011-July 2012. In all, 19 species belonging to seven subgenera were collected and identified, of which seven species and the subgenus Asiabracon Tobias, 1957 are recorded for first time from Iran. Bracon (Orthobracon) persiangulfensis Ameri, Beyarslan & Talebi sp. n. is newly described and illustrated from the Queshm island of Persian Gulf. Morphological characters of the new species were compared with the congeneric species. The newly recorded species from Iran were as follow: B. (Asiabracon) quardrimaculatus Telenga, 1936; B. (Bracon) kozak Telenga, 1936; B. (Glabrobracon) immutator Nees; B. (Habrobracon) telengai (Mulyarskaya, 1955); B. (Habrobracon) variegator Spinola, 1808; B. (Orthobracon) epitriptus Marshall, 1885 and B. (Orthobracon) exhilarator Nees, 1834. A key is presented for identification of Bracon species collected in Hormozgan province as well as an updated checklist of all Bracon species occurring in Iran.
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Farajzadeh R, Ameri A, Faber MJ, van Batenburg DW, Boersma DM, Bruining J. Effect of Continuous, Trapped, and Flowing Gas on Performance of Alkaline Surfactant Polymer (ASP) Flooding. Ind Eng Chem Res 2013. [DOI: 10.1021/ie401475u] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Vararean C, Stefanizzi S, Kerbi-Hamimed N, Ameri A. Atteinte diaphragragmatique et récurrentielle au cours du syndrome de Parsonage Turner : à propos d’un cas et revue de la littérature. Rev Neurol (Paris) 2013. [DOI: 10.1016/j.neurol.2013.01.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ameri A, Englehart KB, Parker PA. A comparison between force and position control strategies in myoelectric prostheses. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2013; 2012:1342-5. [PMID: 23366147 DOI: 10.1109/embc.2012.6346186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This work studies the simultaneous and proportional myoelectric force and position estimation of multiple degrees of freedom (DOFs) for unilateral transradial amputees. Two experiments were conducted to compare force and position control paradigms. In the first, a force experiment, subjects performed isometric contractions, while the force applied by the limb and EMG were recorded. In the second, a position experiment, dynamic contractions were permitted during which position of the limb and EMG were measured. Artificial neural networks (ANNs) were trained to estimate force/position from EMG of the contralateral limb during mirrored bilateral contractions. This study involved contractions with combined activations of three DOFs including wrist: flexion/extension, radial/ulnar deviation and forearm supination/pronation. For the given data set, while force estimation demonstrated high accuracy (R(2)=0.84±0.02), position estimation performance was relatively poor (R(2)=0.57±0.05). Two healthy subjects participated in this work.
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Crassard I, Ameri A, Rougemont D, Bousser MG. Trombosi venose cerebrali. Neurologia 2012. [DOI: 10.1016/s1634-7072(12)63278-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Sauna ZE, Ameri A, Kim B, Yanover C, Viel KR, Rajalingam R, Cole SA, Howard TE. Observations regarding the immunogenicity of BDD-rFVIII derived from a mechanistic personalized medicine perspective. J Thromb Haemost 2012; 10:1961-5. [PMID: 22734827 DOI: 10.1111/j.1538-7836.2012.04830.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hasan-Beikdashti M, Forootanfar H, Safiarian M, Ameri A, Ghahremani M, Khoshayand M, Faramarzi M. Optimization of culture conditions for production of lipase by a newly isolated bacterium Stenotrophomonas maltophilia. J Taiwan Inst Chem Eng 2012. [DOI: 10.1016/j.jtice.2012.03.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Kazemi M, Rostami H, Ameri A. The Study of Compositions and Antimicrobial Properties of Essential Oil of Origanum vulgare and Rosmarinus officinalis on Human Pathogens. ACTA ACUST UNITED AC 2011. [DOI: 10.3923/crb.2012.1.12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Lagarde J, Cret C, Karlin L, Ameri A. [Petrous plasmacytoma revealed by a painful peripheral facial palsy]. Rev Neurol (Paris) 2011; 167:526-9. [PMID: 21195441 DOI: 10.1016/j.neurol.2010.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 10/13/2010] [Indexed: 11/26/2022]
Abstract
INTRODUCTION The classical hypothesis of Bell's palsy, tempting in cases of peripheral facial palsy of rapid onset, must nevertheless be evoked with caution particularly if an intense pain is present, which should lead to search for a tumor of the skull base, especially the petrous bone. CASE REPORT A 43-year-old man presented a peripheral facial palsy of rapidly progressive onset. A petrous bone tumor was diagnosed on the CT scan, which revealed an aspect of a glomic tumor or a metastatic lesion. The final histological diagnosis was plasmacytoma. DISCUSSION This type of tumor has been rarely reported in this location. The radiological features are not specific at all, underlying the importance of searching for some associated signs such as a monoclonal protein and performing a histological examination when the firm diagnosis of a systemic disease like multiple myeloma has not been possible.
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Shidfar F, Keshavarz A, Hosseyni S, Ameri A, Yarahmadi S. Effects of omega-3 fatty acid supplements on serum lipids, apolipoproteins and malondialdehyde in type 2 diabetes patients. EASTERN MEDITERRANEAN HEALTH JOURNAL = LA REVUE DE SANTE DE LA MEDITERRANEE ORIENTALE = AL-MAJALLAH AL-SIHHIYAH LI-SHARQ AL-MUTAWASSIT 2008; 14:305-313. [PMID: 18561722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In order to test whether hyperlipidaemia and glycaemic control can be improved among diabetes patients by dietary supplementation with purified omega-3 fatty acids, we carried out a double-blind, placebo-controlled trial on 50 type 2 diabetes patients randomized to 2 g/day purified omega-3 fatty acids or placebo for 10 weeks. Fasting triglycerides decreased significantly with supplementation relative to placebo (P = 0.01). There was a significant decrease in ApoB-100 and malondialdehyde compared to baseline values and compared to the control group. Omega-3 fatty acids had no significant effect on serum lipid levels, ApoA-I, glucose, insulin and HbA1c.
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Dehghani SM, Sefti MV, Ameri A, Kaveh NS. Minimum miscibility pressure prediction based on a hybrid neural genetic algorithm. Chem Eng Res Des 2008. [DOI: 10.1016/j.cherd.2007.10.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Khodabakhshi R, Yahyazadeh Jabbari S, Gohari M, Sadrolhefazi B, Mosavizadeh A, Shahidi J, Ameri A, Madani H, Sharifi B, Bahor F. Treatment and prognosis of epithelial ovarian cancer in Iran. J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.5586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
5586 Background: Ovarian cancer is the most lethal gynecologic malignancy in the US, with 14,500 women dying of this disease annually. The aims of this study are to describe brief epidemiologic variations, response rate for usual chemotherapy regimen and progression free survival analysis in Iranian patients. Patients and Methods: 98 women with confirmed ovarian cancer who have been undergone surgery followed by chemotherapy at three hospitals in Tehran (Iran) between 1997 and 2003 were enrolled in this retrospective study. FIGO staging system has been applied. We have collected data regarding age, pathologic variations, surgical procedure (complete, partial, biopsy), chemotherapy, response rate, and time to progression of disease. Results: From a total of 98 patients, there were 80 (81.6%) epithelial, 12 (12.2%) germ cell, 5 (5.1%) granulosa cell tumors and one case of lymphoma. Response rate have been evaluated for 60 patients with epithelial cancer. Overall mean age was 46.7 and average age for epithelial tumors and non-epithelial tumors were 49.6 and 34.3 respectively. Complete surgical procedure with staging and optimal residue had been performed for 18 patients. Stage III was the most common stage (46.1%). In 78.3% of patients complete or partial response were seen, while 21.7% of patients showed stable or progressive disease. The most important prognostic factors were stage, and extent of surgical procedure. Median progression-free survival was 24.2 months. Conclusion: Overall average-age of our patients is lower than expected. Besides, a large proportion of the patients are referred in advanced stages. Although, higher response rate has been produced by taxane-based regimen in comparison of traditional chemotherapy; but it was not statistically significant. Retrospective evaluation, low number of the patients, non-uniform usage of chemotherapy regimen could influence our results. No significant financial relationships to disclose.
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Kamga V, Klapczynski F, Stefanizzi S, Beroud P, Ameri A. O - 14 Ictus amnésique révélant un infarctus cérébral — À propos d’un cas. Rev Neurol (Paris) 2007. [DOI: 10.1016/s0035-3787(07)90730-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Khachidze M, Buil A, Viel KR, Porter S, Warren D, Machiah DK, Soria JM, Souto JC, Ameri A, Lathrop M, Blangero J, Fontcuberta J, Warren ST, Almasy L, Howard TE. Genetic determinants of normal variation in coagulation factor (F) IX levels: genome-wide scan and examination of the FIX structural gene. J Thromb Haemost 2006; 4:1537-45. [PMID: 16839351 DOI: 10.1111/j.1538-7836.2006.02024.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND High-normal and elevated plasma FIX activity (FIX:C) levels are associated with increased risk for venous- and possibly arterial-thrombosis. OBJECTIVE Because the broad normal range for FIX:C involves a substantial unknown genetic component, we sought to identify quantitative-trait loci (QTLs) for this medically important hemostasis trait. METHODS We performed a genome-wide screen and a resequencing-based variation scan of the known functional regions of every distinct FIX gene (F9) in the genetic analysis of idiopathic thrombophilia project (GAIT), a collection of 398 Spanish-Caucasians from 21 pedigrees. RESULTS We found no evidence for linkage (LOD scores <1.5) despite genotyping more than 540 uniformly-spaced microsatellites. We identified 27 candidate F9 polymorphisms, including three in cis-elements responsible for the increase in FIX:C that occurs with aging, but found no significant genotype-specific differences in mean FIX:C levels (P-values > or = 0.11) despite evaluating every polymorphism in GAIT by marginal multicovariate measured-genotype association analysis. CONCLUSIONS The heritable component of interindividual FIX:C variability likely involves a collection of QTLs with modest effects that may reside in genes other than F9. Nevertheless, because the alleles of these 27 polymorphisms exhibited a low overall degree of linkage disequilibrium, we are currently defining their haplotypes to interrogate several highly-conserved non-exonic sequences and other F9 segments not examined here.
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Asadi-Lari M, Farshad AA, Assaei SE, Vaez Mahdavi MR, Akbari ME, Ameri A, Salimi Z, Gray D. Applying a basic development needs approach for sustainable and integrated community development in less-developed areas: report of ongoing Iranian experience. Public Health 2005; 119:474-82. [PMID: 15826888 DOI: 10.1016/j.puhe.2004.08.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2004] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Despite considerable achievements in the provision of basic developmental facilities in terms of drinking water, access to primary healthcare services, high-quality and nutritious food, social services, and proper housing facilities, there are many rural and slum communities in Iran where these essential needs remain unfulfilled. Lack of equity is prominent, as large differences exist in underprivileged provinces. New policies developed in the past two decades have resulted in substantial achievements in meeting population needs and reducing the socio-economic gap; nevertheless, poverty levels, unemployment due to a large increase in the birth rate in the early 1980s, and lack of community participation are matters yet to be addressed. To overcome these deficiencies, a basic development needs approach was adopted to promote the concept of community self-help and self-reliance through intersectoral collaboration, creating an environment where people could take an active part in the development process, with the Iranian government providing the necessary support to achieve the desired level of development. DESCRIPTION OF THE PROJECT Following firm commitment from the Iranian government and technical support from the World Health Organization Regional Office, basic development needs was assigned a high priority in health and health-related sectors, reflected in the third National Masterplan (2001-2005). A comprehensive intersectoral plan was designed, and pilot projects were commenced in three villages. Each village elected a representative, and committee clusters were formed to run and monitor projects identified by a process of local needs assessment and priority assignment. In each region, a variety of needs were elicited from these assessments, which were actively supported by local authorities. LESSON LEARNED A basic development needs approach was found to be a reliable discipline to improve community participation, needs-led resource allocation and intersectoral co-operation in community development, particularly in underprivileged areas. Iran's initial experience of basic development needs has gained widespread public support but will require periodical evaluation as it is introduced into other rural and urban regions across the country.
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Shidfar F, Baghai N, Keshavarz A, Ameri A, Shidfar S. Comparison of plasma and leukocyte vitamin C status between asthmatic and healthy subjects. EASTERN MEDITERRANEAN HEALTH JOURNAL = LA REVUE DE SANTE DE LA MEDITERRANEE ORIENTALE = AL-MAJALLAH AL-SIHHIYAH LI-SHARQ AL-MUTAWASSIT 2005; 11:87-95. [PMID: 16532676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In a case-control study the vitamin C status of 50 adults with chronic controlled asthma was compared with that of 50 randomly selected healthy controls. Vitamin C intake was assessed by 3-day dietary recall, and plasma and leukocyte vitamin C concentrations were measured colorimetrically. A positive significant correlation was found between plasma vitamin C and dietary vitamin C intake. Plasma and leukocyte vitamin C levels were significantly lower in the asthma group. Plasma vitamin C was deficient (< 0.4 mg/dL) in significantly more patients than controls (38.0% versus 0%) and leukocyte vitamin C (< 20 microg/10(8) leukocytes) was deficient in 92.0% of asthmatics versus 8.0% of controls. A significant association was observed between duration of asthma and plasma vitamin C level.
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Ameri A, Martin R, Vega R, Bell B, Crenshaw V. Successful management of intramural ureteral hemorrhage in a patient with factor VIII deficiency and high-titer inhibitor. J Thromb Haemost 2004; 2:2273. [PMID: 15613051 DOI: 10.1111/j.1538-7836.2004.01041.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Napolitano M, Keime-Guibert F, Monjour A, Lafitte C, Ameri A, Cornu P, Broët P, Delattre JY. Treatment of supratentorial glioblastoma multiforme with radiotherapy and a combination of BCNU and tamoxifen: a phase II study. J Neurooncol 2000; 45:229-35. [PMID: 10845393 DOI: 10.1023/a:1006390414555] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
From May 1990 to November 1994, 70 consecutive patients suffering from glioblastoma multiforme were treated following surgery with conventional radiotherapy and adjuvant IV BCNU administered alone or in combination with tamoxifen. Twenty-five patients received BCNU alone (control group A) while 24 patients also received 40 mg of tamoxifen (TMX) PO daily (group B) and 21 received 100 mg of TMX PO daily (group C). There were no significant differences between the 3 groups concerning age, type of resection and median post-operative Karnofsky performance status (KPS). Blood toxicity over grade II occurred in 33.5% of patients receiving TMX versus 12% of patients treated with BCNU alone (p < 0.05). Deep venous thrombosis complications were observed in 4 patients of each TMX group, whereas they were not observed in the control group (p < 0.04). Median time to tumor progression (MTTP) was 35 weeks in the control group and 27 weeks in both TMX groups B and C. Median survival time (MST) was 56, 66 and 51 weeks, respectively. These results suggest that the addition of TMX to standard treatment of glioblastomas does not affect the time to tumor progression and overall survival but may increase the risk of deep venous thrombosis or nitrosourea-induced blood toxicity.
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Ameri A, Simmet T. Effects of 2-arachidonylglycerol, an endogenous cannabinoid, on neuronal activity in rat hippocampal slices. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2000; 361:265-72. [PMID: 10731038 DOI: 10.1007/s002109900200] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The monoacylglycerol 2-arachidonylglycerol is an endogenous ligand of cannabinoid receptors. We examined whether 2-arachidonylglycerol can influence excessive neuronal activity by investigating stimulation-induced population spikes and epileptiform activity in rat hippocampal slices. For this purpose, the effects of 2-arachidonylglycerol were compared with those of the synthetic cannabinoid agonist WIN 55,212-2. At concentrations of 10-50 microM, 2-arachidonylglycerol attenuated the amplitude of the orthodromic population spike and the slope of the field excitatory postsynaptic potential (field EPSP). However, the effect of the synthetic cannabinoid WIN 55,212-2 (R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolol[ 1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl)methanone; 0.1 microM and 1 microM) was significantly higher than that of the endogenous ligand. At a concentration of 1 microM, WIN 55,212-2 completely suppressed the field EPSP. However, none of the investigated compounds did affect the presynaptic fiber spike of the afferents. The CB1 receptor antagonist SR 141716 (N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorphenyl)-4-methyl-3- pyrazole-carboxamide) blocked the inhibition evoked by the cannabinoids. Both 2-arachidonylglycerol (30 microM) and WIN 55,212-2 (100 nM) shifted the input-output curve of the postsynaptic spike and the field EPSP to the right and increased the magnitude of paired-pulse facilitation, indicating a presynaptic mechanism of action. 2-Arachidonylglycerol and WIN 55,212-2 attenuated the frequency of spontaneously occurring epileptiform burst discharges in CA3 elicited by omission of Mg2+ and elevation of K+ to 8 mM. The antiepileptiform effect of these cannabinoids was blocked by SR 141716. In conclusion, 2-arachidonylglycerol seems to limit neuronal excitability via cannabinoid receptors of the CB1 type. By acting predominantly at a presynaptic site, it is capable of reducing excitatory neurotransmission, a mechanism which might be involved in the prevention of excessive excitability leading to epileptiform activity.
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Kurachi K, Zhang K, Ameri A, Huo J, Atoda H, Kurachi S. Genetic and molecular mechanisms of age regulation (homeostasis) of blood coagulation. IUBMB Life 2000; 49:189-96. [PMID: 10868909 DOI: 10.1080/713803620] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Blood coagulation plays a critical role not only in hemostasis but also in many physiological and pathological conditions. Epidemiological studies have shown that blood coagulation capacity in humans increases with age. Towards understanding the underlying mechanisms, the age regulation of factor IX, a key blood coagulation factor, was extensively studied. A series of human factor IX minigenes, consisting of various components of the human factor IX gene, were constructed and subjected to systematic analyses with HepG2 cells in culture and over the entire life span of transgenic mice. These studies identified critical gene structures that are essential for the unique age-dependent expression patterns of the human factor IX gene--one acting by stabilizing gene transcription and another increasing the amount of mRNA present, presumably by augmenting mRNA stability. These studies have set the stage for analyzing the overall age-based regulatory mechanisms of blood coagulation.
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Ameri A, Simmet T. Interaction of the structurally related aconitum alkaloids, aconitine and 6-benzyolheteratisine, in the rat hippocampus. Eur J Pharmacol 1999; 386:187-94. [PMID: 10618469 DOI: 10.1016/s0014-2999(99)00692-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Aconitine is a highly toxic diterpenoid alkaloid occurring in plants of the Aconitum genus. Aconitine is known to shift the voltage-dependence of the voltage-dependent Na(+) channel towards hyperpolarized direction, thereby leading to a permanent activation of the channel. 6-benzoylheteratisine is a plant alkaloid which is structurally related with aconitine. The aim of the present study was to investigate the interaction of aconitine and 6-benzoylheteratisine in the rat hippocampus. The experiments were carried out as extracellular recordings of stimulus evoked population spikes and field excitatory postsynaptic potential (EPSP) in rat hippocampal slices. Aconitine (10-100 nM) exerted a concentration-dependent decrease in the amplitude of the orthodromic population spike. When aconitine was applied in presence of 6-benzoylheteratisine (3 microM), the concentration-response curve was shifted to the right. Furthermore, the complete suppression of the population spike evoked by 100 nM aconitine was reversed by 10 microM 6-benzoylheteratisine. The closely related alkaloid heteratisine (3 and 30 microM), however, was not capable to antagonize the aconitine action. 6-benzoylheteratisine shifted the input-output relationship of the presynaptic fiber spike as function of the stimulation intensity and the input-output relationship of the field EPSP as function of the presynaptic fiber spike to the right. Thus, electrophysiologically this alkaloid seems to inhibit predominantly the excitability of the afferent fibres and, in consequence, neurotransmission between Schaffer collaterals and the CA1 neurons, thereby suppressing the firing of the latter. Spontaneously occurring epileptiform activity in area CA3 elicited by omission of Mg(2+) and elevation of K(+) was attenuated by 6-benzoylheteratisine (1 and 10 microM). Patch clamp studies performed on cultured rat hippocampal pyramidal cells revealed an inhibitory action of 6-benzoylheteratisine on whole cell Na(+) currents. It is concluded that the inhibitory and antiepileptiform effect of ajacine and lappaconitine is mediated by an inhibition of the voltage-dependent Na(+) channel which might be important for filtering high frequency bursts of action potentials characteristic for epileptiform activity in the hippocampus. Thus, 6-benzoylheteratisine seems to be a naturally occurring antagonist of the Na(+) channel activator aconitine.
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Biousse V, Ameri A, Bousser MG. Isolated intracranial hypertension as the only sign of cerebral venous thrombosis. Neurology 1999; 53:1537-42. [PMID: 10534264 DOI: 10.1212/wnl.53.7.1537] [Citation(s) in RCA: 210] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Cerebral venous thrombosis (CVT) is often overlooked when intracranial hypertension (ICH) is isolated, hence mimicking idiopathic intracranial hypertension (IIH). OBJECTIVE To describe the characteristics of patients with CVT and ICH. METHODS We examined 160 consecutive patients with CVT between 1975 and 1998. They were separated into two groups according to their clinical presentation--isolated ICH and other neurologic symptoms and signs. RESULTS Fifty-nine patients with CVT (37%) presented with isolated ICH. Neuroimaging showed involvement of more than one sinus in 35 patients (59%). Brain CT was normal in 27 of 50 patients (54%). Lumbar puncture was performed in 44 patients and showed elevated opening pressure in 25 of 32 (78%) and abnormal CSF content in 11 (25%). Etiologies and risk factors included local causes in 7 of 59 (12%), surgery in 1, inflammatory diseases in 18 (30.5%), infection in 2, cancer in 1, postpartum state in 1, coagulopathies in 11 (19%), oral contraception in 7 (12%), and remained unknown in 11 (19%). Anticoagulants were used in 41 of 59 patients (69.5%), steroids or acetazolamide in 26 (44%), therapeutic lumbar puncture in 44 (75%), and surgical shunt in 1. Three patients had optic atrophy with severe visual loss, 1 died from carcinomatous meningitis, and 55 (93%) had complete recovery. CONCLUSIONS Central venous thrombosis (CVT) can present with all the classical criteria for idiopathic intracranial hypertension (IIH), including normal brain CT with normal CSF content. Because the recognition of CVT has crucial prognostic and therapeutic implications, MRI, with magnetic resonance venography when necessary, should be performed in patients with isolated intracranial hypertension. The outcome of CVT is unpredictable, and management of patients with CVT should not differ whether they present with isolated raised intracranial pressure or with other neurologic symptoms and signs. Therefore, isolated raised intracranial pressure from CVT differs in management from IIH and should be classified neither as "IIH" nor "pseudotumor cerebri."
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Ameri A, Simmet T. Antagonism of the aconitine-induced inexcitability by the structurally related Aconitum alkaloids, lappaconitine and ajacine. Brain Res 1999; 842:332-41. [PMID: 10526129 DOI: 10.1016/s0006-8993(99)01838-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Aconitine, lappaconitine and ajacine are structurally related alkaloids occurring in several species of the Aconitum genus. While aconitine is known to activate the voltage-dependent sodium channel, lappaconitine has been reported to block this channel. To investigate a possible antagonism of the aconitine action on neuronal activity by lappaconitine and the closely related alkaloid ajacine, we have performed extracellular recordings of stimulus evoked population spikes and field excitatory postsynaptic potential (EPSP) in rat hippocampal slices. Aconitine (10-100 nM) diminished the amplitude of the orthodromic population spike in a concentration-dependent manner. When aconitine was applied in presence of 10 microM lappaconitine, the concentration-response curve was shifted to the right. Furthermore, the complete suppression of the population spike evoked by 100 nM aconitine was reversed by 10 microM lappaconitine. The action of lappaconitine was mimicked by ajacine, however, the latter alkaloid was less potent. Both lappaconitine and ajacine shifted the input-output relationship of the presynaptic fiber spike as function of the stimulation intensity and of the field EPSP as function of the presynaptic fiber spike to the right. After pharmacological isolation, the presynaptic fiber spike was decreased by both compounds in a frequency-dependent manner indicative for a use-dependent action. Thus, electrophysiologically these alkaloids seem to inhibit predominantly the excitability of the afferent fibres and, in consequence, neurotransmission between Schaffer collaterals and the CA1 neurons, thereby suppressing the firing of the latter. Ajacine and lappaconitine inhibited stimulus-triggered epileptiform population bursts in area CA1 elicited by omission of Mg(2+) as well as spontaneously occurring epileptiform discharges in area CA3 elicited by omission of Mg(2+) and elevation of K(+). It is concluded that the inhibitory and antiepileptiform effect of ajacine and lappaconitine is mediated by a frequency-dependent inhibition of the voltage-dependent sodium channel, thereby decreasing the excitability which might be important for filtering high frequency bursts of action potentials characteristic for epileptiform activity in the hippocampus. Moreover, these alkaloids are naturally occurring antagonists of the sodium channel activator aconitine.
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Ameri A, Fairbanks VF, Yanik GA, Mahdi F, Thibodeau SN, McCormick DJ, Boxer LA, McDonagh KT. Identification of the molecular genetic defect of patients with methemoglobin M-Kankakee (M-Iwate), alpha87 (F8) His --> Tyr: evidence for an electrostatic model of alphaM hemoglobin assembly. Blood 1999; 94:1825-6. [PMID: 10477710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
We determined that the molecular defect of 2 patients with hemoglobin (Hb) M-Kankakee [Hb M-Iwate, alpha87 (F8) His --> Tyr] resides in the alpha1-globin gene. The proportion of Hb M observed is higher than that predicted for an alpha1-globin variant. Our evidence suggests that the greater-than-expected proportion of Hb M-Kankakee results from preferential association of the electronegative beta-globin chains with the alpha(M)-globin chains that are more electropositive than normal alpha-globin chains.
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