Effect of d-Penicillamine on Poliovirus Replication In HeLa Cells

A series of mercaptan compounds were studied with respect to their ability to inhibit the growth of poliovirus in cultured cells. Of the compounds tested only d-penicillamine possessed antiviral activity. There was no direct effect on the virus itself, nor were the processes of adsorption, penetration and uncoating, or virus-induced "shut-off" of host cell protein synthesis inhibited. At concentrations where there was no effect on host cell RNA or protein synthesis, d-penicillamine caused a marked inhibition of virus-specific RNA and protein synthesis. Although much reduced, the relative concentrations of single-stranded and double-stranded viral RNA synthesized in the presence of d-penicillamine was unchanged. Similarly, all apparent precursor and cleavage product proteins could be synthesized in the presence of the drug. The inhibitory effect was reversible, after a lag of 1.5 to 2 h after removal of the drug, and normal yields of virus could be obtained. The structural and functional properties of d-penicillamine are discussed in relation to requirements for anti-polioviral activity.     

Genetic diversity and geographical differentiation of Iranian landrace,cultivars, and exotic chickpea lines as revealed by morphological and microsatellite markers

Assessment of the extent of genetic variability within chickpea is fundamental for chickpea breeding and conservation of genetic resources and is particularly useful as a general guide in the choice of parents for breeding hybrids. To establish genetic diversity among 60 accessions of chickpea comprising landraces, internationally developed improved lines, and cultivars, genetic distances were evaluated using 14 simple sequence repeat markers. These markers showed a high level of polymorphism; a total of 59 different alleles were detected, with a mean of 4.2 alleles per locus. The polymorphic information content (PIC) value ranged from 0.31 to 0.89. All the markers, with the exception of TAA170, TA110, GA34, and Ts35, were considered to be informative (PIC > 0.5), indicating their potential usefulness for cultivar identification. Based on the UNJ clustering method, all accessions were clustered in five groups, which indicated the probable origin and region similarity of Iranian landraces over the other cultivars. It also represents a wide diversity among available germplasm. The result has firmly established that introduction of genetic materials from exotic sources has broadened the genetic base of the national chickpea breeding program. As further implications of the findings, this study can be useful for selective breeding for specific traits and in enhancing the genetic base of breeding programs.     

Promoter analysis of influenza virus RNA polymerase.

Influenza virus polymerase, which was prepared depleted of viral RNA, was used to copy small RNA templates prepared from plasmid-encoded sequences. Template constructions containing only the 3' end of genomic RNA were shown to be efficiently copied, indicating that the promoter lay solely within the 15-nucleotide 3' terminus. Sequences not specific for the influenza virus termini were not copied, and, surprisingly, RNAs containing termini identical to those from plus-sense cRNA were copied at low levels. The specificity for recognition of the virus sense promoter was further defined by site-specific mutagenesis. It was also found that increased levels of viral protein were required in order to catalyze both the cap endonuclease-primed and primer-free RNA synthesis from these model templates, as well as from genomic-length RNAs. This finding indicates that the reconstituted system has catalytic properties very similar to those of native viral ribonucleoprotein complexes.     

Properties of Immature Myeloid Progenitors with Nitric-Oxide-Dependent Immunosuppressive Activity Isolated from Bone Marrow of Tumor-Free Mice

Myeloid derived suppressor cells (MDSCs) from tumor-bearing mice are important negative regulators of anti-cancer immune responses, but the role for immature myeloid cells (IMCs) in non-tumor-bearing mice in the regulation of immune responses are poorly described. We studied the immune-suppressive activity of IMCs from the bone marrow (BM) of C57Bl/6 mice and the mechanism(s) by which they inhibit T–cell activation and proliferation. IMCs, isolated from BM by high-speed FACS, inhibited mitogen-induced proliferation of CD4⁺ and CD8⁺ T-cells in vitro. Cell-to-cell contact of T-cells with viable IMCs was required for suppression. Neither neutralizing antibodies to TGFβ1, nor genetic disruption of indolamine 2,3-dioxygenase, abrogated IMC-mediated suppressive activity. In contrast, suppression of T-cell proliferation was absent in cultures containing IMCs from interferon-γ (IFN-γ) receptor KO mice or T-cells from IFN-γ KO mice (on the C57Bl/6 background). The addition of NO inhibitors to co-cultures of T-cells and IMC significantly reduced the suppressive activity of IMCs. IFN-γ signaling between T-cells and IMCs induced paracrine Nitric Oxide (NO) release in culture, and the degree of inhibition of T-cell proliferation was proportional to NO levels. The suppressive activity of IMCs from the bone marrow of tumor-free mice was comparable with MDSCs from BALB/c bearing mice 4T1 mammary tumors. These results indicate that IMCs have a role in regulating T-cell activation and proliferation in the BM microenvironment.     

Concurrent vitamin D supplementation and exercise training improve cardiac fibrosis via TGF-β/Smad signaling in myocardial infarction model of rats

Journal of Physiology and Biochemistry - Although the role of vitamin D in various types of disorders such as cancer and diabetes has been well recognized, its relation to cardiovascular diseases...     

Analysis of p53 expression in partial hydatidiform mole and hydropic abortion

Background

Gestational trophoblastic disease (GTD) is a heterogeneous group of disorders characterized by abnormal trophoblast tissue. Molar and non-molar hydropic placental changes are the most common forms of GTD. Differential diagnosis of GTD is sometimes problematic. Recently, p53 expression was identified as a good marker for distinguishing GTD types.

Aims

Comparison of p53 expression in partial hydatidiform mole (PHM) and hydropic abortion.

Methods

In this prospective cross-sectional study, molar and non-molar hydropic pregnancy specimens were collected. Immunohistochemical staining, based on the Labeled Streptavidin Biotin (LSAB) technique, was carried out on multiple 4 mm paraffin block sections prepared from formalin-fixed trophoblastic tissues. Polymer-based Envision was used to assess p53 tumor suppressor protein immunoreactivity. p53 expression was then compared between both groups.

Results

In the study, 40 patients were included: 20 with confirmed PHM and 20 with hydropic pregnancy. p53 protein was positive in 60% of patients with PHM and 25% of patients with hydropic pregnancy. The p53 positive rate was significantly higher in patients with PHM (p = 0.027). Moreover, patients with PHM had a significantly high grade of staining (p<0.001).

Conclusion

Our findings indicate that immunohistochemical analysis of p53 protein can be used to distinguish PHM and hydropic pregnancy.

     

Regions in the cytosolic C-terminus of the secretory Na(+)-K(+)-2Cl(-) cotransporter NKCC1 are required for its homodimerization

The "secretory" Na+-K+-2Cl- cotransporter, NKCC1, is a member of a small gene family of electroneutral cation-chloride cotransporters (CCCs) with 9 homologues in vertebrates. A number of these transporters, including NKCC1 itself, have been shown to exist as homodimers in the membrane, suggesting that this may be a common feature of the CCCs. Here we employ chemical cross-linking studies, a novel co-immunoprecipition assay, and NKCC1/CCC chimeras to further explore the basis and significance of NKCC1 dimerization. An N-terminally truncated NKCC1 (nttNKCC1), in which the first 20 kDa of the 28 kDa cytosolic N-terminus are deleted, forms homodimers as well as heterodimers with full-length NKCC1, indicating that this region of N-terminus is not required for dimerization. On the other hand, replacing the 50 kDa NKCC1 C-terminus with that of several other non-NKCC1 homologues results in chimeric proteins that form homodimers but show little or no heterodimerization with NKCC1, demonstrating that the C-terminus of NKCC1 plays an essential role in dimerization and that NKCC1 dimerization exhibits definite homologue-specificity. Using additional chimeras we find that the residues required for dimer formation lie between amino acids 751 and 998 of (rat) NKCC1. We also show that dramatically overexpressing the nonfunctional truncated protein nttNKCC1 relative to the endogenous NKCC1 in the HEK293 cells results in a modest inhibition of fluxes via the endogenous transporter and a change in its sensitivity to the specific inhibitor bumetanide. These latter results indicate that there is a functional interaction between dimer subunits but that nonfunctional subunits do not necessarily have a dominant negative effect as has been previously proposed.