Incorporation of Nanoalumina Improves Mechanical Properties and Osteogenesis of Hydroxyapatite Bioceramics.

A handful of work focused on improving the intrinsic low mechanical properties of hydroxyapatite (HA) by various reinforcing agents. However, the big challenge regarding improving mechanical properties is maintaining bioactivity. To address this issue, we report fabrication of apatite-based composites by incorporation of alumina nanoparticles (n-Al2O3). Although numerous studies have used micron or submicron alumina for reinforcing hydroxyapatite, only few reports are available about the use of n-Al2O3. In this study, spark plasma sintering (SPS) method was utilized to develop HA-nAl2O3 dense bodies. Compared to the conventional sintering, decomposition of HA and formation of calcium aluminates phases are restricted using SPS. Moreover, n-Al2O3 acts as a bioactive agent while its conventional form is an inert bioceramics. The addition of n-Al2O3 resulted in 40% improvement in hardness along with a 110% increase in fracture toughness, while attaining nearly full dense bodies. The in vitro characterization of nanocomposite demonstrated improved bone-specific cell function markers as evidenced by cell attachment and proliferation, alkaline phosphatase activity, calcium and collagen detection and nitric oxide production. Specifically, gene expression analysis demonstrated that introduction of n-Al2O3 in HA matrix resulted in accelerated osteogenic differentiation of osteoblast and mesenchymal stem cells, as expression of Runx-2 and OSP showed 2.5 and 19.6 fold increase after 2 weeks (p < 0.05). Moreover, protein adsorption analysis showed enhanced adsorption of plasma proteins to HA-nAl2O3 sample compared to HA. These findings suggest that HA-nAl2O3 could be a prospective candidate for orthopedic applications due to its improved mechanical and osteogenic properties.

In-silico Metabolome Target Analysis Towards PanC-based Antimycobacterial Agent Discovery.

Mycobacterium tuberculosis, the main cause of tuberculosis (TB), has still remained a global health crisis especially in developing countries. Tuberculosis treatment is a laborious and lengthy process with high risk of noncompliance, cytotoxicity adverse events and drug resistance in patient. Recently, there has been an alarming rise of drug resistant in TB. In this regard, it is an unmet need to develop novel antitubercular medicines that target new or more effective biochemical pathways to prevent drug resistant Mycobacterium. Integrated study of metabolic pathways through in-silico approach played a key role in antimycobacterial design process in this study. Our results suggest that pantothenate synthetase (PanC), anthranilate phosphoribosyl transferase (TrpD) and 3-isopropylmalate dehydratase (LeuD) might be appropriate drug targets. In the next step, in-silico ligand analysis was used for more detailed study of chemical tractability of targets. This was helpful to identify pantothenate synthetase (PanC, Rv3602c) as the best target for antimycobacterial design procedure. Virtual library screening on the best ligand of PanC was then performed for inhibitory ligand design. At the end, five chemical intermediates showed significant inhibition of Mycobacterium bovis with good selectivity indices (SI) ≥10 according to Tuberculosis Antimicrobial Acquisition & Coordinating Facility of US criteria for antimycobacterial screening programs.

Cellular immunity survey against urinary tract infection using pVAX/fimH cassette with mammalian and wild type codon usage as a DNA vaccine.

PURPOSE: FimH (the adhesion fragment of type 1 fimbriae) is implicated in uropathogenic Escherichia coli (UPEC) attachment to epithelial cells through interaction with mannose. Recently, some studies have found that UPEC can thrive intracellularly causing recurrent urinary tract infection (UTI). Almost all vaccines have been designed to induce antibodies against UPEC. Yet, the humoral immune response is not potent enough to overcome neither the primary UTI nor recurrent infections. However, DNA vaccines offer the possibility of inducing cell mediated immune responses and may be a promising preventive tool. MATERIALS AND METHODS: In this study, we employed two different open reading frames within mammalian (mam) and wild type (wt) codons of fimH gene. Optimized fragments were cloned in pVAX-1. Expression of the protein in COS-7 was confirmed by western blot analysis after assessing pVAX/fimH(mam) and pVAX/fimH(wt). The constructs were injected to BALB/c mice at plantar surface of feet followed by electroporation. RESULTS: The mice immunized with both constructs following booster injection with recombinant FimH showed increased interferon-γ and interleukin-12 responses significantly higher than non-immunized ones (p<0.05). The immunized mice were challenged with UPEC and then the number of bacteria recovered from the immunized mice was compared with the non-immunized ones. Decreased colony count in immunized mice along with cytokine responses confirmed the promising immune response by the DNA vaccines developed in this study. CONCLUSION: In conclusion, DNA vaccines of UPEC proteins may confer some levels of protection which can be improved by multiple constructs or boosters.

Prenatal sex determination in suspicious cases of X-linked recessive diseases by the amelogenin gene.

OBJECTIVE(S): To determine the fetal discernment in suspected cases of sex linked recessive disease in the first trimester of pregnancy. MATERIALS AND METHODS: After collection of 100 Chorionic Villi samples, the DNAs were extracted and baby gender was determined. Meanwhile, after increasing the sensitivity, the system was able to detect the sex of each cell which was obtained by biopsy. RESULTS: Early fetal gender of 100 Chorionic Villi samples were assessed by PCR. After increasing sensitivity of the assay, the sexes in 13 fetuses that were in different cellular stages were detected. Morover, sexes were detected in two unfertilized and one fertilized ovum but without any division. CONCLUSION: Sex detection of fetus before delivery in the first trimester of pregnancy, will prevent babies with abnormalities being born. It can also be used in detection of recessive sex related diseases in In Vitro Fertilization cases for sex detection and to transfer female fetus to the mother. Our optimized molecular detection system was designed on the basis of amelogenin gene, which can determine the sex in blood, chorionic villi, and single cell in vitro fertilization with high sensitivity and specificity.

Improgan antinociception does not require neuronal histamine or histamine receptors.

Improgan, a chemical congener of the H(2) antagonist cimetidine, induces antinociception following intracerebroventricular (i.c.v.) administration in rodents, but the mechanism of action of this compound remains unknown. Because the chemical structure of improgan closely resembles those of histamine and certain histamine blockers, and because neuronal histamine is known to participate in pain-relieving responses, the antinociceptive actions of improgan were evaluated in mice containing null mutations in the genes for three histamine receptors (H(1), H(2), and H(3)) and also in the gene for histidine decarboxylase (the histamine biosynthetic enzyme). Similar to earlier findings in Swiss-Webster mice, improgan induced maximal, reversible, dose-related reductions in thermal nociceptive responses in ICR mice, but neither pre-improgan (baseline) nor post-improgan nociceptive latencies were changed in any of the mutant mice as compared with wild-type controls. Improgan also had weak inhibitory activity in vitro (pK(i)=4.7-4.9) on specific binding to three recently-discovered, recombinant isoforms of the rat H(3) receptor (H(3A), H(3B), and H(3C)). The present findings strongly support the hypothesis that neuronal histamine and its receptors fail to play a role in improgan-induced antinociception.

Chemical kindling induced by pentylenetetrazol in histamine H(1) receptor gene knockout mice (H(1)KO), histidine decarboxylase-deficient mice (HDC(-/-)) and mast cell-deficient W/W(v) mice.

The role of brain histamine on seizure development of pentylenetetrazol (PTZ)-induced kindling was examined in H(1)-receptor gene knockout (H(1)KO), histidine decarboxylase-deficient (HDC(-/-)) and mast cell-deficient (W/W(v)) mice. All H(1)KO, HDC(-/-) and W/W(v) mice had accelerated seizure development of PTZ-induced kindling when compared to their respective wild-type mice. The daily PTZ-kindling increased histamine content in the cortex and diencephalon of H(1)KO mice, whereas the histamine content in the diencephalon of W/W(v) mice was decreased. The present study indicates that histamine plays a suppressive role in seizure development through H(1)-receptors.