Publications by authors named "P S Yau"

166 Publications

Aortic Neck Dilatation Following Thoracic Endovascular Aortic Repair.

Ann Vasc Surg 2021 May 15. Epub 2021 May 15.

Division of Vascular and Endovascular Surgery, Montefiore Medical Center and The Albert Einstein College of Medicine, Bronx, NY. Electronic address:

Objective: Thoracic endovascular aortic repair (TEVAR) has become a mainstay of treatment for a variety of thoracic aortic pathologies. Expansion of the proximal aortic neck after endovascular repair of abdominal aortic aneurysms has been demonstrated; however, dilatation of the proximal aortic neck after TEVAR has not been well described. We sought to describe remodeling of the proximal neck following TEVAR.

Methods: This is a retrospective, single institution review of patients who underwent TEVAR for thoracic aortic aneurysm (TAA) and dissection with aneurysmal degeneration from 2010-2019. Postoperative computed tomography (CT) scans were reviewed and aortic diameter was measured in orthogonal planes using 3-dimensional centerline reconstruction software. The primary outcome was change in aortic diameter at the proximal aortic neck as compared to the initial postoperative CT scan. Clinical and operative data were analyzed to identify factors associated with significant neck dilatation.

Results: Of 87 patients who underwent TEVAR during the study period, 30 met inclusion criteria. Median follow up was 20.5 months. Median age was 67 years, and 15 patients (50%) were female. The proximal aortic neck experienced an overall increase over time in aortic diameter. Five mm distal to the graft showed the greatest rate of expansion, with a median increase of 1.3 mm, 2.9 mm, and 6.2 mm at one year, two years, and three years, respectively. When comparing patients who had mean expansion at this location of >2.0 mm/year to patients who did not, a higher percentage had dissection pathology (81.8% vs. 31.6%, p=0.008), had graft placement at aortic landing zone 2 (36.4% vs. 5.3%, p=0.028), and were smokers (100% vs. 52.6%, p=0.006). Higher percent oversizing was shown to be associated with significant aortic neck dilatation for true aneurysms only.

Conclusions: Aortic neck dilatation (AND) occurs over time for the majority of patients following TEVAR with the distal neck experiencing the highest rate of expansion. Dissection pathology, aortic landing zone 2, and smoking were found to be associated with a higher rate of neck dilatation.
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http://dx.doi.org/10.1016/j.avsg.2021.05.001DOI Listing
May 2021

Comparing respiratory polygraphy with pulse transit time analysis versus overnight polysomnography in the diagnosis of obstructive sleep apnoea in children.

Sleep Med 2021 May 1;81:457-462. Epub 2021 Mar 1.

FHKAM(Otolaryngology), Department of Otolaryngology, Tuen Mun Hospital, Hong Kong.

Objective: Obstructive sleep apnea syndrome in children is associated with significant morbidity. Polysomnography is the main diagnostic tool but is time consuming and requires skilled manpower to supervise the patient overnight and hence long referral to diagnosis time. However, there are limitations and underestimation of the apnoea hyponea index (AHI) with alternative home sleep apnoea testing (HSAT), such as type 3 respiratory polygraphy (RP). Prior studies have demonstrated pulse transit time (PTT) to be a reliable indicator of cortical arousals. In this study, the use of PTT together with RP will be studied to determine whether the derived AHI is comparable to that of PSG.

Method: Forty-five patients with suspected OSA met the inclusion criteria underwent PSG in the sleep laboratory for analysis. The raw data for either PSG or RP analysis were allocated separately to two different accredited sleep technicians. The primary outcome AHI derived from PTT with RP was compared to the AHI derived from PSG. Secondary outcomes compared were obstructive apnoea index (OAI), total hypopnoea index (THI) and arousal index (AI). Bland Altman analysis was used to compare the agreement of AHI derived from the 2 modalities and demonstrate whether RP is non inferior or equivalent to the gold standard for diagnosing OSAS.

Results: The patients studied had a median age of 8.8 years (range 3-17 years). The patients were not limited to certain spectrum of severity OSA and had AHI results spread from mild to severe OSA (AHI 0.4/hr to 72.2/hr). The RP with PTT-derived AHI was strongly correlated to the PSG derived AHI as seen on the Spearman plot (r = 0.98). The Bland Altman plot showed no evidence of underestimation of the AHI due to missed arousal related hypopneas. The difference of AHI derived from RP and PSG results were clinically insignificant. The differences between the PSG and RP total hypopnoea index (THI) and arousal index (AI) were also statistically insignificant.

Conclusion: The study shows that RP with PTT can be considered a reliable diagnostic alternative compared with PSG. The role of PTT incorporated with RP was to minimize underestimation of AHI due to missed arousal associated hypopnea events. The results were apparent across mild to severe severity of OSA. There are advantages of RPs particularly in paediatrics. Overall this study offers promising preliminary insights that RP incorporated with PTT can be further explored as an acceptable home diagnostic tool for diagnosing OSA in children.
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http://dx.doi.org/10.1016/j.sleep.2021.02.048DOI Listing
May 2021

Compliance with Standard Precautions and Its Relationship with Views on Infection Control and Prevention Policy among Healthcare Workers during COVID-19 Pandemic.

Int J Environ Res Public Health 2021 03 25;18(7). Epub 2021 Mar 25.

JC School of Public Health and Primary Care, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.

: Standard precautions prevent the spread of infections in healthcare settings. Incompliance with infection control guidelines of healthcare workers (HCWs) may increase their risk of exposure to infectious disease, especially under pandemics. The purpose of this study was to assess the level of compliance with the infection prevention and control practices among HCWs in different healthcare settings and its relationship with their views on workplace infection control measures during the COVID-19 pandemic. : Nurses in Hong Kong were invited to respond to a cross-sectional online survey, in which their views on workplace infection and prevention policy, compliance with standard precautions and self-reported health during pandemics were collected. : The respondents were dissatisfied with workplace infection and prevention policy in terms of comprehensiveness (62%), clarity (64%), timeliness (63%), and transparency (60%). For the protective behavior, the respondents did not fully comply with the standard precautions when they were involved in medical care. Their compliance was relatively low when having proper patient handling (54%) and performing invasive procedures (46%). A multivariate analysis model proved that the level of compliance of the standard precautions was positively associated with the satisfaction on infection control and prevention policy among high risk group (0.020; 95% CI: 0.005-0.036), while older respondents had higher level of compliance among the inpatient and outpatient groups (coefficient range: 0.065-0.076). The higher level of compliance was also significantly associated with working in designated team and having chronic condition of the respondents among high-risk and inpatient groups. : Standard precautions are the most important elements to reduce cross-transmission among HCWs and patients while the satisfaction on infection control and prevention policy would increase the compliance among the high-risk group. An overall suboptimal compliance and poor views on the infection prevention and control guidelines is a warning signal to healthcare system especially during pandemics.
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http://dx.doi.org/10.3390/ijerph18073420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8038100PMC
March 2021

Fate of Macrolide Antibiotics with Different Wastewater Treatment Technologies.

Water Air Soil Pollut 2021 28;232(3):103. Epub 2021 Feb 28.

Faculty of Design and Environment, Technological and Higher Education Institute of Hong Kong, Hong Kong, China.

This comprehensive study addressed the occurrence, seasonal changes, removal efficiencies, and environmental risk assessments of three macrolide antibiotics in five wastewater treatment plants (WWTPs) with conventional and different additional treatment processes. A 1-year monitoring study was conducted, and influents and effluents were collected from Guangzhou (GZ), Shenzhen (SZ), Tai Po (TP), Shatin (ST), and Stonecutters Island (SI) WWTPs. Solid phase extraction and HPLC-MS/MS were used for the pretreatment and determination. The detection limits for azithromycin (AZI), erythromycin (ERY), and roxithromycin (ROX) ranged from 0.80 to 2.13 ng/L for the influent and effluent water samples. AZI was the most abundant antibiotic found in the influents, with average concentrations ranging from 571 ng/L to 1046 ng/L at all the target WWTPs. The seasonal average AZI concentration was the highest in all five WWTPs with the concentration of 984 ng/L in autumn, 849 ng/L in winter, 741 ng/L in summer, and 533 ng/L in spring. The seasonal AZI removal rates in the WWTPs were similar, with an average removal rate above 63.3% from spring to winter. All the treatments in the five WWTPs showed removal abilities for AZI, ERY, and ROX, regardless of the three phase treatments, namely, the UV disinfection process and conventional or chemically enhanced process within the WWTPs. For ERY and ROX, the average total removal rates were significantly decreased in the spring among all five WWTPs, at 53.1% and 57.8%, respectively. The GZ and SZ WWTPs displayed better removal rates than the TP, ST, and SI WWTPs, because the activity underlying the modified A2/O process in the GZ and SZ WWTPs has important effects on the antibiotic removal because the bacteria could produce compact granules and make the antibiotics settle faster in the wastewater. The additional UV disinfection in the SZ WWTP improved the removal efficiencies of the target antibiotics; it enhanced the biodegradability of residual organic pollutants in the WWTP effluent. Moreover, the corresponding environmental risks have been assessed and are viewed as a necessary component of future research.

Supplementary Information: The online version contains supplementary material available at 10.1007/s11270-021-05053-y.
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http://dx.doi.org/10.1007/s11270-021-05053-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7914119PMC
February 2021

Proteome Composition of Bovine Amniotic Membrane and Its Potential Role in Corneal Healing.

Invest Ophthalmol Vis Sci 2021 Feb;62(2):11

Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, Illinois, United States.

Purpose: To investigate the protein profile of bovine amniotic membranes (bAM) and to determine putative associations between protein composition in bAM and known corneal healing pathways.

Methods: The bAM were acquired from normal full-term births (n = 10), processed, and stored at -80°C for two days. Subsequently, the frozen membranes were thawed at room temperature and prepared for proteomic exploration using high-resolution liquid chromatography-mass spectrometry, followed by bioinformatics analysis. Recently identified corneal healing pathways were contrasted with protein profiles and pathways present in bAM.

Results: The analyses identified 2105 proteins, with an interactive network of 1271 nodes (proteins) and 8757 edges (interactions). The proteins with higher betweenness centrality measurements include microfibril-associated protein 4, HSD3B1, CAPNS1, ATP1B3, CAV1, ANXA2, YARS, and GAPDH. The top four pathways in Kyoto Encyclopedia of Genes and Genomes were ribosome, metabolic pathway, spliceosome, and oxidative phosphorylation. The bAM and cornea shared abundant proteins, genome ontology, and signaling pathways.

Conclusions: The high-throughput proteomic profile of the bAM demonstrated that numerous proteins present in the cornea are also present in this fetal membrane. Our findings collectively demonstrate the similarity between bAM and the cornea's protein composition, supporting our hypothesis that bAM can be used to treat corneal diseases.
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http://dx.doi.org/10.1167/iovs.62.2.11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7873491PMC
February 2021