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"Cheung, D"
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Polytobacco product use among current cigarette smokers in Hong Kong, China: results from population surveys (2015–17)
2021
Background
Polytobacco product use is increasingly popular, but little is known about the prevalence, trend, and factors of such use particularly in non-western countries.
Method
A representative sample of 1139 current cigarette smokers aged 15+ (84.1% male) were telephone interviewed in Tobacco Control Policy-related Surveys in 2015–2017. Information collected included poly-tobacco use (PTU), smoking and socio-demographic characteristics. Associations of current PTU with related factors were analyzed using logistic regression with adjustment for confounders. Prevalence was weighted by age and sex of current cigarette users in the general population.
Results
Eighty-four point one percent (95% CI 81.4–86.6%) were exclusive cigarette smokers. Fifteen point nine percent (13.4–18.6%) were current polytobacco product users, 12.3% (10.2–14.8%) used one tobacco product and 2.52% (1.59–3.97%) used two tobacco products in addition to cigarette. Cigarette use with cigar was more common (6.28%, 4.75–8.27%), and the least used product with cigarette was e-cigarette (1.05%, 0.44–2.50%). The changes in overall prevalence of PTU by number of products use varied in 3 years. Current PTU was associated with being male (AOR 2.01, 95% CI 1.12–3.61), younger age (AORs range from 1.34–4.65,
P
for trend < .001) and less ready to quit (2.08, 1.09–3.97).
Conclusions
Prevalence of PTU increased slowly by year, one tobacco product use with cigarette was more common. The most used tobacco product with cigarette was cigar. Being male, younger and less ready to quit were associated with current PTU.
Journal Article
Spatiotemporal immune atlas of a clinical-grade gene-edited pig-to-human kidney xenotransplant
2024
Pig-to-human xenotransplantation is rapidly approaching the clinical arena; however, it is unclear which immunomodulatory regimens will effectively control human immune responses to pig xenografts. Here, we transplant a gene-edited pig kidney into a brain-dead human recipient on pharmacologic immunosuppression and study the human immune response to the xenograft using spatial transcriptomics and single-cell RNA sequencing. Human immune cells are uncommon in the porcine kidney cortex early after xenotransplantation and consist of primarily myeloid cells. Both the porcine resident macrophages and human infiltrating macrophages express genes consistent with an alternatively activated, anti-inflammatory phenotype. No significant infiltration of human B or T cells into the porcine kidney xenograft is detectable. Altogether, these findings provide proof of concept that conventional pharmacologic immunosuppression may be able to restrict infiltration of human immune cells into the xenograft early after compatible pig-to-human kidney xenotransplantation.
Xenotransplantation in humans using pig organs could improve the transplant organ supply. Here the authors transplant pig kidneys into a brain-dead recipient and monitor the human immune cell response early after transplantation using spatial and single cell transcriptomics and show early myeloid cell infiltration.
Journal Article
Resident macrophage subpopulations occupy distinct microenvironments in the kidney
by
Cheung, Matthew D.
,
Lever, Jeremie M.P.
,
Li, Zhang
in
Acute Kidney Injury - metabolism
,
Approximation
,
Bone marrow
2022
The kidney contains a population of resident macrophages from birth that expands as it grows and forms a contiguous network throughout the tissue. Kidney-resident macrophages (KRMs) are important in homeostasis and the response to acute kidney injury. While the kidney contains many microenvironments, it is unknown whether KRMs are a heterogeneous population differentiated by function and location. We combined single-cell RNA-Seq (scRNA-Seq), spatial transcriptomics, flow cytometry, and immunofluorescence imaging to localize, characterize, and validate KRM populations during quiescence and following 19 minutes of bilateral ischemic kidney injury. scRNA-Seq and spatial transcriptomics revealed 7 distinct KRM subpopulations, which are organized into zones corresponding to regions of the nephron. Each subpopulation was identifiable by a unique transcriptomic signature, suggesting distinct functions. Specific protein markers were identified for 2 clusters, allowing analysis by flow cytometry or immunofluorescence imaging. Following injury, the original localization of each subpopulation was lost, either from changing locations or transcriptomic signatures. The original spatial distribution of KRMs was not fully restored for at least 28 days after injury. The change in KRM localization confirmed a long-hypothesized dysregulation of the local immune system following acute injury and may explain the increased risk for chronic kidney disease.
Journal Article
Mask ventilation with two different face masks in the delivery room for preterm infants: a randomized controlled trial
2015
Background:
If an infant fails to initiate spontaneous breathing after birth, international guidelines recommend a positive pressure ventilation (PPV). However, PPV by face mask is frequently inadequate because of leak between the face and mask. Despite a variety of available face masks, none have been prospectively compared in a randomized fashion. We aimed to evaluate and compare leak between two commercially available round face masks (Fisher & Paykel (F&P) and Laerdal) in preterm infants <33 weeks gestational age in the delivery room.
Methods:
Infants born at the Royal Alexandra Hospital from April to September 2013 at <33 weeks gestational age who received mask PPV in the delivery room routinely had a flow sensor placed between the mask and T-piece resuscitator. Infants were randomly assigned to receive PPV with either a F&P or Laerdal face mask. All resuscitators were trained in the use of both face masks. We compared mask leak, airway pressures, tidal volume and ventilation rate between the two groups.
Results:
Fifty-six preterm infants (
n
=28 in each group) were enrolled; mean±s.d. gestational age 28±3 weeks; birth weight 1210±448 g; and 30 (52%) were male. Apgar scores at 1 and 5 min were 5±3 and 7±2, respectively. Infants randomized to the F&P face mask and Laerdal face mask had similar mask leak (30 (25–38) versus 35 (24–46)%, median (interquartile range), respectively,
P
=0.40) and tidal volume (7.1 (4.9–8.9) versus 6.6 (5.2–8.9) ml kg
−1
,
P
=0.69) during PPV. There were no significant differences in ventilation rate, inflation time or airway pressures between groups.
Conclusion:
The use of either face mask during PPV in the delivery room yields similar mask leak in preterm infants <33 weeks gestational age.
Journal Article
An 80-million-year sulphur isotope record of pyrite burial over the Permian–Triassic
by
Salisbury, Jack
,
Ruffell, Alastair
,
Cheung, H. D. R. Ashleigh
in
704/2151/209
,
704/2151/213
,
704/2151/3930
2022
Despite the extensive use of sulphur isotope ratios (δ
34
S) for understanding ancient biogeochemical cycles, many studies focus on specific time-points of interest, such as the end-Permian mass extinction (EPME). We have generated an 80 million-year Permian–Triassic δ
34
S
evap
curve from the Staithes S-20 borehole, Yorkshire, England. The Staithes δ
34
S
evap
record replicates the major features of the global curve, while confirming a new excursion at the Olenekian/Anisian boundary at ~ 247 million years ago. We incorporate the resultant δ
34
S
evap
curve into a sulphur isotope box model. Our modelling approach reveals three significant pyrite burial events (i.e. PBEs) in the Triassic. In particular, it predicts a significant biogeochemical response across the EPME, resulting in a substantial increase in pyrite burial, possibly driven by Siberian Traps volcanism. Our model suggests that after ~ 10 million years pyrite burial achieves relative long-term stability until the latest Triassic.
Journal Article
Selective transduction and photoinhibition of pre-Bötzinger complex neurons that project to the facial nucleus in rats affects nasofacial activity
2023
The pre-Bötzinger complex (preBötC), a key primary generator of the inspiratory breathing rhythm, contains neurons that project directly to facial nucleus (7n) motoneurons to coordinate orofacial and nasofacial activity. To further understand the identity of 7n-projecting preBötC neurons, we used a combination of optogenetic viral transgenic approaches to demonstrate that selective photoinhibition of these neurons affects mystacial pad activity, with minimal effects on breathing. These effects are altered by the type of anesthetic employed and also between anesthetized and conscious states. The population of 7n-projecting preBötC neurons we transduced consisted of both excitatory and inhibitory neurons that also send collaterals to multiple brainstem nuclei involved with the regulation of autonomic activity. We show that modulation of subgroups of preBötC neurons, based on their axonal projections, is a useful strategy to improve our understanding of the mechanisms that coordinate and integrate breathing with different motor and physiological behaviors. This is of fundamental importance, given that abnormal respiratory modulation of autonomic activity and orofacial behaviors have been associated with the development and progression of diseases. While breathing seems to come easy, it is a complex process in which many muscles coordinate to allow air to flow into the lungs. These muscles also control the flow of air we breathe out to allow us to talk, sing, eat, or drink. The brain circuits that control these muscles, can also influence other parts of the brain. The preBötzinger Complex, which is a key region of brainstem circuits that generate and control breathing, contains neurons that also project widely, connecting to other regions of the brain. This helps to modulate the sense of smell, emotional state, heart rate, and even blood pressure. Understanding how the preBötzinger Complex is organized can untangle how breathing can influence these other processes. Melo et al. wanted to learn whether they could manipulate the activity of a subgroup of preBötzinger Complex neurons that project into the facial nucleus – a region of the brain that controls the muscles of the face when we breathe – without affecting breathing. If this can be done, it might also be possible to affect blood pressure by manipulating selective preBötzinger neurons, and thus the development of hypertension, without having any impact on breathing. To test this hypothesis, Melo et al. used rats in which the activation of preBötzinger Complex neurons that project into the facial nucleus was blocked. This decreased the activity of the muscles around the nose with hardly any effect on breathing. Melo et al. also found that the state of consciousness of the rat (anesthetized or conscious) could affect how preBötzinger Complex neurons control these muscles. Melo et al. also observed that preBötzinger Complex neurons projecting into the facial nucleus had projections into many other regions in the brainstem. This might help to the coordinate respiratory, cardiovascular, orofacial, and potentially other physiological functions. The findings of Melo et al. set a technical foundation for exploring the influence of specific subgroups of preBötzinger Complex neurons on respiratory modulation of other physiological activities, including blood pressure and heart rate and in conditions, such as hypertension and heart failure. More broadly, most brain regions contain complex and heterogeneous groups of neurons and the strategy validated by Melo et. al. could be applied to unravel other brain-function relationships.
Journal Article
Genetic control of single lumen formation in the zebrafish gut
by
Mostov, Keith E.
,
Bagnat, Michel
,
Cheung, Isla D.
in
Animals
,
Animals, Genetically Modified
,
Biomedical and Life Sciences
2007
Most organs consist of networks of interconnected tubes that serve as conduits to transport fluid and cells and act as physiological barriers between compartments. Biological tubes are assembled through very diverse developmental processes that generate structures of different shapes and sizes. Nevertheless, all biological tubes invariably possess one single lumen. The mechanisms responsible for single lumen specification are not known. Here we show that zebrafish mutants for the MODY5 and familial GCKD gene
tcf2
(also known as
vhnf1
) fail to specify a single lumen in their gut tube and instead develop multiple lumens. We show that Tcf2 controls single lumen formation by regulating
claudin15
and Na
+
/K
+
-ATPase expression. Our
in vivo
and
in vitro
results indicate that Claudin15 functions in paracellular ion transport to specify single lumen formation. This work shows that single lumen formation is genetically controlled and appears to be driven by the accumulation of fluid.
Journal Article