9 research outputs found
Cloning, Expression, and Purification of Functional Sec11a and Sec11b, Type I Signal Peptidases of the Archaeon Haloferax volcanii
Across evolution, type I signal peptidases are responsible for the cleavage of secretory signal peptides from proteins following their translocation across membranes. In Archaea, type I signal peptidases combine domain-specific features with traits found in either their eukaryal or bacterial counterparts. Eukaryal and bacterial type I signal peptidases differ in terms of catalytic mechanism, pharmacological profile, and oligomeric status. In this study, genes encoding Sec11a and Sec11b, two type I signal peptidases of the halophilic archaeon Haloferax volcanii, were cloned. Although both genes are expressed in cells grown in rich medium, gene deletion approaches suggest that Sec11b, but not Sec11a, is essential. For purification purposes, tagged versions of the protein products of both genes were expressed in transformed Haloferax volcanii, with Sec11a and Sec11b being fused to a cellulose-binding domain capable of interaction with cellulose in hypersaline surroundings. By employing an in vitro signal peptidase assay designed for use with high salt concentrations such as those encountered by halophilic archaea such as Haloferax volcanii, the signal peptide-cleaving activities of both isolated membranes and purified Sec11a and Sec11b were addressed. The results show that the two enzymes differentially cleave the assay substrate, raising the possibility that the Sec11a and Sec11b serve distinct physiological functions
Bridging the gap: challenging attitudes towards smoking in pregnancy among healthcare professionals
Background
Clean Air for Babies is
a Global Bridges project to reduce smoking in pregnancy in a healthcare
organization, 'Meuhedet', with 1.2M
members. One aim is empowering health professionals to provide brief smoking
cessation interventions. In this study we assessed the effectiveness of an
education program for nurses and ultrasound technicians.
Methods
The program consists of
8 hours, and includes smoking and ETS effects during pregnancy, practical tools
and behavioral interventions. Evaluation includes before and after questionnaires
based on Global Bridges tools, and focus groups. We are at the initial stage of
analysis. We will conduct another round of questionnaires 3 months post
intervention.
Results
We conducted 6 courses for 120 maternal health nurses and 60
technicians. Qualitative analysis demonstrates ambivalence regarding ability to
intervene (“This will damage the therapeutic space”) and identification with
smokers (“I have seen how difficult it is to stop, my husband became
unbearable.”). A second theme was hesitance in approaching Muslim or Jewish-Orthodox
spouses due to gender-based hierarchies in the cultural context (“In our
culture it is hard for the women to tell a man what to do…"). A common
theme among technicians was insecurity regarding their role in smoking
cessation.
We completed analysis of 29 nurses´ questionnaires
pre and immediately post intervention. Using paired-t-test analysis we found a
significant improvement in the level of knowledge (mean knowledge items 3.27 to
4.38 on a scale of 5, p< 0.001). No difference was found in self efficacy or
reported behavior.
Conclusions
Initial results indicate
that it is possible to identify specific barriers among caregivers that create
resistance to smoking cessation interventions. Addressing them creates an
opportunity for real organizational change. The improvement in knowledge is
indicative of the appropriateness of the training sessions. We expect that improvement
in self efficacy and reported behavior at the 3 month evaluation
Visceral Adipose Tissue E2F1-miRNA206/210 Pathway Associates with Type 2 Diabetes in Humans with Extreme Obesity
Objective: Up-regulated expression of transcription-factor E2F1 in human visceral adipose
tissue (VAT) characterizes a dysmetabolic obesity sub-phenotype. An E2F1-miRNA network has
been described in multiple cancers. Here we investigated whether elevated VAT-E2F1 in obesity
is associated with VAT-miRNA alterations similar to, or distinct from, those described in cancer.
Furthermore, we assessed if E2F1-associated miRNA changes may contribute to the link between
high- VAT-E2F1 and a dysmetabolic obesity phenotype. Methods: We assembled a cohort of patients
with obesity and high-VAT-E2F1, matched by age, sex, ±BMI to patients with low-VAT-E2F1, with and
without obesity (8 patients/groupX3 groups). We performed Nanostring -based miRNA profiling
of VAT samples from all 24 patients. Candidate E2F1-related miRNAs were validated by qPCR in
an independent cohort of patients with extreme obesity, with or without type-2-diabetes (T2DM)
(n = 20). Bioinformatic tools and manipulation of E2F1 expression in cells were used to establish the
plausibility of the functional VAT-E2F1-miRNA network in obesity. Results: Among n = 798 identified
miRNAs, 17 were differentially expressed in relation to E2F1 and not to obesity itself. No evidence for
the cancer-related E2F1-miRNA network was identified in human VAT in obesity. In HEK293-cells,
overexpression/downregulation of E2F1 correspondingly altered the expression of miRNA-206 and
miRNA-210-5p, two miRNAs with reported metabolic functions consistent with those of E2F1. In
VAT from both cohorts, the expression of both miRNA-206 and 210-5p intercorrelated, and correlated
with the expression of E2F1. In cohort 1 we did not detect significant associations with biochemical
parameters. In cohort 2 of patients with extreme obesity, all those with high VAT-E2F1 showed a
diabetes-complicated obesity phenotype and higher expression of miRNA-206 and miRNA-210-5p,
which also correlated with fasting glucose levels (both miRNAs) and fasting insulin (miRNA-210-5p).
Conclusions: Whilst the previously described cancer-related E2F1-miRNA network does not appear
to operate in VAT in obesity, miRNAs-206 and 210-5p may link high-E2F1 expression in VAT with
diabetes-complicated extreme obesity phenotype
Visceral Adipose Tissue E2F1-miRNA206/210 Pathway Associates with Type 2 Diabetes in Humans with Extreme Obesity
Objective: Up-regulated expression of transcription-factor E2F1 in human visceral adipose
tissue (VAT) characterizes a dysmetabolic obesity sub-phenotype. An E2F1-miRNA network has
been described in multiple cancers. Here we investigated whether elevated VAT-E2F1 in obesity
is associated with VAT-miRNA alterations similar to, or distinct from, those described in cancer.
Furthermore, we assessed if E2F1-associated miRNA changes may contribute to the link between
high- VAT-E2F1 and a dysmetabolic obesity phenotype. Methods: We assembled a cohort of patients
with obesity and high-VAT-E2F1, matched by age, sex, ±BMI to patients with low-VAT-E2F1, with and
without obesity (8 patients/groupX3 groups). We performed Nanostring -based miRNA profiling
of VAT samples from all 24 patients. Candidate E2F1-related miRNAs were validated by qPCR in
an independent cohort of patients with extreme obesity, with or without type-2-diabetes (T2DM)
(n = 20). Bioinformatic tools and manipulation of E2F1 expression in cells were used to establish the
plausibility of the functional VAT-E2F1-miRNA network in obesity. Results: Among n = 798 identified
miRNAs, 17 were differentially expressed in relation to E2F1 and not to obesity itself. No evidence for
the cancer-related E2F1-miRNA network was identified in human VAT in obesity. In HEK293-cells,
overexpression/downregulation of E2F1 correspondingly altered the expression of miRNA-206 and
miRNA-210-5p, two miRNAs with reported metabolic functions consistent with those of E2F1. In
VAT from both cohorts, the expression of both miRNA-206 and 210-5p intercorrelated, and correlated
with the expression of E2F1. In cohort 1 we did not detect significant associations with biochemical
parameters. In cohort 2 of patients with extreme obesity, all those with high VAT-E2F1 showed a
diabetes-complicated obesity phenotype and higher expression of miRNA-206 and miRNA-210-5p,
which also correlated with fasting glucose levels (both miRNAs) and fasting insulin (miRNA-210-5p).
Conclusions: Whilst the previously described cancer-related E2F1-miRNA network does not appear
to operate in VAT in obesity, miRNAs-206 and 210-5p may link high-E2F1 expression in VAT with
diabetes-complicated extreme obesity phenotype
Early preterm delivery due to placenta previa is an independent risk factor for a subsequent spontaneous preterm birth
<p>Abstract</p> <p>Background</p> <p>To determine whether patients with placenta previa who delivered preterm have an increased risk for recurrent spontaneous preterm birth.</p> <p>Methods</p> <p>This retrospective population based cohort study included patients who delivered after a primary cesarean section (n = 9983). The rate of placenta previa, its recurrence, and the risk for recurrent preterm birth were determined.</p> <p>Results</p> <p>Patients who had a placenta previa at the primary CS pregnancy had an increased risk for its recurrence [crude OR of 2.65 (95% CI 1.3-5.5)]. The rate of preterm birth in patients with placenta previa in the primary CS pregnancy was 55.9%; and these patients had a higher rate of recurrent preterm delivery than the rest of the study population (p < .001). Among patients with placenta previa in the primary CS pregnancy, those who delivered preterm had a higher rate of recurrent spontaneous preterm birth regardless of the location of their placenta in the subsequent delivery [OR 3.09 (95% CI 2.1-4.6)]. In comparison to all patients with who had a primary cesarean section, patients who had placenta previa and delivered preterm had an independent increased risk for recurrent preterm birth [OR of 3.6 (95% CI 1.5-8.5)].</p> <p>Conclusions</p> <p>Women with placenta previa, who deliver preterm, especially before 34 weeks of gestation, are at increased risk for recurrent spontaneous preterm birth regardless to the site of placental implantation in the subsequent pregnancy. Thus, strict follow up by high risk pregnancies specialist is recommended.</p