Biochemistry Laboratory

Sfax, Tunisia

Biochemistry Laboratory

Sfax, Tunisia

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Dhillon M.K.,Indian Agricultural Research Institute | Kumar S.,Biochemistry Laboratory
Arthropod-Plant Interactions | Year: 2017

Amount of certain amino acids required by herbivores, and their availability in host plants are of crucial importance for insect growth, development, and life processes. Therefore, we carried out profiling and quantification of 17 amino acids in diverse sorghum genotypes, and on the Chilo partellus larvae reared on them, to understand the association and contribution of different amino acids in plant resistance to insects. Sorghum germplasm lines IS 2205 and IS 2123 had severe detrimental effects on the development and survival of C. partellus followed by varieties ICSV 700 and ICSV 708 in comparison to susceptible check, Swarna. Profiling of sorghum seedlings, seeds, and the C. partellus larvae fed on these genotypes for 17 amino acids revealed that Arginine, Glycine, Isoleucine, Leucine, Proline, and Valine in sorghum seedlings and the C. partellus larvae had significant and positive association, suggesting their role in the development and survival, while negative association of Cystine indicated its contribution in plant defense. Furthermore, C. partellus acquired less of cyclic and aliphatic amino acids per unit amount from the test resistant genotypes, while more from the susceptible check, than their presence in the seedlings. Present studies suggest that Alanine, Cystine, Glycine, and Proline contents in C. partellus larvae; Cystine and Proline contents in sorghum seedlings; and Methionine content in sorghum seeds, have significant and negative association, and contribute to explain >93% and >96%, respectively, of the variability in antibiosis mechanism and overall resistance to C. partellus. These studies have implications for antibiosis and nutritional mechanism of host plant–insect interactions in sorghum against C. partellus. © 2017 Springer Science+Business Media Dordrecht


Mongi S.,University of Sfax | Mahfoud M.,Annaba University | Amel B.,Annaba University | Kamel J.,Biochemistry Laboratory | Abdelfattah E.F.,University of Sfax
Ecotoxicology and Environmental Safety | Year: 2011

Deltamethrin is a synthetic pyrethroid insecticide. It is known for its wide toxic manifestations. The present experiment pertains to the protective role of vitamin C against haematological and biochemical toxicity induced by deltamethrin during 4 weeks. Male Wistar rats were divided into four groups of eight each: Group I served as control rats; Group II received deltamethrin (1.28. mg/kg BW) in drinking water. Group III received both deltamethrin and vitamin C (200. mg/kg BW; by i.p. injection); Group IV received vitamin C (200. mg/kg BW). Exposure of rats to deltamethrin caused significant changes of some haematological parameters (red blood cells (RBC), haemoglobin (Hb), haematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), platelet (Plt) and white blood cells (WBC)) in treated rats compared to controls. Significant increases in the levels of hepatic markers enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), γ-Glutamyl transpeptidase (γ-GT)). Furthermore, renal markers such as urea and creatinine were increased in deltamethrin treated rats. Additionally, serum cholesterol and lipid peroxidation were significantly enhanced. Co-administration of vitamin C to the group III restored all the parameters cited above to near-normal values. Therefore, our investigation revealed that vitamin C appeared to be a promising agent for protection against deltamethrin-induced toxicity. © 2011.


Chillemi G.,CINECA | Davidovich P.,Saint Petersburg Technological Institute | D'Abramo M.,CINECA | Mametnabiev T.,Saint Petersburg Technological Institute | And 4 more authors.
Cell Cycle | Year: 2013

The p53 protein is frequently mutated in a very large proportion of human tumors, where it seems to acquire gain-offunction activity that facilitates tumor onset and progression. A possible mechanism is the ability of mutant p53 proteins to physically interact with other proteins, including members of the same family, namely p63 and p73, inactivating their function. Assuming that this interaction might occurs at the level of the monomer, to investigate the molecular basis for this interaction, here, we sample the structural flexibility of the wild-type p53 monomeric protein. The results show a strong stability up to 850 ns in the DNA binding domain, with major flexibility in the N-terminal transactivations domains (TAD1 and TAD2) as well as in the C-terminal region (tetramerization domain). Several stable hydrogen bonds have been detected between N-terminal or C-terminal and DNA binding domain, and also between N-terminal and C-terminal. Essential dynamics analysis highlights strongly correlated movements involving TAD1 and the proline-rich region in the N-terminal domain, the tetramerization region in the C-terminal domain; Lys120 in the DNA binding region. The herein presented model is a starting point for further investigation of the whole protein tetramer as well as of its mutants. © 2013 Landes Bioscience.


Kassab A.,Biochemistry Laboratory | Piwowar A.,Wroclaw Medical University
Biochimie | Year: 2012

Most known pathways of diabetic complications involve oxidative stress. The mitochondria electron transport chain is a significant source of reactive oxygen species (ROS) in insulin secretory cells, insulin peripheral sensitive cells and endothelial cells. Elevated intracellular glucose level induces tricarboxylic acid cycle electron donor overproduction and mitochondrial proton gradient increase leading to an increase in electron transporter lifetime. Subsequently, the electrons leaked combine with respiratory oxygen (O 2) resulting in superoxide anion (•O2 -) production. Advanced glycation end products derive ROS via interaction with their receptors. Elevated diacylglycerol and ROS activate the protein kinase C pathway which, in turn, activates NADPH oxidases. A vicious circle of pathway derived ROS installs. Pathologic pathways induced ROS are activated and persistent though glycemia returns to normal due to hyperglycemia memory. Endothelial nitric oxide synthase may produce both superoxide anion (•O2 -) and nitric oxide (NO) leading to peroxynitrite (•ONOO-) generation. Homocysteine is also implicated in oxidative stress pathogenesis. In this paper we have highlighted the pathologic mechanisms of ROS on atherosclerosis, renal dysfunction, retina dysfunction and nerve dysfunction in type 2 diabetes. Cell oxidant stress delivery have pivotal role in cell dysfunction onset and progression of angiopathies but an early introduction of good glycemic control may protect cells more efficiently than antioxidants. © 2012 Published by Elsevier Masson SAS. All rights reserved.


Katoch R.,Biochemistry Laboratory
Indian Journal of Agricultural Biochemistry | Year: 2013

The present study was carried out to evaluate the biochemical composition, protein digestibility and protein profile of five important legumes of genus Vigna viz., V. umbellata (rice bean), V. unguiculata (cowpea), V. radiata (mung bean), V. mungo (urad bean) and V. angularis (adzuki bean). The protein and crude fibre content varied from 21.58 to 23.78 per cent and 3.5 to 4.6 per cent, respectively. The carbohydrate, ascorbic acid and ether extract ranged between 41.34 and 55.16 per cent, 0.062 and 0.093 per cent and 0.7 and 0.9 per cent, respectively. Total phenolics varied from 1.31 to 2.38 per cent, whereas simple phenols varied from 0.16 to 0.78 per cent. Total tannins, condensed tannins and hydrolysable tannins were in the range of 1.15 and 1.96 per cent, 0.68 and 0.98 per cent and 0.21 and 1.23 per cent, respectively. In vitro protein digestibility of different Vigna species varied from 70.53 to 73.78 per cent. The protein profile revealed different banding patterns, indicating variation in protein constitution of different Vigna species. Sequential extraction of protein fractions viz., albumins, globulins, prolamins and glutelins also showed variations among species. The results of the study indicated that nutritional composition and protein composition varied among Vigna species with V. radiata having high protein value as well as high protein digestibility whereas V. umbellata showing balance among nutritional and anti-nutritional traits.


Candi E.,Biochemistry Laboratory
Cell Death and Differentiation | Year: 2014

MicroRNAs (miRs) are a class of small noncoding RNAs that suppress the expression of protein-coding genes by repressing protein translation. Although the roles that miRs and the miR processing machinery have in regulating epithelial stem cell biology are not fully understood, their fundamental contributions to these processes have been demonstrated over the last few years. The p53-family member p63 is an essential transcription factor for epidermal morphogenesis and homeostasis. p63 functions as a determinant for keratinocyte cell fate and helps to regulate the balance between stemness, differentiation and senescence. An important factor that regulates p63 function is the reciprocal interaction between p63 and miRs. Some miRs control p63 expression, and p63 regulates the miR expression profile in the epidermis. p63 controls miR expression at different levels. It directly regulates the transcription of several miRs and indirectly regulates their processing by regulating the expression of the miR processing components Dicer and DGCR8. In this review, we will discuss the recent findings on the miR-p63 interaction in epidermal biology, particularly focusing on the ΔNp63-dependent regulation of DGCR8 recently described in the ΔNp63-/- mouse. We provide a unified view of the current knowledge and discuss the apparent discrepancies and perspective therapeutic opportunities.Cell Death and Differentiation advance online publication, 29 August 2014; doi:10.1038/cdd.2014.113.


Katoch R.,Biochemistry Laboratory
Indian Journal of Agricultural Biochemistry | Year: 2014

In the present study, the major incriminating factors were evaluated in rice bean seeds and different processing treatments for their minimization were studied. Among the flatulence causing oligosaccharides the raffinose, stachyose and verbascose contents varied from 2.06g/100g (IC-137194) to 2.84 g/100g (JCR-163), 0.86 (IC-137194) to 1.64 g/100g (JCR-152) and 2.78 g/100g (JCR-178) to 3.33 g/100g (IC-137194), respectively. Lipoxygenase activity (LOX) in rice bean genotypes varied from 732 units/mg (BRS-2) to 820 units/mg (JCR-20) whereas, saponin content varied from 1.2 mg/100g (IC-137194) to 2.5 mg/100g (JCR-163). Different treatments were applied for the reduction of antinutrients in rice bean seeds, among which germination (48h) followed by cooking (30min) was the most effective, whereas roasting for 10 min at 100OC was least effective treatment. The maximum reduction of antinutritient content was observed in genotype IC-140802. The least response to the treatments was observed in genotype JCR-178. These results of the study provide the best option for reducing the levels of incriminating factors in rice bean before routine consumption. © 2014, Indian Society of Agricultural Biochemists. All rights reserved.


Wegner K.A.,Biochemistry Laboratory
Journal of AOAC International | Year: 2014

Chemical testing of custom-blend fertilizers is essential to ensure that the products meet the formulation requirements. For purposes of proper crop nutrition and consumer protection, regulatory oversight promotes compliance and particular attention to blending and formulation specifications. Analyses of custom-blend fertilizer products must be performed and reported within a very narrow window in order to be effective. The Colorado Department of Agriculture's Biochemistry Laboratory is an ISO 17025 accredited facility and conducts analyses of custom-blend fertilizer products primarily during the spring planting season. Using the Lean Six Sigma (LSS) process, the Biochemistry Laboratory has reduced turnaround times from as much as 45 days to as little as 3 days. The LSS methodology focuses on waste reduction through identifying: non-value-added steps, unneeded process reviews, optimization of screening and confirmatory analyses, equipment utilization, nonessential reporting requirements, and inefficient personnel deployment. Eliminating these non-value-added activities helped the laboratory significantly shorten turnaround time and reduce costs. Key improvement elements discovered during the LSS process included: focused sample tracking, equipment redundancy, strategic supply stocking, batch size optimization, critical sample paths, elimination of nonessential QC reviews, and more efficient personnel deployment.


Candi E.,Biochemistry Laboratory | Candi E.,University of Rome Tor Vergata | Amelio I.,University of Leicester | Agostini M.,University of Leicester | And 3 more authors.
Cell Death and Differentiation | Year: 2015

MicroRNAs (miRs) are a class of small noncoding RNAs that suppress the expression of protein-coding genes by repressing protein translation. Although the roles that miRs and the miR processing machinery have in regulating epithelial stem cell biology are not fully understood, their fundamental contributions to these processes have been demonstrated over the last few years. The p53-family member p63 is an essential transcription factor for epidermal morphogenesis and homeostasis. p63 functions as a determinant for keratinocyte cell fate and helps to regulate the balance between stemness, differentiation and senescence. An important factor that regulates p63 function is the reciprocal interaction between p63 and miRs. Some miRs control p63 expression, and p63 regulates the miR expression profile in the epidermis. p63 controls miR expression at different levels. It directly regulates the transcription of several miRs and indirectly regulates their processing by regulating the expression of the miR processing components Dicer and DGCR8. In this review, we will discuss the recent findings on the miR-p63 interaction in epidermal biology, particularly focusing on the ΔNp63-dependent regulation of DGCR8 recently described in the ΔNp63-/- mouse. We provide a unified view of the current knowledge and discuss the apparent discrepancies and perspective therapeutic opportunities. © 2015 Macmillan Publishers Limited.


News Article | November 29, 2016
Site: motherboard.vice.com

For years now, NASA has been puzzled by a mysterious effect of extended space flight: vision damage. Many, though not all, astronauts who have been in space for months at a time experienced their vision slowly degrading, and post-flight inspection revealed that the back of their eyeballs had been squished down and flattened over the course of their trip. But new research presented this week provides a partial answer to what's causing this condition: pressurized spinal fluid. Noam Alperin, a researcher at the University of Miami's Evelyn F. McKnight Brain Institute, presented findings from research he and his peers conducted on 16 astronauts, measuring the volume of cerebrospinal fluid (CSF) in their heads before and after spaceflight. CSF floats around the brain and spine, cushioning it and protecting your brain as you move, such as when you stand up after lying down. Alperin and his team found that astronauts who had been in space for extended trips (about six months) had much higher build up of CSF in the socket around the eye than astronauts who had only gone on short stints (about two weeks). They also designed a new imaging technique to measure exactly how "flat" the astronauts eyeballs had become after extended periods in space. The idea is that, without the assistance of gravity, the fluid isn't pulled down and evenly distributed, allowing it to pool in the eye cavity and build up pressure, which slowly starts to warp the eye and cause the vision damage, called visual impairment intracranial pressure syndrome (VIIP). It's likely some people are more predisposed to this than others, perhaps due to the shape of their skulls, which would explain why some astronauts have not experienced VIIP. But Alperin said his findings suggest anybody could get VIIP if they're in space for a long enough period of time. "We saw structural changes in the eye globe only in the long-duration group," Alperin told me over the phone. "And these changes were associated with increased volumes of the CSF. Our conclusion was that the CSF was playing a major role in the formation of the problem." The results have not been published in a peer-reviewed journal, but Alperin told me the manuscript was recently accepted and will be published shortly. And these reported findings align with what scientists already suspected about the condition, according to Scott M. Smith, the manager of NASA's Nutritional Biochemistry Laboratory at the Johnson Space Center, who's been studying the vision loss issue for the last six years. "I think this fits very well within what others seem to be thinking at the moment," Smith told me. Many astronauts—though, importantly, not all—have experienced this unexplained reduction in eyesight after spending months on the International Space Station, some dropping from perfect 20/20 vision to 20/100 in just six months. Researchers have been gravely concerned about this effect. With plans to send humans to Mars by the 2030s, a mission that would require nine months of space flight one way, we don't really want to risk all of our astronauts going blind in the process. "NASA ranks human health risks and the two top risks are radiation and vision issues," Smith said. "Is it number one or two? Some people would say it's number one, because we don't really know what the long-term implications are." But the better we understand how VIIP occurs, the more likely we are to be able to create a solution. Smith's team is currently conducting a clinical trial to investigate whether polycystic ovarian syndrome—which, despite its name, may indeed occur in men—could have similar effects on vision. This research could help explain who is more likely to experience VIIP, as research like Alperin's explores the physical functions of the condition. What a solution to the condition will look like depends what else we learn: it could be a medication, or a mechanical device to help redistribute fluid, or something else entirely. But each piece to the puzzle helps us get one step closer to sending humans to Mars, and not blinding them in the process.

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