271 research outputs found
Investigation into the role of monocyte tumour necrosis factor-alpha converting enzyme as a regulator of the inflammatory response in sepsis
Sepsis
consists
of
both
the
systemic
inflammatory
response
syndrome
(SIRS)
and
the
compensatory
anti-inflammatory
response
syndrome
(CARS).
How
these
differential
response
states
are
regulated
is
yet
to
be
fully
elucidated.
Tumour
necrosis
factor-alpha
(TNF)
is
one
of
the
principal
cytokines
involved
in
mediating
SIRS.
TNF
is
released
from
cells
by
tumour
necrosis
factor-alpha
converting
enzyme
(TACE),
this
enzyme
is
responsible
for
the
ectodomain
cleavage
of
a
number
of
other
substrates
relevant
to
inflammation
including
both
TNF
receptors
and
the
adhesion
molecule
L-selectin.
How
TACE
contributes
to,
and
functions
in,
SIRS
and
CARS
is
not
yet
known.
My
objective
was
to
investigate
TACE
activity
and
associated
substrate
shedding
in
monocytes,
specifically
how
the
enzyme
behaved
in
the
context
of
in
vitro
models
that
I
designed
to
induce
states
of
priming
and
tolerance.
I
then
obtained
in
vivo
samples
from
critically
ill
patients
to
determine
whether
there
were
similarities
between
the
TACE
activity
profiles
found
in
patient
cells,
and
volunteer
cells
placed
in
the
in
vitro
models.
My
aims
were:
1)
Determine
how
TACE
activity
profiles
were
altered
when
sequential
inflammatory
stimuli
were
utilised
in
a
two-hit
model
of
sepsis
designed
to
induce
states
of
priming
and
tolerance
and
2)
To
perform
a
clinical
study
to
investigate
TACE
behaviour
in
the
context
of
critical
illness.
I
successfully
refined
a
method
of
isolating
primary
monocytes
from
healthy
volunteers
and
patients
that
allowed
determination
of
TACE
activity
profiles.
Furthermore,
I
demonstrated
that
the
LPS-TACE
axis
was
reset
in
the
context
of
a
two-hit
LPS
model
and
in
sepsis.
I
found
evidence
of
differential
signalling
pathway
reprogramming
in
monocytes
taken
from
patients
with
infectious
and
non-infectious
SIRS.
Finally,
I
demonstrated
that
the
monocyte
TACE
response
to
LPS
is
dependent
on
cell
contact.
These
data
provide
new
insights
into
monocyte
inflammatory
function
during
the
immune
response
The Composition of Human Milk and Infant Faecal Microbiota Over the First Three Months of Life: A Pilot Study
peer-reviewedHuman milk contains a diverse array of bioactives and is also a source of bacteria for the developing infant gut. The aim of this study was to characterize the bacterial communities in human milk and infant faeces over the first 3 months of life, in 10 mother-infant pairs. The presence of viable Bifidobacterium and Lactobacillus in human milk was also evaluated. MiSeq sequencing revealed a large diversity of the human milk microbiota, identifying over 207 bacterial genera in milk samples. The phyla Proteobacteria and Firmicutes and the genera Pseudomonas, Staphylococcus and Streptococcus were the predominant bacterial groups. A core of 12 genera represented 81% of the microbiota relative abundance in milk samples at week 1, 3 and 6, decreasing to 73% at week 12. Genera shared between infant faeces and human milk samples accounted for 70–88% of the total relative abundance in infant faecal samples, supporting the hypothesis of vertical transfer of bacteria from milk to the infant gut. In addition, identical strains of Bifidobacterium breve and Lactobacillus plantarum were isolated from the milk and faeces of one mother-infant pair. Vertical transfer of bacteria via breastfeeding may contribute to the initial establishment of the microbiota in the developing infant intestine
Comparative Genomics and in vitro Infection of Field Clonal Isolates of Brucella melitensis Biovar 3 Did Not Identify Signature of Host Adaptation
Brucella spp. are responsible for brucellosis, a widespread zoonosis causing reproductive disorders in animals. Species-classification within this monophyletic genus is based on bacteriological and biochemical phenotyping. Traditionally, Brucella species are reported to have a preferential, but not exclusive mammalian host. However, this concept can be challenged since many Brucella species infect a wide range of animal species. Adaptation to a specific host can be a driver of pathogen variation. It is generally thought that Brucella species have highly stable and conserved genomes, however the degree of genomic variation during natural infection has not been documented. Here, we investigated potential genetic diversity and virulence of Brucella melitensis biovar 3 field isolates obtained from a single outbreak but from different host species (human, bovine, small ruminants). A unique MLVA-16 pattern suggested all isolates were clonal. Comparative genomic analyses showed an almost non-existent genetic diversity among isolates (only one SNP; no architectural rearrangements) and did not highlight any signature specific to host adaptation. Similarly, the strains showed identical capacities to enter and replicate in an in vitro model of macrophage infection. In our study, the absence of genomic variability and similar virulence underline that B. melitensis biovar 3 is a broad-host-range pathogen without the need to adapt to different hosts
Understanding the Patient Experience of Hunger and Improved Quality of Life with Setmelanotide Treatment in POMC and LEPR Deficiencies
Introduction In patients with pro-opiomelanocortin (POMC) or leptin receptor (LEPR) deficiency, managing obesity and hyperphagia can be burdensome for patients and caretakers. The impacts on health-related quality of life are under-recognized and are not well characterized. Methods We conducted in-depth qualitative interviews in patients with POMC (n = 3) and LEPR (n = 2) deficiencies participating in an ongoing open-label extension of phase 3 clinical trials with the melanocortin receptor 4 agonist setmelanotide to describe the patient experience of hyperphagia and characterize changes following treatment with setmelanotide. Results Prior to setmelanotide treatment, all five patients described abnormal sensations of hunger with none indicating feeling satiated after meals and also reported that the burden of hyperphagia impacted their families, emotions, and work and/or school functioning. Following setmelanotide treatment, all five patients reported consistent reductions in hunger and weight, decreased eating, and feeling satiated after meals in addition to substantial improvements in each area of functioning they had previously reported. All five patients indicated they were very satisfied with the impact of setmelanotide on their quality of life and would be upset if treatment was discontinued. Conclusions In patients with POMC or LEPR deficiency, hyperphagia and the inability to feel satiety negatively impacted quality of life. By reducing hunger and improving satiety, setmelanotide facilitated important changes in the lives of these patients. This qualitative research study suggests that the impact of setmelanotide goes beyond favorable clinical changes (e.g., weight and hunger) to also include quality of life improvements that are highly meaningful to patients
Potentiation of latent inhibition by haloperidol and clozapine is attenuated in Dopamine D2 receptor (Drd-2) deficient mice: Do antipsychotics influence learning to ignore irrelevant stimuli via both Drd-2 and non-Drd-2 mechanisms?
Whether the dopamine Drd-2 receptor is necessary for the behavioural action of antipsychotic drugs is an important question, as Drd-2 antagonism is responsible for their debilitating motor side effects. Using Drd-2 null mice (Drd2 -/-) it has previously been shown that Drd-2 is not necessary for antipsychotic drugs to reverse D-amphetamine disruption of latent inhibition (LI), a behavioural measure of learning to ignore irrelevant stimuli. Weiner's 'two-headed' model indicates that antipsychotics not only reverse LI disruption, 'disrupted LI', but also potentiate LI when low/absent in controls, 'persistent' LI. We investigated whether antipsychotic drugs haloperidol or clozapine potentiated LI in wild-type controls or Drd2 -/-. Both drugs potentiated LI in wild-type but not in Drd2 -/- mice, suggesting moderation of this effect of antipsychotics in the absence of Drd-2. Haloperidol potentiated LI similarly in both Drd1 -/- and wild-type mice, indicating no such moderation in Drd1 -/-. These data suggest that antipsychotic drugs can have either Drd-2 or non-Drd-2 effects on learning to ignore irrelevant stimuli, depending on how the abnormality is produced. Identification of the non-Drd-2 mechanism may help to identify novel non-Drd2 based therapeutic strategies for psychosis
Effect of Diet on the Vitamin B Profile of Bovine Milk-Based Protein Ingredients
peer-reviewedThe influence of diet on the water-soluble vitamin composition of skim milk powder and
whey protein ingredients produced from the milk of cows fed pasture or concentrate-based diets
was examined. Fifty-one Holstein-Friesian cows were randomly assigned into three diets (n = 17)
consisting of outdoor grazing of perennial ryegrass (GRS), perennial ryegrass/white clover (CLV),
or indoor feeding of total mixed ration (TMR) for an entire lactation. Raw mid-lactation milk from
each group was processed into skim milk powder and further processed to yield micellar casein whey
and acid whey. Sweet whey was also produced by renneting of pasteurised whole milk from each
system. The water-soluble vitamin profile of each sample was analysed using a combination of direct
injection mass spectrometry and reverse-phase liquid chromatography–mass spectrometry. Vitamin
B3 and B3-amide concentrations were significantly higher (p < 0.05) in TMR-derived samples than
in those from CLV and GRS, respectively. Vitamin B1, B2, and B7 concentrations were significantly
higher in GRS and CLV-derived samples than those from TMR. Significant differences in vitamins B1,
B2, and B3-amide were also observed between protein ingredient types. This study indicates that
bovine feeding systems have a significant effect on B vitamin composition across a range of protein
ingredient types
The drivers of Chinese CO2 emissions from 1980 to 2030
China's energy consumption doubled within the first 25 years of economic reforms initiated at the end of the 1970s, and doubled again in the past 5 years. It has resulted of a threefold CO2 emissions increase since early of 1980s. China's heavy reliance on coal will make it the largest emitter of CO2 in the world. By combining structural decomposition and input–output analysis we seek to assess the driving forces of China's CO2 emissions from 1980 to 2030. In our reference scenario, production-related CO2 emissions will increase another three times by 2030. Household consumption, capital investment and growth in exports will largely drive the increase in CO2 emissions. Efficiency gains will be partially offset the projected increases in consumption, but our scenarios show that this will not be sufficient if China's consumption patterns converge to current US levels. Relying on efficiency improvements alone will not stabilize China's future emissions. Our scenarios show that even extremely optimistic assumptions of widespread installation of carbon dioxide capture and storage will only slow the increase in CO2 emissions
Ex vivo assessment and in vivo validation of non-invasive stent monitoring techniques based on microwave spectrometry
Some conditions are well known to be directly associated with stent failure, including in-stent re-occlusion and stent fracture. Currently, identification of these high-risk conditions requires invasive and complex procedures. This study aims to assess microwave spectrometry (MWS) for monitoring stents non-invasively. Preliminary ex vivo data are presented to move to in vivo validation. Fifteen mice were assigned to receive subcutaneous stent implantations (n¿=¿10) or sham operations (n¿=¿5). MWS measurements were carried out at 0, 2, 4, 7, 14, 22, and 29 days of follow-up. Additionally, 5 stented animals were summited to micro-CT analyses at the same time points. At 29 days, 3 animals were included into a stent fracture subgroup and underwent a last MWS and micro-CT analysis. MWS was able to identify stent position and in-stent stenosis over time, also discerning significant differences from baseline measures (P¿<¿0.001). Moreover, MWS identified fractured vs. non-fractured stents in vivo. Taken together, MWS emerges as a non-invasive, non-ionizing alternative for stent monitoring. MWS analysis clearly distinguished between in-stent stenosis and stent fracture phenomena.Peer ReviewedPostprint (published version
Global phylogenomic diversity of Brucella abortus: spread of a dominant lineage
Brucella abortus is a globally important zoonotic pathogen largely found in cattle hosts and is typically transmitted to humans through contaminated dairy products or contact with diseased animals. Despite the long, shared history of cattle and humans, little is known about how trade in cattle has spread this pathogen throughout the world. Whole genome sequencing provides unparalleled resolution to investigate the global evolutionary history of a bacterium such as B. abortus by providing phylogenetic resolution that has been unobtainable using other methods. We report on large-scale genome sequencing and analysis of B. abortus collected globally from cattle and 16 other hosts from 52 countries. We used single nucleotide polymorphisms (SNPs) to identify genetic variation in 1,074 B. abortus genomes and using maximum parsimony generated a phylogeny that identified four major clades. Two of these clades, clade A (median date 972 CE; 95% HPD, 781–1142 CE) and clade B (median date 150 BCE; 95% HPD, 515 BCE–164 CE), were exceptionally diverse for this species and are exclusively of African origin where provenance is known. The third clade, clade C (median date 949 CE; 95% HPD, 766–1102 CE), had most isolates coming from a broad swath of the Middle East, Europe, and Asia, also had relatively high diversity. Finally, the fourth major clade, clade D (median date 1467 CE; 95% HPD, 1367–1553 CE) comprises the large majority of genomes in a dominant but relatively monomorphic group that predominantly infects cattle in Europe and the Americas. These data are consistent with an African origin for B. abortus and a subsequent spread to the Middle East, Europe, and Asia, probably through the movement of infected cattle. We hypothesize that European arrival to the Americas starting in the 15th century introduced B. abortus from Western Europe through the introduction of a few common cattle breeds infected with strains from clade D. These data provide the foundation of a comprehensive global phylogeny of this important zoonotic pathogen that should be an important resource in human and veterinary epidemiology
Molecular and functional correction of a deep intronic splicing mutation in CFTR by CRISPR-Cas9 gene editing
Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the CFTR gene. The 10th most common mutation, c.3178-2477C>T (3849+10kb C>T), involves a cryptic, intronic splice site. This mutation was corrected in CF primary cells homozygous for this mutation by delivering pairs of guide RNAs (gRNAs) with Cas9 protein in ribonucleoprotein (RNP) complexes that introduce double-strand breaks to flanking sites to excise the 3849+10kb C>T mutation, followed by DNA repair by the non-homologous end-joining pathway, which functions in all cells of the airway epithelium. RNP complexes were delivered to CF basal epithelial cell by a non-viral, receptor-targeted nanocomplex comprising a formulation of targeting peptides and lipids. Canonical CFTR mRNA splicing was, thus, restored leading to the restoration of CFTR protein expression with concomitant restoration of electrophysiological function in airway epithelial air-liquid interface cultures. Off-target editing was not detected by Sanger sequencing of in silico-selected genomic sites with the highest sequence similarities to the gRNAs, although more sensitive unbiased whole genome sequencing methods would be required for possible translational developments. This approach could potentially be used to correct aberrant splicing signals in several other CF mutations and other genetic disorders where deep-intronic mutations are pathogenic
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