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1.
Fattouch S Acheche H M'hirsi S Mellouli L Bejar S Marrakchi M Marzouki N 《Journal of virological methods》2005,127(2):126-132
Genetic diversity was characterized in 20 isolates of Grapevine fanleaf virus (GFLV) recovered from naturally infected grapevine plants (Vitis vinifera) in the North of Tunisia. Viral RNAs were isolated by oligoprobe capture, and a 605 bp fragment containing a part of the viral coat protein gene was amplified by RT-PCR. Sequence variation among isolates was characterized by restriction fragment length polymorphism (RFLP) analysis and confirmed by sequencing. The GFLV infections are found as a complex mixture of closely related genomes. In further studies, RFLP analyses of virus isolates using AluI showed that GFLV populations in Tunisian vineyards consist of two restrictotypes corresponding to distinct sub-populations Sp1 and Sp2. The relative field distribution of these sub-populations showed that Sp2 was more abundant. Individual genomes were recovered by cloning the RT-PCR products. The sequences were found to vary from each other by as much as 11%. Cloning from mixed infections showed that Sp2 are also predominant. 相似文献
2.
Lotfi Aarab Sylvie Siaume-Perez Danielle Chabardès 《Pflügers Archiv : European journal of physiology》1993,425(5-6):417-425
Previous studies have demonstrated that prostaglandin E2 (PGE2) inhibits arginine vasopressin-(AVP)dependent adenosine 3,5-cyclic monophosphate (cAMP) accumulation in microdissected rat outer medullary collecting tubules (OMCD), by a mechanism unrelated to the inhibition of cAMP synthesis. The potential role of the activation of protein kinase C (PKC) to explain the negative regulation elicited by PGE2 was investigated in this study. Single OMCD samples were pre-incubated (10 min, 30°C) in the presence or absence of either activators of PKC, phorbol 12-myristate 13-acetate (PMA), 1-oleoyl-2-acetyl-glycerol (OAG), dioctanoylglycerol (DOG) or an inhibitor of PKC, staurosporine (SSP). These compounds were present also with the agonists tested during the incubation period (4 min, 35°C). In contrast to PGE2, activators of PKC did not decrease AVP-dependent cAMP accumulation (mean ±SEM): 1nM AVP=47.1±6.8 fmol · mm–1· 4 min–1; AVP + 0.3 M PGE2=20.1±2.7, P<0.01 versus AVP; AVP + 10 nM PMA=42.0±4.7, NS versus AVP; AVP + 50 g/ml OAG=44.1±4.8. NS versus AVP, N= 5 experiments. However, 10 nM PMA prevented PGE2-induced inhibition: AVP + PGE2= 44.2±3.5% of the response to AVP and 90.3±3.2% without and with PMA respectively, N= 16. Similar results were obtained with either 50 g/ml OAG or 25 g/ ml DOG (AVP + PGE2 + OAG=92.9±6.6% of the response to AVP, N= 8; AVP + PGE2 + DOG=94.1 ±5.3%, N= 7). OAG, DOG, PMA or PMA + PGE2 had no intrinsic agonist activity in the rat OMCD and the addition of an inactive phorbol ester did not prevent PGE2-induced inhibition. SSP, 50 nM or 0.1 M, did not affect the inhibition due to PGE2 but abolished the reversion by PMA of PGE2-induced inhibition. A similar regulation was observed on forskolin-(FK)dependent cAMP accumulation: 5 M FK + 0.3 M PGE2= 37.7±6.2% of the response to FK; FK + PGE2 + 10 nM PMA=89.5±6.7%; FK + PGE2 + PMA + 0.1 M SSP=43.1±7.9%, N= 4. The inhibition induced by an
2-adrenergic agonist, clonidine 1 M, was not blocked by the activation of PKC. In fura-2-loaded OMCD samples, 10nM PMA decreased by 63.3±5.0% and by 57.2±7.1% the peak and plateau phases, respectively, of the increase in intracellular calcium concentration ([Ca2+]i) obtained with PGE2 when compared to control responses in the same tubules (n=12) and did not affect the increase in [Ca2+]i induced by 0.1 mM carbachol. It is concluded that: (1) in the rat OMCD the activation of PKC by PMA or analogues of diacylglycerol did not reproduce PGE2-induced inhibition of AVP- or FK-dependent cAMP accumulation, but prevented specifically this inhibitory action; and (2) this reversion might be the consequence of the effect of PKC activation which impaired the rises in [Ca2+]i induced by PGE2. 相似文献
3.
I Derakhshan J Lotfi K Abbsssioun 《The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques》1979,6(1):65-68
Clinical and pathological findings in two cases of degenerative progressive myoclonic epilepsy (PME) are described. The clinically difficult task of differentiating a "cerebellar" tremor from an action myoclonus is emphasized. Simultaneous electroencephalography and electrokymography was done, using capacity to ground transients for recording hand movements. This method was found useful in corroborating the cerebellar nature of the remaining disorder, after successful treatment of the myoclonic element with anticonvulsants. 相似文献
4.
Henrik Gren Kourosh Lotfi Anna‐Lena Zackrisson Curt Peterson 《Basic & clinical pharmacology & toxicology》2003,93(6):297-304
Abstract: Increased expression of P‐glycoprotein encoded by the mdr‐1 gene is a well‐characterised mechanism for resistance to cancer chemotherapeutic drugs in cell lines. However, the P‐glycoprotein expression after removal of the selection pressure has not fully been elucidated. The stability of P‐glycoprotein expression in the presence (+) and absence (?) of vincristine (30 or 150 nM) was studied in multidrug resistant K562 cell lines (VCR30+, VCR150+, VCR30? and VCR150?) for 11 months. The P‐glycoprotein protein and mdr‐1 mRNA levels were determined at regular intervals using flow cytometry and real‐time PCR, respectively. Chemosensitivity to a panel of antineoplastic drugs was measured using an MTT assay. The presence of vincristine (VCR30+ and VCR150+) resulted in high and stable levels of P‐glycoprotein and mdr‐1 mRNA during the whole period compared to wild type. As for the VCR30? and VCR150? subcultures, the expressions of P‐glycoprotein and mdr‐1 mRNA were stable for five months, and then the levels decreased rapidly. Concomitantly, the sensitivity to drugs known as P‐glycoprotein substrates was restored. In conclusion, resistant cells growing in the presence of the inducing drug have a stable P‐glycoprotein expression and resistance level, but removing the inducing drug may result in a sudden and rapid lowering of P‐glycoprotein and mdr‐1 mRNA levels as long as five months after drug withdrawal. 相似文献
5.
Faisal K. Algethami Khaled Trabelsi Anouar Hajjaji Mohamed B. Rabha Lotfi Khezami Mohamed R. Elamin Brahim Bessais My Ali El Khakani 《Materials》2022,15(14)
The present work aims to study the photocatalytic properties of nanohybrids composed of silicon nanowires (SiNWs) decorated with PbS nanoparticles (NPs). The elaborated material was intended to be utilized in wastewater treatment. The SiNWs were elaborated from the Metal Assisted Chemical Etching route (MACE), while the PbS NPs were deposited at room temperature onto SiNWs using the pulsed laser deposition (PLD) technique. The influence of decorating SiNWs (having different lengths) with PbS-NPs on their structural, morphological, optoelectronic, and photocatalytic properties was scrutinized. PbS/SiNWs nanohybrids exhibited enhanced photocatalytic degradation towards Black Amido (BA) dye for 20 µm SiNWs length and 0.2% of BA volume concentration. These optimized conditions may insinuate that this nanocomposite-like structure is a promising efficient photocatalytic systems contender, cost-effective, and recyclable for organic compound purification from wastewaters. 相似文献
6.
Asma Sassi Lotfi Loucif Sushim Kumar Gupta Mazouz Dekhil Houria Chettibi Jean-Marc Rolain 《Antimicrobial agents and chemotherapy》2014,58(9):5606-5608
Here, we report the first autochthonous cases of infections caused by blaNDM-5 New Delhi metallo-β-lactamase-producing Escherichia coli strains recovered from urine and blood specimens of three patients from Algeria between January 2012 and February 2013. The three isolates belong to sequence type 2659 and they coexpress blaCTX-M-15 with the blaTEM-1 and blaaadA2 genes. 相似文献
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9.
K. Mursi M.G. El-Sheikh H. AbdelRaouf A.A. Abou-Mohamed Y. Ramadan A. Lotfi 《The African Journal of Urology》2012,18(1):16-19
IntroductionPatients with high-risk superficial transitional cell carcinoma (TCC) of the bladder have a lifelong risk of progression and require particular attention. Intravesical Bacillus Calmette-Guerin (BCG) is recommended as a first-choice adjuvant treatment to reduce the risk of progression of high-grade tumors and carcinoma in situ (CIS).ObjectivesTo evaluate the need for routine transurethral bladder biopsy from the site of previously resected tumor three months following intravesical BCG therapy, even if the urine cytology and cystoscopy were both negative.Subjects and methodsA prospective study was carried out on 45 patients of both genders presenting with superficial bladder cancer. All patients received a six-week course of intravesical BCG. The mean age of the patients was 59 (range 33–80) years. Three months following resection, urine cytology was negative in all patients. Cystoscopy was then performed and although it was negative for any suspicious lesions, a routine biopsy from the previous resection site was taken.ResultsThe indication for BCG instillation was T1G1 in 20 patients (44%), T1G2 in 12 patients (27%) and TaG2 in eight patients (18%). Three patients (7%) had a positive bladder biopsy for malignancy at follow-up despite the negative cystoscopy and cytology. There were no statistically significant differences between patients with positive and those with negative biopsies with regard to the stage and grade of the tumor before resection or the number of resected lesions. The original pathology of the three positive patients was T1G1 (two patients) and T1G2 (one patient). The pathology after BCG treatment was the same as before instillation, T1G1 (two patients) and T1G2 (one patient).ConclusionUntil more studies on larger numbers of patients are done, a routine biopsy from the site of previously resected tumor at the time of check cystoscopy may improve the detection of tumor recurrence. 相似文献
10.
AIDS and Behavior - Sexual transmission accounts for the majority of new HIV infections in Iran. More than 80% of HIV-positive persons are sexually active, and nearly 68% reported never using a... 相似文献