Time-dependent changes in protein phosphorylation patterns in rat brain synaptosomes caused by deltamethrin     

Yoshiro Kanemoto  Essam E. Enan  Fumio Matsumura  Mitsuo Miyazawa 《Pest management science》1992,34(3):281-290

Effects of deltamethrin, a powerful pyrethroid insecticide, on the protein phosphorylation and dephosphorylation processes during depolarization in rat brain synaptosomes were studied by using [³²P]phosphoric acid as a starting radiotracer and high external concentration of potassium ions or veratridine (10^?-5 M) as depolarizing agents. At the onset of depolarization there was a quick rise in phosphorylation in various synaptic proteins for about 15–30 s followed by a gradual decline in levels of phosphorylation. The effect of deltamethrin (10^?-7 M) on this system was found to be dependent on the length of preincubation of the synaptosome with the pesticide prior to depolarization. At an early stage (0–3 min preincubation period) it caused a modest suppression of protein phosphorylation activities. When the period of deltamethrin preincubation was extended to 5–20 min, however, it caused a significant increase in protein phosphorylation throughout the depolarization period. At the later stage of the action of deltamethrin (e.g. preincubation period of 30–40 min), deltamethrin-treated synaptosomes no longer responded to the depolarization signal to raise the level of phosphorylation on many proteins. These results indicate that deltamethrin's actions on the synaptic process are complex. Depending on the length of exposure, its effects on protein phosphorylation responses in intact synaptosomes could be either stimulatory or inhibitory. To study the cause of deltamethrin-induced synaptic block at the later stage, effects of deltamethrin on protein kinases were studied by using lysed synaptic membranes with [gamma-³²P]ATP. Deltamethrin was shown to inhibit calcium–calmodulin-dependent protein phosphorylation activities at 10^?-7 M when given directly to the enzyme source 10 min prior to the addition of [³²P]ATP. Such an observation helps to explain the inhibitory action of deltamethrin on protein phosphorylation which occurs at the late stage of its action (i.e. preincubation time > 20 min).  相似文献   

~(60)Co-γ射线在组织培养中对培养基的消毒作用     

顾永强  曹华兴  吴锷南  何小华 《上海交通大学学报(农业科学版)》1987,(3)

本文报道在植物组织培养中,~(60)Co_(-γ)射线对培养基的消毒作用,旨在探明,用~(60)Co_(-γ)射线消毒培养基的可行性及对培养效果的影响。结果表明,经~(60)Co_(-γ)射线600krad 处理培养基能达到灭菌。其培养基能促进愈伤组织的生长,而对绿苗分化率没有影响。辐射导致的茶色培养瓶可促进水稻愈伤组织根的分化和生长而抑制芽的分化。  相似文献   

Diversity of bacterial pathogens and their antimicrobial resistance profile among commensal rodents in Qatar     

Islam  Md Mazharul  Farag  Elmoubashar  Hassan  Mohammad Mahmudul  Enan  Khalid A.  Mohammad Sabeel  K. V.  Alhaddad  Maryam Mohammed  Smatti  Maria K.  Al-Marri  Abdulla Mohammad  Al-Zeyara  Abdul Azia  Al-Romaihi  Hamad  Yassine  Hadi M.  Sultan  Ali A.  Bansal  Devendra  Mkhize-Kwitshana  Zilungile 《Veterinary research communications》2022,46(2):487-498

Rodents are sources of many zoonotic pathogens that are of public health concern. This study investigated bacterial pathogens and assessed their antimicrobial resistance (AMR) patterns in commensal rodents in Qatar. A total of 148 rodents were captured between August 2019 and February 2020, and blood, ectoparasites, and visceral samples were collected. Gram-negative bacteria were isolated from the intestines, and blood plasma samples were used to detect antibodies against Brucella spp., Chlamydophila abortus, and Coxiella burnetii. PCR assays were performed to detect C. burnetii, Leptospira spp., Rickettsia spp., and Yersinia pestis in rodent tissues and ectoparasite samples. Antimicrobial resistance by the isolated intestinal bacteria was performed using an automated VITEK analyzer. A total of 13 bacterial species were isolated from the intestine samples, namely Acinetobacter baumannii, Aeromonas salmonicida, Citrobacter freundii, Citrobacter koseri, Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Hafnia alvei, Klebsiella pneumoniae, Providencia stuartii, Proteus mirabilis, Pseudomonas aeruginosa, and Salmonella enterica. The majority of them were E. coli (54.63%), followed by P. mirabilis (17.59%) and K. pneumoniae (8.33%). Most of the pathogens were isolated from rodents obtained from livestock farms (50.46%), followed by agricultural farms (26.61%) and other sources (22.94%). No antibodies (0/148) were detected against Brucella spp., C. abortus, or C. burnetii. In addition, 31.58% (6/19) of the flea pools and one (1/1) mite pool was positive for Rickettsia spp., and no sample was positive for C. burnetii, Leptospira spp., and Y. pestis by PCR. A total of 43 (38%) bacterial isolates were identified as multidrug resistant (MDR), whereas A. salmonicida (n?=?1) did not show resistance to any tested antimicrobials. Over 50% of bacterial MDR isolates were resistant to ampicillin, cefalotin, doxycycline, nitrofurantoin, and tetracycline. The presence of MDR pathogens was not correlated with rodent species or the location of rodent trapping. Seven (11.86%) E. coli and 2 (22.2%) K. pneumoniae were extended-spectrum beta-lactamases (ESBL) producers. These findings suggest that rodents can be a source of opportunistic bacteria for human and animal transmission in Qatar. Further studies are needed for the molecular characterization of the identified bacteria in this study.

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Action of deltamethrin on the calcium/calmodulin-dependent protein kinase from the rat brain     

Essam Enan  Fumio Matsumura 《Pest management science》1993,37(1):21-30

The action of deltamethrin on the calcium/calmodulin-dependent protein kinase (CaM-Kinase II) and phosphatase system in the rat brain synapse was studied under various experimental conditions to optimize these enzyme activities and to facilitate the studies of the mechanism of interaction of this pesticide with several components of this enzyme system. To obtain a clear-cut inhibition of this enzyme by deltamethrin the following conditions must be met: (a) the enzyme system should be purified by precipitation with ammonium sulfate (450 g litre^?1) prior to the addition of deltamethrin, (b) both Ca²⁺ and calmodulin (CaM) should be added to the incubated media before the addition of [y-³²P]ATP, (c) deltamethrin should be incubated at least 10 min (but less than 30 min) with the enzyme system before [y-³²P]ATP addition, (d) the incubation temperature should be above 20°C (optimum 30°C), (e) [y-³²P]ATP concentration should be in the order of 10^? M (concentration adjusted using cold ATP), and (f) the incubation time with [y^?P]ATP for incorporation of ³²P into the protein should be in the neighborhood of 60 s. Under these conditions, the inhibitory potency of various active and inactive isomers or analogs of pyrethroids and DDT was tested. The order of the inhibitory power of these active forms of pesticides was 1 R-deltamethrin > (S)(RS) fenvalerate ≥ p,p′-DDT. Other compounds were not active at the concentration tested, indicating the differential sensitivity of this enzyme and the existence of a correlation of inhibitory power to insecticidal activity.  相似文献   

Isolation,identification and differentiation of <Emphasis Type="Italic">Campylobacter</Emphasis> spp. using multiplex PCR assay from goats in Khartoum State,Sudan     

Atif Elbrissi  Y. A. Sabeil  Khalda A. Khalifa  Khalid Enan  Osama M. Khair  A. M. El Hussein 《Tropical animal health and production》2017,49(3):575-581

The aim of this study was to identify and characterize thermophilic Campylobacter species in faecal samples from goats in Khartoum State, Sudan, by application of multiplex polymerase chain reaction. Campylobacteriosis is a zoonotic disease of global concern, and the organisms can be transmitted to human via food, water and through contact with farm animals and pets. There are five clinically related Campylobacter species: Campylobacter jejuni (C. jejuni). Campylobacter coli, Campylobacter lari, Campylobacter upsaliensis and Campylobacter fetus. Conventional cultural methods to diagnose campylobacteriosis are tedious and time consuming. Wide ranges of genes have been reported to be used for PCR-based identification of Campylobacter spp. We used a multiplex PCR assay to simultaneously detect genes from the major five clinically significant Campylobacter spp. The genes selected were hipO (hippuricase) and 23S rRNA from glyA (serine hydroxymethyl transferase) from each of C. jejuni. C. coli, C. lari, and C. upsaliensis; and sapB2 (surface layer protein) from C. fetus subsp. fetus. The assay was used to identify Campylobacter isolates recovered from 336 cultured faecal samples from goats in three localities in Khartoum State. C. coli was the most predominant isolate (234; 69.6%), followed by C. jejuni (19; 5.7%), C. upsaliensis (13; 3.9%), C. fetus subsp. fetus (7; 2.1%) and C. lari (6; 1.8%). Twenty-nine goats showed mixed infection with Campylobacter spp., 21 of which harbored two Campylobacter spp., while eight animals were infected with three species. Ten out of twelve goats that displayed diarrhea harbored C. coli only. C. coli, C. jejuni and C. upsaliensis showed significant variation with localities. The prevalence of C. coli was significantly higher (87; 25.9%) in goats from Omdurman, whereas C. jejuni and C. upsaliensis were significantly higher (11; 3.3%, 9; 2.7%) in goats from Khartoum. The multiplex PCR assay was found to be rapid and easy to perform and had a high sensitivity and specificity for characterizing the isolates, even in mixed cultures. The study demonstrated the significance of goats as reservoirs in the dissemination of Campylobacter spp. which could be considered as potential agent of caprine enteritis and abortion as well as contamination of the wider environment posing serious public health concern in Khartoum State.  相似文献