Assessment of pulmonary toxicity of MgO nanoparticles in rats

In this study, we have evaluated the pulmonary toxicity of MgO nanoparticles (MgO NPs) in rats following their exposure. NPs in phosphate buffered saline + 1% Tween 80 were exposed via intratracheal instillation at a doses of 1 mg/kg or 5 mg/kg into rat lungs and evaluated for various tissue damage markers like alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid and histopathology of lungs at 1, 7, and 30 days of post‐exposure intervals. A dose‐dependant increase in ALP and LDH activity was observed in BAL fluids of rat lungs than sham control at all post‐exposure periods (P <0.05), and a dose‐dependant infiltration of interstitial lymphocytes, peribronchiolar lymphocytic infiltration, and dilated and/or congested vessels at 1 day post‐exposure period, worsened at 1 week period, and were reduced at 1 month at histology, indicating the pulmonary toxicity of MgO NPs. In conclusion, MgO NPs exposure produced a dose‐dependent pulmonary toxicity in rats and was comparable with that of Quartz particles. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 308–314, 2015.     

Complications of calcific tendinitis of the shoulder: a concise review

Calcific tendinitis (CT) of the rotator cuff (RC) muscles in the shoulder is a disorder which remains asymptomatic in a majority of patients. Once manifested, it can present in different ways which can have negative effects both socially and professionally for the patient. The treatment modalities can be either conservative or surgical. There is poor literature evidence on the complications of this condition with little consensus on the treatment of choice. In this review, the literature was extensively searched in order to study and compile together the complications of CT of the shoulder and present it in a clear form to ease the understanding for all the professionals involved in the management of this disorder. Essentially there are five major complications of CT: pain, adhesive capsulitis, RC tears, greater tuberosity osteolysis and ossifying tendinitis. All the above complications have been explained right from their origin to the control measures required for the relief of the patient.Level of evidence 5.     

Ethyl pyruvate prevents lethality in mice with established lethal sepsis and systemic inflammation

Sepsis, a potentially fatal clinical syndrome, is mediated by an early (e.g., tumor necrosis factor and IL-1) and late [e.g., high mobility group B-1 (HMGB1)] proinflammatory cytokine response to infection. Specifically targeting early mediators has not been effective clinically, in part because peak mediator activity often has passed before therapy can be initiated. Late-acting downstream effectors, such as HMGB1, that mediate sepsis lethality may be more relevant therapeutic targets. Ethyl pyruvate (EP) recently was identified as an experimental therapeutic that significantly protects against lethal hemorrhagic shock. Here, we report that EP attenuates lethal systemic inflammation caused by either endotoxemia or sepsis even if treatment begins after the early tumor necrosis factor response. Treatment with EP initiated 24 h after cecal puncture significantly increased survival (vehicle survival = 30% vs. EP survival = 88%, P < 0.005). EP treatment significantly reduced circulating levels of HMGB1 in animals with established endotoxemia or sepsis. In macrophage cultures, EP specifically inhibited activation of p38 mitogen-activated protein kinase and NF-kappaB, two signaling pathways that are critical for cytokine release. This report describes a new strategy to pharmacologically inhibit HMGB1 release with a small molecule that is effective at clinically achievable concentrations. EP now warrants further evaluation as an experimental "rescue" therapeutic for sepsis and other potentially fatal systemic inflammatory disorders.     

Transcutaneous vagus nerve stimulation reduces serum high mobility group box 1 levels and improves survival in murine sepsis

OBJECTIVE: Electrical vagus nerve stimulation inhibits proinflammatory cytokine production and prevents shock during lethal systemic inflammation through an alpha7 nicotinic acetylcholine receptor (alpha7nAChR)-dependent pathway to the spleen, termed the cholinergic anti-inflammatory pathway. Pharmacologic alpha7nAChR agonists inhibit production of the critical proinflammatory mediator high mobility group box 1 (HMGB1) and rescue mice from lethal polymicrobial sepsis. Here we developed a method of transcutaneous mechanical vagus nerve stimulation and then investigated whether this therapy can protect mice against sepsis lethality. DESIGN: Prospective, randomized study. SETTING: Institute-based research laboratory. SUBJECTS: Male BALB/c mice. INTERVENTIONS: Mice received lipopolysaccharide to induce lethal endotoxemia or underwent cecal ligation and puncture to induce polymicrobial sepsis. Mice were then randomized to receive electrical, transcutaneous, or sham vagus nerve stimulation and were followed for survival or euthanized at predetermined time points for cytokine analysis. MEASUREMENTS AND MAIN RESULTS: Transcutaneous vagus nerve stimulation dose-dependently reduced systemic tumor necrosis factor levels during lethal endotoxemia. Treatment with transcutaneous vagus nerve stimulation inhibited HMGB1 levels and improved survival in mice with polymicrobial sepsis, even when administered 24 hrs after the onset of disease. CONCLUSIONS: Transcutaneous vagus nerve stimulation is an efficacious treatment for mice with lethal endotoxemia or polymicrobial sepsis.     

Splenectomy inactivates the cholinergic antiinflammatory pathway during lethal endotoxemia and polymicrobial sepsis

The innate immune system protects against infection and tissue injury through the specialized organs of the reticuloendothelial system, including the lungs, liver, and spleen. The central nervous system regulates innate immune responses via the vagus nerve, a mechanism termed the cholinergic antiinflammatory pathway. Vagus nerve stimulation inhibits proinflammatory cytokine production by signaling through the alpha7 nicotinic acetylcholine receptor subunit. Previously, the functional relationship between the cholinergic antiinflammatory pathway and the reticuloendothelial system was unknown. Here we show that vagus nerve stimulation fails to inhibit tumor necrosis factor (TNF) production in splenectomized animals during lethal endotoxemia. Selective lesioning of the common celiac nerve abolishes TNF suppression by vagus nerve stimulation, suggesting that the cholinergic pathway is functionally hard wired to the spleen via this branch of the vagus nerve. Administration of nicotine, an alpha7 agonist that mimics vagus nerve stimulation, increases proinflammatory cytokine production and lethality from polymicrobial sepsis in splenectomized mice, indicating that the spleen is critical to the protective response of the cholinergic pathway. These results reveal a specific, physiological connection between the nervous and innate immune systems that may be exploited through either electrical vagus nerve stimulation or administration of alpha7 agonists to inhibit proinflammatory cytokine production during infection and tissue injury.     

Synthesis, anticancer and MRP1 inhibitory activities of 4-alkyl/aryl-3,5-bis(carboethoxy/carbomethoxy)-1,4-dihydro-2,6-dimethylpyridines

Fourteen new 4-alkyl/aryl-3,5-bis-(carboethoxy/carbomethoxy)-1,4-dihydro-2,6-dimethylpyridines (4a–4n) have been prepared by conventional and microwave irradiation (MWI) methods from a three component reaction mixture viz., alkyl acetoacetate (1), appropriate aldehyde (2) and ammonium acetate (3). The compounds prepared have been purified and characterized by their spectral (FTIR, ¹H NMR and MS) data. The two synthetic methods employed have been compared in terms of relative yields and reaction times. On comparison, the MWI method has been found to be easy, simple, eco-friendly, rapid and high yielding. The synthesized compounds have been evaluated for their cytotoxic activity against HT-29 (colon cancer) and MDA-MB (breast cancer) cell lines and MRP1 inhibitory activity using the insect cell membrane MRP 1 ATPase assay. Though some of the compounds could exhibit some degree of cytotoxicity it was found to be low in comparison to standard. Among the compounds tested 4g was relatively better in its MRP1 inhibitory action (IC₅₀ = 16 μM) but not comparable to that of benzbromarone (IC₅₀ = 4 μM).     

Association of endothelial nitric oxide synthase gene T-786C promoter polymorphism with gastric cancer

AIM: To investigate the role of endothelial nitric oxide synthase -786T > C promoter polymorphism in the etiology of gastric cancer (GC).METHODS: A total of 150 GC patients and 150 control subjects were included in the study. The information on demographic features was elicited with an informed consent from all the patients and control subjects using a structured questionnaire. Helicobacter pylori (H. pylori) infectivity status was tested in antral biopsies from all the subjects by rapid urease test following the method of Vaira et al. Genomic DNA was isolated from whole blood samples following the salting out method of Lahiri et al. Genotype analysis of the rs2070744 polymorphism was carried out by allele-specific polymerase chain reaction method. The genotypes were determined based on the appearance of bands on an agarose gel stained with ethidium bromide under ultraviolet gel documentation with the help of 100 bp ladder. Odds ratios and corresponding 95%CIs were determined using java stat online software.RESULTS: There was a significant difference in the distribution of C allele (C vs T; P = 0.000, OR = 5.038) in patient group compared to the control subjects exhibiting a fivefold increased risk for GC. When the T/T and C/C genotypes were compared, there was an enhanced GC risk for individuals with C/C genotype (T/T vs C/C; P = 0.000). Among the demographic factors, smoking and alcoholism were the common risk factors in patients compared to the control subjects (P < 0.05). Patients with smoking and alcoholism developed cancer even in heterozygous T/C condition (smoking: P = 0.020 and alcoholism: P = 0.005). Individuals with H. pylori infection showed seven fold increased risk for cancer. All the patients with C/C genotype revealed a significant association between H. pylori infection and GC. Among the patients 2.4% of them revealed familial incidence of GC. No significant difference was noticed between cases and controls with regard to consanguinity (P = 0.473).CONCLUSION: The Present data suggest that eNOS-786 C/C genotype and C allele may be considered as potential risk factors in patients with GC.     

Role of HMGB1 in apoptosis-mediated sepsis lethality

Severe sepsis, a lethal syndrome after infection or injury, is the third leading cause of mortality in the United States. The pathogenesis of severe sepsis is characterized by organ damage and accumulation of apoptotic lymphocytes in the spleen, thymus, and other organs. To examine the potential causal relationships of apoptosis to organ damage, we administered Z-VAD-FMK, a broad-spectrum caspase inhibitor, to mice with sepsis. We found that Z-VAD-FMK-treated septic mice had decreased levels of high mobility group box 1 (HMGB1), a critical cytokine mediator of organ damage in severe sepsis, and suppressed apoptosis in the spleen and thymus. In vitro, apoptotic cells activate macrophages to release HMGB1. Monoclonal antibodies against HMGB1 conferred protection against organ damage but did not prevent the accumulation of apoptotic cells in the spleen. Thus, our data indicate that HMGB1 production is downstream of apoptosis on the final common pathway to organ damage in severe sepsis.     

Reversing established sepsis with antagonists of endogenous high-mobility group box 1

Despite significant advances in intensive care therapy and antibiotics, severe sepsis accounts for 9% of all deaths in the United States annually. The pathological sequelae of sepsis are characterized by a systemic inflammatory response, but experimental therapeutics that target specific early inflammatory mediators [tumor necrosis factor (TNF) and IL-1beta] have not proven efficacious in the clinic. We recently identified high mobility group box 1 (HMGB1) as a late mediator of endotoxin-induced lethality that exhibits significantly delayed kinetics relative to TNF and IL-1beta. Here, we report that serum HMGB1 levels are increased significantly in a standardized model of murine sepsis, beginning 18 h after surgical induction of peritonitis. Specific inhibition of HMGB1 activity [with either anti-HMGB1 antibody (600 microg per mouse) or the DNA-binding A box (600 microg per mouse)] beginning as late as 24 h after surgical induction of peritonitis significantly increased survival (nonimmune IgG-treated controls = 28% vs. anti-HMGB1 antibody group = 72%, P < 0.03; GST control protein = 28% vs. A box = 68%, P < 0.03). Animals treated with either HMGB1 antagonist were protected against the development of organ injury, as evidenced by improved levels of serum creatinine and blood urea nitrogen. These observations demonstrate that specific inhibition of endogenous HMGB1 therapeutically reverses lethality of established sepsis indicating that HMGB1 inhibitors can be administered in a clinically relevant time frame.     

Splenic nerve is required for cholinergic antiinflammatory pathway control of TNF in endotoxemia

The autonomic nervous system maintains homeostasis through its sympathetic and parasympathetic divisions. During infection, cells of the immune system release cytokines and other mediators that cause fever, hypotension, and tissue injury. Although the effect of cytokines on the nervous system has been known for decades, only recently has it become evident that the autonomic nervous system, in turn, regulates cytokine production through neural pathways. We have previously shown that efferent vagus nerve signals regulate cytokine production through the nicotinic acetylcholine receptor subunit α7, a mechanism termed “the cholinergic antiinflammatory pathway.” Here, we show that vagus nerve stimulation during endotoxemia specifically attenuates TNF production by spleen macrophages in the red pulp and the marginal zone. Administration of nicotine, a pharmacological agonist of α7, attenuated TNF immunoreactivity in these specific macrophage subpopulations. Synaptophysin-positive nerve endings were observed in close apposition to red pulp macrophages, but they do not express choline acetyltransferase or vesicular acetylcholine transporter. Surgical ablation of the splenic nerve and catecholamine depletion by reserpine indicate that these nerves are catecholaminergic and are required for functional inhibition of TNF production by vagus nerve stimulation. Thus, the cholinergic antiinflammatory pathway regulates TNF production in discrete macrophage populations via two serially connected neurons: one preganglionic, originating in the dorsal motor nucleus of the vagus nerve, and the second postganglionic, originating in the celiac-superior mesenteric plexus, and projecting in the splenic nerve.