Decreased serum testosterone concentration in male heroin and methadone addicts

The serum concentrations of testosterone, estradiol-17β, FSH and LH were measured in 22 male subjects addicted to heroin or methadone. Serum testosterone concentration was decreased in many of these subjects without consistent abnormalities in the other hormones. It is suggested that decreased sexual function in male addicts may be partially due to a decrease in serum testosterone concentration.     

Intraspecific diversity and relationship between subspecies of Origanum vulgare revealed by comparative AFLP and SAMPL marker analysis

The genus Origanum is often referred to as an under-utilized taxon because of its complex taxonomy. Origanum vulgare L., the most variable species of the genus, is a spice and medicinal herb that is characterized by high morphological diversity (six subspecies). In this study, the relative efficiencies of two PCR-based marker approaches, amplified fragment length polymorphism (AFLP) and selectively amplified microsatellite polymorphic loci (SAMPL), were used for comparable genetic diversity surveys and subspecies discrimination among 42 oregano accessions. Seven assays each of AFLP and SAMPL markers were utilized. Effective multiplex ratio (EMR), average heterozygosity (H_av-p), marker index (MI), and resolving power (RP) of the primer combinations were calculated for the two marker systems. UPGMA and Structure analysis along with PCoA plots derived from the binary data matrices of the two markers depicted the genetic distinction of accessions. Our results indicate that both marker systems are suitable but SAMPL markers are slightly more efficient in differentiating accessions and subspecies than AFLPs.     

Proteome modifications of juvenile beluga (Huso huso) brain as an effect of dietary methylmercury

Methylmercury (MeHg) is the most toxic form of mercury which is bioaccumulated in the aquatic food chain. It has been shown that one of the main targets of MeHg toxicity is the brain, but there is little knowledge of the molecular mechanisms of its toxic effects. In this work we used a proteomics analysis to determine the changes in the brain proteome of juvenile beluga (Huso huso) exposed to dietary MeHg. The juvenile beluga were fed the diet containing 0.8 ppm MeHg for 70 days. Proteins of the brain tissue were analyzed using two-dimensional electrophoresis and MALDI-TOF/TOF mass spectrometry. We found eight proteins with significant altered expression level in the fish brain exposed to MeHg. These proteins are involved in different cell functions including cell metabolism, protein folding, cell division, and signal transduction. Our results support the idea that MeHg exerts its toxicity through oxidative stress induction and apoptotic effects. They also suggest that chronic MeHg exposure would induce an important metabolic deficiency in the brain. These findings provide basic information to understand possible mechanisms of MeHg toxicity in aquatic ecosystems.     

Mechanical properties of the gastrocnemius aponeurosis in wild turkeys

In many muscles, the tendinous structures include both an extramuscular free tendon as well as a sheet-like aponeurosis. In both free tendons and aponeuroses the collagen fascicles are oriented primarily longitudinally, along the muscle's line of action. It is generally assumed that this axis represents the direction of loading for these structures. This assumption is well founded for free tendons, but aponeuroses undergo a more complex loading regime. Unlike free tendons, aponeuroses surround a substantial portion of the muscle belly and are therefore loaded both parallel (longitudinal) and perpendicular (transverse) to a muscle's line of action when contracting muscles bulge to maintain a constant volume. Given this biaxial loading pattern, it is critical to understand the mechanical properties of aponeuroses in both the longitudinal and transverse directions. In this study, we use uniaxial testing of isolated tissue samples from the aponeurosis of the lateral gastrocnemius of wild turkeys to determine mechanical properties of samples loaded longitudinally (along the muscle's line of action) and transversely (orthogonal to the line of action). We find that the aponeurosis has a significantly higher Young's modulus in the longitudinal than in the transverse direction. Our results also show that aponeuroses can behave as efficient springs in both the longitudinal and transverse directions, losing little energy to hysteresis. We also test the failure properties of aponeuroses to quantify the likely safety factor with which these structures operate during muscular force production. These results provide an essential foundation for understanding the mechanical function of aponeuroses as biaxially loaded biological springs.     

Convergent evolution of the head retraction escape response in elongate fishes and amphibians

Aquatic escape responses have typically been described as C-starts. However, another aquatic escape response, head retraction, occurs in several elongate species, but has never been studied in detail. The goals of this study are to describe the head retraction escape response in a phylogenetically diverse sample of species, to trace the evolution of head retraction in anamniote vertebrates, and to correlate key morphological traits with escape response behavior. In analyzing the evolution of escape behavior, we found that the head retraction escape response has evolved at least six times in anamniote vertebrates. Using independent contrast analysis, the head retraction escape response was found to be correlated with an increase in the total number of vertebrae and an increase in the elongation of an animal. Results from this study indicate a correlation between head retraction as an escape response, elongation of the axial skeleton, and living in structured habitats.     

A Dual Drug Sensitive L. major Induces Protection without Lesion in C57BL/6 Mice

Leishmaniasis is a major health problem in some endemic areas and yet, no vaccine is available against any form of the disease. Historically, leishmanization (LZ) which is an inoculation of individual with live Leishmania, is the most effective control measure at least against cutaneous leishmaniasis (CL). Due to various reasons, LZ is not used today. Several live attenuated Leishmania have been developed but their use is limited. Previously, we developed a transgenic strain of L. major that harbors two suicide genes tk and cd genes (lmtkcd^+/+) for use as a challenge strain in vaccine studies. These genes render the parasite susceptible to Ganciclovir (GCV) and 5-flurocytosine (5-FC). The dual drug sensitive strain of L. major was developed using gene targeting technology using a modified Herpes Simplex Virus thymidine kinase gene (hsv-tk) sensitive to Ganciclovir antibiotic and Saccharomyces cerevisae cytosine deaminase gene (cd sensitive to 5-flurocytosine) that were stably introduced into L. major chromosome. BALB/c mice inoculated with lmtkcd^+/+ developed lesions which upon treatment with GCV and 5-FC completely healed. In the current study, the transgenic lmtkcd^+/+strain was assessed as a live vaccine model to determine the time necessary to develop a protective immune response. C57BL/6 mice were inoculated with the transgenic lmtkcd^+/+strain, and treated at the time of inoculation (day0) or at day 8 after inoculation. Immunized animals were challenged with wild-type L. major, and complete protection was induced in mice that were treated at day 8. The results show that in contrast to leishmanization, in group of mice inoculated with a dual sensitive L. major development and persistence of lesion is not necessary to induce Th1 response and protection.     

The effect of high concentrations and orientations of Stone–Wales defects on the thermal conductivity of graphene nanoribbons

The influence of the orientations and concentrations of the Stone–Wales (SW) defects on the thermal conductivity of zigzag and armchair graphene nanoribbons (GNRs) is explored using the reverse non-equilibrium molecular dynamics method. The results show that the thermal conductivity of GNRs with two different chirality cases reaches the minimum in the range of 0.1–0.7% defect concentration. Beyond a critical value of the SW defect concentration, the thermal conductivity increases with the increase in SW concentration for both zigzag and armchair GNRs. It is shown that at high concentrations of the SW defects, the thermal conductivity of zigzag GNRs with Type II defects is larger than the GNRs with Type I defects. Finally, the dependence of the SW defect concentration and orientation on the power spectra overlaps have also been explored.     

The toxicity and synergistic effects of alkyl-succinate oil on the first nymphal instars of the citrus cottony scale,Pulvinaria aurantii Cock. (Hem.: Coccidae)

The citrus cottony scale, Pulvinaria aurantii Cock. (Hem.: Coccidae) is one of the most important citrus pests in Iran. This study investigated the toxicity and synergistic effects of organophosphorous insecticides (Malathion, Chlorpyrifos, Buprofezin and DG oil) on first nymphal instars of P. aurantii in the laboratory conditions (25?±?1?°C, 75?±?5% RH and 16L:8D photoperiod). The values of LC₅₀ for Malathion, Chlorpyrifos and Buprofezin insecticides on the first nymphal instars were calculated as 76.90, 105.25 and 24.70?ppm, respectively. Also, results indicated that Buprofezin and Pyriproxifen are the most effective insecticides on first nymphal instars of P. aurantii. The values of LC₅₀ for each insecticide without oil and in half dose along with DG oil were equal. This was an indication for synergism role of DG oil combination. The results of this study showed that DG oil not only decreases the consumption of insecticides, but also increases their efficacy.