The relationship between respiratory sinus arrhythmia and heart rate during anesthesia in rat.

During inspiration the heart rate (HR) increases and during expiration it decreases. Contribution of respiratory sinus arrhythmia (RSA) to spontaneous heart rate variability (HRV) can be measured as the high frequency (HF) component of variation in consecutive R-R intervals on ECG. In conscious rats, slowing of HR is associated with an increase in HF. The aim of this study was to investigate whether this relationship between HF and HR is preserved during anesthesia in rat. A 15 minutes long ECG signal was recorded from rats (N=15) under moderate chloral hydrate (CHL) anesthesia. Recordings were extended with 45 minutes to investigate the effect of atropine (N=3), against controls (N=3). Short term HRV was investigated in 30 seconds long epochs. HF was considered the frequency band between 0.8 and 1.6 Hz. RSA was quantified as the relative spectral power of the HF. Respiratory frequency (RF) was quantified as the mean spectral frequency within the HF band. One minute estimates of HR, RSA and HF were calculated by averaging 3 epochs of 30 seconds overlapped 50%. The average HR was 427 +/- 3 bpm. The magnitude of RSA was 45 +/- 1% at a RF of 71 +/- 1 rpm. We found that: (1) the decrease in HR that occurs during CHL anesthesia in rat correlates with an increase in RSA; (2) atropine reduces RSA and the time-dependent decrease in HR; (3) the time-dependent increase in RSA is preserved after atropine. We conclude that the correlation between RSA and HR reflects the cardio-pulmonary coupling under parasympathetic control.     

The first study on bacterial flora of pest beetles Sciaphobus squalidus,Tatianaerhynchites aequatus and Byctiscus betulae in the Republic of Moldova

The present study was conducted to identify the microbial flora of pest weevils Sciaphobus squalidus (Gyll.), Tatianaerhynchites aequatus (L.) and Byctiscus betulae L., which may provide novel approaches for insect biocontrol. According to morphological, physiological, biochemical and molecular properties thirteen bacteria were revealed and characterized. Ten of these bacteria were identified at the species level and the rest at the genus level. Isolates were identified as Staphyloccocus haemolyticus (Ta5), Bacillus cereus (Ss1), Pseudomonas moraviensis (Ss4), Pseudomonas fluorescens (Ss2), Pantoea agglomerans (Ss3, Bb3), Klebsiella pneumoniae (Ta1, Ta3, and Ta4), Erwinia billingiae (Ta2) and Erwinia spp. (Bb1, Bb2, Bb4). This is the first record of bacterial isolates (Ss4, Ta2 and Ta5) from any insect. The pathogenicity of bacteria was tested against adults of S. squalidus, T. aequatus and B. betulae and three of them showed insecticidal activity. The highest activity, 93% had B. cereus on S. squalidus and 90% on B. betulae within five days. The maximum activities of other two isolates Ss2 and Ss4 were determined as 73% and 46% against S. squalidus. Our data can offer useful information for future investigations on bacterial agent development and implementation as insecticides in agricultural system.     

Inhibition of inducible nitric oxide synthase prevents lipid peroxidation in osteoarthritic chondrocytes

Nitric oxide (NO) and the lipid peroxidation (LPO) product 4-hydroxynonenal (HNE) are considered to be key mediators of cartilage destruction in osteoarthritis (OA). NO is also known to be an important intermediary in LPO initiation through peroxynitrite formation. The aim of the present study was to assess the ability of the inducible NO synthase (iNOS) inhibitor N-iminoethyl-L-lysine (L-NIL) to prevent HNE generation via NO suppression in human OA chondrocytes and cartilage explants. Human OA chondrocytes and cartilage explants were treated with L-NIL and thereafter with or without interleukin-1beta (IL-1β) or HNE at cytotoxic or non-cytotoxic concentrations. Parameters related to oxidative stress, apoptosis, inflammation, and catabolism were investigated. L-NIL stifled IL-1β-induced NO release, iNOS activity, nitrated proteins, and HNE generation in a dose-dependent manner. It also blocked IL-1β-induced inactivation of the HNE-metabolizing glutathione-s-transferase (GST). L-NIL restored both HNE and GSTA4-4 levels in OA cartilage explants. Interestingly, it also abolished IL-1β-evoked reactive oxygen species (ROS) generation and p47 NADPH oxidase activation. Furthermore, L-NIL significantly attenuated cell death and markers of apoptosis elicited by exposure to a cytotoxic dose of HNE as well as the release of prostaglandin E(2) and metalloproteinase-13 induced by a non-cytotoxic dose of HNE. Altogether, our findings support a beneficial effect of L-NIL in OA by (i) preventing the LPO process and ROS production via NO-dependent and/or independent mechanisms and (ii) attenuating HNE-induced cell death and different mediators of cartilage damage.     

Modulation of respiratory responses to chemoreflex activation by L-glutamate and ATP in the rostral ventrolateral medulla of awake rats

Presympathetic neurons in the different anteroposterior aspects of rostral ventrolateral medulla (RVLM) are colocalized with expiratory [B?tzinger complex (B?tC)] and inspiratory [pre-B?tzinger complex (pre-B?tC)] neurons of ventral respiratory column (VRC), suggesting that this region integrates the cardiovascular and respiratory chemoreflex responses. In the present study, we evaluated in different anteroposterior aspects of RVLM of awake rats the role of ionotropic glutamate and purinergic receptors on cardiorespiratory responses to chemoreflex activation. The bilateral ionotropic glutamate receptors antagonism with kynurenic acid (KYN) (8 nmol/50 nl) in the rostral aspect of RVLM (RVLM/B?tC) enhanced the tachypneic (120 ± 9 vs. 180 ± 9 cpm; P < 0.01) and attenuated the pressor response (55 ± 2 vs. 15 ± 1 mmHg; P < 0.001) to chemoreflex activation (n = 7). On the other hand, bilateral microinjection of KYN into the caudal aspect of RVLM (RVLM/pre-B?tC) caused a respiratory arrest in four awake rats used in the present study. Bilateral P2X receptors antagonism with PPADS (0.25 nmol/50 nl) in the RVLM/B?tC reduced chemoreflex tachypneic response (127 ± 6 vs. 70 ± 5 cpm; P < 0.001; n = 6), but did not change the chemoreflex pressor response. In addition, PPADS into the RVLM/B?tC attenuated the enhancement of the tachypneic response to chemoreflex activation elicited by previous microinjections of KYN into the same subregion (188 ± 2 vs. 157 ± 3 cpm; P < 0.05; n = 5). Our findings indicate that: 1) L-glutamate, but not ATP, in the RVLM/B?tC is required for pressor response to peripheral chemoreflex and 2) both transmitters in the RVLM/B?tC are required for the processing of the ventilatory response to peripheral chemoreflex activation in awake rats.     

Serum 25-Hydroxyvitamin D Status and Longitudinal Changes in Weight and Waist Circumference: Influence of Genetic Predisposition to Adiposity

Studies of the relationship between serum 25-hydroxyvitamin D (25(OH)D) and changes in measures of adiposity have shown inconsistent results, and interaction with genetic predisposition to obesity has rarely been examined. We examined whether 25(OH)D was associated with subsequent annual changes in body weight (ΔBW) or waist circumference (ΔWC), and whether the associations were modified by genetic predisposition to a high BMI, WC or waist-hip ratio adjusted for BMI (WHR_BMI). The study was based on 10,898 individuals from the Danish Inter99, the 1958 British Birth Cohort and the Northern Finland Birth Cohort 1966. We combined 42 adiposity-associated Single Nucleotide Polymorphisms (SNPs) into four scores indicating genetic predisposition to BMI, WC and WHR_BMI, or all three traits combined. Linear regression was used to examine the association between serum 25(OH)D and ΔBW or ΔWC, SNP-score × 25(OH)D interactions were examined, and results from the individual cohorts were meta-analyzed. In the meta-analyses, we found no evidence of an association between 25(OH)D and ΔBW (-9.4 gram/y per 10 nmol/L higher 25(OH)D [95% CI: -23.0, +4.3; P = 0.18]) or ΔWC (-0.06 mm/y per 10 nmol/L higher 25(OH)D [95% CI: -0.17, +0.06; P = 0.33]). Furthermore, we found no statistically significant interactions between the four SNP-scores and 25(OH)D in relation to ΔBW or ΔWC. Thus, in view of the narrow CIs, our results suggest that an association between 25(OH)D and changes in measures of adiposity is absent or marginal. Similarly, the study provided evidence that there is either no or very limited dependence on genetic predisposition to adiposity.     

Short-term responses of the understory to the removal of plant functional groups in the cold-temperate deciduous forest

It is widely believed that functional diversity contributes to the stability of ecosystems. Indeed, greater redundancy among species within functional groups and greater complementarity among functional groups within communities should increase the resistance and resilience of ecosystems. In the present study, we tested for functional group complementarity by examining how the loss of specific functional groups may alter the role that other groups play in ecosystem functions. We removed different functional groups, one at a time, from the understory of three maple-dominated forests in southern Québec (Canada) and followed the understory response over a 2-year period. The experimental design included a control and five removal treatments. Five functional groups were defined: spring-flowering ephemeral species; spring-flowering persistent species; summer-flowering species; fern species; and seedlings and juveniles of woody species. Richness, cover, soil pH and organic matter content were determined after two years of removal. The results of our experiment revealed that richness was significantly lower than what we expected when spring-flowering persistent species or seedlings and juveniles of woody species were removed, suggesting not only direct but also indirect positive effects of both of these groups on understory richness (mostly through effects on summer-flowering species and fern species). Removal of the seedlings and juveniles of woody species and, to a lesser extent, of spring-flowering persistent species and of fern species lead to a decrease in the cover of summer-flowering species, implying a positive effect of the former groups on the latter. The cover–richness relationship in the control and in each one of the five removal treatments was positive and well fitted by a linear regression. Yet, the slope of the relationship differed among treatments, but not between the control and any one of the removal treatments (pair-wise comparisons). Our results suggest that the different functional groups are complementary and that positive interactions predominate over negative ones. Contrary to common belief, understory plants can respond quite rapidly to changes in community functional composition. Although we have not investigated the specific mechanisms responsible for the short-term responses reported here, we suggest that complex intergroup interactions may favour functional diversity and enhance ecosystem functions.     

海州香薷（Elsholtzia splendens）根际铜抗性细菌的筛选及生物多样性

摘要：【目的】重金属耐性植物海州香薷根际铜抗性细菌的筛选及生物多样性研究将有助于了解微生物－超富集植物相互关系和植物修复机理、开发微生物－香薷重金属修复新技术。【方法】采用稀释平板涂布法从海州香薷根际筛选铜抗性菌株,测定菌株溶磷和产生吲哚乙酸、铁载体、1-氨基环丙烷-1-羧酸（ACC）脱氨酶的特性,采用16S rDNA限制性酶切多态性分析（amplified rDNA restriction analysis, ARDRA）研究铜抗性细菌的遗传多样性,根据16S rDNA相似性对产ACC脱氨酶的菌株进行了     

Rapid immunochromatographic serum assay of nontuberculous mycobacterial infections

A rapid immunochromatographic serologic assay (Dot assay) is proposed to be applied on patients infected with nontuberculous mycobacteria (NTM). This assay could evidentiate the infecting species and allow the beginning of the treatment. The test is based on the principle of immunoblotting chromatography, a rapid membrane-based assay, capable of diagnosing NTM infections in serum, in less than 1 hour, with no need of special equipment or skilled staff. The secreted extracellular antigens have been isolated from the unheated culture filtrates of the clinically significant NTM (M. avium, MAI, M. kansasii, M. xenopi, M. chelonaei, M. scrofulaceum, M. marinum, M. fortuitum, M. abscesus, M. szulgai). The patients have been tested against these antigens, as well as from M. tuberculosis H37Rv, due to the possibility of co-infection with tuberculous bacilli. A number of 385 tests on patient sera have been performed (10, with NTM suspected infection, with or without M. tuberculosis co-infection, 5 with confirmed diagnosis of NTM infection, 10 with TB, 10 with other respiratory diseases). The preliminary results presented in this paper support the fact that the rapid immunochromatographic serum assay, combined with clinical and radiographic evidence, could evidentiate the infecting NTM species and allow the start of an earlier treatment, but must be confirmed on a higher number of patients.     

RNase L restricts the mobility of engineered retrotransposons in cultured human cells

Retrotransposons are mobile genetic elements, and their mobility can lead to genomic instability. Retrotransposon insertions are associated with a diverse range of sporadic diseases, including cancer. Thus, it is not a surprise that multiple host defense mechanisms suppress retrotransposition. The 2′,5′-oligoadenylate (2-5A) synthetase (OAS)-RNase L system is a mechanism for restricting viral infections during the interferon antiviral response. Here, we investigated a potential role for the OAS-RNase L system in the restriction of retrotransposons. Expression of wild type (WT) and a constitutively active form of RNase L (NΔ385), but not a catalytically inactive RNase L mutant (R667A), impaired the mobility of engineered human LINE-1 (L1) and mouse intracisternal A-type particle retrotransposons in cultured human cells. Furthermore, WT RNase L, but not an inactive RNase L mutant (R667A), reduced L1 RNA levels and subsequent expression of the L1-encoded proteins (ORF1p and ORF2p). Consistently, confocal immunofluorescent microscopy demonstrated that WT RNase L, but not RNase L R667A, prevented formation of L1 cytoplasmic foci. Finally, siRNA-mediated depletion of endogenous RNase L in a human ovarian cancer cell line (Hey1b) increased the levels of L1 retrotransposition by ∼2-fold. Together, these data suggest that RNase L might function as a suppressor of structurally distinct retrotransposons.