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2.
Sleep Adv ; 3(1): zpac008, 2022.
Article in English | MEDLINE | ID: mdl-37193397

ABSTRACT

[This corrects the article DOI: 10.1093/sleepadvances/zpac002.].

3.
Sleep Adv ; 3(1): zpac002, 2022.
Article in English | MEDLINE | ID: mdl-37193413

ABSTRACT

Study Objectives: To investigate the proportion of children in Aotearoa New Zealand (NZ) who do or do not meet sleep duration and sleep quality guidelines at 24 and 45 months of age and associated sociodemographic factors. Methods: Participants were children (n = 6490) from the Growing Up in New Zealand longitudinal study of child development with sleep data available at 24 and/or 45 months of age (48.2% girls, 51.8% boys; 22.4% Maori [the Indigenous people of NZ], 12.9% Pacific, 13.4% Asian, 45.2% European/Other). Relationships between sociodemographic factors and maternally reported child sleep duration (across 24 hours) and night wakings were investigated cross-sectionally and longitudinally. Estimates of children in NZ meeting sleep guidelines were calculated using a range of analytical techniques including Bayesian linear regression, negative binomial multiple regression, and growth curve models. Results: In NZ, 29.8% and 19.5% of children were estimated to have a high probability of not meeting sleep duration guidelines and 15.4% and 8.3% were estimated to have a high probability of not meeting night waking guidelines at 24 and 45 months respectively, after controlling for multiple sociodemographic variables. Factors associated cross-sectionally with children's sleep included ethnicity, socioeconomic deprivation, material standard of living, rurality, and heavy traffic, and longitudinal sleep trajectories differed by gender, ethnicity, and socioeconomic deprivation. Conclusions: A considerable proportion of young children in NZ have a high probability of not meeting sleep guidelines but this declines across the ages of 24 and 45 months. Sleep health inequities exist as early as 24 months of age in NZ.

4.
NPJ Parkinsons Dis ; 3: 5, 2017.
Article in English | MEDLINE | ID: mdl-28649605

ABSTRACT

Parkinson's disease (PD) is now considered to be a multisystemic disorder consequent on multineuropeptide dysfunction including dopaminergic, serotonergic, cholinergic, and noradrenergic systems. This multipeptide dysfunction leads to expression of a range of non-motor symptoms now known to be integral to the concept of PD and preceding the diagnosis of motor PD. Some non-motor symptoms in PD may have a dopaminergic basis and in this review, we investigate the evidence for this based on imaging techniques using dopamine-based radioligands. To discuss non-motor symptoms we follow the classification as outlined by the validated PD non-motor symptoms scale.

5.
IEEE Trans Vis Comput Graph ; 18(12): 2033-40, 2012 Dec.
Article in English | MEDLINE | ID: mdl-26357109

ABSTRACT

In nuclear science, density functional theory (DFT) is a powerful tool to model the complex interactions within the atomic nucleus, and is the primary theoretical approach used by physicists seeking a better understanding of fission. However DFT simulations result in complex multivariate datasets in which it is difficult to locate the crucial `scission' point at which one nucleus fragments into two, and to identify the precursors to scission. The Joint Contour Net (JCN) has recently been proposed as a new data structure for the topological analysis of multivariate scalar fields, analogous to the contour tree for univariate fields. This paper reports the analysis of DFT simulations using the JCN, the first application of the JCN technique to real data. It makes three contributions to visualization: (i) a set of practical methods for visualizing the JCN, (ii) new insight into the detection of nuclear scission, and (iii) an analysis of aesthetic criteria to drive further work on representing the JCN.

7.
Chemosphere ; 75(7): 955-62, 2009 May.
Article in English | MEDLINE | ID: mdl-19230955

ABSTRACT

This study project aimed to investigate the concentrations of aluminum (Al) in tea products available in Hong Kong markets. Tea samples consisting of 47 different tea bags and 28 samples of tea leaves were analysed for concentrations of Al. All tea samples released Al (0.70-5.93 mg L(-1)) during a standard infusion period. In comparison to the Joint FAO/WHO Provisional Tolerable Weekly Intake guideline of 7 mg Al kg(-1) body weight, it was concluded that tea made with these tea leaves will not impose adverse human health impacts. The relative effects of age, soil available Al, and genetic differences on the levels of Al accumulated by tea bushes were investigated. It was found that there was no definite trend between the amount of Al accumulated and the age of tea bushes. The soil available Al influenced the levels of Al in Camellia sinensis to a certain extent, but it was evident that the ability of different varieties of C. sinensis to accumulate Al was variable. C. sinensis accumulated Al in all stages of growth. Young seedlings had lower contents of Al while the mobility of Al within the tea bushes was high. In a manner typical of hyperaccumulators, Al was not retained in the roots, but was consistently transported to the shoots. Aluminum in the tea bush was distributed between the different parts in the following order: mature leaves>roots>branches>young leaves.


Subject(s)
Aluminum/analysis , Food Contamination/analysis , Soil Pollutants/analysis , Tea/chemistry , Camellia sinensis/chemistry , Camellia sinensis/growth & development , Consumer Product Safety , Hong Kong , India , Plant Leaves/chemistry , Plant Structures/chemistry
8.
Toxicol Lett ; 137(1-2): 111-20, 2003 Jan 31.
Article in English | MEDLINE | ID: mdl-12505437

ABSTRACT

Tea plant takes up a large quantity of aluminium (Al) and fluoride (F) from acidic soils. It has been known that fluorosis can be developed for people who consume a large quantity of tea made from brick tea, a low quality tea consisting mainly of old tea leaves in China. In addition, it has been claimed that Alzheimer's disease (AD) is linked with the Al content in the human brain. Therefore, the high Al content in tea, especially brick tea is also a concern. This article reviews the basis background on tea including classification, growth conditions, types of tea leaves and their production, and processing of tea. Special emphasis is made on the transfer of Al and F from soil to tea plant and then to tea liquor. Health implications of drinking a large quantity of tea liquor especially those made from brick tea are discussed. Recommendations are suggested to reduce the uptake of these two elements by tea plant, and lower their contents in tea products.


Subject(s)
Aluminum/analysis , Fluorides/analysis , Tea/adverse effects , Tea/chemistry , Alzheimer Disease/etiology , Brain Chemistry , Fluorosis, Dental/etiology , Food Contamination/analysis , Food Contamination/prevention & control , Tea/classification
9.
Arch Biochem Biophys ; 387(1): 47-56, 2001 Mar 01.
Article in English | MEDLINE | ID: mdl-11368183

ABSTRACT

The inhibition of soluble guanylyl cyclase by Ca2+ has been kinetically characterized and the results support a two-metal-ion catalytic mechanism for formation of cGMP. Ca2+ reversibly inhibits both the basal and NO-stimulated forms of bovine lung soluble guanylyl cyclase. Inhibition is independent of the activator identity and concentration, revealing that Ca2+ interacts with a site independent of the heme regulatory site. Inhibition by Ca2+ is competitive with respect to Mg2+ in excess of substrate, with Kis values of 29 +/- 4 and 6.6 +/- 0.6 microM for the basal and activated states, respectively. Ca2+ inhibits noncompetitively with respect to the substrate MgGTP in both activity states. The qualitatively similar inhibition pattern and quantitatively different Ki values between the basal and NO-stimulated states suggest that the Ca2+ binding site undergoes some structural modification upon activation of the enzyme. The competitive nature of Ca2+ inhibition with respect to excess Mg2+ is consistent with a two-metal-ion mechanism for cyclization.


Subject(s)
Calcium/pharmacology , Cyclic GMP/metabolism , Guanylate Cyclase/antagonists & inhibitors , Binding Sites , Cations, Divalent/metabolism , Cations, Divalent/pharmacology , Down-Regulation , Enzyme Activation , Gene Expression Regulation, Enzymologic , Kinetics , Magnesium/metabolism , Models, Chemical , Nitric Oxide/metabolism , Solubility
10.
J Endourol ; 14(1): 5-8, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10735566

ABSTRACT

Although it is one of the most frequently utilized devices in the hospitalized patient, the Foley catheter has often been taken for granted. This lack of attention is unfortunate, as the Foley catheter remains one of the primary sources of hospital-acquired infections, which increase morbidity, mortality, and the financial burden on the healthcare system. Although education on the appropriate techniques, proper use, and early removal of Foley catheters is important, such measures unfortunately result in transient benefits. Current technologic advancements have moved the coating technology to a state where bacterial adhesion and migration can be limited and the frequency of catheter-associated urinary tract infections can be reduced. Future technological advances in the Foley catheter will help provide better care and comfort for the catheterized patient.


Subject(s)
Catheterization/history , Catheterization/instrumentation , Biofilms/growth & development , Catheterization/adverse effects , Coated Materials, Biocompatible , Drainage/instrumentation , Drainage/methods , Equipment Design , History, 20th Century , Humans , Surface Properties , United States , Urinary Tract Infections/etiology , Urinary Tract Infections/prevention & control
12.
Ann Vasc Surg ; 10(5): 469-75, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8905067

ABSTRACT

Improved patency of endothelial cell seeded grafts relies on good initial adherence and cell retention when the circulation is restored. In this study human adult endothelial cells (HAECs) were used to evaluate the suitability of commercially available prostheses for seeding. Acutely seeded indium-111 oxine labeled HAECs were used to measure cell adherence to plain and fibronectin (FN)-coated expanded polytetrafluoroethylene (ePTFE), gelatin-impregnated Dacron (Gelseal), and collagen-impregnated Dacron (Hemashield) grafts. Cell loss from FN-coated prostheses, when exposed to a simulated human arterial blood flow of 200 ml/min in an artificial pulsatile circulation, was quantified from the loss of gamma activity from the graft over 24 hours, pressure in the circulation being reduced to 15 mm Hg to reduce fluid loss. Initial HAEC adherence (mean [SD]) to plain grafts was 3(1)%, 47(9)%, and 53(9)% for ePTFE, Gelseal, and Hemashield, respectively. This improved significantly with FN coating (78[6]%, 60[8]%, and 76[4]%). Cell retention after 24 hours of flow to FN-coated grafts was 16(10)%, 25(5)%, and 65(4)% and was confirmed qualitatively by scanning electron microscopy and environmental scanning electron microscopy. FN significantly improved initial cell adherence with Dacron grafts showing the better adherence. Cell retention after 24 hours of flow was better with FN-coated Dacron than with ePTFE but was best with Hemashield grafts.


Subject(s)
Blood Vessel Prosthesis , Endothelium, Vascular/physiology , Polytetrafluoroethylene , Adult , Cell Adhesion/drug effects , Fibronectins/pharmacology , Humans , Pulsatile Flow
13.
Ann Vasc Surg ; 9(6): 542-6, 1995 Nov.
Article in English | MEDLINE | ID: mdl-8746831

ABSTRACT

There is no convincing evidence that endothelial cell seeding of prosthetic grafts in humans confers any of the advantages seen in animals. However, partial endothelial coverage might exert a subtle effect not detectable with indirect end points such as patency or scintigraphy. This study examined seeded cell function by measuring fibrinolytic and platelet activation markers in patients receiving seeded and control prosthetic grafts. Thirty-two patients were randomly assigned to seeded (n = 15) and control (n = 17) groups. Preoperatively and 3, 6, and 12 months postoperatively, plasma levels of fibrinopeptide A (FPA), B beta 1-42 fragment, cross-linked fibrin degradation products (XL-FDP), thromboxane A2 (TXA2), platelet factor 4 (PF4), and beta-thromboglobulin (beta TG) were measured. Patients with seeded grafts had significantly lower levels of FPA at 6 and 12 months (p < 0.05) and a significant overall group effect (p < 0.05). These patients also tended to have higher levels of XL-FDP (p < 0.1). No other significant differences were seen. The lower rate of conversion of fibrinogen to fibrin and the trend toward increased fibrinolysis seen in seeded grafts may be due to the metabolic effects of viable retained seeded cells. Although comparable platelet activation indicates that endothelial coverage remains limited, seeding may exert an antithrombotic influence at the graft surface.


Subject(s)
Blood Vessel Prosthesis , Cell Transplantation , Endothelium, Vascular/cytology , Ischemia/surgery , Leg/blood supply , Platelet Activation/physiology , Postoperative Complications/blood , Adult , Aged , Blood Coagulation Factors/analysis , Female , Femoral Artery/surgery , Follow-Up Studies , Graft Occlusion, Vascular/blood , Humans , Male , Middle Aged , Popliteal Artery/surgery , Prosthesis Design , Surface Properties
14.
Cell Transplant ; 4(3): 291-6, 1995.
Article in English | MEDLINE | ID: mdl-7640868

ABSTRACT

Indium-111 oxine labeling is widely used as a marker of endothelial cell attachment to vascular prostheses. The long term effect of labeling human adult endothelial cells (HAECs) with this isotope has not been determined. In this study the viability of labeled HAECs, leakage of isotope from labeled cells and adherence of circulating isotope to fibronectin coated prostheses were investigated over 24 h. The effect of incubation time on labeling efficiency was also assessed. There were significant differences in cell viability between the labeled and unlabeled groups beyond 4 h (p < 0.005, 2-tailed, unpaired t-test). In the control group cell numbers increased by 42% while in the labeled group this had decreased by 20% at 24 h. Spontaneous leakage increased with time but was maximal in the first 2 h. Adherence of circulating isotope to fibronectin coated expanded polytetrafluoroethylene (ePTFE) grafts was minimal but was significantly greater to gelatin impregnated Dacron (GEL-SEAL) beyond 1 hour (p < 0.05). Incubation times greater than 5 minutes during labeling do not significantly improve labeling efficiency, and may contribute to toxicity by prolonging exposure to oxine. Indium-111 oxine labeling of HAECs is a suitable technique for acute studies of endothelial cell kinetics up to 4 h, but its use in chronic studies may lead to significant underestimations of cell retention.


Subject(s)
Endothelium, Vascular/cytology , Indium Radioisotopes , Isotope Labeling , Organometallic Compounds , Oxyquinoline/analogs & derivatives , Bioprosthesis , Cell Adhesion , Cell Count , Cell Survival , Cells, Cultured , Humans
15.
Protein Expr Purif ; 5(5): 449-57, 1994 Oct.
Article in English | MEDLINE | ID: mdl-7530072

ABSTRACT

We have cloned, expressed, and purified the extracellular domains of types I and II human tumor necrosis factor receptors. Both proteins were expressed in and secreted by murine erythroleukemia cells under the control of the human beta-globin promoter placed down-stream from the human globin locus control region. Secretion of both proteins was directed by the respective tumor necrosis factor receptor signal sequence. Each tumor necrosis factor receptor extracellular domain was expressed as a chimeric protein, fused to a carboxy terminal flexible peptide linker and an antigenic affinity tag. Secretion of both proteins into the growth medium in a hollow fiber bioreactor was achieved. A monoclonal antibody generated against the affinity tag allowed the purification of both proteins. These were isolated as biologically active products in that they bound human tumor necrosis factor-alpha in a 125I-radioiodinated ligand binding assay. The two proteins also bound tumor necrosis factor-alpha at approximately equimolar ratios as demonstrated by BIAcore sensorgram analysis.


Subject(s)
Antigens, CD , Receptors, Tumor Necrosis Factor/biosynthesis , Affinity Labels , Amino Acid Sequence , Animals , Base Sequence , Chromatography, Affinity , Cloning, Molecular , Epitopes/biosynthesis , Epitopes/genetics , Epitopes/isolation & purification , Humans , Leukemia, Erythroblastic, Acute , Mice , Molecular Sequence Data , Receptors, Tumor Necrosis Factor/genetics , Receptors, Tumor Necrosis Factor/isolation & purification , Receptors, Tumor Necrosis Factor, Type I , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/isolation & purification , Selection, Genetic , Tumor Cells, Cultured , Tumor Necrosis Factor-alpha/metabolism
17.
Surgery ; 115(1): 46-51, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8284760

ABSTRACT

BACKGROUND: This study was undertaken to determine the true incidence of renal impairment after aortic surgery and its association with intraoperative fluctuations in renal artery blood flow and cardiac output. METHODS: Direct measurements of renal artery blood flow were undertaken with electromagnetic flowmetry in 19 patients undergoing elective infrarenal aortic surgery. Renal function was assessed before and after operation by measurement of creatinine clearance. RESULTS: Twelve patients (63%) had renal impairment as defined by a 40% or greater reduction in creatinine clearance after operation. This group of patients had significantly lower renal artery blood flow during the period of aortic cross-clamping than had those who preserved their renal function (p < 0.001). CONCLUSIONS: Renal impairment is common after infrarenal aortic surgery and may be a result of intraoperative ischemia secondary to reduced renal artery blood flow.


Subject(s)
Aorta/surgery , Kidney/physiopathology , Renal Artery/physiology , Renal Circulation , Adult , Aged , Female , Humans , Kidney Diseases/etiology , Male , Middle Aged , Postoperative Complications/etiology , Prospective Studies
18.
J Vasc Surg ; 18(5): 858-66, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8230574

ABSTRACT

PURPOSE: In an investigation of the effects of isovolemic hemodilution, 39 consecutive patients undergoing elective infrarenal aortic operation had detailed measurements of renal function, renal artery blood flow, and cardiac hemodynamics. METHODS: The patients were randomly allocated to receive acute preoperative isovolemic hemodilution to a hematocrit of 28%, with 20 patients receiving hemodilution and 19 being control subjects. RESULTS: Twelve (63%) of the control group had renal impairment, compared with only four (20% in the group receiving hemodilution (p < 0.01). Hemodilution also prevented the fall in cardiac output induced by cross-clamping (p < 0.01) and significantly reduced the need for transfusion of donor blood (p < 0.01). CONCLUSIONS: Acute isovolemic hemodilution is clearly a useful adjunct in the management of patients undergoing elective aortic operation.


Subject(s)
Aorta, Abdominal/surgery , Hemodilution , Kidney/physiopathology , Acute Kidney Injury/etiology , Acute Kidney Injury/physiopathology , Adult , Aged , Carbon Dioxide/blood , Cardiac Output , Creatinine/metabolism , Female , Hematocrit , Hemodynamics , Humans , Male , Middle Aged , Oxygen/blood , Postoperative Complications , Prospective Studies , Renal Circulation
19.
Eur J Vasc Surg ; 7(6): 750-2, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8270087

ABSTRACT

Malignant disease is often complicated by coagulation disorders presenting as abnormal clotting or bleeding, acute leukaemia being more often associated with the latter. Acute lymphoblastic leukaemia presenting with peripheral arterial thromboembolism, previously unreported in the literature, is presented. Aetiology, clinical features, and management of coagulation disturbances associated with malignancy are also reviewed.


Subject(s)
Ischemia/etiology , Leg/blood supply , Leukemia-Lymphoma, Adult T-Cell/complications , Thrombosis/etiology , Adult , Amputation, Surgical , Humans , Ischemia/surgery , Male , Thrombosis/surgery
20.
Br J Surg ; 79(10): 1035-7, 1992 Oct.
Article in English | MEDLINE | ID: mdl-1422714

ABSTRACT

Forty carotid endarterectomies were undertaken in 34 patients. Operations were prospectively randomized to periarterial application of either 1 per cent lignocaine (n = 19) or normal saline (n = 21), and detailed measurements taken of intraoperative pulse rate and blood pressure. Patients receiving lignocaine demonstrated a lower pulse rate, and lower systolic and mean blood pressures than those receiving placebo, with significance in relation to clamp application and shunt removal (P < 0.05). It was particularly noticeable that patients receiving lignocaine demonstrated less intraoperative variation in pulse rate and blood pressure. Topical lignocaine stabilizes pulse rate and blood pressure during carotid endarterectomy.


Subject(s)
Endarterectomy, Carotid , Lidocaine/administration & dosage , Administration, Topical , Aged , Blood Pressure/drug effects , Double-Blind Method , Female , Heart Rate/drug effects , Humans , Intraoperative Care , Lidocaine/pharmacology , Male , Middle Aged , Prospective Studies
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