Upregulation of AT1 Receptor Mediates a Pressor Effect Through ROS-SAPK/JNK Signaling in Glutamatergic Neurons of Rostral Ventrolateral Medulla in Rats With Stress-Induced Hypertension

The present study examined whether angiotensin II (Ang II) mediates the pressor effect through nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS)-mitogen-activated protein kinase (MAPK) signaling in the glutamatergic neurons of the rostral ventrolateral medulla (RVLM) in stress-induced hypertensive rats (SIHR). The SIHR model was established using electric foot-shocks combined with noises for 15 days. We observed that Ang II type 1 receptor (AT1R) and the glutamatergic neurons co-localized in the RVLM of SIHR. Furthermore, glutamate levels in the intermediolateral column of the spinal cord were higher in SIHR than in controls. Microinjection of Ang II into the RVLM of SIHR activated stress-activated protein kinase/Jun N-terminal kinase (SAPK/JNK), extracellular signal-regulated protein kinase (ERK) 1/2, and p38MAPK. Compared with controls, the activation of SAPK/JNK, ERK1/2, p38MAPK, and ROS in the RVLM were higher in SIHR, an effect that was blocked by an NADPH oxidase inhibitor (apocynin) and an AT1R antagonist (candesartan). RVLM microinjection of apocynin or a SAPK/JNK inhibitor (SP600125), but not an ERK1/2 inhibitor (U0126) or a p38MAPK inhibitor (SB203580), decreased AT1R mRNA and mean arterial blood pressure (MABP) in SIHR. The increase of AT1R protein expression and MABP was inhibited by intracerebroventricular infusion (ICV), for 14 days, of SP600125, but not U0126 or SB203580 in SIHR. We conclude that Ang II modulates the pressor effect through AT1R-dependent ROS-SAPK/JNK signaling in glutamatergic neurons in the RVLM of SIHR

Possible consequences of relatively decreasing cigarette price in China from 1999 to 2015

Background Cigarette price is an important factor affecting smokers' behavior. While raising price is considered to be a most cost-effective approach to confront the tobacco epidemic, a pricing stratagem could also be used as a weapon to interfere tobacco control efforts by the tobacco industry. The study examined the change of cigarette price from 1999 to 2015 in China, where inhabits a smoking population of more than 300 million, to explore its possible effects on population smoking behavior. Methods National Consumption Price Index (CPI), Tobacco Product Consumption Price Index (TCPI), tobacco consumption data were collected from China Statistical Yearbooks and China Tobacco Yearbooks. Tobacco use and cost data were acquired from two national tobacco surveys in 2010 and 2015. Results The TCPI in China increased 5.6% from 1999 to 2015, while at the same time the national CPI increased 42.3%, which meant the price for cigarettes relatively decreased 25.8% comparing to other commodities. Meanwhile, the annual number of cigarettes sold in China increased from 1.45 trillion to 2.49 trillion, raising 71.7% since 1999. Though the price of cigarettes changed little, the average cost per pack of cigarettes bought by smokers increased 42.9% (from RMB ￥7.0 to ￥10.0) in urban area and 59.2% (from RMB ￥4.9 to ￥7.8) in rural area from 2010 to 2015, which was a result of shift to more expensive cigarette brands, regarding to the dramatic increase in the average resident income (climbing 93.0% in rural, and 63.2% in urban during 2010-2015 in China). Conclusions The cigarette price in China barely changed during a sixteen year period from 1999 to 2015, made cigarettes more and more affordable in China. Combining with the increase in income, it contributed to the huge increase in tobacco consumption and brand shift by smokers in China

E-cigarettes use among urban male tobacco smokers age 15 years or older in China

Background There is paucity of data regarding e-cigarette use in China. Monitoring e-cigarette use is important given the rapid increase of e-cigarette use in some countries. We investigated the prevalence and determinants of e-cigarette use among Chinese male urban tobacco smokers, as most Chinese urban residents who use e-cigarettes are male smokers (~90%). Methods We analyzed data from China City Adult Tobacco Surveys, which were conducted in 14 major Chinese cities individually in 2013-14 with 15,008 males aged &#8805;15 years. Current e-cigarette users were defined as persons who reported using e-cigarette daily or less than daily at the time of the survey. We calculated the prevalence of e-cigarette use among male current tobacco smokers. Multivariate logistic regression was used to assess determinants of e-cigarette use, including age, education, quit attempts in the past 12 months, cigarettes smoked per day, and monthly expenditure on cigarettes. Results Among urban male current smokers in China, 3.6% were current e-cigarette users. The likelihood of being current e-cigarette users was significantly higher among: smokers aged 15-29 (OR=2.5) or 30-49 (OR=2.1) years than 50+ years; those who attempted to quit than those who made no attempt (OR=4.5); those with ≥college education than those with ≤high school education (OR=2.6); and those who smoked ≥15 cigarettes per day (OR=2.7) than those who smoked 1-14 cigarettes per day (all p< 0.05). Conclusions Among urban male tobacco smokers in China, current e-cigarette use was higher among those who were younger, had more education, attempted to quit smoking in the past year, and smoked more cigarettes per day. Given that e-cigarettes are not currently regulated and often marketed as healthier alternatives to cigarettes in China, continued monitoring of e-cigarette use is important to inform public health policy, planning, and practice

Characteristics of spontaneous and evoked GABAergic synaptic currents in cardiac vagal neurons in rats

Despite the importance of GABAergic input to cardiac vagal neurons the electrophysiological properties and possible origins of this innervation have not yet been studied. Individual cardiac vagal neurons were identified by a retrograde fluorescent tracer and were studied in an in vitro slice preparation using patch-clamp electrophysiology. Cardiac vagal neurons received spontaneous GABAergic inhibitory post-synaptic currents (IPSCs) that were blocked by the GABAA receptor antagonist bicuculline. The spontaneous presynaptic GABAergic input to cardiac vagal neurons in the nucleus ambiguus occurred at a significantly lower frequency than that recorded in cardiac vagal neurons in the dorsal motor nucleus of the vagus. To identify a possible source of the GABAergic innervation to cardiac vagal neurons the nucleus tractus solitarius was electrically stimulated. GABAergic synaptic currents in cardiac vagal neurons, in both the dorsal motor nucleus of the vagus (DMNX) and the nucleus ambiguus (NA), were consistently evoked upon stimulation of the nucleus tractus solitarius and these responses were also blocked by bicuculline. © 2001 Elsevier Science B.V

Agatoxin-IVA-sensitive calcium channels mediate the presynaptic and postsynaptic nicotinic activation of cardiac vagal neurons

Whole cell currents and miniature glutamatergic synaptic events (minis) were recorded in vitro from cardiac vagal neurons in the nucleus ambiguus using the patch-clamp technique. We examined whether voltage-dependent calcium channels were involved in the nicotinic excitation of cardiac vagal neurons. Nicotine evoked an inward current, increase in mini amplitude, and increase in mini frequency in cardiac vagal neurons. These responses were inhibited by the nonselective voltage-dependent calcium channel blocker Cd (100 μM). The P-type voltage-dependent calcium channel blocker agatoxin IV A (100 nM) abolished the nicotine-evoked responses. Nimodipine (2 μM), an antagonist of L-type calcium channels, inhibited the increase in mini amplitude and frequency but did not block the ligand gated inward current. The N- and Q-type voltage-dependent calcium channel antagonists conotoxin GVIA (1 μM) and conotoxin MVIIC (5 μM) had no effect. We conclude that the presynaptic and postsynaptic facilitation of glutamatergic neurotransmission to cardiac vagal neurons by nicotine involves activation of agatoxin-IV A-sensitive and possibly L-type voltage-dependent calcium channels. The postsynaptic inward current elicited by nicotine is dependent on activation of agatoxin-IV A-sensitive voltage-dependent calcium channels

Stability and Hydrocarbon/Fluorocarbon Sorption of a Metal-Organic Framework with Fluorinated Channels

The stabilities and hydrocarbon/fluorocarbon sorption properties of a zeolite-like metal-organic framework (MOF) Zn(hfipbb) with fluorinated channels has been studied. By the combination of thermogravimetric analysis (TGA) and powder X-ray diffraction (PXRD) measurements, we confirm that Zn(hfipbb) has exceptionally high hydrothermal and thermal stabilities. The adsorption behaviors of water and methanol by Zn(hfipbb) indicate that it is highly hydrophobic but with high adsorption of alcohols. Hexane and perfluorohexane adsorption measurements show that the fluorinated channels in Zn(hfipbb) have high affinity with hydrocarbon and fluorocarbon. The high fluorophilic nature of the channels and the high stability of the compound suggest its potential utility in practical separation applications

Nociceptin inhibits γ-aminobutyric acidergic inputs to cardiac parasympathetic neurons in the nucleus ambiguus

Studies have shown that nociceptin, the endogenous ligand for the opioid receptor-like receptor (ORL1), modulates central control of cardiovascular activity. The nucleus ambiguus, an area containing cardiac parasympathetic neurons, contains both ORL1 receptors and neurons that contain nociceptin itself. Although previous work has shown that nociceptin acts to increase parasympathetic outflow to the heart, the mechanisms by which this is achieved are unknown. In the present study, the effects of nociceptin on spontaneous γ-aminobutyric acidergic (GABAergic) input to cardiac parasympathetic neurons (IPSCs) was examined. At 100 μM, nociceptin inhibited both the frequency (-35.6%) and the amplitude (-49.5%) of spontaneous GABAergic IPSCs in cardiac vagal neurons. Nociceptin also caused a novel postsynaptic inhibition of the responses evoked by exogenous application of GABA. These results indicate that nociceptin acts both on neurons precedent to cardiovascular neurons to decrease the activity of GABAergic neurons that synapse upon cardiovascular neurons and directly, inhibiting the postsynaptic currents evoked by GABA. This inhibition by nociceptin would increase parasympathetic outflow to the heart, thus providing a possible mechanism for nociceptin-induced bradycardia

Development of high strength polyvinyl alcohol gel for water shutoff in carbonate reservoirs

To provide a high-strength, non-resin organic plugging agent for water shutoff in carbonate fracture and cave reservoirs, a high-strength gel was prepared with polyvinyl alcohol 1788 as gelant and p-phthalaldehyde as crosslinker in this study. By selecting latent acids rather than strong acid such as hydrochloric acid and sulfuric acid as catalysts, and by adding clay and sulphonated phenolic resin as stabilisers to the gelation, the drawbacks of short gelation time of polyvinyl alcohol and high dehydration rate of the formed gel soaking in brine were overcame. The evaluation results showed that the gellant composed of 7wt% polyvinyl alcohol, 4wt% clay, 0.3wt% aldehyde crosslinker, 0.25wt% latent acid, 1.5wt% sulfonated phenolic resin, and 0.3wt% hexamethylenetetramine had a gelation time of 2 h at 130 °C. The storage modulus of the gel was up to 2000 Pa, and the dehydration rate of the gel after soaking in synthetic brine for 30 days was less than 15%. Furthermore, the breakthrough pressure gradient in a slim tube with a diameter of 3mm reached 15 MPa / m, which indicated that the gel is a temperature and salinity resistant plugging agent with strong plugging ability