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1.
Metab Eng ; 64: 74-84, 2021 03.
Article in English | MEDLINE | ID: mdl-33486094

ABSTRACT

Constraint-based, genome-scale metabolic models are an essential tool to guide metabolic engineering. However, they lack the detail and time dimension that kinetic models with enzyme dynamics offer. Model reduction can be used to bridge the gap between the two methods and allow for the integration of kinetic models into the Design-Built-Test-Learn cycle. Here we show that these reduced size models can be representative of the dynamics of the original model and demonstrate the automated generation and parameterisation of such models. Using these minimal models of metabolism could allow for further exploration of dynamic responses in metabolic networks.


Subject(s)
Metabolic Networks and Pathways , Models, Biological , Genome , Kinetics , Metabolic Engineering , Metabolic Networks and Pathways/genetics
2.
J Neonatal Perinatal Med ; 10(1): 39-42, 2017.
Article in English | MEDLINE | ID: mdl-28282820

ABSTRACT

OBJECTIVE: To determine the maximum dilution of human milk (HM) that yields reliable results for protein, fat and lactose when analyzed by mid-infrared spectroscopy. STUDY DESIGN: De-identified samples of frozen HM were obtained. Milk was thawed and warmed (40°C) prior to analysis. Undiluted (native) HM was analyzed by mid-infrared spectroscopy for macronutrient composition: total protein (P), fat (F), carbohydrate (C); Energy (E) was calculated from the macronutrient results. Subsequent analyses were done with 1 : 2, 1 : 3, 1 : 5 and 1 : 10 dilutions of each sample with distilled water. Additional samples were sent to a certified lab for external validation. RESULTS: Quantitatively, F and P showed statistically significant but clinically non-critical differences in 1 : 2 and 1 : 3 dilutions. Differences at higher dilutions were statistically significant and deviated from native values enough to render those dilutions unreliable. External validation studies also showed statistically significant but clinically unimportant differences at 1 : 2 and 1 : 3 dilutions. CONCLUSIONS: The Calais Human Milk Analyzer can be used with HM samples diluted 1 : 2 and 1 : 3 and return results within 5% of values from undiluted HM. At a 1 : 5 or 1 : 10 dilution, however, results vary as much as 10%, especially with P and F. At the 1 : 2 and 1 : 3 dilutions these differences appear to be insignificant in the context of nutritional management. However, the accuracy and reliability of the 1 : 5 and 1 : 10 dilutions are questionable.


Subject(s)
Dietary Fats/analysis , Lactose/analysis , Milk Proteins/analysis , Milk, Human/chemistry , Dietary Proteins/analysis , Female , Humans , Reproducibility of Results , Spectrum Analysis/methods
3.
Radiat Prot Dosimetry ; 170(1-4): 412-5, 2016 Sep.
Article in English | MEDLINE | ID: mdl-26759476

ABSTRACT

The Public Health England fortuitous dosimetry capability is reviewed, with particular attention focussed on the derivation of its energy and fading corrections, the Monte Carlo techniques used to generate the calibration factors between phone and body doses, and the procedures set in place to facilitate a reliable and effective service.


Subject(s)
Cell Phone , Environmental Exposure/analysis , Radiation Dosage , Radiometry/instrumentation , Radiometry/methods , Algorithms , Calibration , England , Humans , Iridium Radioisotopes , Light , Luminescence , Models, Statistical , Monte Carlo Method , Photons , Radiation Dosimeters , Radioactive Hazard Release , Radiometry/standards , Reproducibility of Results , Software
4.
Radiat Prot Dosimetry ; 164(1-2): 89-92, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25841040

ABSTRACT

Work is presented on the development of a retrospective/fortuitous accident dosimetry service using optically stimulated luminescence of resistors found in mobile phones to determine the doses of radiation to members of the public following a radiological accident or terrorist incident. The system is described and discussed in terms of its likely accuracy in a real incident.


Subject(s)
Cell Phone , Radiation Exposure/analysis , Radioactive Hazard Release , Terrorism , Thermoluminescent Dosimetry/instrumentation , Electric Impedance , Equipment Design , Equipment Failure Analysis , Radiation Dosage , Reproducibility of Results , Sensitivity and Specificity
7.
Eur J Prosthodont Restor Dent ; 19(4): 168-74, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22645803

ABSTRACT

Four different shades were used to produce 20 samples of resin-based composite and 20 samples of porcelain to evaluate the performance ability of an intra oral test spectrophotometer compared to a reference spectrophotometer. The absolute colour coordinates CIELAB values measured with both spectrophotometers were significantly different (p < 0.001). However, a high correlation was found (p < 0.001) despite the low concordance noticed. The colour difference deltaE* values calculated between different shades also were significantly different between both spectrophotometers (p < 0.05). Therefore, the Easy Shade can be used in dental practice and dental research with some limitations.


Subject(s)
Composite Resins/chemistry , Dental Materials/chemistry , Dental Porcelain/chemistry , Spectrophotometry/instrumentation , Algorithms , Carbon Compounds, Inorganic/chemistry , Color , Dental Polishing/methods , Esthetics, Dental , Humans , Materials Testing , Silicon Compounds/chemistry , Spectrophotometry/standards , Surface Properties
8.
Acute Med ; 9(2): 97; 100-1, 2010.
Article in English | MEDLINE | ID: mdl-21597583
9.
Eur J Clin Nutr ; 63(12): 1404-10, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19707226

ABSTRACT

BACKGROUND/OBJECTIVES: Skeletal muscle plays important role in the regulation of whole-body metabolism. In skeletal muscle, uptakes of glucose and fatty acid from circulation are facilitated by transmembrane substrate transporters GLUT4 and FAT/CD36, respectively. The aim of this study was to determine the effect of dietary glycemic index (GI) on GLUT4 and FAT/CD36 gene expressions in human skeletal muscle after a single bout of exercise. SUBJECTS/METHODS: Eight male subjects completed a 60-min cycling exercise at 75% maximal oxygen consumption (VO(2 max)), and were immediately fed an isocaloric meal containing either high-GI (HGI) or low-GI (LGI) diets, with similar proportions of carbohydrate, fat and protein in a crossover design. Muscle samples from deep vastus lateralis were taken by needle biopsy immediately after exercise and 3 h after exercise. RESULTS: After exercise, the HGI diet produced significantly greater glucose and insulin responses compared with the LGI diet, as indicated by the greater area under the curves. Both diets resulted in rapid reductions in plasma fatty acid and glycerol below fasting level. GLUT4 mRNA was downregulated by both HGI and LGI diets to a comparable extent, whereas GLUT4 protein levels were not changed during this short period. FAT/CD36 mRNA and protein levels were substantially decreased with the HGI diet below baseline, but not with the LGI diet. CONCLUSION: This study found a significant dietary GI effect on post-exercise FAT/CD36 gene expression in human skeletal muscle. This result implicates that the differences in dietary GI are sufficient to alter fat metabolism.


Subject(s)
CD36 Antigens/metabolism , Dietary Carbohydrates/metabolism , Exercise/physiology , Glucose Transporter Type 4/metabolism , Glycemic Index , Muscle, Skeletal/metabolism , Area Under Curve , Biopsy , Blood Glucose/metabolism , CD36 Antigens/genetics , Cross-Over Studies , Glucose Transporter Type 4/genetics , Glycogen/metabolism , Humans , Insulin/metabolism , Male , Muscle, Skeletal/pathology , Postprandial Period , RNA, Messenger/analysis , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Young Adult
10.
Environ Sci Technol ; 43(9): 3335-42, 2009 May 01.
Article in English | MEDLINE | ID: mdl-19534155

ABSTRACT

Radiation-induced bystander effects are established consequences of exposure to ionizing radiation. The operation of this mechanism has been seen in vitro and also between fish, mammals, and plants in vive where stress signals from treated organisms induce responses in neighbors. In vitro research shows that DNA repair deficient cells produce more toxic bystander responses. To test this in vivo two strains of Japanese medaka were tested. One is a mutant, repair deficient strain (ric2) and the other, the wildtype repair proficient strain (CAB). Irradiated fish swam with unirradiated partners in a strain mix and match protocol. The data suggest that medaka produce signals, when exposed to radiation, that induce unirradiated fish ofthe same strain swimming with them to produce an altered response to that seen in bystanders to sham irradiated fish. More apoptosis was seen in bystanders to repair deficient fish. When the strains are mixed, the bystanders of either strain respond like the donor strain. Measurements of Bcl-2 and cmyc proteins in the explants confirmed these observations. A possible role for p53 was also identified in that the use of reporters with mutant p53 demonstrated that CAB signals killed all the reporter cells by apoptosis. Use of a similar but p53 wildtype cell line had no such effect. The data add to the body of knowledge showing that bystander signals operate at hierarchical levels of organization greater than the individual and may therefore have relevance in radioecology and (eco)systems biology.


Subject(s)
DNA Repair/radiation effects , Oryzias/metabolism , Radiation , Signal Transduction/radiation effects , Animals , Apoptosis/radiation effects , Cell Line , Cell Survival/radiation effects , Colony-Forming Units Assay , Humans , Mutation/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Skin/cytology , Skin/metabolism , Skin/radiation effects , X-Rays
11.
J Plast Reconstr Aesthet Surg ; 62(11): 1464-9, 2009 Nov.
Article in English | MEDLINE | ID: mdl-18708309

ABSTRACT

The deep inferior epigastric perforator (DIEP) flap is normally the first choice in breast reconstruction; however, due to the considerable vascular anatomical variation and the learning curve for the procedure, muscle-sparing transverse rectus abdominis musculocutaneous (TRAM) flaps are still frequently performed to reduce the rate of complications. Accurate preoperative investigation of the perforators would allow better operative preparation and possibly shorten the learning curve. In an effort to increase accuracy of preoperative planning and to aid preoperative decision-making in free abdominal flap breast reconstruction, we have acquired the use of VoNavix, software that creates three dimensional images from computerised tomography angiography (CTA) data. The use of the VoNavix software for analysis of CTA provides superior imaging that can be viewed in theatre. It, together with CTA, enables decisions to be made preoperatively, including: which side to raise the flap; whether to aim for a medial or lateral row perforator; whether to take a segment of muscle and whether to expect an easy or difficult dissection. We have now performed over 60 free abdominal flap breast reconstructions aided with CTA, and 10 of these cases also used VoNavix technology. This paper presents our initial experience with the use of this software, illustrated with three patient examples. The advantages and disadvantages are discussed.


Subject(s)
Angiography/methods , Epigastric Arteries , Mammaplasty/methods , Radiographic Image Interpretation, Computer-Assisted , Rectus Abdominis/transplantation , Tomography, X-Ray Computed/methods , Breast Neoplasms/surgery , Female , Follow-Up Studies , Graft Rejection , Graft Survival , Humans , Imaging, Three-Dimensional/methods , Mammaplasty/instrumentation , Mastectomy/methods , Middle Aged , Preoperative Care/methods , Rectus Abdominis/blood supply , Sampling Studies , Software , Surgical Flaps/blood supply , Treatment Outcome , Wound Healing/physiology
12.
Environ Sci Technol ; 42(9): 3441-6, 2008 May 01.
Article in English | MEDLINE | ID: mdl-18522131

ABSTRACT

These experiments were designed to identify stress effects in 3 key organs in Atlantic Salmon (Salmo salar, L.) after exposure in vivo to very low doses of radiation, and subtoxic levels of aluminum (Al) and cadmium (Cd) alone or in combination. Six fish per group were sacrificed after exposure and the anterior kidney, fin, and gill were dissected and sentfor assay of bystander signal production as a stress response end point. Radiation doses as low as 4 mGy delivered over 5 h, alone or in combination with Cd and/or Al, caused bystander signals to be produced in tissues harvested from in vivo exposed salmon. The effects vary among different organs and are not consistently additive or synergistic for a given treatment although gill cells do show high degrees of synergism between radiation and metal exposure. Data for individual fish did not suggest any systemic sensitivity to the stressors. Interestingly, the data for Cd suggest that lower toxicity is found when the metal is used in combination with radiation exposure. Expression of two proteins associated with survival responses (Bcl-2) or death responses (cmyc) after radiation was measured in the tissue cultures and showed a highly significant correlation with response outcome. The results, although complex, indicate that these stress signal responses may aid in the mechanistic investigation of mixed contaminant effects in fish exposed to metals and radiation.


Subject(s)
Environmental Pollutants/analysis , Metals, Heavy/toxicity , Radioactive Pollutants/analysis , Water Pollutants, Chemical/analysis , Aluminum/analysis , Aluminum/chemistry , Animals , Biomarkers , Cadmium/analysis , Cadmium/chemistry , Gene Expression Regulation/drug effects , Hydrogen-Ion Concentration , Proto-Oncogene Proteins c-myc/metabolism , Radiation , Salmo salar , Time Factors , Water/chemistry
13.
Tissue Antigens ; 69(1): 38-46, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17212706

ABSTRACT

Little is known about the relationship between human leukocyte antigen (HLA) class II genes and family history of asthma or atopy in relation to the incidence of childhood asthma. The objective of the study was to determine whether specific HLA class II genes (e.g., DRB1*03) are associated with asthma and whether such association explains the influences of family history of asthma or atopy on asthma incidence. A stratified random sample of 340 children who had HLA data available from the Rochester Family Measles Study cohort (n= 876) and a convenience sample of healthy children aged 5-12 years were the participants. We conducted comprehensive medical record reviews to determine asthma status of these children. The associations between the presence of specific HLA alleles and development of asthma and the role of family history of asthma or atopy in the association were evaluated by fitting Cox models. The cumulative incidence of asthma by 12 years of age among children who carry HLA DRB1*03 was 33%, compared to 24.2% among those who did not carry this allele. Adjusting for family history of asthma or atopy, gender, low birth weight, season of birth, HLA DRB1*04, and HLA DQB1*0302, the hazards ratio for HLA DRB1*03 carriers was 1.8 (95% confidence interval: 1.1-2.9, P= 0.020). We concluded that the HLA DRB1*03 allele is associated with asthma. However, the HLA class II gene does not explain the influences of family history of asthma or atopy on development of asthma. The mechanism underlying the association between asthma and HLA genes needs to be elucidated.


Subject(s)
Asthma/genetics , Asthma/immunology , Genetic Predisposition to Disease , HLA-D Antigens/genetics , HLA-D Antigens/immunology , Adolescent , Child , Child, Preschool , Cohort Studies , Female , HLA-D Antigens/classification , Humans , Infant , Male , Retrospective Studies
14.
Environ Sci Technol ; 40(21): 6859-64, 2006 Nov 01.
Article in English | MEDLINE | ID: mdl-17144322

ABSTRACT

We report data in this paper suggesting that fish irradiated to 0.5 Gy total body dose can release factors into the water that signal other unexposed fish and cause induction of bystander effects expressed as increased cell death in a reporter system. Radiation-induced bystander effects, resulting in the appearance of radiation damage or induction of typical radiation responses in unirradiated cells and tissues are now an established consequence of exposure to low doses of ionizing radiation, however little work has been done in vivo or in species other than humans or mice. In these experiments rainbow trout were irradiated and then paired with unirradiated fish for two hours. Additionally, unirradiated fish were placed in water which had previously been used to hold irradiated fish for 2 h. Sham-irradiated fish and absolute control fish were also examined all using blind protocols. Following a two h incubation period, at these various exposure regimes, the fish were killed by a blow to the head and dissected. Five organs were removed from each fish and tissue explants were cultured using an established technique. After 2 days, the culture medium was harvested and used in a reporter assay to determine whether a bystander effect had been induced. The explants were cultured on in Clonetics growth medium for a further 14 days then fixed for assay of radiation response proteins. The responses varied according to the cell type in the original explants, with the gill and fin showing the most pronounced response. The results suggest that communication signals leading to a typical radiation response can be passed between fish and seem to involve secretion of a chemical messenger into the water.


Subject(s)
Radiation Injuries, Experimental/etiology , Radiation Injuries/etiology , X-Rays , Animals , Bystander Effect , Cell Communication , Dose-Response Relationship, Radiation , Oncorhynchus mykiss , Radiation , Radiation Injuries/pathology , Radiation Injuries, Experimental/pathology , Radiation Tolerance , Radiation, Ionizing , Time Factors
15.
J Exp Biol ; 209(Pt 19): 3828-36, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16985199

ABSTRACT

Honeybees, Apis mellifera, gradually increase their rate of forage uptake as they gain foraging experience. This increase in foraging performance has been proposed to occur as a result of learning; however, factors affecting flight ability such as changes in physiological components of flight metabolism could also contribute to this pattern. Thus, the purpose of this study was to assess the contribution of physiological changes to the increase in honeybee foraging performance. We investigated aspects of honeybee flight muscle biochemistry throughout the adult life, from non-foraging hive bees, through young and mature foragers, to old foragers near the end of their lifespan. Two-dimensional gel proteomic analysis on honeybee thorax muscle revealed an increase in several proteins from hive bees to mature foragers including troponin T 10a, aldolase and superoxide dismutase. By contrast, the activities (V(max)) of enzymes involved in aerobic performance, phosphofructokinase, hexokinase, pyruvate kinase and cytochrome c oxidase, did not increase in the flight muscles of hive bees, young foragers, mature foragers and old foragers. However, citrate synthase activity was found to increase with foraging experience. Hence, our results suggest plasticity in both structural and metabolic components of flight muscles with foraging experience.


Subject(s)
Appetitive Behavior/physiology , Bees/physiology , Feeding Behavior/physiology , Flight, Animal , Muscles/physiology , Age Factors , Analysis of Variance , Animals , Base Sequence , Bees/enzymology , Citrate (si)-Synthase/metabolism , Electrophoresis, Gel, Two-Dimensional , Fructose-Bisphosphate Aldolase/genetics , Fructose-Bisphosphate Aldolase/metabolism , Mass Spectrometry , Molecular Sequence Data , Muscles/enzymology , Ontario , Sequence Analysis, DNA , Superoxide Dismutase/metabolism , Troponin T/genetics , Troponin T/metabolism
17.
J Mater Sci Mater Med ; 16(12): 1179-84, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16362219

ABSTRACT

Tricalcium phosphate (TCP) powders synthesised using the Ca(NO3)2 and Ca(OH)2 routes were doped with TiO2, ZrO2 and Al2O3 in order to increase their compressive strength. An ultimate compressive strength (UCS) of 255 +/- 6 MPa was achieved for approximately 10 vol% TiO2 doping compared to 30 +/- 3 MPa for an un-doped control processed and tested in the same manner. Higher levels of TiO2 doping resulted in smaller increases in UCS with 30 and 50 vol% achieving 213 +/- 9 and 178 +/- 15 MPa, respectively. Very small amounts of Al2O3 doping (< 0.5 vol%) also resulted in a stronger materials. However, under the processing conditions employed, higher levels of Al2O3 and ZrO2 doping resulted in no beneficial effect on the UCS. Polyvinyl alcohol (PVA) was used as binding agent to facilitate processing. As expected, higher levels of PVA were associated with smaller increases in UCS. Powders synthesised using the Ca(OH)2 route had smaller particle size and resulted in larger increases in UCS compared to the Ca(NO3)2-synthesised powders. Although some powders contained alpha and beta-TCP phases, no other calcium phosphate, CaO, CaTiO3 or CaZrO3 phases were detected. In conclusion, a significant increase in the UCS of TCP was achieved by doping with approximately 10 vol% TiO2 which is expected to have little or no effect on the bioactivity or bioresorbability of the material.


Subject(s)
Aluminum Oxide/chemistry , Calcium Phosphates/chemistry , Titanium/chemistry , Zirconium/chemistry , Materials Testing , Microscopy, Electron, Scanning , X-Ray Diffraction
18.
Biochem Soc Trans ; 33(Pt 3): 499-501, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15916551

ABSTRACT

The herpes simplex virus 1 ICP27 is an essential, highly conserved protein involved in various steps of herpes simplex virus 1 gene regulation as well as in the shut-off of host gene expression during infection. It functions primarily at the post-transcriptional level in inhibiting precursor mRNA splicing and in promoting nuclear export of viral transcripts. These activities are discussed.


Subject(s)
Gene Expression Regulation/genetics , Immediate-Early Proteins/metabolism , Animals , Humans , Immediate-Early Proteins/chemistry , Protein Transport , RNA Splicing/genetics , RNA Transport , Transcription, Genetic/genetics
19.
J Chem Phys ; 122(14): 144503, 2005 Apr 08.
Article in English | MEDLINE | ID: mdl-15847541

ABSTRACT

We studied temperature dependence of complex capacitance, impedance, and polarized Raman spectra of single crystal Cs2Nb4O11. First, we observed a sharp lambda-shaped peak at 165 degrees C in the complex capacitance, then found drastic changes in the Raman spectra in the same temperature range. Utilizing the pseudosymmetry search of structure space group, we attributed the observed anomalies to a structural change from the room temperature orthorhombic Pnn2 to another orthorhombic Imm2. We also measured room temperature polarized Raman spectra in different symmetries of normal vibrations and assigned high wavenumber Raman bands to the internal vibrations of NbO6 octahedra and NbO4 tetrahedra.

20.
Ann N Y Acad Sci ; 1027: 110-28, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15644350

ABSTRACT

Liquid diffusion experiments conducted on the MIR space station using the Canadian Space Agency QUELD II processing facility and the microgravity isolation mount (MIM) showed that g-jitter significantly increased the measured solute diffusion coefficients. In some experiments, milli-g forced vibration was superimposed on the sample when isolated from the ambient g-jitter; this resulted in markedly increased solute transport. To further explore the effects arising in these long capillary diffusion couples from the absence of unit-gravity and the presence of the forced g-jitter, the effects of a 1 milli-g forcing vibration on the mass transport in a 1.5 mm diameter long capillary diffusion couple have been simulated. In addition, to increase understanding of the role of unit gravity in determining the extent to which gravity can influence measured diffusion coefficient values, comparative experiments involving gold, silver, and antimony diffusing in liquid lead have been carried out using a similar QUELD II facility to that employed in the QUELD II/MIM/MIR campaign but under terrestrial conditions. It was found that buoyancy-driven convection may still persist in the liquid even when conditions are arranged for a continuously decreasing density gradient up the axis of a vertical long capillary diffusion couple due to the presence of small radial temperature gradients.


Subject(s)
Biophysics/methods , Acceleration , Alloys , Antimony/chemistry , Biological Transport , Computer Simulation , Convection , Diffusion , Gold/chemistry , Gravitation , Gravity, Altered , Lead/chemistry , Macromolecular Substances , Silver/chemistry , Space Flight , Spacecraft , Temperature , Weightlessness
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