Repeated oral administration of capsaicin increases anxiety-like behaviours with prolonged stress-response in rats

This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy counts and rostral grooming were significantly increased, and caudal grooming decreased, in capsaicin-treated rats during the ambulatory activity test. In elevated plus maze test, not only the time spent in open arms but also the percent arm entry into open arms was reduced in capsaicin-treated rats compared with control rats. In forced swim test, although swimming duration was decreased, struggling increased in the capsaicin group, immobility duration did not differ between the groups. Repeated oral capsaicin did not affect the basal levels of plasma corticosterone; however, the stress-induced elevation of plasma corticosterone was prolonged in capsaicin treated rats. Oral capsaicin exposure significantly increased c-Fos expression not only in the nucleus tractus of solitarius but also in the paraventricular nucleus. Results suggest that repeated oral exposure to capsaicin increases anxiety-like behaviours in rats, and dysfunction of the hypothalamic-pituitary-adrenal axis may play a role in its pathophysiology.     

Long-term treadmill exercise improves spatial memory of male APPswe/PS1dE9 mice by regulation of BDNF expression and microglia activation

Increasing evidence suggests that physical activity could delay or attenuate the symptoms of Alzheimer''s disease (AD). But the underlying mechanisms are still not fully understood. To investigate the effect of long-term treadmill exercise on the spatial memory of AD mice and the possible role of β-amyloid, brain-derived neurotrophic factor (BDNF) and microglia in the effect, male APPswe/PS1dE9 AD mice aged 4 months were subjected to treadmill exercise for 5 months with 6 sessions per week and gradually increased load. A Morris water maze was used to evaluate the spatial memory. Expression levels of β-amyloid, BDNF and Iba-1 (a microglia marker) in brain tissue were detected by immunohistochemistry. Sedentary AD mice and wildtype C57BL/6J mice served as controls. The results showed that 5-month treadmill exercise significantly decreased the escape latencies (P < 0.01 on the 4th day) and improved the spatial memory of the AD mice in the water maze test. Meanwhile, treadmill exercise significantly increased the number of BDNF-positive cells and decreased the ratios of activated microglia in both the cerebral cortex and the hippocampus. However, treadmill exercise did not significantly alleviate the accumulation of β-amyloid in either the cerebral cortex or the hippocampus of the AD mice (P > 0.05). The study suggested that long-term treadmill exercise could improve the spatial memory of the male APPswe/PS1dE9 AD mice. The increase in BDNF-positive cells and decrease in activated microglia might underpin the beneficial effect.     

三种裸趾虎核型及银带的研究

裸趾虎属Ｃｙｒｔｏｄａｃｔｙｌｕｓ动物 ,已知有 6 0余种 (Ｗｅｒ ｍｕｔｈ ,196 5 ) ,分布于亚州南部及西南部、欧州及大洋洲。中国记载有 5种 (Ｚｈａｏ等 ,1993) ,分布于西北部的干旱荒漠区及西藏东南部。有关其染色体研究报道甚少 ,仅国外记载 7种 (Ｓｚｃｚｅｒｂａｋ等 ,1996 ) ,且所提供的数据较为粗略。为此 ,本文对长裸趾虎Ｃ ｅｌｏｎｇａｔｕｓ、墨脱裸趾虎Ｃ ｍｅｄｏｇｅｎｓｉｓ和西藏裸趾虎Ｃ ｔｉｂｅｔａｎｕｓ核型进行研究 ,并首次报道其银带。旨在为分类及系统进化学提供细胞遗传学信息。1　材料和方法实验动物见表 1…     

Quantitative Mass Spectrometry Analysis Reveals that Deletion of the TRPV1 Receptor in Mice Alters Substance P and Neurokinin A Expression in the Central Nervous System

Vanilloid receptors have a central role in the processing of nociceptive stimuli. TRPV1 null mice showed significant decrease in response to heat noxious stimuli. However, thermal sensitivity is still present suggesting that the TRPV1 is not an exclusive transducer of thermal stimuli. Additionally, tachykinin peptides play a central role in pain processing and expression levels may also contribute in modifying the pain threshold. The LC?CMS/MS analysis revealed that SP and NKA were significantly down-regulated in TRPV1^?/? in spinal cord and brain tissues. In spinal cord, SP concentrations were 23.4?% lower (p?<?0.0049) and NKA concentrations were 22.0?% lower (p?<?0.0022) in TRPV1 null mice. Additionally, brain SP concentrations were 26.9?% lower (p?<?0.0260) and brain NKA concentrations were 31.9?% lower (p?<?0.0063) in TRPV1 null mice. These results clearly demonstrate that TPRV1 null mice exhibit lower SP and NKA concentrations in the central nervous system. The deficit of thermal responses may also be related to the down-regulations of SP and NKA.     

Explaining diversity of livestock-farming management strategies of multiple-job holders: importance of level of production objectives and role of farming in the household

We characterised the livestock-farming management strategies of multiple-job holders and identified which variables contributed most to the differentiation of these strategies. We hypothesised that they would mainly be differentiated by the contribution of the farming income to the total household income and the availability of the household members for farming. The multiple-job holding livestock-farmer's motivations, decisions and actions about both multiple-job holding and livestock farming were obtained in semi-directed interviews of 35 sheep farmers who held multiple jobs, on farm and off farm. They were synthesised into six variables characterising the diversity of the livestock-farming objectives and management guidelines. Thanks to a multiple factorial analysis, we showed that the diversity of the sheep-farming management strategies of multiple-job holders was better explained by two factors 'level of motivation of the farmer to get high technical results' and 'more personal fulfilling v. the family business conception of farming', than the factors we hypothesised. Within our sample, the performances ranged from 0.7 to 1.4 weaned lambs per ewe per year. Six sheep-farming management strategies were identified. They illustrated the importance of the level of production objectives and of farming income expectation, which were found to be independent, in explaining diversity. No direct relationship between farm work organisation and sheep-farming management strategy was identified. Explaining the diversity of the livestock-farming management strategies of multiple-job holders appears to require that all the benefits expected from farming and their hierarchy be identified before analysing how they are translated into production objectives and management guidelines.     

Molecular localization of a redox-modulated process regulating plant mitochondrial electron transport

Using in organellar assays, we found that significant tobacco alternative oxidase (AOX) activity is dependent on both reduction of a putative regulatory disulfide bond and the presence of pyruvate, which may interact with a Cys sulfhydryl. This redox modulation and pyruvate activation thus may be important in determining the partitioning of electrons to AOX in vivo. To investigate these regulatory mechanisms, we generated tobacco plants expressing mutated AOX proteins. Mutation of the most N-terminal Cys residue (Cys-126) to an Ala residue produced an AOX that could not be converted to the disulfide-linked form, thus identifying this Cys residue as being responsible for redox modulation. Although this mutation might be expected to produce an AOX with constitutive high activity in the presence of pyruvate, we found it to have minimal in organellar activity in the presence of pyruvate. Nonetheless, the Cys-126 mutation did not appear to have compromised the catalytic function of AOX, given that cells expressing the protein displayed high rates of cyanide-resistant respiration in vivo. The striking difference between in vivo and in organellar results suggests that an additional mechanism(s), as yet unidentified by in organellar assays, may promote activity in vivo. Mutation of the Cys residue nearest the presumptive active site (Cys-176) to an Ala residue did not prevent disulfide bond formation or affect the ability of AOX to be stimulated by pyruvate, indicating that this Cys residue is involved in neither redox modulation nor pyruvate activation.     

Reflooding the Faguibine floodplain system,northern Mali: potential benefits and challenges

The Faguibine system, northern Mali, consists of a series of interconnected floodplains of which the flooded surface area declined from about 1 000 km² in the late 19th century to only some 90 km² in 2010. Flood extent depends on the height of the Niger River flood peak at Diré. Satellite imagery analysis indicated that a phase shift may have occurred in the year 2000, probably as a delayed consequence of the Sahelian drought of the 1970s compounded by the collapse of societal controls on water use during recent civil conflict. An economic evaluation of the system in 2011 showed US$100 000 per year of net income per flooded km² in Lake Faguibine, allowing vulnerable people to practise recession agriculture, to fish and to graze livestock. An intensive investment phase, combined with an approach of rebuilding local governance systems and environmental management capacity, could yield net benefits to the user communities of the order of ten times the maintenance costs, contributing to human well-being. The system is currently threatened by the building of the Fomi Dam in Guinea and by the planned expansion of irrigation upstream. There is also a risk of the return of a prolonged drought linked to the Atlantic multi-decadal oscillation index.     

Expression,localization and possible functions of aquaporins 3 and 8 in rat digestive system

Although aquaporins (AQPs) play important roles in transcellular water movement, their precise quantification and localization remains controversial. We investigated expression levels and localizations of AQP3 and AQP8 and their possible functions in the rat digestive system using real-time polymerase chain reactions, western blot analysis and immunohistochemistry. We investigated the expression levels and localizations of AQP3 and AQP8 in esophagus, forestomach, glandular stomach, duodenum, jejunum, ileum, proximal and distal colon, and liver. AQP3 was expressed in the basolateral membranes of stratified epithelia (esophagus and forestomach) and simple columnar epithelia (glandular stomach, ileum, and proximal and distal colon). Expression was particularly abundant in the esophagus, and proximal and distal colon. AQP8 was found in the subapical compartment of columnar epithelial cells of the jejunum, ileum, proximal colon and liver; the most intense staining occurred in the jejunum. Our results suggest that AQP3 and AQP8 play significant roles in intestinal function and/or fluid homeostasis and may be an important subject for future investigation of disorders that involve disruption of intestinal fluid homeostasis, such as inflammatory bowel disease and irritable bowel syndrome.     

The variability of the hepatitis B virus genome: statistical analysis and biological implications

A statistical analysis of the nucleotide sequence variability in 14 published hepatitis B virus (HBV) genomes was carried out using parametric and nonparametric methods. A parametric statistical model revealed that the different regions of the genome differed significantly in their variability. The conclusion was supported by a nonparametric kernel-density model of the HBV genome. Genes S, C, and P, region X, the precore region, and the pre-S2/pre-S1 regions were ranked in order of increasing variability. In many instances, conserved regions of the genome identified with sequences of known function in HBV biology. However, other characterized regions (such as pre-S) showed much variability despite the involvement of their encoded peptides in specific functions. Point mutations that may result in the formation of stop codons and amino acid changes may affect the clinical picture of HBV infection and may be reflected in atypical serological patterns.