Mutation to Overproduction of Bacteriophage T4 Gene Products

R9 was isolated as one of several mutations that enhanced the growth of a leaky amber (am) mutant of bacteriophage T4 gene 62 (product required for phage DNA synthesis) under conditions of partial suppression by ribosomal ambiguity. R9 also enhanced the growth of leaky am mutants of some, but not all, other T4 “early” gene functions. R9 mapped between mutations in genes 43 and 62. By using assays involving polyacrylamide slab gel electrophoresis in the presence of sodium dodecyl sulfate, we observed the following. (i) R9 resulted in an overproduction of many T4 “early” proteins in infected cells. The most pronounced effects of R9 were observed when phage DNA synthesis and/or the functions of maturation genes 55 and 33 were not expressed. (ii) In rifampintreated infected cells, the capacity to synthesize T4 “early” proteins decayed more slowly in the presence of the R9 mutation than in the presence of the wild-type counterpart of R9. R9 appeared to have no effect on the rates of RNA synthesis either during early or late times after infection. The results suggest that the R9 mutation leads to increased functional stability of T4 “early” messengers.     

Bee venom ameliorates cardiac dysfunction in diabetic hyperlipidemic rats

High levels of blood glucose and lipids are well-known risk factors for heart diseases. Bee venom is a natural product that has a potent hypoglycemic, hypolipidemic, anti-inflammatory, and antioxidant effects. The current study aimed to determine the bee venom effects on cardiac dysfunction compared to combined therapy of metformin and atorvastatin in diabetic hyperlipidemic rats. The median lethal dose of bee venom was estimated, and then 50 adult male albino rats were categorized into five groups. One group was fed a standard diet and served as a negative control, while the other groups were given nicotinamide and streptozotocin injections to induce type 2 diabetes. After confirming diabetes, the rats were fed a high-fat diet for four weeks. The four groups were divided as follows: one group served as a positive control, whereas the other three groups were treated with bee venom (0.5 mg/kg), bee venom (1.23 mg/kg), and combined therapy of metformin (60 mg/kg) and atorvastatin (10 mg/kg), respectively, for four weeks. Upon termination of the experiment, blood samples and heart tissue were obtained. Administration of bee venom using both doses (0.5 and 1.23 mg/kg) and combined therapy of metformin and atorvastatin revealed a significant decrease in the concentrations of glucose, total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, troponin I, creatine kinase, and lactate dehydrogenase activities. Moreover, a significant decrease had been detedcted in malondialdehyde, nuclear factor-kappa-β levels, and relative mRNA expression of vascular cell adhesion molecule-1 and galectin-3 in heart tissue compared to the positive control (P < 0.0001). Furthermore, there was a significant increase in bodyweight levels of insulin, high-density lipoprotein cholesterol, and total antioxidant capacity in heart tissue compared to the positive control (P < 0.0001). The results indicate that bee venom can ameliorate cardiac dysfunction through attenuating oxidative stress and downregulating the NF-κβ signaling pathway.     

A new <Emphasis Type="Italic">Gephyraulus</Emphasis> species (Diptera: Cecidomyiidae) inducing flower bud galls on the European sea rocket <Emphasis Type="Italic">Cakile maritima</Emphasis> Scop. (Brassicaceae)

The European sea rocket Cakile maritima Scop. (Brassicaceae) is a common herb growing on sandy coastlines worldwide and is considered a useful plant because of its medicinal importance, its edibility, and potential as an oilseed crop. However, C. maritima is an invasive plant over a wide range, e.g., eastern South America, North America, northern Iran, Australia and New Zealand, and has a limited number of associated herbivorous insects. During investigations on gall midges (Diptera: Cecidomyiidae) in Egypt, we found a gall midge inducing flower bud galls on C. maritima and preventing fruit production, which suggested that this gall midge is a potential pest of this plant. In this paper, we describe this gall midge species, Gephyraulus zewaili Elsayed and Tokuda sp. nov., as new to science by comparing its morphology with that of close congeners. Partial sequence data of the mitochondrial DNA cytochrome oxidase subunit I gene are also provided.     

Lifetime prevalence of mental disorders in Lebanon: first onset, treatment, and exposure to war

Background

There are no published data on national lifetime prevalence and treatment of mental disorders in the Arab region. Furthermore, the effect of war on first onset of disorders has not been addressed previously on a national level, especially in the Arab region. Thus, the current study aims at investigating the lifetime prevalence, treatment, age of onset of mental disorders, and their relationship to war in Lebanon.

Methods and Findings

The Lebanese Evaluation of the Burden of Ailments and Needs Of the Nation study was carried out on a nationally representative sample of the Lebanese population (n = 2,857 adults). Respondents were interviewed using the fully structured WHO Composite International Diagnostic Interview 3.0. Lifetime prevalence of any Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) disorder was 25.8%. Anxiety (16.7%) and mood (12.6%) were more common than impulse control (4.4%) and substance (2.2%) disorders. Only a minority of people with any mental disorder ever received professional treatment, with substantial delays (6 to 28 y) between the onset of disorders and onset of treatment. War exposure increased the risk of first onset of anxiety (odds ratio [OR] 5.92, 95% confidence interval [CI] 2.5–14.1), mood (OR 3.32, 95% CI 2.0–5.6), and impulse control disorders (OR 12.72, 95% CI 4.5–35.7).

Conclusions

About one-fourth of the sample (25.8%) met criteria for at least one of the DSM-IV disorders at some point in their lives. There is a substantial unmet need for early identification and treatment. Exposure to war events increases the odds of first onset of mental disorders.     

Visualization of body thermoregulation by infrared imaging

This paper analyzes two mechanisms applied on the human body in order to study the thermoregulatory system according to heat generation and heat loss. Two approaches are presented. The first approach is based on plethysmography, where an armband is placed on the forearm in order to modulate the blood flow. The second approach uses a cold stimulation. The visualization is achieved using infrared imaging devices. The resulting images reveal a temperature balance between the stimulated and the non-stimulated hands. The thermal behavior and typical thermographic recordings on each subject are discussed and analyzed in response to different stimulations.     

Synaptic removal of diacylglycerol by DGKζ and PSD‐95 regulates dendritic spine maintenance

Diacylglycerol (DAG) is an important lipid signalling molecule that exerts an effect on various effector proteins including protein kinase C. A main mechanism for DAG removal is to convert it to phosphatidic acid (PA) by DAG kinases (DGKs). However, it is not well understood how DGKs are targeted to specific subcellular sites and tightly regulates DAG levels. The neuronal synapse is a prominent site of DAG production. Here, we show that DGKζ is targeted to excitatory synapses through its direct interaction with the postsynaptic PDZ scaffold PSD‐95. Overexpression of DGKζ in cultured neurons increases the number of dendritic spines, which receive the majority of excitatory synaptic inputs, in a manner requiring its catalytic activity and PSD‐95 binding. Conversely, DGKζ knockdown reduces spine density. Mice deficient in DGKζ expression show reduced spine density and excitatory synaptic transmission. Time‐lapse imaging indicates that DGKζ is required for spine maintenance but not formation. We propose that PSD‐95 targets DGKζ to synaptic DAG‐producing receptors to tightly couple synaptic DAG production to its conversion to PA for the maintenance of spine density.     

Independent evolution of functional Pm3 resistance genes in wild tetraploid wheat and domesticated bread wheat

The Pm3 alleles of cultivated bread wheat confer gene for gene resistance to the powdery mildew fungus. They represent a particular case of plant disease resistance gene evolution, because of their recent origin and possible evolution after the formation of hexaploid wheat. The Pm3 locus is conserved in tetraploid wheat, thereby allowing the comparative evolutionary study of the same resistance locus in a domesticated species and in one of its wild ancestors. We have identified 61 Pm3 allelic sequences from wild and domesticated tetraploid wheat subspecies. The Pm3 sequences corresponded to 24 different haplotypes. They showed low sequence diversity, differing by only a few polymorphic sequence blocks that were further reshuffled between alleles by gene conversion and recombination. Polymorphic sequence blocks are different from the blocks found in functional Pm3 alleles of hexaploid wheat, indicating an independent evolution of the Pm3 loci in the two species. A new functional gene was identified in a wild wheat accession from Syria. This gene, Pm3k , conferred intermediate race-specific resistance to powdery mildew, and consists of a mosaic of gene segments derived from non-functional alleles. This demonstrates that Pm3 -based resistance is not very frequent in wild tetraploid wheat, and that the evolution of functional resistance genes occurred independently in wild tetraploid and bread wheat. The Pm3 sequence variability and geographic distribution indicated that diversity was higher in wild emmer wheat from the Levant area, compared with the accessions from Turkey. Further screens for Pm3 functional genes in wild wheat should therefore focus on accessions from the Levant region.     

Phytoaccumulation of zinc by the aquatic plant, Lemna gibba L.

The uptake of zinc (Zn) by the duckweed Lemna gibba L., native to the north-east region of Algeria, was investigated in quarter Coïc solutions enriched with 6.0, 10.0, 14.0 and 18.0 mg l⁻¹ of Zn supplied as zinc sulphate (ZnSO₄). Zinc concentrations were measured in the water daily and in duckweed biomass at the end of the experiments. These results showed that under experimental conditions (pH = 6.0 ± 0.1, T = 21 ± 1 °C, photoperiod = 12 h/j), L. gibba was able to accumulate in its biomass 4.23; 15.62; 23.88 and 25.81 mg g⁻¹ DM, respectively for the four initial concentrations selected. At these concentrations, the metal removed percentages were 61–71%. The mass balance performed on the system showed that about 49–68% of Zn (depending on the initial concentration in water) was removed by precipitation as zinc phosphate. The results showed that this aquatic plant can be successfully used for Zn removal.     

Biophysical Characterization of <Emphasis Type="Italic">β</Emphasis>-Thalassemic Red Blood Cells

Thalassemia is the world’s most common hereditary disease; therefore, more interest has been devoted for the development of the screening procedure of this disease. In β-thalassemia major, the subject of the current study, impaired biosynthesis of beta-globin leads to accumulation of unpaired alpha-globin chain. The objective of the present study, was to examine many of the biophysical properties of β-thalassemia major red blood cells (RBCs) and to study the possibility of use of any of them as a preliminary screening tool for β-thalassemia. The percentage of normal hemolysis, osmotic fragility test, turbidity test, rheological properties, and dielectric properties, were studied in 20 regularly blood transfused thalassemia major patients who were under chelation therapy and their status were compared with those of 10 healthy subjects. There was an increase in the percentage of hemolysis for β-thalassemia by 114.6% compared to the normal RBCs. The fragility curve for β-thalassemia RBCs showed a shift toward lower NaCl concentration compared to the normal curve. The average osmotic fragility (H ₅₀: the NaCl concentration producing 50% homolysis) for β-thalassemia was found to be 3.21 ± 0.67 g/l, whereas for normal RBCs it was 5.5 ± 0.31 g/l. The turbidity curve of the β-thalassemic RBCs showed a shift toward higher detergent concentration of the normal curve, with higher value for the average membrane solubilization (S ₅₀). The viscosity value of whole blood β-thalassemia was found to be 3.916 ± 0.56 cp whereas for normal blood was 2.516 ± 0.36 cp. The relative permittivity, dielectric loss, and AC conductivity of RBCs decreased significantly compared to normal samples. This could be attributed to the loss of the insulating properties of the membrane and loss of its surface charge of thalassemic RBCs. As can be noticed, several factors showed clear difference between thalassemic and normal blood samples. Some of these parameters could be measured immediately after sample withdrawal and require short time to perform the measurements. This offers the advantages of being effective, low cost, and fast techniques, therefore, we suggest that these techniques could be applied for β-thalassemia major screening purposes.     

Regulated RalBP1 Binding to RalA and PSD-95 Controls AMPA Receptor Endocytosis and LTD

Long-term depression (LTD) is a long-lasting activity-dependent decrease in synaptic strength. NMDA receptor (NMDAR)–dependent LTD, an extensively studied form of LTD, involves the endocytosis of AMPA receptors (AMPARs) via protein dephosphorylation, but the underlying mechanism has remained unclear. We show here that a regulated interaction of the endocytic adaptor RalBP1 with two synaptic proteins, the small GTPase RalA and the postsynaptic scaffolding protein PSD-95, controls NMDAR-dependent AMPAR endocytosis during LTD. NMDAR activation stimulates RalA, which binds and translocates widespread RalBP1 to synapses. In addition, NMDAR activation dephosphorylates RalBP1, promoting the interaction of RalBP1 with PSD-95. These two regulated interactions are required for NMDAR-dependent AMPAR endocytosis and LTD and are sufficient to induce AMPAR endocytosis in the absence of NMDAR activation. RalA in the basal state, however, maintains surface AMPARs. We propose that NMDAR activation brings RalBP1 close to PSD-95 to promote the interaction of RalBP1-associated endocytic proteins with PSD-95-associated AMPARs. This suggests that scaffolding proteins at specialized cellular junctions can switch their function from maintenance to endocytosis of interacting membrane proteins in a regulated manner.