Biological and ecological studies on the sugar-beet fly,Pegomyia mixta Vill. (Diptera: Anthomyiidae) on sugar-beet in Egypt

The sugar-beet fly, Pegomyia mixta Vill., is the most serious insect pest affecting sugar-beet plantations in Egypt. This study wase carried out in field in the El-Nubaria region ofEl-Behare Governorate. Peak numbers of flies were taken in sweep nets in December. Development of the fly appeared to be restricted to the months between November and May. In the hot months, adults were most active early in the morning and late in the afternoon, but in the cold months the peak of activity occurred at about midday. The flies were generally found on the upper surfaces of the leaves at temperatures below 16 °C and on the lower surfaces at temperatures above 24 °C. Females were generally more numerous than males. The eggs were observed from the first week of November to the end of April; the population was three blotches of eggs and 17 larvae/20 plants. The highest infestation of this insect in El-Nubaria was recorded at the end of March in both seasons (10 blotches of eggs, 20 larvae, and five pupae, and 12 blotches of eggs, 22 larvae, 13 pupae, respectively). The eggs are deposited in groups (3–8 eggs). The larvae bore its blotch in the leaf, about 3–7 larvae may be found in one blotch.     

Variability in host plant resistance of Sorghum to Striga Hermonthica infestation in West Africa

Fourteen elite sorghum lines were evaluated for their resistance to Striga hermonthica at three locations in Nigeria and Mali. Results showed that many of the lines especially MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64 (Keninkédié) and the check SRN 39 remained resistant to Striga in all locations with low emerged Striga counts, while SAMSORG 14 had the highest Striga infestation in all locations. Considerable variation in reaction to Striga infestation was observed on Séguètana, 97-SB-F5DT-63 (Wasa), 97-SB-F5DT-65, CMDT 38, CMDT 39 and CMDT 45 which were susceptible to Striga at Samaru, Nigeria but were resistant to Striga at both locations in Mali. Based on low Striga resistance and high grain yield, lines MALISOR 84-1, SAMSORG 41, 97-SB-F5DT-64, 97-SB-F5DT-65, CMDT 39 and SAMSORT 14 have been nominated for wider evaluation across more West African countries.     

Two common nonsynonymous paraoxonase 1 (<Emphasis Type="Italic">PON1</Emphasis>) gene polymorphisms and brain astrocytoma and meningioma

Background  

Human serum paraoxonase 1 (PON1) plays a major role in the metabolism of several organophosphorus compounds. The enzyme is encoded by the polymorphic gene PON1, located on chromosome 7q21.3. Aiming to identify genetic variations related to the risk of developing brain tumors, we investigated the putative association between common nonsynonymous PON1 polymorphisms and the risk of developing astrocytoma and meningioma.     

Long-term effects of graduated compression stockings on cardiorespiratory performance

The use of graduated compression stockings (GCS) in sport has been increasing in the last years due to their potential positive effects for athletes. However, there is little evidence to support whether these types of garments actually improve cardiorespiratory performance. The aim of this study was to examine the cardiorespiratory responses of GCS during running after three weeks of regular use. Twenty recreational runners performed three tests on different days: test 1) – a 5-min maximal effort run in order to determine the participants’ maximal aerobic speed; and tests 2) and 3) – a fatigue running test of 30 minutes at 80% of their maximal aerobic speed with either GCS or PLACEBO stockings at random. Cardiorespiratory parameters (minute ventilation, heart rate, relative oxygen consumption, relative carbon dioxide production, ventilatory equivalents for oxygen and carbon dioxide, and oxygen pulse) were measured. Before each test in the laboratory, the participants trained with the randomly assigned stockings (GCS or PLACEBO) for three weeks. No significant differences between GCS and PLACEBO were found in any of the cardiorespiratory parameters. In conclusion, the present study provides evidence that running with GCS for three weeks does not influence cardiorespiratory parameters in recreational runners.     

Fusarithioamide B,a new benzamide derivative from the endophytic fungus Fusarium chlamydosporium with potent cytotoxic and antimicrobial activities

Fusarithioamide B (6), a new aminobenzamide derivative with unprecedented carbon skeleton and five known metabolites: stigmast-4-ene-3-one (1), stigmasta-4,6,8(14),22-tetraen-3-one (2), p-hydroxyacetophenone (3), tyrosol (4), and fusarithioamide A (5) were separated from Fusarium chlamydosporium EtOAc extract isolated from Anvillea garcinii (Burm.f.) DC. leaves (Asteraceae). The structure elucidation and complete assignment of the isolated metabolites were performed mainly by the aid of various NMR and MS data. Fusarithioamide B (6) has been assessed for antibacterial and antifungal activities towards various microbial strains by disc diffusion assay. It exhibited selective antifungal activity towards C. albicans (MIC 1.9?µg/ml and IZD 14.5?mm), comparing to clotrimazole (MIC 2.8?µg/ml and IZD 17.9?mm). Also, it possessed high antibacterial potential towards E. coli, B. cereus, and S. aureus compared to ciprofloxacin. Furthermore, 6 was tested for the in vitro cytotoxic effect against KB, HCT-116, BT-549, MCF-7, SKOV-3, and SK-MEL cell lines. It had selective and potent effect towards BT-549, MCF-7, SKOV-3, and HCT-116 cell lines with IC₅₀s 0.09, 0.21, 1.23, and 0.59?μM, respectively compared to doxorubicin (IC₅₀s 0.046, 0.05, 0.321, and 0.24?μM, respectively). Fusarithioamide B may provide a lead molecule for future developing of antitumor and antimicrobial agents.     

Testicular disorders induced by plant growth regulators: cellular protection with proanthocyanidins grape seeds extract

The present study aims to investigate the adverse effects of plant growth regulators : gibberellic acid (GA₃) and indoleacetic acid (IAA) on testicular functions in rats, and extends to investigate the possible protective role of grape seed extract, proanthocyanidin (PAC). Male rats were divided into six groups; control group, PAC, GA₃, IAA, GA₃ + PAC and IAA + PAC groups. The data showed that GA₃ and IAA caused significant increase in total lipids, total cholesterol, triglycerides, phospholipids and low-density-lipoprotein cholesterol in the serum, concomitant with a significant decrease in high-density-lipoprotein cholesterol, total protein, and testosterone levels. In addition, there was significant decrease in the activity of alkaline phosphatase, acid phosphatase, and gamma-glutamyl transferase. A significant decrease was detected also in epididymyal fructose along with a significant reduction in sperm count. Testicular lipid peroxidation product and hydrogen peroxide (H₂O₂) levels were significantly increased. Meanwhile, the total antioxidant capacity, glutathione, sulphahydryl group content, as well as superoxide dismutase, catalase, and glucose-6-phosphate dehydrogenase activity were significantly decreased. Moreover, there were a number of histopathological testicular changes including Leydig’s cell degeneration, reduction in seminiferous tubule and necrotic symptoms and sperm degeneration in both GA₃- and IAA-treated rats. However, an obvious recovery of all the above biochemical and histological testicular disorders was detected when PAC seed extract was supplemented to rats administered with GA₃ or IAA indicating its protective effect. Therefore it was concluded that supplementation with PAC had ameliorative effects on those adverse effects of the mentioned plant growth regulators through its natural antioxidant properties.     

Intragenic duplication and divergence in the spectrin superfamily of proteins

Many structural, signaling, and adhesion molecules contain tandemly repeated amino acid motifs. The alpha-actinin/spectrin/dystrophin superfamily of F-actin-crosslinking proteins contains an array of triple alpha-helical motifs (spectrin repeats). We present here the complete sequence of the novel beta-spectrin isoform beta(Heavy)- spectrin (beta H). The sequence of beta H supports the origin of alpha- and beta-spectrins from a common ancestor, and we present a novel model for the origin of the spectrins from a homodimeric actin-crosslinking precursor. The pattern of similarity between the spectrin repeat units indicates that they have evolved by a series of nested, nonuniform duplications. Furthermore, the spectrins and dystrophins clearly have common ancestry, yet the repeat unit is of a different length in each family. Together, these observations suggest a dynamic period of increase in repeat number accompanied by homogenization within each array by concerted evolution. However, today, there is greater similarity of homologous repeats between species than there is across repeats within species, suggesting that concerted evolution ceased some time before the arthropod/vertebrate split. We propose a two-phase model for the evolution of the spectrin repeat arrays in which an initial phase of concerted evolution is subsequently retarded as each new protein becomes constrained to a specific length and the repeats diverge at the DNA level. This evolutionary model has general applicability to the origins of the many other proteins that have tandemly repeated motifs.      

Higher‐order assemblies of oligomeric cargo receptor complexes form the membrane scaffold of the Cvt vesicle

Selective autophagy is the mechanism by which large cargos are specifically sequestered for degradation. The structural details of cargo and receptor assembly giving rise to autophagic vesicles remain to be elucidated. We utilize the yeast cytoplasm‐to‐vacuole targeting (Cvt) pathway, a prototype of selective autophagy, together with a multi‐scale analysis approach to study the molecular structure of Cvt vesicles. We report the oligomeric nature of the major Cvt cargo Ape1 with a combined 2.8 Å X‐ray and negative stain EM structure, as well as the secondary cargo Ams1 with a 6.3 Å cryo‐EM structure. We show that the major dodecameric cargo prApe1 exhibits a tendency to form higher‐order chain structures that are broken upon interaction with the receptor Atg19 in vitro. The stoichiometry of these cargo–receptor complexes is key to maintaining the size of the Cvt aggregate in vivo. Using correlative light and electron microscopy, we further visualize key stages of Cvt vesicle biogenesis. Our findings suggest that Atg19 interaction limits Ape1 aggregate size while serving as a vehicle for vacuolar delivery of tetrameric Ams1.     

Endothelial cell junctions

In the course of a freeze-cleave study on intercellular junctions in the regenerating rat liver, we observed an unusual array of intramembranous particles located in regions of contact between endothelial cells lining the hepatic sinusoids. These arrays were characterized by an accumulation of particles which resembled a zonula occludens in their linear deployment but differed in that the contact regions were composed of individual particles which remained separated from each other by regular particle-free intervals.