Phage display-derived immunorecognition elements LSPR nanobiosensor for peptide hormone glycine-extended gastrin 17 detection

The current study intended to evaluate two types of biorecognition element (BRE), namely recombinant antibody fragments and M13 bacteriophage-displayed antibody fragments, where protein L and electrostatic interactions were used to respectively conjugated antibodies and bacteriophages on AuNPs. The functionalization process was examined by DLS to monitor the changes in the size and zeta potential. The formation of the BRE-G17-Gly immunological complexes was manifested by aggregation (confirmed by FE-SEM) and color change from red to dark blue visible to the naked eye. Local refractive index variations of functionalized AuNPs were monitored by a UV - vis spectrophotometer, showing increasing size and decreasing zeta potential in all stages. The calibration plot was developed in the concentration range 1-5 µg/mL and the limit of detection (LOD) was 1 µg/mL. The LSRP nanobiosensor in combination with the phage-based BRE was an affordable and simple approach, as it was able to eliminate the time-consuming and costly step of extracting antibodies. Contrary to the traditional immunoassays, this method does not require additional amplification, e.g., enzymatic, to read the result. The proposed LSPR nanobiosensor model can be adapted to detect a wide range of pathogens, viruses, and biomarkers in the shortest possible time.

Recent progress on developing of plasmon biosensing of tumor biomarkers: Efficient method towards early stage recognition of cancer

Cancer is the second most extended disease with an improved death rate over the past several time. Due to the restrictions of cancer analysis methods, the patient's real survival rate is unknown. Therefore, early stage diagnosis of cancer is crucial for its strong detection. Bio-analysis based on biomarkers may help to overcome the problem Biosensors with high sensitivity and specificity, low-cost, high analysis speed and minimum limit of detection are practical alternatives for laboratory tests. Surface plasmon resonance (SPR) is reaching a maturity level sufficient for their application in detection and determination cancer biomarkers in clinical samples. This review discusses main concepts and performance characteristics of SPR biosensor. Mainly, it focuses on newly emerged enhanced SPR biosensors towards high-throughput and ultrasensitive screening of cancer biomarkers such as PSA, α-fetoprotein, CEA, CA125, CA 15-3, HER2, ctDNA, ALCAM, hCG, VEGF, TNF, Interleukin, IFN-γ, CD24, CD44, Ferritin, COLIV using labeling processes with focusing on the future application in biomedical research and clinical diagnosis. This article reviews current status of the field, showcasing a series of early successes in the application of SPR for clinical bioanalysis of cancer related biomolecules and detailing a series of considerations regarding sensing schemes, exposing issues with analysis in biofluids, while providing an outlook of the challenges currently associated with plasmonic materials, bioreceptor selection, microfluidics, and validation of a clinical bioassay for applying SPR biosensors to clinical samples. Research opportunities are proposed to further advance the field and transition SPR biosensors from research proof-of-concept stage to actual clinical usage.

Autosomal recessive mutations in THOC6 cause intellectual disability: syndrome delineation requiring forward and reverse phenotyping

THOC6 is a part of the THO complex, which is involved in coordinating mRNA processing with export. The THO complex interacts with additional components to form the larger TREX complex (transcription export complex). Previously, a homozygous missense mutation in THOC6 in the Hutterite population was reported in association with syndromic intellectual disability. Using exome sequencing, we identified three unrelated patients with bi-allelic mutations in THOC6 associated with intellectual disability and additional clinical features. Two of the patients were compound heterozygous for a stop and a missense mutation, and the third was homozygous for a missense mutation; the missense mutations were predicted to be pathogenic by in silico analysis and modeling. Clinical features of the three newly identified patients and those previously reported are reviewed; intellectual disability is moderate to severe, and malformations are variable including renal and heart defects, cleft palate, microcephaly, and corpus callosum dysgenesis. Facial features are variable and include tall forehead, short upslanting palpebral fissures +/- deep set eyes, and a long nose with overhanging columella. These subtle facial features render the diagnosis difficult to make in isolation with certainty. Our results expand the mutational and clinical spectrum of this rare disease, confirm that THOC6 is an intellectual disability causing gene, while providing insight into the importance of the THO complex in neurodevelopment.

Prevalence of ACTN3 (the athlete gene) R577X polymorphism in Iranian population

BACKGROUND

Ability of athletes in speed or endurance contests somehow is determined by inherited muscle fiber types. One of the important genes involved in sport genetics is ACTN3 that is located on chromosome 11q13-q14 and encodes α-actinin-3, which belongs to highly conserved family of α-actinin proteins. Genetic analysis of α-actinin-3 gene has showed a polymorphism R577X (rs1815739), which results in premature stop codon and leads to non functional α-actnin-3 protein. ACTN3 genotype can contribute to the performance in elite and endurance activities. R577X polymorphism replaces arginine by stop codon. Individuals homozygous for R577 have full copy of α-actinin-3 and elite and power sprint athletes show significantly higher frequency of 577R allele. In the other hand, some studies represented that X allele have high level of frequency in endurance athletes. However, this data remains controversial Since there is no information about the frequency of ACTN3 genotype in our population therefore as the first step it is essential to determine the genetic background of Iranian population. The objective of this study was to genotype normal Iranian individuals to determine the prevalence of each allele in our population.

METHODS

We used PCR-RFLP method for genotyping 210 normal individuals.

RESULTS

Total of 210 Iranian normal individuals for distribution of R577X and R alleles were genotyped. The different genotypes were as follow; 24% RR (50/210), 65%RX (136/210) and 11%XX (24/210), with allelic distribution of 0.56 and 0.44 for 577R and 577X alleles of ACTN3.

CONCLUSION

This allelic distribution for Iranian's is more close to Caucasian population, which is concurrent with the route of ancient human's migration from Iran Plateau toward Europe. Our results showed no different patterns of allelic distribution among female and males, which was the same in other studies too, although some differences has been reported in the studies on athletes population.

Variable hearing impairment in a DFNB2 family with a novel MYO7A missense mutation

Myosin VIIA mutations have been associated with non-syndromic hearing loss (DFNB2; DFNA11) and Usher syndrome type 1B (USH1B). We report clinical and genetic analyses of a consanguineous Iranian family segregating autosomal recessive non-syndromic hearing loss (ARNSHL). The hearing impairment was mapped to the DFNB2 locus using Affymetrix 50K GeneChips; direct sequencing of the MYO7A gene was completed. The Iranian family (L-1419) was shown to segregate a novel homozygous missense mutation (c.1184G>A) that results in a p.R395H amino acid substitution in the motor domain of the myosin VIIA protein. As one affected family member had significantly less severe hearing loss, we used a candidate approach to search for a genetic modifier. This novel MYO7A mutation is the first reported to cause DFNB2 in the Iranian population and this DFNB2 family is the first to be associated with a potential modifier. The absence of vestibular and retinal defects, and less severe low frequency hearing loss, is consistent with the phenotype of a recently reported Pakistani DFNB2 family. Thus, we conclude this family has non-syndromic hearing loss (DFNB2) rather than USH1B, providing further evidence that these two diseases represent discrete disorders.

Role of the cholinergic system in the rat basolateral amygdala on morphine-induced conditioned place preference

The effects of intra-basolateral amygdala (intra-BLA) injections of physostigmine, atropine, nicotine and/or mecamylamine on morphine-induced conditioned place preference (CPP) in rats was investigated by using an unbiased 3-day schedule of place conditioning design. Animals that received 3 daily injections of morphine (0.5-10 mg/kg) subcutaneously (s.c.) or saline (1.0 ml/kg, s.c.) showed a significant preference for compartment paired with morphine. The maximum response was observed with 7.5 mg/kg of the opioid. Administration of the anticholinesterase drug, physostigmine (1, 3 and 5 microg/rat) with an ineffective dose of morphine (0.5 mg/kg) elicited a significant CPP. Injections of antimuscarinic receptor agent, atropine (1, 4 and 7 microg/rat) dose-dependently inhibited the morphine (7.5 mg/kg)-induced place preference. The injections of nicotine (0.75, 1 and 2 microg/rat) potentiated the morphine (0.5 mg/kg)-induced place preference, while the nicotinic receptor antagonist, mecamylamine (1, 3 and 6 microg/rat) dose-dependently inhibited the morphine (7.5 mg/kg)-induced place preference. Furthermore, administration of atropine (7 microg/rat) but not mecamylamine (6 microg/rat) reduced the response induced by different doses of physostigmine plus morphine. Moreover, mecamylamine (6 microg/rat) but not atropine (7 microg/rat) reduced the response induced by different doses of nicotine plus morphine. It is concluded that the muscarinic and nicotinic receptor mechanisms in the BLA may be involved in the acquisition of morphine-induced place preference.