Diagnostic accuracy of a prehospital electrocardiogram rule-based algorithm for ST-elevation myocardial infarction: results from a population-wide project.

INTRODUCTION: This study reviewed the diagnostic accuracy of the prehospital electrocardiogram (PHECG) rule-based algorithm for ST-elevation myocardial infarction (STEMI) universally utilised in Hong Kong. METHODS: This prospective observational study was linked to a population-wide project. We analysed 2210 PHECGs performed on patients who presented to the emergency medical service (EMS) with chest pain from 1 October to 31 December 2021. The diagnostic accuracy of the adopted rulebased algorithm, the Hannover Electrocardiogram System, was evaluated using the adjudicated blinded rating by two investigators as the primary reference standard. Diagnostic accuracy was also evaluated using the attending emergency physician's diagnosis and the diagnosis on hospital discharge as secondary reference standards. RESULTS: The prevalence of STEMI was 5.1% (95% confidence interval [CI]=4.2%-6.1%). Using the adjudicated blinded rating by investigators as the reference standard, the rule-based PHECG algorithm had a sensitivity of 94.6% (95% CI=88.2%-97.8%), specificity of 87.9% (95% CI=86.4%-89.2%), positive predictive value of 29.4% (95% CI=24.8%-34.4%), and negative predictive value of 99.7% (95% CI=99.3%-99.9%) [all P<0.05]. CONCLUSION: The rule-based PHECG algorithm that is widely used in Hong Kong demonstrated high sensitivity and fair specificity for the diagnosis of STEMI.

Mindfulness Meditation, Mental Health, and Health-Related Quality of Life in Chinese Buddhist Monastics.

OBJECTIVE: To determine associations between mindfulness meditation and mental health and health-related quality of life among Buddhist monastics. METHODS: This is a cross-sectional study of Chinese Buddhist monastics aged ≥18 years who practised mindfulness meditation daily. Mental health was assessed by the 12-item General Health Questionnaire (GHQ-12), whereas health-related quality of life was assessed by the 12-item Short Form Health Survey (SF-12). The number of years and the average daily amount of time spent in mindfulness meditation were collected. RESULTS: 47 monastics completed the interview. They practised mindfulness meditation for a mean of 7.3 years, 1.1 hours per day. Both the number of years (ß = -0.48, p = 0.03) and amount of daily practice (ß = -0.53, p < 0.001) of mindfulness meditation were associated with the GHQ-12 score, after adjusting for age, sex, education, and years of being a monastic. Only the amount of daily practice (ß = 0.44, p = 0.004) was associated with the mental component summary of SF-12. Neither was associated with the physical component summary of SF-12. CONCLUSIONS: Among Chinese Buddhist monastics who practise daily mindfulness meditation, spending more time each day and having longer years of practice were associated with better mental health.

Prehospital electrocardiogram shortens ischaemic time in patients with ST-segment elevation myocardial infarction.

INTRODUCTION: Total ischaemic time should be shortened as much as possible in patients with ST-segment elevation myocardial infarction (STEMI). This study evaluated whether prehospital 12-lead electrocardiogram (ECG) could shorten system delay in STEMI management. METHODS: From November 2015 to November 2017, 15 ambulances equipped with X Series Monitor/ Defibrillator (Zoll Medical Corporation) were used in the catchment area of Queen Mary Hospital, Hong Kong. Prehospital ECG was performed for patients with chest pain; the data were tele-transmitted to attending emergency physicians at the Accident and Emergency Department (AED) for rapid assessment. Data from patients with STEMI who were transported by these 15 ambulances were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or who used self-arranged transport. RESULTS: Data were analysed from 197 patients with STEMI. The median patient delay for activation of the emergency response system was 90 minutes; 12% of patients experienced a delay of >12 hours. There was a significant difference in delay between patients transported by ambulance and those who used self-arranged transport (P<0.001). For system delay, the use of prehospital ECG shortened the median time from ambulance on scene to first ECG (P<0.001). When performed upon ambulance on scene, prehospital ECG was available 5 minutes earlier than if performed in ambulance compartment before departure. Use of prehospital ECG significantly shortened AED door-to-triage time, AED door-to-first AED ECG time, AED door-to-physician consultation time, and length of stay in the AED (P<0.001 for all comparisons). CONCLUSION: Prehospital ECG shortened ischaemic time prior to hospital admission.

Prehospital 12-lead electrocardiogram for patients with chest pain: a pilot study.

INTRODUCTION: After ST-segment elevation myocardial infarction (STEMI), it is vital to shorten reperfusion time. This study examined data from a pilot project to shorten the door-to-balloon (D2B) time by using prehospital 12-lead electrocardiogram (ECG). METHODS: Fifteen ambulances equipped with X Series® Monitor/Defibrillator (Zoll Medical Corporation) were deployed to the catchment area of Queen Mary Hospital, Hong Kong, from November 2015 to December 2016. For patients with chest pain, prehospital 12-lead ECG was performed and tele-transmitted to attending physicians at the accident and emergency department for immediate interpretation. The on-call cardiologist was called before patient arrival if STEMI was suspected. Data from this group of patients with STEMI were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or by self-arranged transport. RESULTS: From 841 patients with chest pain, 731 gave verbal consent and prehospital ECG was performed and transmitted. Of these, 25 patients with clinically diagnosed STEMI required emergency coronary angiogram with or without primary percutaneous coronary intervention. The mean D2B time for these 25 patients (93 minutes) was significantly shorter (P=0.003) than that for 58 patients with STEMI transported by ambulances without prehospital ECG (112 minutes) and that for 41 patients with STEMI with self-arranged transport (138 minutes). However, shorter reperfusion time was only recorded during daytime hours (08:00-17:59). No statistically significant difference in 30-day mortality was found. CONCLUSION: Prehospital ECG is technologically feasible in Hong Kong and shortens the D2B time. However, shorter reperfusion time was only recorded during daytime hours.

Disinfection byproduct precursor dynamics and water treatability during an extreme flooding event in a coastal blackwater river in southeastern United States.

Coastal blackwater rivers, characterized by high concentrations of natural organic matter, are source water for millions of people in the southeastern US. In October 2015, large areas of coastal South Carolina were flooded by Hurricane Joaquin. This so-called "thousand-year" rainfall mobilized and flushed large amounts of terrestrial organic matter and associated pollutants (e.g. mercury) into source water, affecting water quality and safety of municipal water supply. To understand the dynamics of water quality and water treatability during this extreme flood, water samples were collected from Waccamaw River (a typical blackwater river in the southeastern US) during rising limb, peak discharge, falling limb, and base flow. Despite decreasing water flow after peak discharge, dissolved organic carbon (DOC) levels (increased by up to 125%), and formation potentials of trihalomethanes and haloacetic acids (increased by up to 150%) remained high for an extended period of time (>eight weeks after peak discharge), while variation in the N-nitrosodimethylamine (NDMA) FP was negligible. Coagulation with alum and ferric at optimal dosage significantly reduced concentrations of DOC by 51-76%, but up to 10 mg/L of DOC still remained in treated waters. For an extended period of time, elevated levels of THMs (71-448 µg/L) and HAAs (88-406 µg/L) were quantified in laboratory chlorination experiments under uniform formation conditions (UFC), exceeding the United States Environmental Protection Agency's (USEPA) maximum contaminant level of 80 and 60 µg/L, respectively. Results demonstrated that populations in coastal cities are at high risk with disinfection by-products (DBPs) under the changing climate.

Monitoring and assessment of heavy metal contamination in a constructed wetland in Shaoguan (Guangdong Province, China): bioaccumulation of Pb, Zn, Cu and Cd in aquatic and terrestrial components.

The objective of this study is to evaluate the current status of heavy metal concentrations in constructed wetland, Shaoguan (Guangdong, China). Sediments, three wetland plants (Typha latifolia, Phragmites australis, and Cyperus malaccensis), and six freshwater fish species [Carassius auratus (Goldfish), Cirrhinus molitorella (Mud carp), Ctenopharyngodon idellus (Grass carp), Cyprinus carpio (Wild common carp), Nicholsicypris normalis (Mandarin fish), Sarcocheilichthys kiangsiensis (Minnows)] in a constructed wetland in Shaoguan were collected and analyzed for their heavy metal compositions. Levels of Pb, Zn, Cu, and Cd in sediments exceeded approximately 532, 285, 11, and 66 times of the Dutch Intervention value. From the current study, the concentrations of Pb and Zn in three plants were generally high, especially in root tissues. For fish, concentrations of all studied metals in whole body of N. mormalis were the highest among all the fishes investigated (Pb 113.4 mg/kg, dw; Zn 183.1 mg/kg, dw; Cu 19.41 mg/kg, dw; 0.846 mg/kg, dw). Heavy metal accumulation in different ecological compartments was analyzed by principle component analysis (PCA), and there is one majority of grouped heavy metals concentration as similar in composition of ecological compartment, with the Cd concentration quite dissimilar. In relation to future prospect, phytoremediation technology for enhanced heavy metal accumulation by constructed wetland is still in early stage and needs more attention in gene manipulation area.

Risk factors for hospital readmission for COPD after implementation of the GOLD guidelines.

BACKGROUND: Few updated studies have investigated risk factors for readmission for chronic obstructive pulmonary disease (COPD) since the implementation of the latest treatment guidelines. OBJECTIVE: To evaluate a series of potential risk factors for readmission in patients with COPD and in a subgroup with very frequent readmissions after implementation of the Global Initiative for Chronic Obstructive Lung Disease guidelines. DESIGN: Two hundred and fifty patients admitted for acute exacerbation of COPD (AECOPD) were recruited over 1 year. The readmission frequency in the ensuing year following hospital discharge was recorded and analysed against potential risk factors collected during the index admission. RESULTS: In the ensuing year, 183 (73.2%) patients were readmitted at least once for AECOPD. Previous non-invasive ventilation for AECOPD (HR 1.56, 95%CI 1.08-2.26), COPD Assessment Test score (HR 1.03, 95%CI 1.00-1.05), 6-minute walk distance (HR 0.98 per 10 m increase, 95%CI 0.97-0.99) and number of admissions for AECOPD in the previous year (HR 1.11, 95%CI 1.06-1.16) were independently associated with time to first readmission. Subgroup analysis showed that anxiety (OR 3.97, 95%CI 1.49-10.57) was strongly associated with very frequent readmissions (⩾4 in 1 year). CONCLUSIONS: AECOPD is associated with high rates of readmission. Anxiety is a potential modifiable factor associated with very frequent readmissions.

Thermodynamic approach to boron nitride nanotube solubility and dispersion.

Inadequate dispersion of nanomaterials is a critical issue that significantly limits the potential properties of nanocomposites and when overcome, will enable further enhancement of material properties. The most common methods used to improve dispersion include surface functionalization, surfactants, polymer wrapping, and sonication. Although these approaches have proven effective, they often achieve dispersion by altering the surface or structure of the nanomaterial and ultimately, their intrinsic properties. Co-solvents are commonly utilized in the polymer, paint, and art conservation industries to selectively dissolve materials. These co-solvents are utilized based on thermodynamic interaction parameters and are chosen so that the original materials are not affected. The same concept was applied to enhance the dispersion of boron nitride nanotubes (BNNTs) to facilitate the fabrication of BNNT nanocomposites. Of the solvents tested, dimethylacetamide (DMAc) exhibited the most stable, uniform dispersion of BNNTs, followed by N,N-dimethylformamide (DMF), acetone, and N-methyl-2-pyrrolidone (NMP). Utilizing the known Hansen solubility parameters of these solvents in comparison to the BNNT dispersion state, a region of good solubility was proposed. This solubility region was used to identify co-solvent systems that led to improved BNNT dispersion in poor solvents such as toluene, hexane, and ethanol. Incorporating the data from the co-solvent studies further refined the proposed solubility region. From this region, the Hansen solubility parameters for BNNTs are thought to lie at the midpoint of the solubility sphere: 16.8, 10.7, and 9.0 MPa(1/2) for δd, δp, and δh, respectively, with a calculated Hildebrand parameter of 21.8 MPa(1/2).

Two cases of severe intoxication associated with analytically confirmed use of the novel psychoactive substances 25B-NBOMe and 25C-NBOMe.

CONTEXT: A new group of novel psychoactive substance, the N-methoxybenzyl (NBOMe) derivatives of substituted phenethylamine, has recently emerged on the drug market, among which 25I-NBOMe and 25B-NBOMe have previously been implicated in clinical intoxications and fatalities. We report two cases of acute intoxication associated with these substances. CASE DETAILS: Two male patients (17 and 31 years of age) had ingested drugs labelled as 'NBOMe' or 'Holland film' and developed confusion, agitation, hypertension, tachycardia, hyperthermia, sweating and dilated pupils. Other features included convulsion, rhabdomyolysis and deranged liver function. The patients required benzodiazepines and other drugs for the control of symptoms. Urine samples from both patients were analysed using liquid-chromatography tandem mass spectrometry (LC-MS/MS) following glucuronidase digestion and solid-phase extraction. Identification was based upon comparison of the retention time and enhanced product ion scan with reference standards. In both urine samples, 25B-NBOMe was detected. Additionally, 25C-NBOMe was identified in one of the urine samples. DISCUSSION: The NBOMe compounds are highly potent 5HT2A receptor agonists and are also agonists at alpha-adrenergic receptors, which likely account for their serotonergic and sympathomimetic symptoms. The clinical testing of NBOMe drugs is not commonly available. Clinicians as well as laboratory staff play an important role in facilitating the detection of this group of potentially dangerous emerging drugs.

Optimisation of synthetic vector systems for cancer gene therapy - the role of the excess of cationic dendrimer under physiological conditions.

We have previously demonstrated in a therapeutic study that a single systemic course of DAB-Am16 dendriplexes loaded with plasmid expressing TNFα over a period of time of 10 days led to a regression of 100% of tumours and to long term cures of up to 80% of animals. However, the formulation had a relatively low colloidal stability requiring administration soon after nanoparticle preparation. Similar to other cationic polyplex and dendrimer DNA delivery systems, DAB-AM16 dendrimer formulations contained a substantial proportion of free polymer; this free polymer is present independently of the specific polymer:DNA ratio and increases with increasing proportion of polymer (N:P charge ratio) in the formulation. It has previously been shown for this and other systems that the excess of polymer plays a role in promoting the transfection efficiency of synthetic vectors. This has been linked to effects of the polymer on the efficiency of intracellular processing, e.g. endosomal release. However, the free polymer may have additional effects that are relevant to the efficiency of the formulation. This study therefore considered the effect of free dendrimer on the colloidal stability of the complexes, the interaction of the complex with the formulation medium, and with biological components, i.e. electrolytes and serum proteins after administration. Analysis of the total potential of interaction shows that, even at high N:P ratios, the excess of free dendrimer in the medium is not enough to induce the aggregation of the formulation due to depletion forces. This finding is unusual and can be attributed to the particularly low Mw of these dendrimers (1.6 kDa). On the other hand, formulations are highly sensitive to the strength of the dendrimer:DNA interactions. These can be controlled by the degree of protonation (α) of the dendrimer which is strongly dependent on bulk pH. Modulation of the protonation level to α≥0.4 allows reproducible production of colloidally stable particles. Finally, we have demonstrated that electrolytes and proteins present in physiological media play a crucial role to favour the efficiency of these synthetic vectors reducing the toxicity associated with their cationic groups.

An improved high-throughput Nile red fluorescence assay for estimating intracellular lipids in a variety of yeast species.

A rapid and inexpensive method for estimating lipid content of yeasts is needed for screening large numbers of yeasts samples. Nile red is a fluorescent lipophilic dye used for detection and quantification of intracellular lipid droplets in various biological system including algae, yeasts and filamentous fungi. However, a published assay for yeast is affected by variable diffusion across the cell membrane, and variation in the time required to reach maximal fluorescence emission. In this study, parameters that may influence the emission were varied to determine optimal assay conditions. An improved assay with a high-throughput capability was developed that includes the addition of dimethyl sulfoxide (DMSO) solvent to improve cell permeability, elimination of the washing step, the reduction of Nile red concentration, kinetic readings rather than single time-point reading, and utilization of a black 96-well microplate. The improved method was validated by comparison to gravimetric determination of lipid content of a broad variety of ascomycete and basidiomycete yeast species.

Diagnostic cytological features of polyacrylamide gel injection augmentation mammoplasty.

AIMS: To study the cytological features of breast lesions associated with hydrophilic polyacrylamide gel (PAAG) injection augmentation mammoplasty and to determine the specific diagnostic features. METHODS: Fine needle aspiration (FNA) cytology smears from 14 patients who presented with breast lump and a clinical history of PAAG injection were reviewed. The staining properties of the PAAG material in Papanicolaou (Pap), Haematoxylin and Eosin (H&E) and Diff-Quik stains, as well as the cellular background, were studied. Cell blocks were also studied with H&E, periodic acid-Schiff (PAS), periodic acid-Schiff with diastase digestion (PASD) and mucicarmine (MC) stains. RESULTS: PAAG was stained consistently pinkish with a homogenous smooth texture on H&E (100%), polychromasia on Pap (100%) and magenta violet with bubbly vacuoles on Diff-Quik (100%). Half (7) of the cases showed sharp borders. The presence of foreign body type giant cells with histiocytes (5 cases, 36%) and scanty clusters of benign ductal cells (4 cases, 29%) were seen in the background of a minority of the cases. PAAG was represented by blocks of homogenous grey-purplish acellular material with a sharp border on cell block sections, which were negative for PAS, PASD and MC. CONCLUSION: PAAG shows a consistent staining pattern in various common cytological staining preparations. Blocks of acellular gelatinous material, stained homogenous pinkish on H&E, polychromasia on Pap and magenta violet with bubbly vacuoles on Diff-Quik, are the reliable cytological features of PAAG.

Environmental fate and non-target impact of glyphosate-based herbicide (Roundup) in a subtropical wetland.

Mai Po Nature Reserve (Hong Kong) is an internationally important wetland for waterbirds. Roundup, a formulation based on glyphosate, has been used to control the widespread weeds within the reserve for many years but the fate and non-target impact of the herbicide is unknown. To fill this knowledge gap, we applied Roundup by hand-held sprayer to an estuarine and a freshwater pond in the dry season of year 2002. The surface water and sediment were sampled routinely for glyphosate concentrations following one month of application. In situ bioassays using local edible fish species were performed along with the herbicide application. Up to 52% of glyphosate in the surface water was transported to the unapplied regions by wind-driven current in the estuarine pond at 1 DPT (day post treatment). For both ponds, glyphosate concentrations in the water decreased rapidly after 1-3 DPT, but then decreased gradually over time. Both physical adsorption to the bottom sediments and microbial degradation are thought to contribute to these decreases. Interestingly, the persistence of glyphosate in the freshwater pond was longer than in the estuarine system, which is likely due to the considerably higher concentrations of chelating metals (i.e. Cu and Fe) present in the sediment (4.5 and 11-fold higher, respectively) which potentially reduced the bioavailability of glyphosate to the microbial decomposers. Lastly, fishes used in the in situ bioassays (both in applied and unapplied areas) showed similar survival rates, indicating that the use of Roundup at the provided application rate posed no serious hazard.

An autoinhibitory mechanism for nonsyntaxin SNARE proteins revealed by the structure of Ykt6p.

Ykt6p is a nonsyntaxin SNARE implicated in multiple intracellular membrane trafficking steps. Here we present the structure of the NH2-terminal domain of Ykt6p (Ykt6pN, residues 1 to 140). The structure of Ykt6pN differed entirely from that of syntaxin and resembled the overall fold of the actin regulatory protein, profilin. Like some syntaxins, Ykt6p adopted a folded back conformation in which Ykt6pN bound to its COOH-terminal core domain. The NH2-terminal domain plays an important biological role in the function of Ykt6p, which in vitro studies revealed to include influencing the kinetics and proper assembly of SNARE complexes.

Selective formation of Sed5p-containing SNARE complexes is mediated by combinatorial binding interactions.

Sed5p is the only syntaxin family member required for protein transport through the yeast Golgi and it is known to bind up to nine other soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins in vivo. We describe in vitro binding experiments in which we identify ternary and quaternary Sed5p-containing SNARE complexes. The formation of SNARE complexes among these endoplasmic reticulum- and Golgi-localized proteins requires Sed5p and is syntaxin-selective. In addition, Sed5p-containing SNARE complexes form selectively and this selectivity is mediated by Sed5p-containing intermediates that discriminate among subsequent binding partners. Although many of these SNAREs have overlapping distributions in vivo, the SNAREs that form complexes with Sed5p in vitro reflect their functionally distinct locales. Although SNARE-SNARE interactions are promiscuous and a single SNARE protein is often found in more than one complex, both the biochemical as well as genetic analyses reported here suggest that this is not a result of nonselective direct substitution of one SNARE for another. Rather our data are consistent with the existence of multiple (perhaps parallel) trafficking pathways where Sed5p-containing SNARE complexes play overlapping and/or distinct functional roles.