Synthesis of ZnO nanoparticles and their antibacterial effects

The zinc oxide nanoparticles with the average particle size of about 30 nm were synthesized by the chemical technique and their properties were studied with the help of scanning electron microscope and X-ray diffraction. The aim of this study was to detect the antibacterial properties of 0.01, 0.5 and 1% nano-ZnO against Escherichia coli. E. coli was cultured in liquid and agar nutrient medium to evaluate the antibacterial effects of 0.01, 0.05 and 1% of ZnO via the optical density (OD) and log CFU/ml measurements. Non-significant effect was seen for 0.01% of ZnO nano-particles, while 0.05 and 1% of nanoparticles showed considerably decreased bacterial number. A 4.385 and 2.04 times decrease in the OD value was found in the presence of 1 and 0.5% nano-ZnO, respectively (P<0.001) as compared to the control. In the second study, 6.3 log CFU/ml of E. coli were present in the cultures treated with 1% nano-ZnO at 4°C in water. Control E. coli cells survived for 12 days, while complete cell death was seen when 1% nano-ZnO was applied for 24 h. In the third study, E. coli was grown in the agar medium with and without nanoparticles and suppressed growth (8.56 times; P<0.001) was seen in the presence of 1% nano-ZnO.Keywords: ZnO-nanoparticle, antibacterial, bactericidal, Escherichia col

Effect of insecticide poisoning of methoxychlor on the production of gonadotropin hormones in adult male rats

Background and aims: Methoxychlor pesticide is widely used to replace DDT. In this study, the possible effect of Methoxychlor was investigated on the hormone level of LH, FSH, testosterone, spermatogenesis and its possible role in male infertility. Methods: In this experimental study, 48 Wistar male rats were studied in six groups of 8. Different concentrations of the substance were injected in the experimental groups, i.e. 5, 50, 100, 500 and 1000 grams per liter per day. After 15 days, blood samples were taken and the levels of the hormone were checked. Normal distribution and statistical evaluation of data respectively was performed using ANOVA one-way analysis of variance and Paired t-test. P less than 0.05 were considered as statistically significant. Results: Results showed a significant decrease in the amount of FSH and testosterone concentrations in the experimental group injected 100, 500 and 1000 grams per liter Methoxychlor, but LH levels in groups of 500 and 1000 grams per liter Methoxychlor showed a significant decrease. Due to chlorine in the group 1000 mg per liter. The density of sperm cells in the center of the spermatogenesis tube in the experimental group which received 1000mg/lit methoxychlor decreased compared to the control group.s Conclusion: Methoxychlor causes male sexual imbalances by changing in LH, FSH hormones concentrations, sperm condense, body and tastes weigh

Detection of Sea, Seb, Sec, Seq genes in staphylococcus aureus isolated from nasal carriers in Tehran province, Iran; by multiplex PCR

Staphylococcus(S.) aureus  produces different extra-cellular protein toxins and virulence factors. One of the most important extra-cellular proteins is an enterotoxin which causes staphylococcal food poisoning (SFP) due to their enterotoxins. Different methods have been used to detect this toxin, each of which has advantages and disadvantages. DNA amplification methods, however, can show the presence of enterotoxigenic strains of S. aureus before the expression of enterotoxins on the basis of specific gene sequences. In this study, 150 S. aureus strains isolated from nasal carriers were confirmed by biochemical testing. PCR was used to amplify the staphylococcal enterotoxin A, B, C and Q genes, as well as the staphylococcal nuclease gene.  Among the 150 healthy human isolates from the nasal carrier, 95 were confirmed as S. aureus.  Only 58.9% of the isolates were diagnosed as sea, b, c, q positive. There were 24 (25.3%) isolates associated with the sea gene, 15.8% isolates associated with the seb gene, 9.5% of the isolates were associated with the sec gene, and 8.4% of the isolates associated with the seq gene. Of these isolates, 41% might be possessing additional se genes but they were not see (178 bp) and sed (319 bp) genes.  The nuc gene, which encodes thermo nuclease, was used as a target DNA to identify S. aureus. Additionally, one of these enterotoxigenic isolates carried more than one toxin gene

An Effector of Hemoglobin Structure: The Guanosine 3\u27, 5\u27-Triphosphate

The effect of guanosine 3\u27, 5\u27-triphosphate (GTP) on the hemoglobin structure was studied by UV-visible, fluorescence and circular dichroism (CD) spectroscopies, and cyclic voltammetry. UV-visible absorption spectra showed an increase in absorbance in the regions of 420 nm and 280 nm. Fluorescence spectra showed that the Trp fluorescence intensity increased upon excitation at 280 nm, when guanosine 3\u27, 5\u27-triphosphate concentration was increased in hemoglobin solution. Along with the increased fluorescence intensity, a slightly shift of λmax was also observed toward the higher wavelengths. CD spectral analysis demonstrated a significant decrease in negative ellipsity in the region of 205–235 nm. After adding guanosine 3\u27, 5\u27-triphosphate to the hemoglobin solution α-helix structure decreases by 20 % while β-sheet conformation increases by 9 %. The effects of GTP on hemoglobin resulted in a 61 mV shift in the cathodic and 40 mV for anodic peak of hemoglobin in the CD. Our data showed the change of secondary and tertiary structure of hemoglobin in the presence of guanosine 3\u27, 5\u27-triphosphate. (doi: 10.5562/cca1955

Genetic analysis of Penthorum chinense Pursh by improved RAPD and ISSR in China

Background: Penthorum chinense Pursh (P. chinense) is a well-known traditional Chinese medicine (TCM) plant, which has long been used for the prevention and treatment of hepatic diseases. This study aimed to genetically characterize the varieties of P. chinense from different geographic localities of China by random amplification of polymorphic DNA (RAPD)-PCR technique and verified with inter-simple sequence repeat (ISSR) markers. Results: The P. chinense samples were collected from nine different geographic localities. Previously improved RAPD and ISSR markers were utilized for genetic analysis using DNA amplification. The genetic relationship dendrogram was obtained by conducting cluster analysis to the similarity coefficient of improved RAPD and ISSR markers. Improved RAPD yielded 185 scorable amplified products, of which 68.6% of the bands were polymorphic, with an average amplification of 9.25 bands per primer. The ISSR markers revealed 156 alleles with 7.8 bands per primers, where 59.7% bands were polymorphic. Furthermore, the similarity coefficient ranges of RAPD and ISSR markers were 0.71\u20130.91 and 0.66\u20130.89, respectively. Conclusions: This study indicated that improved RAPD and ISSR methods are useful tools for evaluating the genetic diversity and characterizing P. chinense. Our findings can provide the theoretical basis for cultivar identification, standardization, and molecular-assisted breeding of P. chinense for medicinal use

Genetic Identification and Molecular Modeling Characterization Reveal a Novel PROM1 Mutation in Stargardt4-like Macular Dystrophy

Stargardt disease-4 (STGD4) is an autosomal dominant complex, genetically heterogeneous macular degeneration/dystrophy (MD) disorder. In this paper, we used targeted next generation sequencing and multiple molecular dynamics analyses to identify and characterize a disease-causing genetic variant in four generations of a Chinese family with STGD4-like MD. We found a novel heterozygous missense mutation, c.734T\u3eC (p.L245P) in the PROM1 gene. Structurally, this mutation most likely impairs PROM1 protein stability, flexibility, and amino acid interaction network after changing the amino acid residue Leucine into Proline in the basic helix-loop-helix leucine zipper domain. Molecular dynamic simulation and principal component analysis provide compelling evidence that this PROM1 mutation contributes to disease causativeness or susceptibility variants in patients with STGD4-like MD. Thus, this finding defines new approaches in genetic characterization, accurate diagnosis, and prevention of STGD4-like MD

Advances in the application of CRISPR-Cas technology in rapid detection of pathogen nucleic acid

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) are widely used as gene editing tools in biology, microbiology, and other fields. CRISPR is composed of highly conserved repetitive sequences and spacer sequences in tandem. The spacer sequence has homology with foreign nucleic acids such as viruses and plasmids; Cas effector proteins have endonucleases, and become a hotspot in the field of molecular diagnosis because they recognize and cut specific DNA or RNA sequences. Researchers have developed many diagnostic platforms with high sensitivity, high specificity, and low cost by using Cas proteins (Cas9, Cas12, Cas13, Cas14, etc.) in combination with signal amplification and transformation technologies (fluorescence method, lateral flow technology, etc.), providing a new way for rapid detection of pathogen nucleic acid. This paper introduces the biological mechanism and classification of CRISPR-Cas technology, summarizes the existing rapid detection technology for pathogen nucleic acid based on the trans cleavage activity of Cas, describes its characteristics, functions, and application scenarios, and prospects the future application of this technology

Chemoresistance in breast cancer: PI3K/Akt pathway inhibitors vs the current chemotherapy

Breast cancer is the most prevalent type of cancer among women. Several types of drugs, targeting the specific proteins expressed on the breast cancer cell surface (such as receptor tyrosine kinases and immune checkpoint regulators) and proteins involved in cell cycle and motility (including cyclin-dependent kinases, DNA stabilisers, and cytoskeleton modulators) are approved for different subtypes of breast cancer. However, breast cancer also has a poor response to conventional chemotherapy due to intrinsic and acquired resistance, and an Akt fingerprint is detectable in most drug-resistant cases. Overactivation of Akt and its upstream and downstream regulators in resistant breast cancer cells is considered a major potential target for novel anti-cancer therapies, suggesting that Akt signalling acts as a cellular mechanism against chemotherapy. The present review has shown that sustained activation of Akt results in resistance to different types of chemotherapy. Akt signalling plays a cellular defence role against chemotherapy and (1) enhances multi-drug resistance, (2) increases reactive oxygen species at breast tumor microenvironment, (3) enhances anaerobic metabolism, (4) inhibits the tricarboxylic cycle, (5) promotes PD-L1 upregulation, (6) inhibits apoptosis, (7) increases glucose uptake, and more importantly (8) recruits and interconnects the plasma membrane, nucleus, endoplasmic reticulum, and mitochondria to hijack breast cancer cells and rescue these cells from chemotherapy. Therefore, Akt signalling is considered a cellular defence mechanism employed against chemotherapeutic effects. In addition, interfering roles of PI3K/Akt signalling on the current cytotoxic and molecularly targeted therapy as well as immunotherapy of breast cancer are discussed with a clinical approach. Although, alpelisib, a PIK3CA inhibitor, is the only PI3K/Akt pathway inhibitor approved for breast cancer, we also highlight well-evaluated inhibitors of PI3K/Akt signalling based on different subtypes of breast cancer, which are under clinical trials whether as monotherapy or in combination with other types of chemotherapy