PubMed Health⌕ Search

Biomedical subjects

J H Taylor

Publications and source records attributed to J H Taylor.

At least 19 recordsLinked to original sources
PubMed2003

Inheritance of plant regeneration from maize (Zea mays L.) shoot meristem cultures derived from germinated seeds and the identification of associated RAPD and SSR markers.

The inheritance of shoot regeneration through shoot-tip meristem culture derived from maize seedling was evaluated, and the markers (RAPD and SSR) associated with this regeneration character were identified both in a group of North American maize inbreds and a crossing population. A discrete distribution of percent regeneration and no. of shoots per explant was observed in the inbred group and the F(2) population. The results suggested that this regenerable trait was controlled by several major genes. Five RAPD markers were identified to be relevant to percent regeneration in maize shoot-tip culture system. One RAPD marker and three SSR markers were associated with no. of shoot per explant and its relevant traits. Of them marker BC603-1600 explained 18% of the variation for no. of shoot per explant and 16% of the variation for callus size. The BC603-1600 was sequenced and assigned in linkage group 7 based on a NCBI blast search. The information provided here should benefit to determine the genetic mechanisms involved in the maize regeneration response related to shoot meristem culture pathway and benefit to select high regenerable germplasm by using marker assisted selection.

Analysis of Variance↗
PubMed2002

Biocide use in the food industry and the disinfectant resistance of persistent strains of Listeria monocytogenes and Escherichia coli.

AIMS: The aims of the project were threefold: to survey the use of disinfectants in the UK food industry; to assess the product and environmental microflora of selected food factories for the persistence of Listeria monocytogenes and Escherichia coli; and to determine the disinfectant resistance of any persistent strains. METHODS AND RESULTS: A survey of the use of disinfectants in the UK food industry was undertaken in which a total of 40 sites were visited and a further 77 postal questionnaires were returned from farms, food manufacture, food transport and food retail sites. Quaternary ammonium compounds (QACs) were predominantly used, applied in small volumes as a mist. Approximately 30,000 samples from the product and environment of five chilled food factories were examined for L. monocytogenes and E. coli over a 3 year period. A total of 181 L. monocytogenes and 176 E. coli isolates were ribotyped to yield 19 and 34 ribogroups, respectively. Some strains were isolated only from the product, a number only from the environment and others from both niches. Some strains were seen to be persistent for the duration of the sampling exercise (2-3 years). The most common L. monocytogenes and E. coli strains, together with two environmental L. monocytogenes strains, were assessed for any resistance to commercial disinfectants as compared with a laboratory L. monocytogenes disinfectant testing strain. The resistance of the L. monocytogenes and E. coli strains isolated from the factory were not significantly different from the laboratory control strain. CONCLUSIONS: Persistent strains of L. monocytogenes and E. coli are found in the UK food industry, though this persistence is not related to their increased susceptibility to the most commonly used disinfectants. SIGNIFICANCE AND IMPACT OF THE STUDY: The concept of a persistent microflora in food factories will have an impact on the future selection of suitable control options, including the use of biocides.

DNA Fingerprinting↗
PubMed2002

Biocide use in the food industry and the disinfectant resistance of persistent strains of Listeria monocytogenes and Escherichia coli.

AIMS: The aims of the project were threefold: to survey the use of disinfectants in the UK food industry; to assess the product and environmental microflora of selected food factories for the persistence of Listeria monocytogenes and Escherichia coli; and to determine the disinfectant resistance of any persistent strains. METHODS AND RESULTS: A survey of the use of disinfectants in the UK food industry was undertaken in which a total of 40 sites were visited and a further 77 postal questionnaires were returned from farms, food manufacture, food transport and food retail sites. Quaternary ammonium compounds (QACs) were predominantly used, applied in small volumes as a mist. Approximately 30,000 samples from the product and environment of five chilled food factories were examined for L. monocytogenes and E. coli over a 3 year period. A total of 181 L. monocytogenes and 176 E. coli isolates were ribotyped to yield 19 and 34 ribogroups, respectively. Some strains were isolated only from the product, a number only from the environment and others from both niches. Some strains were seen to be persistent for the duration of the sampling exercise (2-3 years). The most common L. monocytogenes and E. coli strains, together with two environmental L. monocytogenes strains, were assessed for any resistance to commercial disinfectants as compared with a laboratory L. monocytogenes disinfectant testing strain. The resistance of the L. monocytogenes and E. coli strains isolated from the factory were not significantly different from the laboratory control strain. CONCLUSIONS: Persistent strains of L. monocytogenes and E. coli are found in the UK food industry, though this persistence is not related to their increased susceptibility to the most commonly used disinfectants. SIGNIFICANCE AND IMPACT OF THE STUDY: The concept of a persistent microflora in food factories will have an impact on the future selection of suitable control options, including the use of biocides.

Anti-Bacterial Agents↗
PubMed2000

A microbiological evaluation of warm air hand driers with respect to hand hygiene and the washroom environment.

A finger rinse technique for counting micro-organisms on hands showed no significant difference in the level of recovered micro-organisms following hand drying using either warm air or paper towels. Contact plate results appeared to reflect the degree of dampness of hands after drying rather than the actual numbers of micro-organisms on the hands. In laboratory tests, a reduction in airborne count of Pseudomonas aeruginosa and Staphylococcus aureus of between 40 and 75% was achieved from 600 readings comparing inlets and outlets of warm air hand driers. In washroom trials, the number of airborne micro-organisms was reduced by between 30 and 75%. Air emitted from the outlet of the driers contained significantly fewer micro-organisms than air entering the driers. Drying of hands with hand driers was no more likely to generate airborne micro-organisms than drying with paper towels. Levels of micro-organisms on external surfaces of hand driers were not significantly different to those on other washroom surfaces. This work shows that warm air hand driers, of the type used in this study, are a hygienic method of drying hands and therefore appropriate for use in both the healthcare and food industry.

Air Microbiology↗
PubMed2000

Influence of tramadol on the ventilatory response to hypoxia in humans.

We studied the effect of tramadol on the ventilatory response to 7 min acute isocapnic hypoxia (SpO2 85.1 (SD 0.4)%) during steady mild hypercapnia (PE'CO2 0.7 kPa above normoxic baseline) in 14 healthy volunteers (seven male). The acute hypoxic response was measured before and 1 h after oral placebo or tramadol (100 mg). After tramadol, ventilation during mild hypercapnia (mean 11.28 litres min-1) was significantly less (P < 0.05) than during placebo baseline (13.93 litres min-1), tramadol baseline (14.63 litres min-1), or after placebo (14.95 litres min-1), confirming that tramadol has a small depressive effect on the hypercapnic ventilatory response. There was no significant difference in the hypoxic ventilation/SpO2 response (1 min-1 %-1) measured during the placebo baseline (0.99), placebo (1.18), tramadol baseline (0.78) or tramadol (0.68) runs. These data suggest that tramadol does not depress the hypoxic ventilatory response.

Adolescent↗
PubMed1999

Effectiveness of cleaning techniques used in the food industry in terms of the removal of bacterial biofilms.

The effectiveness of cleaning was investigated through food factory trials and laboratory experiments using a naturally occurring biofilm from a food factory environment and generated biofilms. The efficacy of factory cleaning and disinfection programmes was assessed by swabbing and total viable count (TVC) analysis of surfaces before cleaning, after cleaning and after disinfection. Cleaning produced a 0.91 log reduction in the attached population. Investigation of the effectiveness of a variety of cleaning methods in the removal of a naturally occurring food factory biofilm showed that the high pressure spray and the mechanical floor scrubber, which use a high degree of mechanical action, were most effective. Cleaning trials with biofilms of Pseudomonas aeruginosa or Staphylococcus aureus showed that spraying with water at pressures of 34.5, 51.7 and 68.9 bar did not significantly increase the removal, as assessed by direct epifluorescent microscopy (DEM) and swabbing and TVC analysis, beyond the three log reduction observed at 17.2 bar. The effect of spray time at 17.2 bar showed that increasing spray time from 1 to 10 s did not significantly increase removal of Ps. aeruginosa biofilm. Investigation of the optimum distance of the spray lance from the surface at 17.2 bar was found to be between 125 and 250 mm. The use of an alkaline, acidic or neutral detergent prior to spraying with water at 17.2 bar did not significantly increase the removal of Ps. aeruginosa or Staph. aureus. However, the acidic and alkaline products significantly (P = 0.05) affected the viability of Staph. aureus and Ps. aeruginosa, respectively, thereby minimizing the potential for the spread of contamination.

Bacterial Adhesion↗
PubMed1999

A comparison of the bactericidal efficacy of 18 disinfectants used in the food industry against Escherichia coli O157:H7 and Pseudomonas aeruginosa at 10 and 20 degrees C.

A number of proprietary disinfectant products (18) used in the food industry were tested for their bactericidal efficacy against Pseudomonas aeruginosa and Escherichia coli O157:H7 at 20 and 10 degrees C according to the BS EN 1276 (1997) quantitative suspension test for the evaluation of bactericidal activity of chemical disinfectants and antiseptics used in food, industrial, domestic and institutional areas. At 20 degrees C, 13 products passed at their in-use concentration (under clean and dirty conditions) against Ps. aeruginosa and 15 passed against E. coli O157:H7. The number of products passing the test at 10 degrees C was 11 and 14 for Ps. aeruginosa and E. coli O157:H7, respectively. The products exhibiting reduced efficacy at the lower temperature were amphoterics and quaternary ammonium compounds although some of these types of products were effective at both temperatures. Products that passed against Ps. aeruginosa generally also passed against E. coli O157:H7. Taking all the results together, only 11 of the total of 18 products achieved a pass result under all the parameters tested. This work demonstrates the need for final verification of disinfectant efficacy by undertaking field trials in the food-processing environment in which the product is intended for use.

Cold Temperature↗
PubMed1999

Drug choice and therapeutic drug monitoring in the management of canine primary epilepsy.

Therapeutic drug monitoring is an underutilised resource in the management of canine primary epilepsy. Many of the anti-epileptic drugs, including phenobarbitone, have variable pharmacokinetic profiles in different dogs, with each individual animal showing variable rates of absorption, distribution, metabolism and excretion. This results in variable serum drug concentrations with the same oral dose. Many clinicians interpret this situation as therapeutic failure and classify these patients as refractory to treatment. By measuring blood concentrations of drugs at appropriate times, it is possible to explain the efficacy or failure of treatment, and also to prevent serum concentrations from reaching toxic levels. By analysing paired samples, key pharmacokinetic parameters may be calculated for each patient and a profile for the disposition of the drug obtained. Individual optimal drug dosage can be calculated for each patient at little cost to the pet owner.

Animals↗
PubMed1997

The pathophysiology and medical management of canine osteoarthritis.

Osteoarthritis or degenerative joint disease is a condition characterised by degeneration of articular cartilage often associated with the formation of new bone at joint surfaces on margins. Commonly encountered in dogs, osteoarthritis may have a gradual onset, but may also occur acutely. Osteoarthritis can be a primary disease of joint cartilage, but is more after secondary to abnormal stresses on joints. This article describes the pathogenesis and progression of cartilage degeneration as well as the dietary, lifestyle and pharmacological management of osteoarthritis. Recent pharmacological developments allow the clinician not only to control clinical signs of the disease, but also to slow the progression of cartilage degeneration.

Animals↗
PubMed1997

The effect of diminazene aceturate on cholinesterase activity in dogs with canine babesiosis.

A clinical trial was designed to evaluate the effects of diminazene aceturate and its stabiliser antipyrine on serum pseudocholinesterase (PChE) and red blood cell acetylcholinesterase (RBC AChE) in dogs with babesiosis. The trial was conducted on naturally occurring, uncomplicated cases of babesiosis (n = 20) that were randomly allocated to groups receiving a standard therapeutic dose of diminazene aceturate with antipyrine stabiliser (n = 10) or antipyrine alone (n = 10). Blood was drawn immediately before and every 15 minutes for 1 hour after treatment. Plasma PChE showed a 4% decrease between 0 and 60 min within the treatment group (p < 0.05). No statistically significant differences were found between the treatment and control groups at any of the time intervals for PChE. There was an increase in RBC AChE activity at 15 min in the treatment group (p < 0.05). No significant differences were found between the treatment and control groups at any time interval for RBC AChE. In view of the difference in PChE, samples from additional, new cases (n = 10) of canine babesiosis were collected to identify the affect of the drug over 12 hours. No significant depression was identified over this time interval. The results suggests that the underlying mechanism in producing side-effects, when they do occur, is unlikely to be through cholinesterase depression.

Acetylcholinesterase↗
PubMed1995

Differences in the oral bioavailability of three rafoxanide formulations in sheep.

The bioavailability of a modified rafoxanide oral suspension was compared to the original innovator product and a generic formulation in a single dose, randomised, parallel design study in sheep (n = 30). The area under the rafoxanide plasma concentration versus time curve (AUC), AUC extrapolated to infinity, and maximum plasma rafoxanide concentrations (Cmax), were used to compare the extent of absorption of the formulations. All 3 parameters were significantly (p < or = 0.01) smaller for both the modified and generic formulations relative to the original product. There were no significant (p > 0.05) differences between the modified and generic formulations. The mean point ratio % of the modified to original and modified to generic formulations for the 3 parameters were 36.4%, 35%, 45.9% and 70.9%, 70%, 79.7%, respectively. In terms of the calculated 90% confidence t-intervals of the mean % ratios, the modified and generic formulations were not bioequivalent to the original product, since they were substantially below the accepted range of 80-125%. No significant differences (p > 0.05) were noted for the time to Cmax and Cmax/AUC, both measurements of rate of absorption. A lag period before absorption of rafoxanide for all formulations of c 5 h was observed. The differences in oral bioavailability of rafoxanide and related anthelmintic formulations have implications for the efficacy and registration of generic products.

Administration, Oral↗
PubMed1995

Electrophoretic separation of canine haemoglobin in dogs with babesiosis.

Venous blood was collected from clinically healthy (n = 5) and B. canis (n = 5) infected dogs. Parasitised red blood cells were not removed from blood samples prior to preparation. The erythrocytes were washed, lysed, the haem ring removed from the haemoglobin molecule and the globin chains denatured by breaking disulphide linkages between amino acids. These haemolysates were then subjected to electrophoresis in polyacrylamide gels containing acid, urea and the non-ionic detergent Triton X-100. In all 5 B. canis infected dogs a protein band was observed above the beta chain of haemoglobin. This band was absent in all 5 healthy dogs. It is postulated that this band represents a fragment of the globin chain that remains after proteolysis caused by the B. canis parasite. Further study is needed to exclude the possibility that the electrophoretic band might be of parasitic origin.

Animals↗
PubMed1993

The effect of Babesia canis induced haemolysis on the canine haemoglobin oxygen dissociation curve.

Samples of blood from normal healthy (n = 7) and Babesia canis-infected dogs (n = 7) were subjected to varying oxygen tensions in a tonometer, after which the samples were subjected to blood gas analysis and haemoximetry. This data was used to plot haemoglobin oxygen dissociation curves (ODC) for both groups of dogs. States of acidosis and hypercapnia were then simulated by modelling, and the response of the 2 haemoglobin oxygen dissociation curves compared. The ODC of the B. canis-infected group showed a decreased ability to shift to the right when compared to that of the normal, healthy ODC. This decreased Bohr effect probably exacerbates the severe tissue hypoxia associated with this disease by impairing the ability of haemoglobin to off-load oxygen at the tissue level.

Animals↗
PubMed1992

Interstitial microwave hyperthermia and brachytherapy for malignancies of the vulva and vagina. I: Design and testing of a modified intracavitary obturator.

A vaginal obturator was fabricated to be used in combination with implanted catheters to provide microwave hyperthermia and brachytherapy to the vulva and vaginal wall. This site is difficult to heat or irradiate solely with interstitial techniques. The obturator was modified to provide grooves for the mounting of interstitial catheters into the outer wall and was matched with a template for circumferential implants. Power deposition tests were done using arrays of three microwave antenna designs: dipole (hA = hB = 3.9 cm), helical (3.9 cm coil, shorted), and modified dipole (1.0 cm helix on dipole tip) to test the performance of the obturator. The obturator and four non-obturator catheters were positioned in muscle-equivalent phantom. Two obturator catheters along with two free-standing catheters formed the obturator array. Four freestanding catheters formed the non-obturator array. Power deposition or specific absorption rate (SAR) measurements were made along the central axis, bisect, and diagonal transect of each array. SAR results showed that antennas in the obturator wall radiated as dipole theory predicts, although with less power density when compared to antennas in the same catheters spaced 1.8 cm from the obturator. This could be compensated for by increasing the power to the antennas in the obturator by 42%. Adjacent pairs of antennas were placed 90 degrees out of phase for 0.25 sec and rotated around the array. Phase rotation demonstrated that the central array SAR peaks could be lowered from 100% to 50% SAR, with dipole antennas thus resulting in lowered peak temperatures and the ability to heat larger volumes by improving the distribution of power. With helical antennas, there was 50% SAR at the array center when operated coherently without phase rotation. Three patients were treated with the obturator and a custom-made template using dipole antennas, and temperatures were measured in five obturator catheters. Therapeutic heating was measured in the catheters on the obturator between antennas in contact with the vaginal mucosa.

Brachytherapy↗