Update: severe acute respiratory syndrome--Toronto, 2003.
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Cross Infection↗
Biomedical subjects
T Wong
Publications and source records attributed to T Wong.
Spontaneous venous thrombosis in inflammatory bowel disease: relevance of factor V Leiden and the prothrombin gene mutation.
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Case-Control Studies↗
Severe infective keratitis leading to hospital admission in New Zealand.
AIM: To identify key risk factors and the management and outcome of severe infective keratitis leading to public hospital admission in New Zealand. METHODS: Over a 2 year period, all admissions of presumed infective keratitis to Auckland Hospital were identified. The clinical records of all 103 cases were retrospectively reviewed with respect to clinical features, risk factors, management, and outcomes. RESULTS: The mean time from first symptoms or signs and presentation to hospital was 8.9 (SD 15.5) days. The majority of subjects, 88%, had at least one of the risk factors commonly associated with infective keratitis including previous ocular surgery (30%), contact lens wear (26%), topical corticosteroid use (25%), and ocular trauma (24%). Corneal scraping was performed in 92% and of a total of 105 scrapes, 71% were positive. Bacteria were isolated in all these cases, the majority being Gram positive organisms (72%). The most common isolates identified were coagulase negative Staphylococcus (16%), Propionibacterium acnes (14%), Staphylococcus epidermidis (11%), and Streptococcus pneumoniae (9%). In addition, yeasts were isolated in 5%, fungi in 4%, virus in 2%, and chlamydia in 1%. Importantly, polymicrobial infection accounted for 33% of culture positive cases. Antimicrobial treatment was changed on the basis of culture results in 17 cases (16.5%). Median initial visual and final best corrected visual acuity was 6/36-6/48 (logMAR 0.86) (IQR 0.39-2.00) and 6/12-6/15 (logMAR 0.360) (IQR 0.15-1.70), respectively. Previous ocular surgery and topical corticosteroid use were significantly associated with poorer visual acuity. The mean hospital stay was 5.8 days and the median 4.0 (IQR 2.0-8.0) days. Longer duration of stay was associated with the presence of hypopyon, larger ulcers, previous ocular surgery, and poor visual acuity. CONCLUSIONS: Infectious keratitis is an important cause of ocular morbidity. A significant proportion of cases have potentially modifiable risk factors. Previous ocular surgery and topical corticosteroid use, in particular, were associated with poorer visual outcomes. Many cases of severe keratitis might be avoided, or their severity reduced, by appropriate education of patients and ophthalmologists.
Administration, Topical↗
Larvae of Contracaecum sp. among inshore fish species of southwestern Australia.
Larval nematode infections were investigated in 236 fish from 17 estuarine and near-shore species in southwestern Australia. Larvae of the genus Contracaecum were found in 4 species of fish (Acanthopagrus butcheri, Sillaginodes punctata, Mugil cephalus and Aldrichetta forsteri). The prevalence and intensity of infection was highest in the 2 species of mullet: 81% infected and 9.8 +/- 1.5 larvae fish(-1) for M. cephalus; 100% and 12.7 +/- 3.7 larvae fish(-1) for A. forsteri. There was no evidence of post-mortem migration of worms from the visceral organs to the musculature of the fish.
Animals↗
Drug release properties of pectinate microspheres prepared by emulsification method.
This study explored the potential of pectin for use in making microspheres for sustained-release of drugs. The pectin microspheres were prepared by external gelation using an emulsification technique with calcium chloride as the crosslinking agent. The influences of drug core (sulphanilamide, sulphaguanidine and sulphathiazole) and dissolution media (distilled water, USP HCl and phosphate buffers) on the drug release properties of the pectinate microspheres were examined. The morphology and drug content of the microspheres, and the solubility and solution pH of the drugs were also determined. Pectinate microspheres were successfully prepared by the emulsification technique. The rate of drug released from microspheres was highest in USP HCl buffer, followed by USP phosphate buffer and distilled water. Interestingly, the lowest percentage of drug released was produced by microspheres which were smallest in size and therefore largest in specific surface area, and consisting of sulphanilamide, the most water soluble drug. Further investigation showed that the microspheres consisted of both bound and unbound drugs. The percentage of drug released was predominantly determined by the relative contents of bound and unbound drugs embedded in the pectinate matrix.
Anti-Infective Agents↗
Influence of polyvinylpyrrolidone on aggregation propensity of coated spheroids.
The influence of polyvinylpyrrolidone (PVP), a commonly used binder and adhesive, on the aggregation of spheroids coated with hydroxypropylmethylcellulose (HPMC) was studied. The aggregation propensities of spheroids coated by HPMC alone and by HPMC with polyethylene glycol (PEG) were compared with those coated by HPMC with PVP and the viscosity of the coating solutions determined. The coating was conducted at a maximum spray rate of 11 g/min to avoid premature termination of the coating process at higher spray rates due to uncontrollable aggregation of spheroids. PVP was able to reduce the extent of aggregation of spheroids. It was more effective in reducing spheroid aggregation than PEG. The reduction in spheroid aggregation propensity was ascribed to viscosity lowering effects of PVP. The viscosity of the coating solutions determined over the temperature range of 28-58 degrees C was found to increase in the following order: HPMC-PVP<HPMC-PEG<HPMC.
Excipients↗
Metabolic bone disease is present at diagnosis in patients with inflammatory bowel disease.
AIM: To establish whether bone disease is present at diagnosis in inflammatory bowel disease and to identify contributory metabolic abnormalities. METHODS: Newly diagnosed patients with inflammatory bowel disease (19 males, 15 females; mean age, 44 years; range, 17-79 years; 23 ulcerative colitis, 11 Crohn's disease) were compared against standard reference ranges and a control group with irritable bowel syndrome (eight males, 10 females; mean age, 40 years; range, 19-64 years). Bone mineral density (g/cm2, dual-energy X-ray absorptiometry: lumbar spine and femoral neck) and biochemical bone markers were measured. RESULTS: Femoral neck bone mineral density, T- and Z-scores (mean +/- s.d., respectively) were lower in inflammatory bowel disease patients than in irritable bowel syndrome controls (0.78 +/- 0.12 vs. 0.90 +/- 0.16, P = 0.0046; - 0.88 +/- 0.92 vs. 0.12 +/- 1.17, P = 0.0018; - 0.30 +/- 0.89 vs. 0.61 +/- 1.10, P = 0.0030). Lumbar spine bone mineral density and T-scores were also significantly lower in patients than controls (0.98 +/- 0.15 vs. 1.08 +/- 0.13, P = 0.0342; - 1.05 +/- 1.39 vs. - 0.14 +/- 1.19, P = 0.0304). Compared with controls, the urinary deoxypyridinoline : creatinine ratio was increased (7.66 vs. 5.70 nmol/mmol, P = 0.0163) and serum 25-hydroxy vitamin D was decreased (18.7 vs. 28.5 micro g/L, P = 0.0016); plasma osteocalcin and serum parathyroid hormone did not differ (P > 0.05). CONCLUSIONS: The bone mineral density is reduced at diagnosis, prior to corticosteroid treatment, in both Crohn's disease and ulcerative colitis. Our data suggest that this is attributable to increased resorption rather than decreased bone formation.
Adolescent↗
Asymptomatic aortic dissection in Marfan syndrome.
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Adult↗
Heterosexual outbreak of infectious syphilis: epidemiological and ethnographic analysis and implications for control.
This study describes the epidemiology and ethnography of an outbreak of infectious syphilis in Vancouver, British Columbia. Between 1996 and 1999, British Columbias's rate of infectious syphilis rose from 0.5 to 3.4 per 100,000, with a dense concentration of cases among sex trade workers, their clients, and street-involved people in the downtown eastside area of Vancouver. Sexual networks were imported cases with secondary spread (dyads and triads), large densely connected dendritic networks of sex trade workers and clients, or occasional starburst networks among gay men. Only 232 of 429 partners were documented as having been treated (54% of those named, or 0.9 per case). The geographical and demographic concentration of this outbreak led to consideration of a programme of focused mass treatment with single dose azithromycin.
Adolescent↗
Canadian STI national goals and phase specific strategies.
National goals should be "SMART"-specific, measurable, achievable, resource sensitive, and timed. To be meaningful, these goals must be sustainable and realistic within the time frame and fiscal limitations. Multisector partnerships are essential for the goals to become operational.
Canada↗
Mitogen-activated protein kinase regulates early phosphorylation and delayed expression of Ca2+/calmodulin-dependent protein kinase II in long-term potentiation.
Activation of mitogen-activated protein kinase (MAPK) and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) are required for numerous forms of neuronal plasticity, including long-term potentiation (LTP). We induced LTP in rat hippocampal area CA1 using theta-pulse stimulation (TPS) paired with beta-adrenergic receptor activation [isoproterenol (ISO)], a protocol that may be particularly relevant to normal patterns of hippocampal activity during learning. This stimulation resulted in a transient phosphorylation of p42 MAPK, and the resulting LTP was MAPK dependent. In addition, CaMKII was regulated in two, temporally distinct ways after TPS-ISO: a transient rise in the fraction of phosphorylated CaMKII and a subsequent persistent increase in CaMKII expression. The increases in MAPK and CaMKII phosphorylation were strongly colocalized in the dendrites and cell bodies of CA1 pyramidal cells, and both the transient phosphorylation and delayed expression of CaMKII were prevented by inhibiting p42/p44 MAPK. These results establish a novel bimodal regulation of CaMKII by MAPK, which may contribute to both post-translational modification and increased gene expression.
Adrenergic beta-Agonists↗
Spontaneous entrapment of polynucleotides upon electrostatic interaction with ethanol-destabilized cationic liposomes.
This study describes the effect of ethanol and the presence of poly(ethylene) glycol (PEG) lipids on the interaction of nucleotide-based polyelectrolytes with cationic liposomes. It is shown that preformed large unilamellar vesicles (LUVs) containing a cationic lipid and a PEG coating can be induced to entrap polynucleotides such as antisense oligonucleotides and plasmid DNA in the presence of ethanol. The interaction of the cationic liposomes with the polynucleotides leads to the formation of multilamellar liposomes ranging in size from 70 to 120 nm, only slightly bigger than the parent LUVs from which they originated. The degree of lamellarity as well as the size and polydispersity of the liposomes formed increases with increasing polynucleotide-to-lipid ratio. A direct correlation between the entrapment efficiency and the membrane-destabilizing effect of ethanol was observed. Although the morphology of the liposomes is still preserved at the ethanol concentrations used for entrapment (25-40%, v/v), entrapped low-molecular-weight solutes leak rapidly. In addition, lipids can flip-flop across the membrane and exchange rapidly between liposomes. Furthermore, there are indications that the interaction of the polynucleotides with the cationic liposomes in ethanol leads to formation of polynucleotide-cationic lipid domains, which act as adhesion points between liposomes. It is suggested that the spreading of this contact area leads to expulsion of PEG-ceramide and triggers processes that result in the formation of multilamellar systems with internalized polynucleotides. The high entrapment efficiencies achieved at high polyelectrolyte-to-lipid ratios and the small size and neutral character of these novel liposomal systems are of utility for liposomal delivery of macromolecular drugs.
Cations↗
The effect of technology on the caring attributes of an international sample of nurses.
This paper commences by refining the psychometric characteristics of a quantitative instrument, which was developed to examine the caring attributes of an international sample of 1957 nurses working in 11 countries. Using factor analysis to support the construct validity, and removing weak items, the original 60 caring items were reduced to a 31 item global caring scale which revealed the sub-scales: 'caring communication'; 'caring involvement'; 'caring advocacy'; and 'learning to care'. The sub-scales were internally consistent and revealed generally high correlation coefficients. The subjects also responded to a scale, which was designed to measure degree of technological influence and provide a score for each respondent to reflect how highly they were influenced by technology in the work units of their hospital. The sample was then divided into three equal groups to reflect high, medium and low technological influence. The caring attribute scores then became the dependent variable by which the degree of technology was compared. The group with the lowest technological influence recorded the lowest mean score for caring while the group with the highest technological influence recorded the highest mean score for caring. A significant difference between the group with lowest and highest technological influence (F=6.84, p<0.001) was noted. This also applied to the 'caring communication' and 'caring involvement' sub-scales. For 'caring advocacy' the lowest technology group recorded the highest caring mean which was found to be significantly different to both mean scores for medium and highest technology groups (F=7.15, p<0.001). These results are discussed in the light of the international sample and suggestions for future research are raised.
Attitude of Health Personnel↗
Extended field-of-view ultrasound.
When ultrasound became a clinical reality in the 1970s, extended field of view was the only form of imaging available because all ultrasound images were created with articulated arm scanners that encompassed the area of interest in its entirety. With the advent of high-quality real-time imaging in the 1980s, the extended field of view was lost, and with it went an important diagnostic component as well as an important means of communicating diagnostic findings to referring clinicians. Through the magic of computer technology, extended field of view imaging is back! Extended field of view images can now be created very easily and conveniently, in real time. The convenience and accuracy of real-time imaging is maintained while important anatomical perspectives are added. This article reviews the status of real-time extended field of view sonography. The technical details as well as the clinical relevance of this method are summarized. The day-to-day clinical utility of extended field of view imaging is liberally illustrated.
Computer Systems↗
Nursing competencies: personal characteristics contributing to effective nursing performance.
AIMS OF THE STUDY: Core competencies are important in enabling an individual to adapt to new environments and perform superior professional practice. This study was to identify the underlying competencies which contributed to effective nursing performance. BACKGROUND: Most of the previous competencies are either derived from researchers' conceptual analysis or based on practitioners' direct report. Competencies derived from these methods either are subject to bias or are unable to identify the essential elements for effective nursing care. METHOD: Following the McBer method, 50 experienced nurses in China were asked to report 82 valid critical incidents in their jobs. Two individuals coded the scripts and decided the presence of each competency according to a pre-established coding system. RESULTS: Ten competencies including interpersonal understanding, commitment, information gathering, etc. were identified. Each competency was illustrated by behavioural indicators. CONCLUSIONS: Skills, traits, motives and attitudes all contribute to effective nursing performance. The findings assist in the delineation and development of nursing competencies and thus provide realistic working behaviours for nursing education and management.
Adult↗
The interferon-inducible Stat2:Stat1 heterodimer preferentially binds in vitro to a consensus element found in the promoters of a subset of interferon-stimulated genes.
Regulated expression of type I interferon (IFN)-stimulated genes (ISG) requires the binding of the signal transducer and activator of transcription (Stat) complexes to enhancer elements located in the ISG promoters. These enhancer elements include the IFN-stimulated response element (ISRE) and the palindromic IFN-gamma activation site (GAS) element. Regulated expression of ISRE containing ISG depends on IFN-stimulated gene factor 3 (ISGF3), a heterodimer involving Stat1 and Stat2 in association with a DNA-binding adapter protein, p48/IFN regulatory factor-9 (IRF-9). Several GAS binding Stat complexes involving Stat1, Stat3, Stat4, and Stat5 have been described, but their contribution to GAS-dependent ISG expression remains to be established. We and others previously identified an IFN-alpha-inducible Stat2:1 heterodimer that exhibits binding to the GAS element of the IRF-1 gene. These previous studies raise the possibility that Stat2:1 may participate in the transcriptional activation of the subset of ISG containing GAS elements. To address this question, we performed a PCR-assisted binding site selection procedure to define the Stat2:1 recognition sequence. The data reveal that Stat2:1 preferentially binds to a palindromic sequence similar to the consensus GAS element found in the promoter of several ISG. Our results establish that in addition to the classic complex formation involving Stat2, Stat1, and p48 associations, Stat2:1 heterodimers are formed in response to IFN treatment that may play an important role in the transcriptional regulation of certain ISG.
Base Sequence↗
P2Y(11), a purinergic receptor acting via cAMP, mediates secretion by pancreatic duct epithelial cells.
Pancreatic duct epithelial cells (PDEC) mediate the exocrine secretion of fluid and electrolytes. We previously reported that ATP and UTP interact with P2Y(2) receptors on nontransformed canine PDEC to increase intracellular free Ca2+ concentration ([Ca2+](i)) and stimulate Ca2+-activated Cl- and K+ channels. We now report that ATP interacts with additional purinergic receptors to increase cAMP and activate Cl- channels. ATP, 2-methylthio-ATP, and ATP-gamma-S stimulated a 4- to 10-fold cAMP increase with EC(50) of 10-100 microM. Neither UTP nor adenosine stimulated a cAMP increase, excluding a role for P2Y(2) or P1 receptors. Although UTP stimulated an (125)I(-) efflux that was fully inhibited by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetra(acetoxymethyl) ester (BAPTA-AM), ATP stimulated a partially resistant efflux, suggesting activation of additional Cl- conductances through P2Y(2)-independent and Ca2+-independent pathways. In Ussing chambers, increased cAMP stimulated a much larger short-circuit current (I(sc)) increase from basolaterally permeabilized PDEC monolayers than increased [Ca2+](i). Luminal ATP and UTP and serosal UTP stimulated a small Ca2+-type I(sc) increase, whereas serosal ATP stimulated a large cAMP-type I(sc) response. Serosal ATP effect was inhibited by P2 receptor blockers and unaffected by BAPTA-AM, supporting ATP activation of Cl- conductances through P2 receptors and a Ca2+-independent pathway. RT-PCR confirmed the presence of P2Y(11) receptor mRNA, the only P2Y receptor acting via cAMP.
Adenosine Triphosphate↗
Molecular diagnosis of early pancreatic ductal adenocarcinoma in high-risk patients.
The prevalence of pancreatic cancer in the general population is too low--even in high-prevalence areas such as Northern Europe and North America (8-12 per 10(5) population)--relative to the diagnostic accuracy of present detection methods to permit primary screening in the asymptomatic adult population. The recognition that the lifetime risk of developing pancreatic cancer for patients with hereditary pancreatitis (HP) is extremely high (20% by the age of 60 years and 40% by the age of 70 years) poses considerable challenges and opportunities for secondary screening in those patients without any clinical features of pancreatic cancer. Even for secondary screening, the detection of cancer at a biological stage that would be amenable to cure by surgery (total pancreatectomy) still requires diagnostic modalities with a very high sensitivity and specificity. Conventional radiological imaging methods such as endoluminal ultrasound and endoscopic retrograde pancreatography, which have proved to be valuable in the early detection of early neoplastic lesions in patients with familial pancreatic cancer, may well be applicable to patients with HP but only in those without gross morphological features of chronic pancreatitis (other than parenchymal atrophy). Unfortunately, most cases of HP also have associated gross features of chronic pancreatitis that are likely to seriously undermine the diagnostic value of these conventional imaging modalities. Pre-malignant molecular changes can be detected in the pancreatic juice of patients. Thus, the application of molecular screening in patients with HP is potentially the most powerful method of detection of early pancreatic cancer. Although mutant (mt) K-ras can be detected in the pancreatic juice of most patients with pancreatic cancer, it is also present in patients with non-inherited chronic pancreatitis who do not progress to pancreatic cancer (at least in the short to medium term), as well as increasingly in the older population without pancreatic disease. Nevertheless, the presence of mt-K-ras may identify a genuinely higher-risk group, enabling additional diagnostic imaging and molecular resources to be focussed on such a group. What is clear is that prospective multi-centre studies, such as that being pursued by the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC), are essential for the development of an effective secondary screening programme for these patients.
Biomarkers, Tumor↗