Most of over a thousand mitochondrial proteins are encoded by nuclear genes and must be imported from the cytosol. Little is known about the cytosolic events regulating mitochondrial protein import, ...partly due to the lack of appropriate tools for its assessment in living cells. We engineered an inducible biosensor for monitoring the main presequence-mediated import pathway with a quantitative, luminescence-based readout. This tool was used to explore the regulation of mitochondrial import by the PINK1 kinase-driven Parkin ubiquitin ligase, which is dysfunctional in autosomal recessive Parkinson's disease. We show that mitochondrial import was stimulated by Parkin, but not by disease-causing Parkin variants. This effect was dependent on Parkin activation by PINK1 and accompanied by an increase in the abundance of K11 ubiquitin chains on mitochondria and by ubiquitylation of subunits of the translocase of outer mitochondrial membrane. Mitochondrial import efficiency was abnormally low in cells from patients with PINK1- and PARK2-linked Parkinson's disease and was restored by phosphomimetic ubiquitin in cells with residual Parkin activity. Altogether, these findings uncover a role of ubiquitylation in mitochondrial import regulation and suggest that loss of this regulatory loop may underlie the pathophysiology of Parkinson's disease, providing novel opportunities for therapeutic intervention.
In milk-fed calves, the effects of sodium-butyrate (Na-butyrate) to replace flavomycin on growth performance and some mechanisms involved were studied. Pancreatic and intestinal morphology, digestive ...enzyme activities, plasma gut regulatory peptide concentrations, and expression of their receptors in the gastrointestinal tract were measured. Gastrointestinal tract defense systems were examined by measuring protein levels of 2 heat-shock proteins (HSP27 and HSP70). The calves were randomly allocated into 2 groups fed the same basic diet with flavomycin as an antimicrobial growth promoter or with Na-butyrate (3 g/kg of dry matter). Sodium-butyrate disappeared quickly in the upper gut and was not found in circulating blood. Supplementation with Na-butyrate enhanced growth rate and improved feed conversion into body weight gain compared with the flavomycin group. Supplementation with Na-butyrate was likely associated with an improvement in efficacy of the gastrointestinal tract digestive capacities expressed by enhanced production of digestive enzymes and increased absorptive capacities in the upper small intestine. The effects could have been controlled by insulin-like growth factor-1 but probably not by any of the cholecystokinin/gastrin peptide family. Concentrations of HSP27 and HSP70 were increased in stomach and colon of calves receiving Na-butyrate, thereby assuring protection of cells with intensive metabolism (chaperone function). In conclusion, beneficial effects of Na-butyrate on maturation of gastrointestinal functions were shown in milk-fed calves and may be applied to young mammals of other species.
The Canadian approach for long-term management of used nuclear fuel waste is Adaptive Phased Management (APM) which includes development of a Deep Geological Repository (DGR) and placement of nuclear ...fuel waste in corrosion-resistant copper containers excavated at a depth of 500–1000 m in a suitable host rock formation. The containers would be surrounded by compacted bentonite-based buffers and backfills. This study examined the conditions required to suppress microbial activity in compacted bentonite, such that microbially influenced corrosion (MIC) of copper waste containers in a future DGR would be insignificant. Experiments (of 40–90 days duration) were carried out to determine the effects of dry density and porewater salinity on swelling pressure, water activity (
a
w) and the culturable and viable microbial community indigenous to MX-80 Wyoming bentonite. A low
a
w (<
0.96) and a swelling pressure >
2 MPa appear to suppress microbial aerobic culturability below background levels (2.1
×
10
2 Colony-Forming Units/g) in as-purchased bentonite. To actually impose conditions of
a
w <
0.96 and swelling pressure >
2 MPa in compacted bentonite in a DGR, dry density needs to be maintained at 1.6 g/cm
3 or higher for porewater salinities at ≤
50 g/L. High porewater salinity (>
100 g/L) also keeps
a
w <
0.96 and aerobic culturability below background values. Under such conditions, cells likely survive as dormant cells or inactive spores (as suggested by phospholipid fatty acid analysis), which reduces the possibility of significant MIC. Observations in natural clay-rich environments support these findings. The geological timescale of microbial survival in dormant form is at present unknown. Interfacial locations in a DGR could form environments where (temporarily at least) the physical conditions necessary to suppress microbial activity would not always be met. The extent and potential importance of such interfaces with respect to revived microbial activity (and MIC) in a DGR require further study.
Emotional, behavioural, and health benefits of gentle stroking and vocalizations, otherwise known as gentling, have been documented for several species, but little is known about the effect of ...gentling on cats in stressful situations. In this study, 139 cats rated as anxious upon admission to an animal shelter were allocated to either a Gentled or Control group. Cats were gentled four times daily for 10min over a period of 10 days, with the aid of a tool for cats that were too aggressive to handle. The cats’ mood, or persistent emotional state, was rated daily for 10 d as Anxious, Frustrated or Content. Gentled cats were less likely to have negatively valenced moods (Anxious or Frustrated) than Control cats (Incidence Rate Ratio IRR=0.61 CI 0.42–0.88, P=0.007). Total secretory immunoglobulin A (S-IgA) was quantified from faeces by enzyme-linked immunosorbent assay. Gentled cats had increased S-IgA (6.9±0.7logeμg/g) compared to Control cats (5.9±0.5logeμg/g) (P<0.0001). Within the Gentled group of cats, S-IgA values were higher for cats that responded positively to gentling (7.03±0.6, logeμg/g), compared with those that responded negatively (6.14±0.8, logeμg/g). Combined conjunctival and oropharyngeal swab specimens were tested by quantitative real-time polymerase chain reaction (rPCR) for feline herpesvirus type 1 (FHV-1), feline calicivirus (FCV), Mycoplasma felis, Chlamydophila felis, and Bordetella bronchiseptica. There was a significant increase in shedding over time in Control cats (23%, 35%, 52% on days 1, 4 and 10, respectively), but not in gentled cats (32%, 26%, 30% on days 1, 4 and 10, respectively) (P=0.001). Onset of upper respiratory disease was determined by veterinary staff based on clinical signs, in particular ocular and/or nasal discharge. Control cats were 2.4 (CI: 1.35–4.15) times more likely to develop upper respiratory disease over time than gentled cats (P<0.0001). It is concluded that gentling anxious cats in animal shelters can induce positive affect (contentment), increase production of S-IgA, and reduce the incidence of upper respiratory disease.
This study aimed to evaluate whether functional variants in the ankyrin repeat and kinase domain‐containing 1 (ANKK1) gene and/or the dopamine receptor D2 (DRD2) gene modulate the subjective effects ...(reward or non‐reward response to a stimulus) produced by cocaine administration. Cocaine‐dependent participants (N = 47) were administered 40 mg of cocaine or placebo at time 0, and a subjective effects questionnaire (visual analog scale) was administered 15 min prior to cocaine administration, and at 5, 10, 15 and 20 min following administration. The influence of polymorphisms in the ANKK1 and DRD2 genes on subjective experience of cocaine in the laboratory was tested. Participants with a T allele of ANKK1 rs1800497 experienced greater subjective ‘high’ (P = 0.00006), ‘any drug effect’ (P = 0.0003) and ‘like’ (P = 0.0004) relative to the CC genotype group. Although the variant in the DRD2 gene was shown to be associated with subjective effects, linkage disequilibrium analysis revealed that this association was driven by the ANKK1 rs1800497 variant. A participant's ANKK1 genotype may identify individuals who are likely to experience greater positive subjective effects following cocaine exposure, including greater ‘high’ and ‘like’, and these individuals may have increased vulnerability to continue using cocaine or they may be at greater risk to relapse during periods of abstinence. However, these results are preliminary and replication is necessary to confirm these findings.
This preliminary study found that a variant in the ANKK1 gene may modulate subjective response to cocaine administration in the laboratory. Specifically, individuals with a T allele of ANKK1 rs1800497 experienced greater subjective ‘high’, ‘any drug effect’ and ‘like’ after cocaine administration than the other genotype group did. Therefore, a participant's ANKK1 genotype may identify individuals who are likely to experience greater positive subjective effects following cocaine exposure, and these individuals may have increased vulnerability to continue using cocaine or they may be at greater risk to relapse during periods of abstinence.
► Geochemical parameters were measured in Opalinus Clay porewater. ► Unexpected microbial activity occurred in porewater. ► Microorganisms were sustained by organic contamination. ► Microbial ...activity affected geochemical conditions. ► Fe(III)- reduction, sulphate-reduction and methanogenesis occurred.
The purpose of the Porewater Chemistry (PC) experiment at the Mont Terri (MT) Underground Rock Laboratory (URL) was to measure geochemical parameters, such as pH, Eh and pCO
2, in the porewater of the Opalinus Clay formation. Although the PC experiment was designed and implemented carefully from a geochemical perspective, conditions were not sterile and some microbial and nutrient contamination likely occurred. Microbial activity in the added synthetic porewater in the borehole was apparent shortly after initiation of the experiment and affected the geochemical parameters observed in the porewater. This paper summarizes the results from microbial analyses of post-termination PC water and overcore clay samples, conducted to attempt to elucidate the role of microbial activity in the evolution of the geochemical conditions in the PC experiment. Microbial analyses of the PC borehole water, and of clay overcore samples from around the borehole, were carried out at three laboratories and included both molecular biology and culturing methods.
Results indicated the presence of heterotrophic aerobic and anaerobic organisms that resulted likely from the initial, non-sterile conditions, sustained by suspected contamination with organic matter (glycerol, acetone). The results also indicated the presence of NO
3-reducers, Fe-reducers, SO
4-reducers and methanogens (i.e.,
Bacteria as well as
Archaea), suggesting a reducing environment with Fe(III)- and SO
4 reduction, and methanogenesis occurring in the PC water and adjacent clay. A black precipitate containing pyrite (identified by XRD and SEM) and a strong H
2S smell in the porewater confirmed the occurrence of SO
4 reduction. Microorganisms identified in the porewater included
Pseudomonas stutzeri,
Bacillus licheniformis,
Desulfosporosinus spp. and
Hyphomonas spp. Species identified in enrichment cultures from the overcore samples included
Pseudomonas stutzeri, three species of
Trichococcus spp.,
Caldanaerocella colombiensis,
Geosporobacter subterrenus and
Desulfosporosinus lacus. Overall the results indicated a thriving microbial community in the PC water and adjacent clay in contrast to “undisturbed” Opalinus Clay for which limited evidence for a small viable microbial community has been given in a previous study.
Aim
Bronchopulmonary dysplasia (BPD) remains the most common respiratory morbidity in immature infants. This review describes the diagnosis of BPD has evolved and summarises the therapeutic ...approaches that have made it possible to limit the incidence of BPD.
Method
We reviewed the literature from the first definition of BPD by Northway in 1967 to the surfactant treatment policies that are currently in use, drawing on more than 50 papers up to 2017.
Results
Our review showed that improvements in neonatal survival have been associated with an increased risk of severe BPD, significant levels of long‐term morbidity and the increased use of healthcare resources. These issues have encouraged researchers to explore potential new treatments that limit the incidence of BPD. Repeated surfactant instillation and the use of surfactant as a vehicle for budesonide are promising strategies for alleviating the burden of chronic lung disease. Ongoing research on surfactant or stem cell therapy may further improve the respiratory prognosis for prematurely born children.
Conclusion
Considerable research has been carried out into the increase in BPD, which has resulted from improvements in neonatal survival. Key areas of research include repeated surfactant administration, using surfactant as a vehicle for budesonide and stem cell therapy.
Tolerance to delay of gratification, taken to reflect impulsiveness, has been proposed to be under the preferential control of central serotonin (5-HT) processes.
The present study further examined ...the effects of drugs which directly or indirectly alter 5-HT transmission, on behaviour controlled by a delayed positive reinforcer.
Rats were given the choice in a T-maze between two magnitudes of reward: small (two food pellets) and immediate versus large (ten pellets) but delayed. When a 15-s waiting period was imposed in the arm leading to the large reward, rats selected this arm on 65-70% of the trials. This frequency was reduced to less than 40% when the large reward was delayed by 25 s.
In rats whose ascending 5-HT pathways had been lesioned by infusion of 5,7-dihydroxytryptamine (5,7-DHT) into the dorsal raphe, the introduction of the 15-s delay contingency resulted in a transient larger reduction of the frequency of choice of the now-delayed reward, compared to sham operated controls. In contrast, choice behaviour of rats given 5,7-DHT into the substantia nigra did not differ from controls. para-Chlorophenylalanine (pCPA, 150 mg/kg IP, daily for 3 days), a 5-HT synthesis inhibitor, bretazenil (0.5-8 mg/kg IP), a benzodiazepine (BZD) receptor partial agonist, and muscimol (0.25-1 mg/kg IP), a GABA(A) receptor agonist, induced a shift toward immediate reward. In contrast to the other BZDs, alprazolam (1-2 mg/kg IP) enhanced the frequency of choice of the large-but-25 s-delayed reward. Similar increased preference for the large-but-delayed reward was induced by the selective 5-HT reuptake inhibitors, fluoxetine (4-8 mg/kg IP) and fluvoxamine (4 mg/kg IP). The full 5-HT(1A) receptor agonist, 8-OH-DPAT (0.015-0.5 mg/kg IP) enhanced the frequency of choice of the large reward delayed by 25 s, whereas the partial agonists, buspirone (1-4 mg/kg IP), ipsapirone (0.5-1 mg/kg IP) and MDL 73005EF (1-2 mg/kg SC), and the antagonist, WAY 100635 (4 mg/kg SC), reduced the number of choices of the large reward delayed by 15 s. Unexpectedly, WAY 100635 (2 mg/kg), which had no effect on choice whatever the delay, did not counteract the increased tolerance to delay induced by 8-OH-DPAT (0.06 mg/kg) and further reduced the frequency of choice of the large-but- 15 s-delayed reward induced by ipsapirone (0.5 mg/kg).
These effects on tolerance to delay may be accounted for by a subtle balance between the opposing functional consequences of pre- versus post-synaptic 5-HT(1A) receptor activation or blockade. Overall, the present results provide further support to the idea that 5-HT processes participate in the control of impulsive-related behaviour, as assessed from tolerance to delay of reward in this particular T-maze procedure.
We examined 250 cats at an animal shelter in the coastal temperate region of Canada to determine whether age, source, gender, and sterilization status influenced risk of shedding at intake, ...transmission of infection, and development of clinical upper respiratory disease (URD). On admission, 28% of the cats were positive for 1 or more infectious agent related to URD; 21% were carriers of Mycoplasma felis and < 3% were carriers of feline calicivirus (FCV), feline herpesvirus-1 (FHV-1) or Bordetella bronchiseptica. Chlamydophila felis and H1N1 influenza virus were not detected. Carrier status was not affected by source, gender, sterilization status, or age (P > 0.05). Viral and bacterial shedding increased by 9% and 11%, respectively, over 3 sampling times (days 1, 4, and 10). Over 40 days after admission, the cumulative probability of developing URD was 2.2 times greater for stray than owner-surrendered cats (P = 0.02) and 0.5 times as great for neutered cats as for intact cats (P = 0.03). Cats that were shedding at intake were 2.6 times more likely to develop URD than were non-carriers (P < 0.002). Cats with FHV-1 and B. bronchiseptica infections were most at risk compared with non-shedding cats (P < 0.01).
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