Biochemical characterization of digestive α-amylase, α-glucosidase and β-glucosidase in pistachio green stink bug, Brachynema germari Kolenati (Hemiptera: Pentatomidae)

Samar Ramzi,Vahid Hosseininaveh 한국응용곤충학회 2010 Journal of Asia-Pacific Entomology Vol.13 No.3

The pistachio green stink bug, Brachynema germari, has 3–5 generations per year and causes severe damages to pistachio crops in Iran. Physiological digestive processes, such as digestive carbohydrases, can be used to design new strategies in IPM programs for controlling this pest. The enzyme α-amylase digests starch during the initial stage of digestion. Complete breakdown of carbohydrates takes place in the midgut where α- and β-glucosidic activities are highest. Alpha-amylase and α- and β-glucosidase activities were found in the midgut and salivary glands of pistachio green stink bug adults. Overall enzyme activities were significantly higher in the midgut than in salivary glands. The highest α-amylase and α- and β-glucosidase activities were in section v3, whereas the lowest activities were in section v4. Vmax was higher and Km was lower in the midgut than in the salivary glands for these enzymes. In the pistachio green stink bug, the optimal pH was pH 5–6.5 and the optimal temperature was 30 °C to 35 °C for these enzymes. Alpha-amylase activity in the midgut and salivary glands decreased as the concentrations of MgCl2, EDTA and SDS increased. Enzyme activities in both midgut and salivary glands increased in the presence of NaCl, CaCl2, and KCl. NaCl had a negative effect on alpha-amylase extracted from salivary glands.

Clinical and ultrasonographic screening for carpal tunnel syndrome in hemodialysis patients

( Samar Tharwat ),( Mohammed Kamal Nassar ) 대한신장학회 2020 Kidney Research and Clinical Practice Vol.39 No.2

Background: Carpal tunnel syndrome (CTS) is one of the most common complications among hemodialysis (HD) patients. This study aimed to assess the prevalence of CTS in HD patients using clinical and noninvasive ultrasound (US) criteria. Methods: A cross-sectional, observational study was conducted on 94 HD patients to evaluate CTS manifestations and demographic, clinical, and laboratory data. The median nerve (MN) cross sectional area (CSA) (MN-CSA) was estimated by US examination at the pisiform and hamate levels. Both hands were evaluated, and the higher MN-CSA was considered. Results: Neuropathic pain and nocturnal numbness at MN distribution were present in 40.4% and 18.1%, respectively, while Tinel’s test was positive in 25.5% of patients. A MN-CSA ≥ 11.5 mm² identified the probability of CTS with 63% sensitivity and 80% specificity. Patients with CTS had higher serum calcium (P = 0.02) and lower parathyroid hormone (PTH) (P = 0.02). CTS was frequently developed on the same side of an arteriovenous fistula. The MN-CSA had positive correlations with age, serum phosphorus, and visual analogue scale (VAS) score (P = 0.01, 0.01, and 0.03 respectively) and a negative correlation with PTH level (P = 0.007). Serum phosphorus level (P = 0.015) and VAS (P = 0.04) were the significant predictors of MN-CSA. Conclusion: CTS appears to frequently occur in HD patients. US examination may be helpful in detection of CTS and can be an alternative to electrodiagnostic studies in HD patients.

Effects of Citrullus colocynthis agglutinin on intermediary metabolism of Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae)

Samar Ramzi,Ahad Sahragard,Arash Zibaee 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.3

In the current study,we examined the effects of Citrullus colocynthis agglutinin (CCA) on the intermediary metabolismofEctomyelois ceratoniae larvae as a means of determining effectiveness of the lectin in pest control. Larvaewere fed on control diets and diets containing CCA (2%) for 24 and 48 h. The activities of digestive α-amylase andgeneral proteases significantly decreased in the larvae fed on the CCA diet, but no statistically significant changeswere found in the case of TAG-lipase. Meanwhile, the activities of all specific proteases, except aminopeptidase,changed in the treated larvae for all time intervals. The activity of alanine aminotransferase significantly decreasedin the treated larvae but the activities of aspartate aminotransferase and γ-glutamyl transferase increased24 h post-feeding on the CCA diet. The activity of aldolase decreased 48 h post-feeding but lactatedehydrogenase (LDH) showed inverse results at the same time interval. The activities of acid phosphatase(ACP) and alkaline phosphatase (ALP) decreased 48 h post-feeding for ACP and at both time intervals for ALP. The amount of high-density lipoprotein (HDL) showed no statistical differences between control and CCA-fedlarvae, but the amount of low-density lipoprotein (LDL) significantly increased in the CCA-fed larvae at bothtime intervals. The amount of protein increased in the larvae fed on the CCA diet, but the amounts of glycogenand triacylglycerol significantly decreased at both time intervals. Results of the current study clearly revealthat ingestion of CCA significantly influences the activities of digestive enzymes and disrupts the intermediarymetabolism of E. ceratoniae larvae. Further studies on genetic engineering of CCA to provide resistant varietiesmight open a new avenue for safe and efficient control of the pest.

Comparison of glutathione S-transferase and general esterase in two bugs, Eurygaster integriceps Puton (Heteroptera: Scutelleridae) and Brachynema germari Kolenati (Heteroptera: Pentatomidae)

Samar RAMZI,Ali Reza BANDANI1,Arash ZIBAEE,권오석 한국곤충학회 2009 Entomological Research Vol.39 No.4

Glutathione S-transferases (GSTs) and general esterases play important roles in the detoxification of many substances including allelochemicals from plants and chemical pesticides. In this study, to determine the feeding status and effects of agronomical practices on GST and general esterase, two bug species, Eurygaster integriceps and Brachynema germari, were selected with differences in these cases. GST and general esterase responses varied when switching from 1-chloro-2,4-dinitrobenzene (CDNB) and a-naphtyl to 1,2-dichloro-4-nitro-benzene (DCNB) and b-naphtyl in E. integriceps and B. germari, respectively. The activities of GST and esterase by using CDNB and a-naphtyl were higher than that of DCNB and b-naphtyl for both insects. It was shown that the optimal pH for GST and general esterase activity varied between pH 5.5 and 6. While the Michaelis constant (Km) value related to E. integriceps toward CDNB and a-naphtyl was lower than Km for B. germari, Km values calculated for E. integriceps toward DCNB and b-naphtyl corresponding to those related to A. hejeri were similar to CDNB and a-naphtyl values. The maximal reaction velocity (Vmax) values related to E. integriceps for both substrates (CDNB and a-naphtyl) were always higher than those from B. germari and showed significant differences. At the basement of the native-PAGE electrophoresis, five bands were observed in for GST and three were visualized for B. germari, with a large, darker band for E. integriceps in the case of esterases. Studies on the detoxification enzymes of herbivores should be undertaken to determine accurately the effect of the host plants on the organisms eating them, particularly in terms of biochemical and ecological advantages.

In Situ Microfluidic Preparation and Solidification of Alginate Microgels

Samar Damiati 한국고분자학회 2020 Macromolecular Research Vol.28 No.11

Biomimetic fabrication of alginate beads has promising applications in the field of synthetic bioarchitecture. Combining microfluidic technology with in situ gelation enables the creation of alginate microgels with precisely tunable size, as well as allowing control of the crosslinking process. Owing to the wide range of applications of alginate microgel beads, this study aimed to develop various microfluidic models for the generation of such beads by investigating the influence of several parameters on their morphologies and dispersity. Four types of glass microfluidic chips with flow focusing or co-flowing droplet generators were used to continuously form alginate droplets, with the possibility of either internal or external alginate gelation by a crosslinking agent supplied by a microfluidic channel. In all four models, alginate was used at a fixed concentration, Span 80 was used as a surfactant to improve the long-term stability of the beads, either mineral oil or oleic acid was used as a continuous phase, and either calcium carbonate (CaCO3) or calcium chloride (CaCl2) was used as a crosslinking agent. The generated beads exhibited various architectures, including individual monodisperse or polydisperse beads, small clusters, and multicompartment systems. The results of the study revealed the importance of microfluidic design and gelation strategy for the generation of stable polymeric architectures. The current study proposes a simple user’s guide to create alginate microgels in various architectures. The fabricated biomimetic models in the form of polymeric-based vesicles can be further exploited in several applications, including cell-like structures, tissue engineering, and cell and drug encapsulation. Additional investigations will be needed, however, to improve these models so that they more closely resemble the natural structures of cells and tissues.

Erratum to: Dehydroascorbate reductase and glutathione reductase play an important role in scavenging hydrogen peroxide during natural and artificial dehydration of Jatropha curcas seeds

Samar A. Omar,Nabil I. Elsheery,Hazem M. Kalaji,Zeng-Fu Xu,Song Song-Quan,Robert Carpentier,이춘환,Suleyman I. Allakhverdiev 한국식물학회 2013 Journal of Plant Biology Vol.56 No.4

Changes in H2O2 and the main antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR), in endospermic and embryonic tissues were studied in developing and artificially dried Jatropha curcas seeds. Immature seeds were desiccation-tolerant at 80 days after flowering, as they were able to germinate fully after artificial drying on silica gel had reduced their water content to 10–12% of fresh weight. In both endospermic and embryonic tissues, H2O2 level and, consequently, lipid peroxide content, decreased during seed development as well as after artificial dehydration of developing seeds. All examined antioxidant enzymes except DHAR showed a decrease in total activity in mature stages as compared with early stages. Expression analysis of SOD genes revealed that the decrease in total SOD activities was related to the decrease in Cu/Zn-SOD expression, while the continuous activity of SOD during maturation was related to an increase in Mn-SOD expression. Artificial drying resulted in increased SOD and DHAR activity, irrespective of the developmental stage. Our results revealed weak participation of CAT and APX in H2O2 scavenging, as well as no significant alterations in GR activities either during maturation or after artificial drying. Changes in SOD and GR isoenzyme patterns occurred during maturation-related drying, but not after artificial drying. These results highlight the role of ascorbate-glutathione cycle enzymes (DHAR and GR) in H2O2 scavenging during maturation or after artificial drying of developing J. curcas seeds.

Tectonic evolution of the Fawakhir area, and its implication to Central Eastern Desert of Egypt

Samar Yoosef,Chang Whan Oh,Mohamed Abdelkareem 대한지질학회 2022 대한지질학회 학술대회 Vol.2022 No.10

Bioactive Eicosanoids: Role of Prostaglandin F2α and F2-Isoprostanes in Inflammation and Oxidative Stress Related Pathology

Samar Basu 한국분자세포생물학회 2010 Molecules and cells Vol.30 No.5

Oxidative stress and inflammation are supposed to be the key players of several acute and chronic diseases, and also for progressive aging process. Eicosanoids, especially prostaglandin F2α ( P GF2α) and F2-isoprostanes are endogenous compounds that are involved both in physiology and the above mentioned pathologies. These compounds are biosynthesized mainly from esterified arachidonic acid through both enzymatic and non-enzymatic free radical-catalysed reactions in vivo, respectively. They have shown to possess potent biological activities in addition to their application as biomarkers of oxidative stress and inflammation. Recent advancement of methodologies has made it possible to quantify these compounds more reliably and apply them in various in vivo studies successfully. Today, experimental and clinical studies have revealed that both PGF2α and F2-isoprostanes are involved in severe acute or chronic inflammatory conditions such as rheumatic diseases, asthma, risk factors of atherosclerosis,diabetes, ischemia-reperfusion, septic shock and many others. These evidences promote that assessment of bioactive PGF2α and F2-isoprostanes simultaneously in body fluids offers unique non-invasive analytical opportunity to study the function of these eicosanoids in physiology,oxidative stress-related and inflammatory diseases, and also in the determination of potency of various radical scavengers, anti-inflammatory compounds, drugs, antioxidants and diet.

Case Report : Full term broad ligament pregnancy through a Cesarean scar

( Samar Rudra ),( Suhasini Gupta ),( Bal Krishan Taneja ),( Ranjana Gupta ) 대한산부인과학회 2013 Obstetrics & Gynecology Science Vol.56 No.6

A broad ligament pregnancy is an extremely rare condition. Diagnosis is often missed and finally made during laparotomy. We present a case which remained undiagnosed throughout her pregnancy till she reached term and unfortunately had intrauterine foetal demise when she reported to our hospital. On clinical suspicion, ultrasound and magnetic resonance imaging evaluation was done which picked up the diagnosis of abdominal pregnancy. On laparotomy a broad ligament pregnancy was found with a rent in the previous Cesarean scar towards the gestational sac in the broad ligament.

Microstructure Evaluation and High-Temperature Wear Performance of Hard Protective Layer Deposited on Titanium Alloy via Laser Metal Deposition (LMD)

Samar Reda Al‑Sayed,Haytham Elgazzar,Adel Nofal 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.11

To improve the poor wear resistance of titanium and its alloys, a blended powder consisting of 60 wt% tungsten carbide(WC) and 40 wt% NiCrSiBC was produced by Laser Metal Deposition (LMD) on the surface of Ti–6Al–4V (α + β) titaniumalloy. A 3 KW TRUDISK 3001 Yb:YAG disk laser (1030 nm wavelength) attached with a coaxial jet nozzle coupled with apowder feeding system was used in this study. Different powder feeding rates were used aiming to make the LMD processmore economic. In addition, the deposited layer performance at elevated temperature was also evaluated. The results showedcrack-free structures when using the optimized conditions. At a powder feeding rate of 20 ɡ min−1, the matrix structure consistsof a small continuous network of WC granular clusters in a solid solution of Cr in Ni and Ti alloy matrix. In contrast,at higher powder feeding rates of 40 and 60 ɡ min−1, such granular clusters transformed into mostly fragile needle-type androd-type W2Cthat grew epitaxially from the surface of the partially melted WC particles, respectively. The results showedan increase by more than four folds in the microhardness values of the clad layers in addition to a significant wear resistanceat 500 °C compared to that of Ti–6Al–4V substrates. A reduction by 66% in the friction coefficient at 60 ɡ min−1 wasrecorded as compared with the as-received samples. Such improvement in surface properties at elevated temperatures meetsthe industrial requirements for such engineering alloys.