Genetic Analysis of the Latent Period of Stripe Rust in Wheat Seedlings

Genetics of slow‐rusting resistance to yellow rust (Puccinia striiformis f.sp. tritici) was studied by a half‐diallel design using six wheat varieties, Tiritea (susceptible), Tancred, Kotare, Otane, Karamu, and Briscard. The parents and 15 F₁ progenies were evaluated in the greenhouse by three pathotypes 7E18A^?, 38E0A⁺, and 134E134A⁺. The latent period was measured as the number of days from inoculation to the appearance of the first pustule. For each pathotype a randomized complete block design was used and data were analysed by methods of Griffing and Hayman. The range of average degree of dominance was from complete dominance to over‐dominance. Positive and negative degrees of dominance were observed for each pathotype that showed the reversal of dominance. Analysis of variance showed the importance of both additive and dominance effects in controlling the latent period. Broad‐sense heritabilities were 0.99 and narrow‐sense heritabilities ranged from 0.85 to 0.94. Briscard and Karamu for the pathotypes 38E0A⁺ and 134E134A⁺, Kotare for the pathotype 7E18A^? and Tancred for the pathotype 38E0A⁺ had significant and positive general combining ability (GCA) (more resistance) for latent period. The crosses of Kotare with Tancred, Briscard and Karamu indicated the highest and positive specific combining ability (SCA) for the pathotype 7E18A^?. Significant additive genetic component and moderate narrow‐sense heritability indicate the possibility of improving for longer latent period of stripe rust in breeding programmes.     

Infection of Human B Lymphocytes with Lymphocryptoviruses Related to Epstein-Barr Virus

Lymphocryptoviruses (LCVs) naturally infecting Old World nonhuman primates are closely related to the human LCV, Epstein-Barr virus (EBV), and share similar genome organization and sequences, biologic properties, epidemiology, and pathogenesis. LCVs can efficiently immortalize B lymphocytes from the autologous species, but the ability of a given LCV to immortalize B cells from other Old World primate species is variable. We found that LCV from rhesus monkeys did not immortalize human B cells, and EBV did not immortalize rhesus monkey B cells. In this study, baboon LCV could not immortalize human peripheral blood B cells but could readily immortalize rhesus monkey B cells. Thus, efficient LCV-induced B-cell immortalization across distant Old World primate species appears to be restricted by a species-specific block. To further characterize this species restriction, we first cloned the rhesus monkey LCV major membrane glycoprotein and discovered that the binding epitope for the EBV receptor, CD21, was highly conserved. Stable infections of human B cells with recombinant amplicons packaged in rhesus monkey or baboon LCV envelopes were also consistent with a species-restricted block occurring after virus binding and penetration. Transient infections of human B cells with simian LCV resulted in latent LCV EBNA-2 gene expression and activation of cell CD23 gene expression. EBV-immortalized human B cells could be coinfected with baboon LCV, and the simian virus persisted and replicated in human B cells. Thus, several lines of evidence indicate that the species restriction for efficient LCV-induced B-cell immortalization occurs beyond virus binding and penetration. This has important implications for the study of LCV infection in Old World primate models and for human xenotransplantation where simian LCVs may be inadvertently introduced into humans.     

High-pressure hydrocephalus: a novel analytical modeling approach

Hydrocephalus is an abnormal accumulation of cerebrospinal fluid (CSF) within ventricles and subarachnoid space (SAS) as a result of disturbances in secretion or absorption procedures. It is believed that arachnoid villi cells, which are microscopic projections of pia-arachnoid mater that extend into venous channels in sagittal sinus, are the main sites for CSF absorption, but it is tempting to speculate that a significant portion of CSF is removed from the SAS by nasal lymphatic vessels around olfactory nerve. Thus, in this paper, we propose an analytical model of CSF-lymphatic-blood circulation, in which these two output pathways for CSF absorption have been considered. Mathematical relations governing the pressures in different interacting compartments of the brain are considered. In addition, for increasing the similarity of our model to the physiological conditions, the bulk flow mechanism, which is supposed to occur during CSF absorption, has been considered in our model. We used our model to simulate hydrocephalus. The results indicate that the lymphatic disorders have more considerable effect in decreasing CSF absorption, compared to the disturbances in arachnoid villi cells. Based on our modeling, we believe that disorders in lymphatic pathway may be a cause of high-pressure hydrocephalus. Surely experimental studies are required to validate our hypothesis.     

Do high-mobility group box 1 gene polymorphisms affect the incidence of differentiation syndrome in acute promyelocytic leukemia?

Molecular Biology Reports - Differentiation syndrome (DS) is an inflammatory complication seen in some patients with acute promyelocytic leukemia (APL) undergoing differentiation therapy with...     

The nematicidal potential of local Bacillus species against the root-knot nematode infecting greenhouse tomatoes

Bacillus spp. were isolated from Iranian tomato fields and evaluated for their efficacy against root-knot nematodes, Meloidogyne javanica. The 52 spore-forming bacterium isolates were obtained from tomato rhizosphere following heat treatment. Eight isolates were chosen based on their potency in prevention of M. javanica egg hatch and juvenile mortality and production of proteolytic enzymes in Petri plates. Their ability to form biofilms were also determined in pot experiments. According to phenotypic traits and 16s rDNA sequencing, all selected isolates belonged to Bacillus spp. including B. cereus and B. pumilus. Treatment with bacterial culture filtrates in vitro caused juvenile mortality of 72 to 99% after 48 h. After four days, the percentage of egg hatch ranged from 1.6 to 59% depending on the isolate. Bacillus pumilus (ToIr-MA) and Bacillus sp. (ToIr-10) were found to have significant ability to produce extracellular proteases and to form maximum biofilm, considerably reducing the number of egg masses and root gall index (P = 0.05) in comparison to untreated plants. Application of ToIr-MA and ToIr-10 enhanced the fresh and dry weights of shoot and root systems. There was significant enhancement in dry root weight (45 and 50%) and shoot weight (67 and 75%). Results suggest that these two Bacillus spp. have potential as biocontrol agents against root-knot disease in tomato production.     

Target-specific glutamatergic regulation of dopamine neurons in the ventral tegmental area

Dopamine (DA) neurons in the ventral tegmental area (VTA) are thought to play a critical role in affective, motivational, and cognitive functioning. There are fundamental target-specific differences in the functional characteristics of subsets of these neurons. For example, DA afferents to the prefrontal cortex (PFC) have a higher firing and transmitter turnover rate and are more responsive to some pharmacological and environmental stimuli than DA projections to the nucleus accumbens (NAc). These functional differences may be attributed in part to differences in tonic regulation by glutamate. The present study provides evidence for this mechanism: In freely moving animals, blockade of basal glutamatergic activity in the VTA by the selective alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate antagonist LY293558 produced an increase in DA release in the NAc while significantly decreasing DA release in the PFC. These data support an AMPA receptor-mediated tonic inhibitory regulation of mesoaccumbens neurons and a tonic excitatory regulation of mesoprefrontal DA neurons. This differential regulation may result in target-specific effects on the basal output of DA neurons and on the regulatory influence of voltage-gated NMDA receptors in response to phasic activation by behaviorally relevant stimuli.     

Trace Element Level in Different Tissues of <Emphasis Type="Italic">Rutilus frisii kutum</Emphasis> Collected from Tajan River,Iran

Tajan River is among the most significant rivers of the Caspian Sea water basin. In this study, the concentration of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in brain, heart, liver, gill, bile, and muscle of Rutilus frisii kutum which has great economic value in the Mazandaran state. Trace element levels in fish samples were analyzed by means of atomic absorption spectrometry. Nearly all non-essential metals levels (Ni, Pb, Cd) detected in tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, non-essential metals (Ni, Pb) were so much higher in muscle than the essential metals (Cu, Zn, and Mn) except Fe, which was higher than other metals in nearly all parts, except in gills. Fe distribution pattern in tissues was in order of heart > brain > liver > muscle > bile > gill. Distribution patterns of metal concentrations in the muscle of fish as a main edible part followed the sequence: Fe > Pb > Ni > Cu > Mn > Zn > Cd.     

Glutamatergic Control of Dopamine Release During Stress in the Rat Prefrontal Cortex

Abstract: In vivo microdialysis was used to assess the hypothesis that the stress-induced increase in dopamine release in the prefrontal cortex is mediated by stress-activated glutamate neurotransmission in this region. Local perfusion of an α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, blocked the stress-induced increase in dopamine levels, whereas an NMDA receptor antagonist, 2-amino-5-phosphonopentanoic acid, at the dose tested, was not able to alter this response significantly. These data indicate that the effect of stress on dopamine release in the prefrontal cortex is mediated locally by activation of AMPA/kainate receptors, which modulate the release of dopamine in this region.     

The identification of <Emphasis Type="Italic">Cryptosporidium</Emphasis> species in Isfahan,Iran by PCR-RFLP analysis of the 18S rRNA gene

Cryptosporidium is an important protozoan that causes diarrheal illness in humans and animals. Different species of Cryptosporidium have been reported and it is believed that species characteristics are an important factor to be considered in strategic planning for control. We therefore analyzed oocysts from human and animal isolates of Cryptosporidium by PCR-RFLP to determine strain variation in Isfahan. In total, 642 human fecal samples from children under five years of age, imunocompromised patients, and high-risk persons and 480 randomly selected rectal specimens of cows and calves in Isfahan were examined. Microscopic examination showed that 4.7% (30/642) of human samples and 6.2% (30/480) of animal samples were infected with Cryptosporidium. After identification of the samples infected with the parasite, oocysts were purified and their DNA was extracted. We used PCR-RFLP analysis of a 1750-bp region of the 18S rRNA gene to identify Cryptosporidium species. The human samples were infected with Cryptosporidium parvum II, C. muris, C. wrairi, and a new genotype of Cryptosporidium (GenBank accession no. DQ520951). The cattle samples were identified as C. parvum II, C. muris, C. wrairi, C. serpentis, C. baileyi, and a new genotype of Cryptosporidium (GenBank accession no. DQ520952). We also found a new genotype infecting both human and cattle samples (GenBank accession no. DQ520950). In addition to demonstrating the widespread occurrence of most species of Cryptosporidium, C. parvum, we also observed extensive polymorphism within species. Furthermore, the occurrence of the same species of parasite in both animal and human samples shows the importance of the animal and human cycle. Published in Russian in Molekulyarnaya Biologiya, 2007, Vol. 41, No. 5, pp. 934–939. The article was translated by the authors.