Interferon‐α accelerates murine systemic lupus erythematosus in a T cell–dependent manner

Objective

To investigate the mechanism by which interferon‐α (IFNα) accelerates systemic lupus erythematosus (SLE) in (NZB × NZW)F₁ (NZB/NZW) mice.

Methods

NZB/NZW mice were treated with an adenovirus expressing IFNα. In some mice, T cells were depleted with an anti‐CD4 antibody. The production of anti–double‐stranded DNA (anti‐dsDNA) antibodies was measured by enzyme‐linked immunosorbent assay and enzyme‐linked immunospot assay. Germinal centers and antibody‐secreting cells (ASCs) in spleens and IgG deposition and leukocyte infiltrates in kidneys were visualized by immunofluorescence staining. The phenotype of splenic cells was determined by flow cytometry. Finally, somatic hypermutation and gene usage in V_H regions of IgG2a and IgG3 were studied by single‐cell polymerase chain reaction.

Results

IFNα‐accelerated lupus in NZB/NZW mice was associated with elevated serum levels of IgG2 and IgG3 anti‐dsDNA antibodies and accumulation of many IgG ASCs in the spleen, which did not develop into long‐lived plasma cells. Furthermore, IgG2a and IgG3 antibodies in the mice were highly somatically mutated and used distinct repertoires of V_H genes. The induction of SLE in the mice was associated with an increase in B cell Toll‐like receptor 7 expression, increased serum levels of BAFF, interleukin‐6 (IL‐6), and tumor necrosis factor α, and induction of T cells expressing IL‐21. Although IFNα drove a T cell–independent increase in serum levels of IgG, autoantibody induction and the development of nephritis were both completely dependent on CD4+ T cell help.

Conclusion

These findings demonstrate that, although IFNα activates both innate and adaptive immune responses in NZB/NZW mice, CD4+ T cells are necessary for IFNα‐driven induction of anti‐dsDNA antibodies and clinical SLE.

     

Anti-cariogenic effect of a cetylpyridinium chloride-containing nanoemulsion

Objectives

The aim of this pilot study was to investigate the anticaries activity of a nanoemulsion composed of soybean oil, water, Triton X-100 and cetylpyridinium chloride.

Methods

Tooth blocks (3 mm length × 3 mm width × 2 mm thickness) were cut from smooth surfaces of selected molar teeth using a water-cooled diamond wire saw. The blocks were randomly assigned to three experimental groups: (A) nanoemulsion, (B) 0.12% chlorhexidine gluconate, and (C) no treatment. The formation of dental caries in human tooth enamel was tested using a continuous flow dual-organism (Streptococcus mutans and Lactobacillus casei), biofilm model, which acts as an artificial mouth and simulates the biological and physiological activities observed within the oral environment. Experimental groups A and B were treated with their respective solutions once daily for 30 s on each occasion, while group C received no treatment. 10% sucrose was supplied every 6 h for 6 min to simulate meals and pH cycling. The experiment lasted for 5 days, and the tooth blocks were harvested and processed for demineralization assessment using transverse microradiography (TMR).

Results

For both lesion depth and mineral loss, statistical analysis indicated that Emulsion was significantly lower than Control and Chlorhexidine, and Chlorhexidine was significantly lower than Control.

Conclusions

We conclude that cetylpyridinium-containing nanoemulsions appear to present a feasible means of preventing the occurrence of early caries.     

Lung cancer: New biological insights and recent therapeutic advances

Approximately 1.6 million new cases of lung cancer are diagnosed each year throughout the world. In many countries, the mortality related to lung cancer continues to rise. The outcomes for patients with all stages of lung cancer have improved in recent years. The use of systemic therapy in conjunction with local therapy has led to improved cure rates in both resectable and unresectable patient groups. For patients with advanced stage disease, modest but real improvements in overall survival and quality of life have been achieved with systemic chemotherapy. A major focus of research has been the development of molecularly targeted agents and the identification of biomarkers for patient selection. Patients with non-small cell lung cancer with mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain achieve response rates of greater than 70% and superior progression-free survival when treated with an EGFR tyrosine kinase inhibitor compared with standard chemotherapy. This has now emerged as the preferred therapeutic approach for the subset of patients with a mutation in exons 19 or 21 of the EGFR. Another promising targeted approach involves the use of an anaplastic lymphoma kinase (ALK) inhibitor in patients with a translocation involving the echinoderm microtubule-associated protein-like 4 (EML4) and -ALK genes. Finally, a paradigm shift in favor of maintenance therapy for patients with advanced stage disease has gained strength from recent data. All of these advances have been made possible by developing a greater understanding of the biology, the discovery of novel anticancer agents, and improved supportive care measures. This article reviews the major strides made in the treatment of lung cancer in the recent past.     

Chlorophyll revisited: anti-inflammatory activities of chlorophyll a and inhibition of expression of TNF-α gene by the same

In view of the folklore use of green leaves to treat inflammation, the anti-inflammatory property of chlorophylls and their degradation products were studied. Chlorophyll a and pheophytin a (magnesium-free chlorophyll a) from fresh leaves showed potent anti-inflammatory activity against carrageenan-induced paw edema in mice and formalin-induced paw edema in rats. Chlorophyll a inhibited bacterial lipopolysaccharide-induced TNF-α (a pro-inflammatory cytokine) gene expression in HEK293 cells, but it did not influence the expression of inducible nitric acid synthase and cyclooxygenase-2 genes. Chlorophyll b only marginally inhibited both inflammation and TNF-α gene expression. But both chlorophyll a and chlorophyll b showed the same level of marginal inhibition on 12-O-tetradecanoyl-phorbol-13-acetate-induced NF-κB activation. Chlorophylls and pheophytins showed in vitro anti-oxidant activity. The study shows that chlorophyll a and its degradation products are valuable and abundantly available anti-inflammatory agents and promising for the development of phytomedicine or conventional medicine to treat inflammation and related diseases.     

Intermediate term outcome after electrogram guided segmental ostial pulmonary vein isolation using an 8 mm tip catheter for paroxysmal atrial fibrillation

IntroductionPulmonary vein isolation (PVI) is the most widely used procedure for ablation in patients with paroxysmal atrial fibrillation (AF). Not withstanding recent advancements in this field, including sophisticated three-dimensional (3D) based imaging and advanced ablation catheters with contact force technology, many patients and healthcare systems in developing countries will not afford such an expensive therapeutic procedure. There are no data from India analyzing the efficacy of PVI for PAF using conventional mapping and ablation. In this article, we have summarized the intermediate term outcome following PVI in patients with PAF using electrogram-based mapping and a 8 mm tip ablation catheter.MethodA total of 42 consecutive patients who underwent PVI for symptomatic PAF not controlled with at least one antiarrhythmic drug were studied in a tertiary care institute from March 2011 to June 2018. Patients with rheumatic AF were excluded. The pulmonary vein (PV) anatomy was assessed by pulmonary angiography during the ablation procedure. Using conventional electrophysiologic mapping, a variable curve Lasso catheter placed in the PVs was used to guide the earliest site of breakthrough. The segmental ostial PVI was performed using a 8 mm tip radiofrequency (RF) ablation catheter. Elimination of all PV ostial potentials and complete entrance block into the PV were considered indicative of complete electrical isolation. Follow-up visits were scheduled at one, three, and six months after the procedure, and every six months thereafter. History, symptom review, clinical examination, and 12-lead ECG were performed at each follow-up.ResultsAt pre-discharge, 34 patients (81%) were in sinus rhythm, while eight patients (19%) continued to have atrial fibrillation. The age of the study population was 51.5 ± 11.7 yrs. The mean follow-up duration was 44 ± 21 months (range 6–84 months). The number of PVs isolated included one (five patients, 11.9%), two (20 patients, 47.6%), three (12 patients, 28.6%), and four (five patients, 11.9%). In 42 patients, a total of 101 PVs were isolated. The right superior PV (RSPV) was isolated in 37 patients, the left superior PV (LSPV) was isolated in 39 patients, the left inferior PV (LIPV) was isolated in 14 patients, and the right inferior PV (RIPV) was isolated in six patients. The procedure duration was 125 ± 29 min and the fluoroscopy time was 47 ± 13 min. The number of patients who remained in sinus rhythm at 1, 6, 12, and 24 months were 34 (81%), 32 (76%), 30 (71%), and 26 (62%), respectively. Two patients of these underwent repeat PVI, which was successful, and they had freedom from AF episodes. Complications were rare. One patient had a minor pericardial effusion, and one patient had transient sinus pauses, which were conservatively managed.ConclusionConventional RF ablation using PV potential-based mapping and ablation with 8 mm tip catheters is safe for patients with PAF. The intermediate term outcome is satisfactory and cost-effective in our setting with limited resources.     

Modulatory effects of black tea polyphenols on oxidant–antioxidant profile and expression of proliferation,apoptosis, and angiogenesis-associated proteins in the rat forestomach carcinogenesis model

Background Chemoprevention by dietary constituents has emerged as a novel approach to control stomach cancer incidence. We therefore evaluated the chemopreventive effects of black tea polyphenols (Polyphenon-B) on oxidant–antioxidant status, cell proliferation, apoptosis, and angiogenesis during N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis. Methods Male Wistar rats were divided into four groups. Rats in group 1 and 2 were given MNNG (150 mg/kg body weight) by intragastric intubation three times at 2 week intervals and followed for 26 weeks. Rats in group 2 received in addition a basal diet containing 0.05% Polyphenon-B. Group 3 animals were given 0.05% Polyphenon-B alone. Group 4 animals served as controls. The status of lipid peroxidation and antioxidants and the expression of the lipid peroxidation marker 4-hydroxy nonenal (4-HNE), proliferating cell nuclear antigen (PCNA), glutathiones-transferase (GST)-π, Bcl-2, Bax, cytochrome C, caspase 3, cytokeratins, and vascular endothelial growth factor (VEGF) were used as biomarkers. Results Intragastric administration of MNNG induced well-differentiated squamous cell carcinomas that showed diminished lipid and protein oxidation and an increase in antioxidant status. This was associated with increased cell proliferation, angiogenesis, and invasive potential coupled with apoptosis evasion as revealed by upregulation of PCNA, GST-π, Bcl-2, cytokeratins, and VEGF and downregulation of Bax, cytochrome C, and caspase 3 protein expression. Dietary administration of Polyphenon-B effectively suppressed MNNG-induced gastric carcinogenesis, as evidenced by modulation of oxidant–antioxidant status, inhibition of cell proliferation and infiltration, and angiogenesis associated with apoptosis induction. Conclusions The present study provides evidence that Polyphenon-B exerts multifunctional inhibitory effects on MNNG-induced gastric carcinogenesis and suggests that it can be developed as a potential chemopreventive agent.     

Microfluidic handling of PCR solution and DNA amplification on a reaction chamber array biochip

A microfluidic biochip for conducting an array of polymerase chain reaction (PCR) simultaneously was fabricated to understand the microfluidic loading process of PCR solution into microfabricated glass reaction chambers. The geometrical factors of the microfluidic structure, including the shape and depth of the microchamber, shape and size of the microchannels were investigated on the formation of air bubbles trapped within the microchamber during the PCR solution loading process. Furthermore, the effects of surface properties of the microfluidic structure, including hydrophilicity of the microchamber and inlet channel, and hydrophobicity of the outlet channel, on the loading of PCR solution, especially on the formation of air bubbles were studied. As a result, the surface wetting property of the microchamber was found to be the main reason for the formation of the air bubbles inside the microchamber during the loading of PCR solution in the biochips. A solution to avoid the air trapping has been proposed and investigated.