Mechanisms and Kinetics Studies of Butylated Hydroxytoluene Degradation to Isobutene.

2,6-Di-tert-butyl-hydroxytotulene (BHT) is a widely used antioxidant in various fields. In this study, we explored comprehensively the mechanisms and kinetics of BHT degradation to produce isobutene using the density functional theory method. Furthermore, the intrinsic chemical reactivity of BHT was investigated using the electrostatic potential, average local ionization energy, and Fukui function, and the most likely reaction site with OH radical was predicted. Two initiation pathways of BHT with OH radicals were reported. The OH addition pathways at the C2 site of BHT was found more likely to occur than the pathways of H abstracts from the t-butyl group due to the lower energy barrier. Rate constants of two initiation pathways were calculated by transition state theory, and they were promoted by the temperature rise. Mayer bond order and localized molecular orbitals analysis were conducted to reveal the variation of the chemical bonds in the reaction process. The tertiary butyl radical that had been generated in the OH-addition reaction was more likely to generate isobutene with the participation of oxygen. Overall, this research could help to reveal the transformation mechanism of isobutene produced by BHT degradation.

1α, 25-Dihydroxyvitamin D3 protects gastric mucosa epithelial cells against Helicobacter pylori-infected apoptosis through a vitamin D receptor-dependent c-Raf/MEK/ERK pathway.

CONTEXT: Due to the resistance of Helicobacter pylori to antibiotics, it is difficult to eradicate this pathogenic bacterium from the host. The role of 1α, 25-dihydroxyvitamin D3 (1,25-D3) in H. pylori-infected gastric mucosa epithelial cells remains unknown. OBJECTIVE: This study investigates the protective property of 1,25-D3 against H. pylori-infected apoptosis in gastric mucosa epithelial cells and its potential molecular mechanisms. MATERIALS AND METHODS: GES-1 cells were infected with H. pylori SS1 strain (MOI: 100) and treated with 1,25-D3 at 100, 200, and 300 nM for 24 h. Mice were orally gavaged with 108 CFUs of H. pylori and 25 µg/kg 1,25-D3 every other day for 1 month. CCK-8, LDH assay, TUNEL assay and western blot were used to determine the effect of 1,25-D3 on H. pylori-induced apoptosis. RESULTS: H. pylori infection decreased cell viability to 59.2%, while 100-300 nM 1,25-D3 increased cell viability to 62.2%, 78.4% and 87.1%, respectively. Compared with positive control (4.53-fold), 1,25-D3 reduced caspase-3 activity to 4.49-, 2.88- and 1.49-fold, reduced caspase-6 activity to 2.36-, 1.88- and 1.50-fold, reduced caspase-9 activity to 4.55-, 2.91- and 2.01-fold. 1,25-D3 alters Bcl-2 family, caspase protein expression and c-Raf/MEK/ERK phosphorylation levels in vivo and in vitro. Suppression of 1,25-D3 in apoptosis was reliant on binding to vitamin D receptor. The pharmacological inhibition of c-Raf/MEK/ERK phosphorylation blocked the anti-apoptotic effect of 1,25-D3. DISCUSSION AND CONCLUSION: 1,25-D3 protected gastric mucosa epithelial cells against H. pylori-infected apoptosis through a VDR-dependent c-Raf/MEK/ERK pathway.

Dysregulation of circulating CDC42 and its correlation with demographic characteristics, comorbidities, tumor features, chemotherapeutic regimen and survival profile in non-small-cell lung cancer patients.

OBJECTIVE: Cell division control protein 42 (CDC42) induces the immune escape, represses the CD8+ T-cell activation, and further leads to the tumor metastasis in various neoplasms, whereas the correlation of circulating CDC42 with clinical features and prognosis of non-small-cell lung cancer (NSCLC) remains elusive. Hence, the current study aimed to investigate this topic. METHODS: Peripheral blood mononuclear cells from 263 NSCLC patients before treatment and 50 health controls (HC) were used for CDC42 determination by reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay. RESULTS: CDC42 expression was higher in NSCLC patients than HCs (p < 0.001). Besides, elevated CDC42 expression was correlated with the occurrence of lymph node (LYN) metastasis (p = 0.003) and advanced TNM stage (p = 0.007), but not related to other tumor features, demographic characteristics, comorbidities, nor neoadjuvant/adjuvant chemotherapy (all p > 0.05). Additionally, elevated CDC42 expression was correlated with unfavorable accumulating disease-free survival (DFS) (p < 0.001) and overall survival (OS) (p = 0.025). More importantly, multivariate Cox's proportional hazard regression analysis revealed that elevated CDC42 expression (hazard ratio (HR): 1.284, p < 0.001) and higher TNM stage (HR: 1.428, p = 0.003) were independently associated with shorter DFS, meanwhile elevated CDC42 expression (HR: 1.193, p = 0.035), higher pathological grade (HR: 1.558, p = 0.003), higher TNM stage (HR: 1.703, p = 0.001) and higher Eastern Cooperative Oncology Group performance status (ECOG PS) score (HR: 1.538, p = 0.038) were independently correlated with unsatisfying OS. CONCLUSION: Circulating CDC42 is highly expressed with its overexpression linked with LYN metastasis, poor DFS, and OS in NSCLC patients.

Protection of montelukast on OVA-induced eosinophilic gastroenteritis via modulating IL-5, eotaxin-1 and MBP expression.

The aim of this study was to further explore the possible mechanisms of montelukast on oral mice ovalbumin-induced eosinophilic gastroenteritis in a mouse model. The results indicated that montelukast could prevent levels of eotaxin-1 and interleukin-5 in intestinal mucosa homogenate when compared with model group. Interestingly, the increase of major basic protein expression in jejunal tissue also was attenuated by treated with montelukast.

The effects of montelukast on eosinophilic gastroenteritis in a mouse model.

Gastrointestinal eosinophilic (EG) is a rare and heterogeneous condition characterized by patchy or diffuse eosinophilic infiltration of gastrointestinal tissue. Pharmacological study so far has demonstrated that montelukast, an oral leukotriene receptor antagonist, might be considered in patients with this disease. The aim of this study was to evaluate the effect of montelukast on oral ovalbumin (OVA) allergen induced EG inflammation in mice and to suggest some mechanisms underlying this effect. Twenty-four mice were divided into three experimental groups: PBS control, OVA group, and montelukast treated group. The mice were sensitized intraperitoneally and challenged intragastrically with OVA, and were treated with montelukast. Gastrointestinal symptoms were observed after challenged intragastrically with OVA. Eosinophils count in blood, serum OVA specific IgE and gastrointestinal histology were evaluated. Montelukast could significantly reduce the severity of oral allergen-induced eosinophilic inflammation, villous atrophy, and associated symptoms of weight loss associated with diarrhea. Montelukast also could ameliorate OVA-induced gastrointestinal pathological lesions, which was associated with the decrease of IgE and LTD4 levels, and this might be one of the important mechanisms of montelukast that protected gastrointestinal injury from EG. These findings indicated that montelukast therapy may be a novel therapeutic approach for EG and other eosinophil-mediated diseases.

[Severe sepsis as an initial presentation in children with Wernicke' s encephalopathy: report of a case and literature review].

OBJECTIVE: Wernicke's encephalopathy (WE) is an acute neuropsychiatric syndrome resulting from thiamine deficiency, which is associated with significant morbidity and mortality. The disorder is still greatly underdiagnosed in children because of either a relatively non-specific clinical presentation in some cases or unrecognized clinical setting. The aim of this literature review was to provide knowledge of pediatric WE in an effort to assist in early diagnosis, thereby reducing the morbidity and mortality. METHODS: The clinical manifestations, characteristic magnetic resonance imaging (MRI), diagnosis and treatment of one case and the other 35 cases reported in the last decade in children were summarized. RESULTS: Thirty-six cases (22 boys and 14 girls, 2-month to 16-year-old) were analyzed. All the other 35 cases except for our case had underlying diseases: improper feeding in 25/35 cases, long-time vomiting in 5/35 cases, immunosuppressive therapy in 4/35 cases, long-time total parenteral nutrition without multivitamin preparations supplementation in 3/35 cases and anorexia nervosa in 1/35 case. The classic triad (mental-status changes, nystagmus and ophthalmoplegia, and ataxia) was seen in 6/36 cases. The other clinical manifestations included consciousness disturbance in 24/36 cases, infection in 22/36 cases, pathological reflex and muscular tension changes in 18/36 cases, convulsion in 17/36 cases, developmental delay in 4/36 cases and failure to thrive in 2/36 cases. Cerebrospinal fluid examination was performed in 31/36 cases, and a slightly raised protein concentration was seen in 7/31 cases. The cerebrospinal fluid lactate levels were detected in 4/36 cases (all increased), serum lactic acid levels in 7/36 cases (6/7 cases increased), serum pyruvate in 4/36 cases (all increased), thiamine pyrophosphate effect (TPPE) in 9/36 cases (all increased), and serum thiamine in 2/36 cases (increased in 1/2 cases). The brain computed tomography (CT) scan was conducted in 20/36 cases and 16/20 cases showed abnormal hypodensity in bilateral basal ganglia, one case revealed diffuse cortical atrophy. The brain MR scan was conducted in 13/36 cases and all the 13 cases revealed symmetrical abnormal signal in bilateral mamillary body and basal ganglia, and 7/13 cases showed abnormal signals in the tegmentum of midbrain, cerebral aqueduct and white matter around the third and fourth ventricles. The diagnosis of WE was confirmed by MR in 12 cases, triad combined with MR in 3 cases, autopsy in 1 case among the 13 cases who underwent MR scan. The diagnosis of WE was confirmed by the TPPE and/or lactate levels in 9/11 cases. The initial thiamine was given by intravenous or intramuscular infusion in 33/36 cases, unknown method in 1 case, orally in 1 case and no thiamine was used in 1 case. The dosage of thiamine was 100 mg daily in 29/35 cases, unknown in 3/35 cases, 50 mg daily in 2/35 cases, 600 mg daily in 1/35 case. 34/35 patients' clinical symptoms improved during 24 hours to 1 week after initial treatment, and 1 case died due to no response to thiamine. Nineteen patients were followed up for 2-2.5 months and 17 cases recovered completely. CONCLUSION: Wernicke's encephalopathy can be difficult to diagnose because of a relatively non-specific clinical presentation. The characteristic MRI findings and the dramatic response of neurological signs to parenteral thiamine will assist early clinical diagnosis. Early and timely thiamine supplementation could reverse the clinical features and improve the prognosis in most cases.