Revealing key interactions in the metabolic network: a model of primary phosphate transport in bacteria]

One of the main problems of metabolic engineering is to determine the genetically controlled limiting links of a metabolic network. We have built a model of the primary transport of inorganic phosphates (Pi), analyzed the Pi metabolic network in Gram-negative bacteria, and determined the factors controlling the phosphate exchange. The model explains why the Pi primary transport is not observed at the release stage. The nonlinearity of primary transport and the differences in its parameters in the membrane and within the cell give rise to transport asymmetry, i.e., the Pi release rate is low as compared with the uptake rate, and is small at the background of secondary transport. Discussed is a general scheme of coordination between primary and secondary transport, which are interconnected through the substrate-product reration.     

Effect of lead on the photosynthetic apparatus of annual grasses

The effect of lead (in the form of Pb(CH₃COO)₂ 3H₂O at concentrations of 200, 400, and 800 mg/kg substrate) on the photosynthetic apparatus of barley (cv. Dina) and oat (cv. Falensky) was studied. Exposure to low concentrations of lead (200 mg/kg) slightly increased the content of chlorophyll in leaves and the rate of photosynthesis. Medium concentrations of lead (400 mg/kg) had no marked effect on the parameters analyzed, whereas high concentrations (800 mg/kg) decreased the area of leaves, the content of green pigments in them, and the rate of photosynthesis.Translated from Izvestiya Akademii Nauk, Seriya Biologicheskaya, No. 2, 2005, pp. 184–188.Original Russian Text Copyright © 2005 by Kaznina, Laidinen, Titov, Talanov.     

Study of hybridization in four species of ground squirrels (spermophilus: Rodentia,Sciuridae) by molecular genetic methods

Four species of ground squirrel--yellow (Spermophilus fulvus), russet (S. major), small (S. pygmaeus), and spotted (S. suslicus)--occur in the Volga region. Between S. major and S. pigmaeus, S. major and S. fulvus, and S. major and S. suslicus, sporadic hybridization was reported. Using sequencing and restriction analysis, we have examined the mtDNA C region in 13 yellow, 60 russet, 61 small, 45 spotted ground squirrels, and 9 phenotypic hybrids between these species. It was shown that 43% of S. major individuals had "alien" mitotypes typical of S. fulvus and S. pygmaeus. Alien mitotypes occurred both within and outside sympatric zones. No alien mitotypes were found in 119 animals of the other three species, which suggests that only one parental species (S. major) predominantly participates in backcrosses. Phenotypic hybrids S. fulvus x S. major and S. major x S. pygmaeus) were reliably identified using RAPD-PCR of nuclear DNA. However, we could find no significant traces of hybridization in S. major with alien mitotypes. Analysis of p53 pseudogenes of S. major and S. fulvus that were for the first time described in the present study produced similar results: 59 out of 60 individuals of S. major (including S. major with S. fulvus mitotypes) had only the pseudogene variant specific for S. major. This situation is possible even at low hybridization frequencies (less than 1% according to field observations and 1.4 to 2.7% according to nuclear DNA analysis) if dispersal of S. major from the sympatric zones mainly involved animals that obtained alien mtDNA via backcrossing. The prevalence of animals with alien mitotypes in some S. major populations can be explained by the founder effect. Further studies based on large samples are required for clarifying the discrepancies between mitochondrial and nuclear DNA data.     

Advantages and limitations of Internet‐based interventions for common mental disorders

Several Internet interventions have been developed and tested for common mental disorders, and the evidence to date shows that these treatments often result in similar outcomes as in face‐to‐face psychotherapy and that they are cost‐effective. In this paper, we first review the pros and cons of how participants in Internet treatment trials have been recruited. We then comment on the assessment procedures often involved in Internet interventions and conclude that, while online questionnaires yield robust results, diagnoses cannot be determined without any contact with the patient. We then review the role of the therapist and conclude that, although treatments including guidance seem to lead to better outcomes than unguided treatments, this guidance can be mainly practical and supportive rather than explicitly therapeutic in orientation. Then we briefly describe the advantages and disadvantages of treatments for mood and anxiety disorders and comment on ways to handle comorbidity often associated with these disorders. Finally we discuss challenges when disseminating Internet interventions. In conclusion, there is now a large body of evidence suggesting that Internet interventions work. Several research questions remain open, including how Internet interventions can be blended with traditional forms of care.     

Rapid and simple approach for identification of Mycobacterium tuberculosis and M. bovis by detection of regulatory gene whiB7

Identification of Mycobacterium tuberculosis and M. bovis is necessary for the application of adequate drug therapy. PCR amplification is a good tool for this purpose, but choosing proper target is of a great concern. We describe a PCR assay for fast detection of M. tuberculosis and M. bovis.As a BLAST and BLASTP search we selected regulatory gene whiB7 that encodes multi-drug resistance in this bacterium. Thirty clinical isolates of M. tuberculosis were sequenced and all the mutations in gene whiB7 were detected. The best set of several pairs of primers was selected and used in comparison by rpoB gene for differentiation of M. bovis, M. avium, M. kansasii, M. phlei, M. fortuitum, M. terrae, seven non-pathogenic Mycobacterium isolates and 30 clinical isolates of M. tuberculosis.It was proved that only clinical isolates of M. tuberculosis and M. bovis have positive bands of 667 bp whiB7. Other non-tuberculous and non-pathogenic isolates did not show any positive sign. Furthermore, 667-bp PCR products of whiB7 gene were observed for ten positive sputum samples (preliminarily approved to be positive for M. tuberculosis by commercially real-time based method), but no bands were detected in 5 negative sputum samples. RpoB gene could not differentiate non-tuberculous strains and non-pathogenic isolates from pathogenic clinical isolates. We concluded that PCR amplification of the gene coding for the WhiB7 protein could be successfully used as a good tool for rapid identification of M. tuberculosis and M. bovis. We propose application of this method as a rapid and simple approach in mycobacteriological laboratories.     

Effect of low-temperature hardening on activities of proteolytic enzymes and their inhibitors in the leaves of wheat and cucumber seedlings

On seedlings of winter wheat (Triticum aestivum L.) and cucumber (Cucumis sativus L.), the dynamics of cysteine and serine trypsin-like proteinases and also trypsin inhibitors at cold hardening (5°C for wheat and 10°C for cucumber) was studied. Activation of proteinases and inhibitors coincided in time or preceded an increased tolerance in wheat and cucumber seedlings in the early period of their hardening. After attaining the highest wheat tolerance, activity amidases reduced, whereas the increased activity levels of cysteine proteinases and trypsin inhibitors was maintained during the entire period of hardening. In cucumber, in these period activities of amidases and trypsin inhibitors reduced, whereas the activity of cysteine proteinases was maintained at the level close to the initial one. It is suggested that cysteine proteinases, amidases, and trypsin inhibitors are involved in plant adaptation to cold.     

UV-C-irradiated Arabidopsis and tobacco emit volatiles that trigger genomic instability in neighboring plants

We have previously shown that local exposure of plants to stress results in a systemic increase in genome instability. Here, we show that UV-C-irradiated plants produce a volatile signal that triggers an increase in genome instability in neighboring nonirradiated Arabidopsis thaliana plants. This volatile signal is interspecific, as UV-C-irradiated Arabidopsis plants transmit genome destabilization to naive tobacco (Nicotiana tabacum) plants and vice versa. We report that plants exposed to the volatile hormones methyl salicylate (MeSA) or methyl jasmonate (MeJA) exhibit a similar level of genome destabilization as UV-C-irradiated plants. We also found that irradiated Arabidopsis plants produce MeSA and MeJA. The analysis of mutants impaired in the synthesis and/or response to salicylic acid (SA) and/or jasmonic acid showed that at least one other volatile compound besides MeSA and MeJA can communicate interplant genome instability. The NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (npr1) mutant, defective in SA signaling, is impaired in both the production and the perception of the volatile signals, demonstrating a key role for NPR1 as a central regulator of genome stability. Finally, various forms of stress resulting in the formation of necrotic lesions also generate a volatile signal that leads to genomic instability.     

A RCT of a transdiagnostic internet-delivered treatment for three anxiety disorders: examination of support roles and disorder-specific outcomes

Background

Anxiety disorders share common vulnerabilities and symptoms. Disorder-specific treatment is efficacious, but few access evidence-based care. Administering transdiagnostic cognitive-behavioral therapy via the internet (iCBT) may increase access to evidence-based treatment, with a recent randomized controlled trial (RCT) providing preliminary support for this approach. This study extends those findings and aims to answer three questions: Is a transdiagnostic iCBT program for anxiety disorders efficacious and acceptable? Does it result in change for specific disorders? Can good clinical outcomes be obtained when guidance is provided via a Coach rather than a Clinician?

Method

RCT (N = 131) comparing three groups: Clinician-supported (CL) vs. Coach-supported (CO) vs. waitlist control (Control). Individuals met DSM-IV criteria for a principal diagnosis of generalized anxiety disorder (GAD), social phobia (SP) or panic disorder with or without agoraphobia (Pan/Ag). Treatment consisted of an 8-lesson/10 week iCBT program with weekly contact from a Clinician or Coach, and follow-up at 3-months post-treatment.

Results

Outcomes for the pooled treatment groups (CL+CO) were superior to the Control group on measures of anxiety, depression and disability, were associated with medium to large effect sizes (Cohen''s d = .76 – 1.44) (response rate = 89–100%), and were maintained at follow-up. Significant reductions were found on disorder-specific outcomes for each of the target diagnoses, and were associated with large effect sizes. CO participants achieved similar outcomes to CL participants at post-treatment, yet had significantly lower symptom severity scores on general anxiety, panic-disorder, depression and disability at follow-up (d = .45 – .46). Seventy-four percent of CO and 76% of CL participants completed the program. Less than 70 minutes of Clinician or Coach time was required per participant during the program.

Discussion

This transdiagnostic iCBT course for anxiety appears to be efficacious, associated with significant change for three target disorders, and is efficacious when guided by either a Clinician or Coach.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12610000242022     

The acceptability of Internet-based treatment and characteristics of an adult sample with obsessive compulsive disorder: an Internet survey

Background

Obsessive-compulsive disorder (OCD) is a disabling anxiety disorder, but most individuals delay seeking treatment. Internet-based cognitive behavioural therapy (iCBT) is an innovative service delivery method that may help to improve access to care, but the acceptability to consumers of such programs has not yet been established.

Methodology

People with symptoms of OCD were invited to complete an online survey enquiring about demographic characteristics, symptom severity, and acceptability of Internet-based treatment. Demographic and symptom severity data were compared with people with OCD identified in a national epidemiological survey and with a sample of patients with OCD from a specialist outpatient anxiety clinic.

Participants

129 volunteers to an online Internet survey, 135 patients at a specialist anxiety disorders outpatient clinic, and 297 cases identified in a national epidemiological survey.

Main Measures

Demographic characteristics, and severity of symptoms as measured by the Kessler 10-Item scale, the 12-item World Health Organisation Disability Assessment Schedule - Second Edition and the Yale Brown Obsessive Compulsive Scale - Self Report Version.

Principal Findings

The Internet sample was similar demographically but reported more severe symptoms than the comparison groups, although had similar severity of symptoms of OCD compared with other clinical samples reported in the literature. Participants reported Internet-based treatment for OCD would be highly acceptable.

Conclusions

Internet-based treatment may reduce barriers to accessing treatment to people with OCD. Individuals in this study were similar demographically to other samples and had similar severity of symptoms as those identified in other clinical samples, suggesting that Internet-based treatment using techniques employed in face-to-face treatment may be effective in this group. Internet-based treatments for OCD need to be developed and evaluated.