DNA interaction studies of a platinum(II) complex containing L-histidine and 1,10-phenanthroline ligands

The aim of this study was developing coordination complexes that can be used as inorganic medicinal agents. The water soluble [Pt(phen)(His)]NO(3)·3H(2)O complex in which phen=1,10-phenantheroline and His=L-histidine was synthesized and characterized using physicochemical methods. Binding interaction of this complex with calf thymus (CT) DNA was investigated by emission, absorption, circular dichroism, and viscosity measurement techniques. Upon addition of CT-DNA, changes were observed in the characteristic ultraviolet-visible (UV-Vis) bands (hypochromism) of the complex. The complex binds to CT-DNA in an intercalative mode. The calculated binding constant, K(b), was 8 ± 0.2 × 10(4) M(-1). In addition, circular dichroism (CD) study showed that the phenanthroline ligand was inserted between the base pair stack of the double-helical structure of DNA. Also, the fluorescence spectral characteristics showed an increase in fluorescence intensity of the platinum complex in the presence of increasing amounts of DNA solution. The experimental results showed that the platinum complex binds to DNA via intercalative and hydrogen bonding mode.     

Synthetic human monoclonal antibodies toward staphylococcal enterotoxin B (SEB) protective against toxic shock syndrome

Staphylococcal enterotoxin B (SEB) is a potent toxin that can cause toxic shock syndrome and act as a lethal and incapacitating agent when used as a bioweapon. There are currently no vaccines or immunotherapeutics available against this toxin. Using phage display technology, human antigen-binding fragments (Fabs) were selected against SEB, and proteins were produced in Escherichia coli cells and characterized for their binding affinity and their toxin neutralizing activity in vitro and in vivo. Highly protective Fabs were converted into full-length IgGs and produced in mammalian cells. Additionally, the production of anti-SEB antibodies was explored in the Nicotiana benthamiana plant expression system. Affinity maturation was performed to produce optimized lead anti-SEB antibody candidates with subnanomolar affinities. IgGs produced in N. benthamiana showed characteristics comparable with those of counterparts produced in mammalian cells. IgGs were tested for their therapeutic efficacy in the mouse toxic shock model using different challenge doses of SEB and a treatment with 200 μg of IgGs 1 h after SEB challenge. The lead candidates displayed full protection from lethal challenge over a wide range of SEB challenge doses. Furthermore, mice that were treated with anti-SEB IgG had significantly lower IFNγ and IL-2 levels in serum compared with mock-treated mice. In summary, these anti-SEB monoclonal antibodies represent excellent therapeutic candidates for further preclinical and clinical development.     

Inducing Dendritic Growth in Cultured Sympathetic Neurons

The shape of the dendritic arbor determines the total synaptic input a neuron can receive ^1-3, and influences the types and distribution of these inputs ^4-6. Altered patterns of dendritic growth and plasticity are associated with impaired neurobehavioral function in experimental models ⁷, and are thought to contribute to clinical symptoms observed in both neurodevelopmental disorders ^8-10 and neurodegenerative diseases ^11-13. Such observations underscore the functional importance of precisely regulating dendritic morphology, and suggest that identifying mechanisms that control dendritic growth will not only advance understanding of how neuronal connectivity is regulated during normal development, but may also provide insight on novel therapeutic strategies for diverse neurological diseases.Mechanistic studies of dendritic growth would be greatly facilitated by the availability of a model system that allows neurons to be experimentally switched from a state in which they do not extend dendrites to one in which they elaborate a dendritic arbor comparable to that of their in vivo counterparts. Primary cultures of sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rodents provide such a model. When cultured in defined medium in the absence of serum and ganglionic glial cells, sympathetic neurons extend a single process which is axonal, and this unipolar state persists for weeks to months in culture ^14,15. However, the addition of either bone morphogenetic protein-7 (BMP-7) ^16,17 or Matrigel ¹⁸ to the culture medium triggers these neurons to extend multiple processes that meet the morphologic, biochemical and functional criteria for dendrites. Sympathetic neurons dissociated from the SCG of perinatal rodents and grown under defined conditions are a homogenous population of neurons ¹⁹ that respond uniformly to the dendrite-promoting activity of Matrigel, BMP-7 and other BMPs of the decapentaplegic (dpp) and 60A subfamilies ^17,18,20,21. Importantly, Matrigel- and BMP-induced dendrite formation occurs in the absence of changes in cell survival or axonal growth ^17,18.Here, we describe how to set up dissociated cultures of sympathetic neurons derived from the SCG of perinatal rats so that they are responsive to the selective dendrite-promoting activity of Matrigel or BMPs.     

The evaluation of food allergy on behavior in autistic children

Background:

Despite many efforts, the etiology of autism remains unknown. Food allergy has been suggested as a pathogenic factor in Autism Spectrum Disorder (ASD). Our aim in this study was to determine whether food allergy could be considered as a risk factor for autistic children.

Methods:

Thirty-nine autistic children were examined by the skin prick test (SPT), and total serum IgE was evaluated by ELISA. SPTs were performed for egg whites, oranges, peanuts, tomatoes, tuna fish, walnuts, aubergines, melons, grapes, and cow milk. Parents and teachers were then asked to exclude these items from the childrens’ diets for six months. After the treatment period, the autistic children who tested positive for food allergies were re-assessed by a standard questionnaire to obtain further information about their medical histories.

Results:

Three of the study’s 39 autistic children (7.7%) tested positive on the SPT. Total serum IgE levels were elevated in 56.4% of the subjects (mean=164±24.5, cut-off >155 IU/ml). The results showed a decreased mean in the childrens’ autistic behaviors on the Children Autism Rating Scale (CARS) after both eight weeks and six months; however, this decrease was not statistically significant.

Conclusion:

Food allergy may play a role in the pathophysiology of autism. We conclude that avoidance of certain foods benefits the behavior of autistic children.Key Words: Autism, Food allergy, Skin prick test     

Biodegradation kinetics of trans-4-methyl-1-cyclohexane carboxylic acid

Naphthenic acids are a complex mixture of organic compounds which naturally occur in crude oil. Low molecular weight components of the naphthenic acids are known to be toxic in aquatic environments and there is a need to better understand the factors controlling the kinetics of their biodegradation. In this study, a relatively low molecular weight naphthenic acid compound (trans-isomer of 4-methyl-1-cyclohexane carboxylic acid) and a microbial culture developed in our laboratory were used to study the biodegradation of this naphthenic acid and to evaluate the kinetics of the process in batch cultures. The initial concentration of trans-4-methyl-1-cyclohexane carboxylic acid (50–750 mg l⁻¹) did not affect the maximum specific growth rate of the bacteria at 23°C (0.52 day⁻¹) to the maximum biodegradable concentration (750 mg l⁻¹). The maximum yield observed at this temperature and at a neutral pH was 0.21 mg of biomass per milligram of substrate. Batch experiments indicated that biodegradation can be achieved at low temperatures; however, the biodegradation rate at room temperature (23°C) and neutral pH was 5 times faster than that observed at 4°C. Biodegradation at various pH conditions indicated a maximum specific growth rate of 1.69 day⁻¹ and yield (0.41 mg mg⁻¹) at a pH of 10.     

Expression analysis of circulating plasma long noncoding RNAs in colorectal cancer: The relevance of lncRNAs ATB and CCAT1 as potential clinical hallmarks

Long noncoding RNAs (lncRNAs) have been demonstrated to regulate a variety of cell processes and involve in the development and progression of colorectal cancer (CRC). Recently, the circulating lncRNAs have emerged as minimally invasive biomarkers for cancer diagnosis and prognosis. We aimed to examine the plasma expression level of long noncoding RNAs lnc-ATB, lnc-CCAT1, and lnc-OCC-1 in CRC patients and evaluate the clinical values. A total of 74 pretreatment CRC and 74 healthy blood biopsies were subjected to differentially evaluate the expression levels of three lncRNAs (OCC-1, CCAT1, and ATB). Briefly, after plasma separation and total RNA extraction, RNAs were reversely transcribed to complementary DNA followed by amplification using a quantitative real-time polymerase chain reaction technique for lncRNA expression analysis. The results showed that the expression levels of lnc-ATB (p < 0.001) and CCAT1 (p = 0.024), but not OCC-1 (p = 0.24), were significantly upregulated in the CRC compared with the healthy group. The calculated AUC of ROC was 0.78 (95% confidence interval [CI]: 0.811–0.94) for lnc-ATB and 0.64 (95% CI: 0.811–0.94) for CCAT1, which were indicative of a high discriminatory power (p < 0.001). The highest accuracy for lncRNA-ATB was obtained at a cutoff point of 2.5, which corresponded to sensitivity and specificity of 82% and 75%, respectively. Our results suggested a significant accuracy of lncRNA-ATB and lncRNA-CCAT1 in distinguishing CRC patients from healthy individuals.