Effect of Molybdenum Nanoparticles on Blood Cells,Liver Enzymes,and Sexual Hormones in Male Rats

Despite an increasing surge in application of nanoparticles in industries, there is a serious lack of information concerning their impact on human health and the environment. The present study investigated effects of molybdenum nanoparticles (Mo NPs) injected intraperitoneally into Sprague-Dawley rats at different doses of Mo NPs (5, 10, and 15 mg/kg BW per day) during a period of 28 days. Hematological and biochemical parameters as well as sexual hormones and histopathological examinations of the liver and testis were assessed and compared with control group. The results showed that the serum levels of testosterone decreased significantly in both groups of 10 and 15 mg (Mo NPs)/kg BW in comparison with the control group (p < 0.05). However, there were insignificant differences observed in luteinizing hormone (LH) levels and hematological parameters when compared with the control group (p > 0.05). The results of liver enzymes showed that serum levels of aspartate aminotransferase (AST) decreased significantly in both dosage groups of 5 and 10 mg/kg BW (Mo NPs) when compared with the control group (p < 0.05), and significant decrease obtained in lactate dehydrogenase (LDH) levels at dose of 5 mg/kg BW in comparison with the control group (p < 0.05). The histopathological examination of testis showed a decrease in number of Leydig cells. Also, the number of chronic inflammatory cells increased in portal triad and parenchyma in liver tissue of rats exposed to Mo NPs.     

Competitive interactions of Persian oak coppice trees (<Emphasis Type="Italic">Quercus brantii</Emphasis> var. <Emphasis Type="Italic">persica</Emphasis>) in a pure dry woodland revealed through point pattern analysis

Understanding intraspecific interactions among Persian oaks is essential to predict the responses of Zagros dry woodlands purely covered by these coppice trees to environmental changes (such as drought) that have direct effects on the sustainability of these woodlands. This investigation attempted to explore the scale-dependent competition among Persian oaks and highlight the impacts of competitive interactions on their biophysical properties (i.e. tree height, diameter at root collar and crown attributes) via point pattern analysis. Structurally different summary statistics were implemented to analyse the spatial pattern of Persian oaks in a pure 9-ha study plot. Nearest neighbour distribution function D(r) indicated that these coppice trees had no nearest neighbours up to the spatial scale of 2 m, and they all had a nearest neighbour at distances shorter than 12 m. Furthermore, pair correlation function g(r) showed the significant dispersion of Persian oaks up to the scale of 5 m, which may be the outcome of intraspecific competition for resources such as soil nutrients and water. As explored by mark variograms γ _m (r), Persian oaks of the same size had significant spatial correlations that illustrated the competitive (not facilitative) interactions of these coppice trees in the study plot. Mark correlation function k _mm (r) additionally revealed negative correlations of height and radial growth up to large spatial scales. Consequently, the outcome of this study highlighted the significant effects of competitive intraspecific interactions among Persian oak coppice trees on their spatial pattern and biophysical properties.     

Potato starch synthases: Functions and relationships

Starch, a very compact form of glucose units, is the most abundant form of storage polyglucan in nature. The starch synthesis pathway is among the central biochemical pathways, however, our understanding of this important pathway regarding genetic elements controlling this pathway, is still insufficient. Starch biosynthesis requires the action of several enzymes. Soluble starch synthases (SSs) are a group of key players in starch biosynthesis which have proven their impact on different aspects of the starch biosynthesis and functionalities. These enzymes have been studied in different plant species and organs in detail, however, there seem to be key differences among species regarding their contributions to the starch synthesis. In this review, we consider an update on various SSs with an emphasis on potato SSs as a model for storage organs. The genetics and regulatory mechanisms of potato starch synthases will be highlighted. Different aspects of various isoforms of SSs are also discussed.     

A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy

Continuous measurement of local brain oxygen saturation (SO₂) can be used to monitor the status of brain trauma patients in the neurocritical care unit. Currently, micro‐oxygen‐electrodes are considered as the “gold standard” in measuring cerebral oxygen pressure (pO₂), which is closely related to SO₂ through the oxygen dissociation curve (ODC) of hemoglobin, but with the drawback of slow in response time. The present study suggests estimation of SO₂ in brain tissue using diffuse reflectance spectroscopy (DRS) for finding an analytical relation between measured spectra and the SO₂ for different blood concentrations. The P₃ diffusion approximation is used to generate a set of spectra simulating brain tissue for various levels of blood concentrations in order to estimate SO₂. The algorithm is evaluated on optical phantoms mimicking white brain matter (blood volume of 0.5–2%) where pO₂ and temperature is controlled and on clinical data collected during brain surgery. The suggested method is capable of estimating the blood fraction and oxygen saturation changes from the spectroscopic signal and the hemoglobin absorption profile.

     

A medium invasiveness multi-level patient’s specific template for pedicle screw placement in the scoliosis surgery

Background

Several methods including free-hand technique, fluoroscopic guidance, image-guided navigation, computer-assisted surgery system, robotic platform and patient’s specific templates are being used for pedicle screw placement. These methods have screw misplacements and are not always easy to be applied. Furthermore, it is necessary to expose completely a large portions of the spine in order to access fit entirely around the vertebrae.

Methods

In this study, a multi-level patient’s specific template with medium invasiveness was proposed for pedicle screw placement in the scoliosis surgery. It helps to solve the problems related to the soft tissues removal. After a computer tomography (CT) scan of the spine, the templates were designed based on surgical considerations. Each template was manufactured using three-dimensional printing technology under a semi-flexible post processing. The templates were placed on vertebras at four points—at the base of the superior-inferior articular processes on both left–right sides. This helps to obtain less invasive and more accurate procedure as well as true-stable and easy placement in a unique position. The accuracy of screw positions was confirmed by CT scan after screw placement.

Results

The result showed the correct alignment in pedicle screw placement. In addition, the template has been initially tested on a metal wire series Moulage (height 70 cm and material is PVC). The results demonstrated that it could be possible to implement it on a real patient.

Conclusions

The proposed template significantly reduced screw misplacements, increased stability, and decreased the sliding & the intervention invasiveness.

     

Detection and evaluation of non-recombinants in cDNA libraries by multiple cloning region PCR.

Bacteriophages that are routinely used in cDNA libraries do not require any biological selection for forming plaques. Thus parental non-recombinant phages are always found in variable proportions together with recombinant ones in all cDNA libraries. The presence of non-recombinants in significant proportions dilutes the abundance of rare cDNA species and makes library screening difficult. If the exact proportion of non-recombinants in a library were known, then one would screen proportionately more plaques to get a positive clone. In the absence of such information, screening is conventionally conducted on a number that is based on the titer of the library. We have devised a method using the flanking sequences from either side of the multiple cloning region (MCR) of all lambda phage vector derivatives as primers for PCR amplification. A non-recombinant phage produces a fragment equal to the size of the MCR, whereas a recombinant phage produces a fragment larger than the MCR, which is an MCR+ fragment. All cDNA libraries that we have studied show the presence of the MCR fragment (indicating non-recombinants) at variable proportions ranging between 6% and 36% of the total phages present. We also show that their presence negatively influences the retrieval of target cDNA sequences.     

Crystal structure of pea Toc34, a novel GTPase of the chloroplast protein translocon.

Toc34, a 34-kDa integral membrane protein, is a member of the Toc (translocon at the outer-envelope membrane of chloroplasts) complex, which associates with precursor proteins during protein transport across the chloroplast outer membrane. Here we report the 2.0 A resolution crystal structure of the cytosolic part of pea Toc34 in complex with GDP and Mg2+. In the crystal, Toc34 molecules exist as dimers with features resembling those found in a small GTPase in complex with a GTPase activating protein (GAP). However, gel filtration experiments revealed that dimeric and monomeric forms of Toc34 coexisted in phosphate saline buffer solution at pH 7.2. Mutation of Arg 128, an essential residue for dimerization, to an Ala residue led to the formation of an exclusively monomeric species whose GTPase activity is significantly reduced compared to that of wild type Toc34. These results, together with a number of structural features unique to Toc34, suggest that each monomer acts as a GAP on the other interacting monomer.     

Differences in the mechanisms of the thermoregulatory impairment induced by capsaicin in newborn and adult rats

The function of heat defence was compared in rats pretreated as adults (A-rats) and neonates (N-rats) with capsaicin. The thermoregulatory impairment as tested by whole body heating was similar in A-rats and N-rats. The thermosensitivity and chemosensitivity of the preoptic region (RPO) seemed to be normal in N-rats. A deficiency of RPO mechanisms could be demonstrated in A-rats. It is suggested that the preoptic effects of capsaicin have but a minor significance for the thermoregulatory impairment. It seems that the main cause of decreased heat tolerance is a reduction of peripheral warm sensation due to degeneration of unmyelinated C-fibre primary neurons in both A-rats and N-rats. The results do not support the primary importance of preoptic warm sensation in physiological thermoregulation.