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1.
Mohammed Safwat Abdel-Salam Walter Klingmüller 《Molecular & general genetics : MGG》1987,210(1):165-170
Summary A method for transposon mutagenesis in Azospirillum lipoferum 29708 is reported with transposon Tn5. The suicide plasmid pSUP2021 was used to deliver Tn5 in A. lipoferum using Escherichia coli SM10 as the donor. Neomycin-resistant transconjugants were detected at a frequency of 6x10-6 per recipient. Different types of mutants were isolated, e.g. auxotrophic, coloured, IAA-negative, and IAA-overproducers. Among the auxotrophic mutants, cysteine and methionine requirers prevailed. Random Tn5-insertion with only one copy per mutant was demonstrated by Southern blotting and hybridization. Tn5-induced mutants are relatively stable, with reversion rates of 2–20×10-8. A gene which is a part of the carotenoid pathway is closely linked to the histidine genes. The existence of two pathways for IAA production in A. lipoferum is discussed. 相似文献
2.
Mohamed Yara Ahmed Hassaneen H. M. El-Dessouky Mohamed A. Safwat Gehan Hassan Naglaa Abu-Mandil Amr Khalda 《Molecular biology reports》2021,48(7):5497-5502
Molecular Biology Reports - A cluster of many risk factors for type 2 diabetes and cardiovascular disease is used to describe the metabolic syndrome (MetS). Moreover, genetic differences associated... 相似文献
3.
Expression of a heterologous S-adenosylmethionine decarboxylase cDNA in plants demonstrates that changes in S-adenosyl-L-methionine decarboxylase activity determine levels of the higher polyamines spermidine and spermine 下载免费PDF全文
Thu-Hang P Bassie L Safwat G Trung-Nghia P Christou P Capell T 《Plant physiology》2002,129(4):1744-1754
We posed the question of whether steady-state levels of the higher polyamines spermidine and spermine in plants can be influenced by overexpression of a heterologous cDNA involved in the later steps of the pathway, in the absence of any further manipulation of the two synthases that are also involved in their biosynthesis. Transgenic rice (Oryza sativa) plants engineered with the heterologous Datura stramonium S-adenosylmethionine decarboxylase (samdc) cDNA exhibited accumulation of the transgene steady-state mRNA. Transgene expression did not affect expression of the orthologous samdc gene. Significant increases in SAMDC activity translated to a direct increase in the level of spermidine, but not spermine, in leaves. Seeds recovered from a number of plants exhibited significant increases in spermidine and spermine levels. We demonstrate that overexpression of the D. stramonium samdc cDNA in transgenic rice is sufficient for accumulation of spermidine in leaves and spermidine and spermine in seeds. These findings suggest that increases in enzyme activity in one of the two components of the later parts of the pathway leading to the higher polyamines is sufficient to alter their levels mostly in seeds and, to some extent, in vegetative tissue such as leaves. Implications of our results on the design of rational approaches for the modulation of the polyamine pathway in plants are discussed in the general framework of metabolic pathway engineering. 相似文献
4.
Amany K. Ibrahim Mohamed M. Radwan Safwat A. Ahmed Desmond Slade Samir A. Ross Mahmoud A. ElSohly Ikhlas A. Khan 《Phytochemistry》2010,71(8-9):1014-1019
Microbial metabolism of cannflavin A (1) and B (2), two biologically active flavonoids isolated from Cannabis sativa L., produced five metabolites (3–7). Incubation of 1 and 2 with Mucor ramannianus (ATCC 9628) and Beauveria bassiana (ATCC 13144), respectively, yielded 6″S,7″-dihydroxycannflavin A (3), 6″S,7″-dihydroxycannflavin A 7-sulfate (4) and 6″S,7″-dihydroxycannflavin A 4′-O-α-l-rhamnopyranoside (5), and cannflavin B 7-O-β-d-4?-O-methylglucopyranoside (6) and cannflavin B 7-sulfate (7), respectively. All compounds were evaluated for antimicrobial and antiprotozoal activity. 相似文献
5.
6.
Monosodium glutamate (MSG) is a natural constituent of many foods and was reported to have neurotoxic effects. The aim of this study was to investigate the possible toxic effect of MSG on histological and glial fibrillary acidic protein
(GFAP) immunohistochemical features of cerebellar cortex of albino rats and to evaluate the possible protective role of vitamin
C against this effect. Thirty rats were divided into 3 equal groups. Group I, control; Group II, treated with 3 g/kg/day of
MSG and Group III, received 100 mg/kg/day of vitamin C simultaneously with MSG. After 14 days, cerebellar tissues were obtained
and processed to prepare sections stained with H&E, toluidine blue. The GFAP was detected immunohistochemically. Histological
examination of group II showed degenerative changes as pyknotic Purkinje and granule cells with areas of degeneration surrounded
by inflammatory cells in granular layer. However, group III showed more preserved histological structure of cerebellar cortex.
Statistical analysis of area percent of the GFAP immunoreaction among studied groups showed significant increase in group
III when compared with group I and group II. However, a non significant increase was detected in group II when compared with
group I. In conclusion, MSG has neurotoxic effect leading to degenerative changes in neurons and astrocytes in cerebellar
cortex of albino rats and vitamin C supplementation could protect from these changes. Getting more attention to the constituents
of food products is recommended and vitamin C could be advised to protect people from food oxidants additives. 相似文献
7.
Earthworm survival in oil contaminated soil 总被引:4,自引:0,他引:4
Earthworms are an important component of the soil biota and their response to oil pollution needs to be better understood. Laboratory investigations were undertaken to determine the concentrations of crude oil in soil that leads to death of Lumbricus terrestris and Eisenia fetida and to determine the propensity of L. terrestris to move away from contaminated soil. Clemville sandy clay loam was amended to contain maximum oil contents of 1.5 – 2.5% depending on the particular experiment. Additionally, the ability of L. terrestristo survive in bioremediated oil-contaminated soil was evaluated. An oil content of 0.5% was not harmful to survival of earthworms for 7 d but an oil concentration of 1.5% reduced survival to less than 40%. Bioremediated soil containing 1.2% oil did not reduce survival of L. terrestrisduring 10 d. Survival of L. terrestrisin unweathered oil was improved when free movement between contaminated and uncontaminated soil was possible. Casts of earthworms exposed to oil-containing soil contained 0.2% total petroleum hydrocarbons. An allowable regulatory level of 1% oil contamination in soil may not allow for survival of earthworms. 相似文献
8.
Ninna Aggerholm-Pedersen Katja Maretty-Kongstad Johnny Keller Steen Baerentzen Akmal Safwat 《Translational oncology》2016,9(4):322-328
OBJECTIVE: Certain biomarkers such as the C-reactive protein, serum albumin, and the neutrophils to lymphocyte ratio are of prognostic significance regarding survival in different types of cancers. Data from sarcoma patients are sparse and mainly derived from soft tissue sarcoma and/or metastatic cases. Adjusting for confounders such as comorbidity and age is an essential safeguard against erroneous conclusions regarding the possible prognostic value of these biomarkers. The aim of this study was to assess the prognostic value of a battery of pretreatment biomarkers in the serum of patients with localized bone sarcomas and to adjust for potential confounders. MATERIAL AND METHODS: All patients diagnosed with localized intermediate and high-grade bone sarcoma during 1994 to 2008 were extracted from the Aarhus Sarcoma Registry. The serum levels of albumin, C-reactive protein, hemoglobin, neutrophils, lymphocytes, and sodium were collected from the patient records. The prognostic values of overall and disease-specific mortality were tested for each individual biomarker as well as for the Glasgow prognostic score (GPS) and for a new composite score incorporating five biomarkers (Aarhus composite biomarker score: ACBS). Adjustments were made for comorbidity as well as other possible prognostic factors, such as size, histological type, margin, chemotherapy, and soft tissue extension, using the Cox proportional hazard model. RESULTS: A total of 172 patients with high- or intermediate-grade localized bone sarcoma were included. Of these patients, 63 were diagnosed with chondrosarcoma and 109 patients with Ewing/osteosarcoma. The median age was 55 years for chondrosarcoma and 19 years for Ewing/osteosarcoma patients. The overall 5-year mortality was 31% [95% confidence interval (CI): 21-44] and 41% (95% CI: 33-51), whereas the 5-year disease-specific mortality was 21% (95% CI: 12-34) and 39% (95% CI: 31-49) for chondrosarcoma and Ewing/osteosarcoma, respectively. Comorbidities were present in 12% of the Ewing/osteosarcoma patients and in 24% of the chondrosarcoma patients. After adjustment for comorbidity and other confounders, it was found that elevated levels of CRP, low hemoglobin, low sodium, high GPS, and high ACBS were associated with increased overall mortality. Furthermore, elevated levels of CRP, low hemoglobin, high GPS, and high ACBS were associated with increased disease-specific mortality. CONCLUSION: Elevated levels of CRP, low hemoglobin, high GPS, and high ACBS were all independent prognostic factors for both overall and disease-specific mortality. ACBS is a new three-level score of five biomarkers, but its value has to be confirmed in an independent data set. 相似文献
9.
Tectorigenin inhibits RANKL‐induced osteoclastogenesis via suppression of NF‐κB signalling and decreases bone loss in ovariectomized C57BL/6 下载免费PDF全文
Chiyuan Ma Kai Xu Jiahong Meng Jisheng Ran Safwat Adel Abdo Moqbel An Liu Shigui Yan Lidong Wu 《Journal of cellular and molecular medicine》2018,22(10):5121-5131
Metabolism of bone is regulated by the balance between osteoblast‐mediated bone formation and osteoclast‐mediated bone resorption. Activation of osteoclasts could lead to osteoporosis. Thus, inhibiting the activity of osteoclasts becomes an available strategy for the treatment of osteoporosis. Tectorigenin is an extract of Belamcanda chinensis In the present study, the anti‐osteoclastogenesis effects of tectorigenin were investigated in vitro and in vivo. The results showed preventive and therapeutic effects of tectorigenin at concentrations of 0, 10, 40, and 80 μmol/L in the maturation and activation of osteoclasts. A signalling study also indicated that tectorigenin treatment reduces activation of NF‐κB signalling in osteoclastogenesis. Animal experiment demonstrated that tectorigenin treatment (1‐10 mg/kg, abdominal injection every 3 days) significantly inhibits bone loss in ovariectomized C57BL/6. Our data suggest that tectorigenin is a potential pharmacological choice for osteoporosis. 相似文献
10.
Katja Maretty-Kongstad Ninna Aggerholm-Pedersen Johnny Keller Akmal Safwat 《Translational oncology》2017,10(6):942-948
BACKGROUND: The prognostic value of serum biomarkers in soft tissue sarcoma (STS) is limited, and its clinical applicability is compromised by a common inability to adjust for important confounders. The aim of this study was to determine the prognostic value of pretreatment biomarkers on disease-specific survival (DSS) adjusted for confounders. METHODS: The study included 818 patients with localized STS. Pretreatment levels of albumin, C-reactive protein, hemoglobin, neutrophils, and lymphocytes were tested individually and combined in prognostic scores: neutrophil/lymphocyte ratio (NLR), Glasgow Prognostic Score (GPS), and Aarhus Composite Biomarker Score (ACBS) which includes all five biomarkers. Patients were randomly split into a test cohort and a validation cohort. The prognostic value of biomarkers on DSS was estimated using crude and adjusted Cox proportional hazard models. The different biomarker scores were compared using Akaike's information criteria. RESULTS: In the test cohort of 403 patients, all biomarkers except lymphocyte count were significant prognostic factors for DSS also after adjusting for confounders. NLR, GPS, and ACBS were independently associated with decreased survival; however, ACBS was significantly superior to NLR (P = .02) and GPS (P = .002). These findings were validated in the randomly assigned validation cohort of 415 patients. In the pooled data of 818 patients, the ACBS performed better than GPS and NLR. ACBS 2 was independently associated with decreased DSS compared to ACBS 0, hazard ratio 2.3[95% confidence interval: 1.5-3.5], P < .001. CONCLUSION: Patients with abnormal values in more than one serum biomarkers had a significant additional risk of dying compared to patients with only one abnormal value. ACBS was validated as an independent prognostic factor that is superior to both NLR and GPS. 相似文献