PubMed Health⌕ Search

Biomedical subjects

S A Turner

Publications and source records attributed to S A Turner.

At least 19 recordsLinked to original sources
PubMed2004

Survey for papillomatous digital dermatitis in Australian dairy cattle.

OBJECTIVE: To determine whether Treponema-associated papillomatous digital dermatitis (PDD) occurs in Australian dairy cattle. DESIGN: Mail-out questionnaire and histological and bacteriological examination of biopsy tissue from suspect PDD lesions. PROCEDURE: The questionnaire was mailed to 375 veterinarians to evaluate their knowledge of PDD, determine if they had observed the disease in Australian dairy cattle, and to request biopsy material from suspicious cases. Biopsies were examined for histological and bacteriological evidence of PDD, including for the presence of spirochaetes. RESULTS: Eighty-eight replies to the questionnaire were received (23.5%). Of 52 respondents who were aware of PDD as a possible cause of lameness, 26 reported observing the condition in Australian cattle. Of 32 respondents who were unaware of the condition, 6 reported observing lesions that might have been PDD. The majority of reports of PDD-like lesions came from the southern Australian states, the condition occurring during periods of high rainfall and proving responsive to topical or parenteral application of antimicrobials. Biopsies from five erosive lesions showed histological similarity to PDD whereas biopsies from five proliferative lesions were consistent with chronic inflammation, fibroma or cutaneous papilloma. The presence of spirochaetes was not demonstrated in any of the lesions by histological or bacteriological methods. CONCLUSION: Anecdotal reports and analysis of biopsy material confirm that a condition similar to PDD does occur sporadically in dairy cattle in southern Australia. However, this condition has so far not been shown to be associated with the presence of spirochaetes in the lesions.

Animals↗
PubMed2001

Ferric dicitrate transport system (Fec) of Shigella flexneri 2a YSH6000 is encoded on a novel pathogenicity island carrying multiple antibiotic resistance genes.

Iron uptake systems which are critical for bacterial survival and which may play important roles in bacterial virulence are often carried on mobile elements, such as plasmids and pathogenicity islands (PAIs). In the present study, we identified and characterized a ferric dicitrate uptake system (Fec) in Shigella flexneri serotype 2a that is encoded by a novel PAI termed the Shigella resistance locus (SRL) PAI. The fec genes are transcribed in S. flexneri, and complementation of a fec deletion in Escherichia coli demonstrated that they are functional. However, insertional inactivation of fecI, leading to a loss in fec gene expression, did not impair the growth of the parent strain of S. flexneri in iron-limited culture media, suggesting that S. flexneri carries additional iron uptake systems capable of compensating for the loss of Fec-mediated iron uptake. DNA sequence analysis showed that the fec genes are linked to a cluster of multiple antibiotic resistance determinants, designated the SRL, on the chromosome of S. flexneri 2a. Both the SRL and fec loci are carried on the 66,257-bp SRL PAI, which has integrated into the serX tRNA gene and which carries at least 22 prophage-related open reading frames, including one for a P4-like integrase. This is the first example of a PAI that carries genes encoding antibiotic resistance and the first report of a ferric dicitrate uptake system in Shigella.

Bacterial Proteins↗
PubMed2001

Nested deletions of the SRL pathogenicity island of Shigella flexneri 2a.

In this study, we determined the boundaries of a 99-kb deletable element of Shigella flexneri 2a strain YSH6000. The element, designated the multiple-antibiotic resistance deletable element (MRDE), had recently been found to contain a 66-kb pathogenicity island (PAI)-like element (designated the SRL PAI) which carries the Shigella resistance locus (SRL), encoding resistance determinants to streptomycin, ampicillin, chloramphenicol, and tetracycline. The YSH6000 MRDE was found to be flanked by two identical IS91 elements present at the S. flexneri homologs of the Escherichia coli genes putA and mdoA on NotI fragment D. Sequence data from two YSH6000-derived MRDE deletants, YSH6000T and S2430, revealed that deletion of the MRDE occurred between the two flanking IS91 elements, resulting in a single IS91 element spanning the two original IS91 loci. Selection for the loss of tetracycline resistance confirmed that the MRDE deletion occurred reproducibly from the same chromosomal site and also showed that the SRL PAI and the SRL itself were capable of independent deletion from the chromosome, thus revealing a unique set of nested deletions. The excision frequency of the SRL PAI was estimated to be 10(-5) per cell in the wild type, and mutation of a P4-like integrase gene (int) at the left end of the SRL PAI revealed that int mediates precise deletion of the PAI.

Anti-Bacterial Agents↗
PubMed2000

Mapping access to food in a deprived area: the development of price and availability indices.

OBJECTIVE: To develop and map indices to illustrate variation in the cost and availability of healthy food. DESIGN: Two contiguous wards in London were selected by virtue of their high Carstairs deprivation scores. A 2-km area was defined around a randomly chosen central point. All retail outlets selling food within the area were visited and their location recorded. A list of foods, acceptable to the local ethnically diverse population, which met current dietary guidelines, was devised. Data on the availability and price of 71 food items were collected. Indices were developed using SPSS and mapped using Geographic Information System (GIS) software. RESULTS: Information on availability and prices were collected from 199 outlets. The mean price index shows how expensive a shop is relative to other shops in the area. The least cost index shows the relative expense of a shop using the cheapest ways of buying their range of foods. Shorthand indices were tested, using data on 19 of the 71 prices. Availability indices are also discussed, including a green availability index and a fresh green availability index. Illustrative maps of the shop locations and the mean price index and fresh green availability index are shown. CONCLUSIONS: Data can be collected and indices developed which indicate geographic variation in shop 'expensiveness', and in the price and availability of healthy food. GIS software can be used to map these indices, to identify areas with high food prices or low availability.

Abstracting and Indexing↗
PubMed2000

A calcimimetic agent lowers plasma parathyroid hormone levels in patients with secondary hyperparathyroidism.

BACKGROUND: The calcimimetic agent R-568 lowers plasma parathyroid hormone (PTH) levels in hemodialysis patients with mild secondary hyperparathyroidism, but its efficacy in those with more severe secondary hyperparathyroidism has not been studied. METHODS: Twenty-one patients undergoing hemodialysis three times per week with plasma PTH levels between 300 and 1200 pg/mL were randomly assigned to 15 days of treatment with either 100 mg of R-568 (N = 16) or placebo (N = 5). Plasma PTH and blood ionized calcium levels were measured at intervals of up to 24 hours after oral doses on days 1, 2, 3, 5, 8, 11, 12, and 15. RESULTS: Pretreatment PTH levels were 599 +/- 105 (mean +/- SE) and 600 +/- 90 pg/mL in subjects given R-568 or placebo, respectively, and values on the first day of treatment did not change in those given placebo. In contrast, PTH levels fell by 66 +/- 5%, 78 +/- 3%, and 70 +/- 3% at one, two, and four hours, respectively, after initial doses of R-568, remaining below pretreatment values for 24 hours. Blood ionized calcium levels also decreased after the first dose of R-568 but did not change in patients given placebo. Despite lower ionized calcium concentrations on both the second and third days of treatment, predose PTH levels were 422 +/- 70 and 443 +/- 105 pg/mL, respectively, in patients given R-568, and values fell each day by more than 50% two hours after drug administration. Predose PTH levels declined progressively over the first nine days of treatment with R-568 and remained below pretreatment levels for the duration of study. Serum total and blood ionized calcium concentrations decreased from pretreatment levels in patients given R-568, whereas values were unchanged in those given placebo. Blood ionized calcium levels fell below 1.0 mmol/L in 7 of 16 patients receiving R-568; five patients withdrew from study after developing symptoms of hypocalcemia, whereas three completed treatment after the dose of R-568 was reduced. CONCLUSIONS: The calcimimetic R-568 rapidly and markedly lowers plasma PTH levels in patients with secondary hyperparathyroidism caused by end-stage renal disease.

Adult↗
PubMed1999

A randomized phase 3 study of peripheral blood progenitor cell mobilization with stem cell factor and filgrastim in high-risk breast cancer patients.

This randomized study compared the number of leukaphereses required to collect an optimal target yield of 5 x 10(6) CD34(+) peripheral blood progenitor cells/kg, using either stem cell factor (SCF) at 20 micrograms/kg/d in combination with Filgrastim at 10 micrograms/kg/d or Filgrastim alone at 10 micrograms/kg/d, from 203 patients with high-risk stage II, III, or IV breast cancer. Leukapheresis began on day 5 of cytokine administration and continued daily until the target yield of CD34(+) cells had been reached or a maximum of 5 leukaphereses performed. By day 5 of leukapheresis, 63% of the patients treated with SCF plus Filgrastim (n = 100) compared with 47% of those receiving Filgrastim alone (n = 103) reached the CD34(+) cell target yield. There was a clinically and statistically significant reduction (P <.05) in the number of leukaphereses required to reach the target yield for the patients receiving SCF plus Filgrastim (median, 4 leukaphereses) compared with patients receiving Filgrastim alone (median, 6 or more leukapherses; ie, <50% of patients reached the target in 5 leukaphereses). All patients receiving SCF were premedicated with antihistamines, albuterol, and pseudoephedrine. Treatment was safe, generally well tolerated, and not associated with life-threatening or fatal toxicity. In conclusion, SCF plus Filgrastim is a more effective peripheral blood progenitor cell (PBPC)-mobilization regimen than Filgrastim alone. In addition to the potential for reduced leukapheresis-related morbidity and costs, SCF offers additional options for obtaining cells for further graft manipulation.

Adult↗
PubMed1999

Pressure sore prevention in hospital patients: a clinical audit.

Pressure sores cause significant mortality and morbidity as well as being a financial burden on health-care services. Reduction of pressure sore incidence is a Department of Health priority. Pressure sores are accepted as largely preventable complications of illness and disability and the means to achieve prevention are available. The aim of this clinical audit was to identify potential contributing factors to pressure sore acquisition in an acute hospital setting. The results suggest that substantial changes in the approach to clinical management may be needed.

Adult↗
PubMed1998

No evidence for basolateral secretion of milk protein in the mammary gland of lactating goats.

Recent research suggests that a small percentage of milk proteins may be secreted basolaterally, which would have implications for our work on the permeability of tight junctions in the mammary epithelium. In our work, the presence of alpha-lactalbumin (LA) or lactose in plasma is used as an indicator of permeability. The aim of this study was to examine basolateral secretion by determining the presence of milk proteins in efferent mammary lymph. Five Saanen goats were fitted with mammary lymph catheters and were administered intramammary isosmotic bolus infusions of sucrose control solutions or ethylene glycolbis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to induce leaky tight junctions. Lymph samples were collected before and approximately 5 h after infusion. Lymph was analyzed by Western blotting for the presence of alpha-casein (CN), beta-CN, and alpha-LA No alpha-CN or beta-CN was detected in lymph, but alpha-LA was detected in all lymph samples. Moreover, the signal was much stronger in samples from goats that were treated with ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, and concentrations of alpha-LA in lymph were significantly increased with this treatment. These changes and the absence of casein in lymph suggest increased permeability of tight junctions rather than basolateral secretion. In summary, these data do not support basolateral secretion.

Animals↗
PubMed1997

Peripheral blood progenitor cell mobilization using stem cell factor in combination with filgrastim in breast cancer patients.

The safety and optimal dose and schedule of stem cell factor (SCF) administered in combination with filgrastim for the mobilization of peripheral blood progenitor cells (PBPCs) was determined in 215 patients with high-risk breast cancer. Patients received either filgrastim alone (10 microg/kg/d for 7 days) or the combination of 10 microg/kg/d filgrastim and 5 to 30 microg/kg/d SCF for either 7, 10, or 13 days. SCF patients were premedicated with antiallergy prophylaxis. Leukapheresis was performed on the final 3 days of cytokine therapy and, after high-dose chemotherapy and infusion of PBPCs, patients received 10 microg/kg/d filgrastim until absolute neutrophil count recovery. The median number of CD34+ cells collected was greater for patients receiving the combination of filgrastim and SCF, at doses greater than 10 microg/kg/d, than for those receiving filgrastim alone (7.7 v 3.2 x 10(6)/kg, P < .05). There were significantly (P < .05) more CD34+ cells harvested for the 20 microg/kg/d SCF (median, 7.9 x 10(6)/kg) and 25 microg/kg/d SCF (median, 13.6 x 10(6)/kg) 7-day combination groups than for the filgrastim alone patients (median, 3.2 x 10(6)/kg). The duration of administration of SCF and filgrastim (7, 10, or 13 days) did not significantly affect CD34+ cell yield. Treatment groups mobilized with filgrastim alone or with the cytokine combination had similar hematopoietic engraftment and overall survival after PBPC infusion. In conclusion, the results of this study indicate that SCF therapy enhances CD34+ cell yield and is associated with manageable levels of toxicity when combined with filgrastim for PBPC mobilization. The combination of 20 microg/kg/d SCF and 10 microg/kg/d filgrastim with daily apheresis beginning on day 5 was selected as the optimal dose and schedule for the mobilization of PBPCs.

Adolescent↗
PubMed1990

Occlusal indices revisited.

With the increased interest in measuring the need for orthodontic treatment and the quality of the outcome of orthodontic care, the difficulties in using Grainger's Treatment Priority Index (TPI) to screen children in their tenth year is considered. The first part of the study investigated the level of validity of the TPI using 137 study models and three orthodontists. In the light of the results obtained, the TPI was modified. The clinical judgement of a further two orthodontists was compared with the scores obtained form the modified TPI, using another 121 study models. Three Community Dental Officers were employed initially to assess the training needs for personnel who were not trained in orthodontics. A further five Community Dental Officers were involved in the final training programmes. It was concluded that it will be very difficult to produce an index which considers all aspects of malocclusion and which can be used consistently by personnel untrained in orthodontics.

Adolescent↗
PubMed1986

Amygdaloid influences on brain-stem neurones in the rabbit.

1. Electrical stimulation of the central nucleus of the amygdala in the urethane or alpha-chloralose anaesthetized rabbit evokes a bradycardia with a rapid onset and a concomitant fall in arterial blood pressure. 2. Extracellular neuronal activity was recorded in the ipsilateral nucleus tractus solitarius and dorsal vagal nucleus whilst stimulating the ipsilateral central nucleus of the amygdala, the aortic and vagus nerves. 3. A total of 213 neurones were activated by stimulation of at least one of these inputs. 93 of these neurones received a marked excitatory input from the central nucleus with a wide range of latencies (2-100 ms). 50 of these cells also received inputs from either the aortic or vagus nerves, or both. 4. The activity of 42 vagal preganglionic neurones was recorded in the dorsal vagal nucleus of which 22 had properties typical of cardioinhibitory neurones. 9 of these vagal motoneurones received inputs from the central nucleus with latencies between 2 and 100 ms. Of these, 5 had physiological properties indicating they were cardio-inhibitory neurones. 5. We conclude that neurones in the nucleus tractus solitarius and dorsal vagal nucleus can be influenced by descending inputs arising from the central nucleus of the amygdala. Some of these neurones are also likely to be influenced by afferents innervating the thoracic viscera and arterial baroreceptors. The implications of these observations on the role of forebrain-brain-stem interactions in cardiovascular control are discussed.

Action Potentials↗
PubMed1985

The effects of a multicomponent smoking cessation program with chronic obstructive pulmonary disease outpatients.

While a number of multicomponent treatments have been utilized to control smoking, many of these are not suitable for some populations such as chronic obstructive pulmonary disease (COPD) patients because they consist of aversion procedures which can stress the body's cardiovascular system. Little research has been published regarding nonaversive approaches to smoking control in a COPD patient population. This study examined the long-term effects of a nonaversive multicomponent smoking cessation program consisting of brand fading and stimulus control with a COPD outpatient population as measured by self-report. Using four COPD outpatients, this study employed a multiple baseline design across subjects for a visual analysis of treatment effects. At 3- and 6-month follow-up, one subject had quit smoking. Two subjects who continued to smoke reduced their smoking frequency and drastically reduced their nicotine intake by brand fading to a cigarette containing lower amounts of nicotine. A fourth subject returned to her original brand of cigarettes, although she reduced her smoking frequency. Collaborators and measurements of thiocyanate levels were used as reliability checks on subjects' self-report.

Adult↗
PubMed1984

Comparison of dopamine and dobutamine therapy during intraaortic balloon pumping for the treatment of postcardiotomy low-output syndrome.

Treatment of postcardiotomy low-output syndrome includes intraaortic balloon pumping (IABP), volume loading, pharmacological afterload reduction, and stimulation with an inotropic agent. This study compares the effectiveness of combined nitroprusside and dopamine therapy and nitroprusside and dobutamine therapy in 12 patients requiring IABP postoperatively. Serial hemodynamic measurements were made before and during infusion of nitroprusside and after administration of the combined therapy (N = 6 in each group). Prior to pharmacological therapy, cardiac index was 1.47 +/- 0.31 L/min/m2 and systemic vascular resistance (SVR) was 3,114 +/- 1,350 dynes sec cm-5 in patients subsequently given dopamine, and 1.59 +/- 0.38 L/min/m2 and 2,661 +/- 405 dynes sec cm-5, respectively, in those given dobutamine. With infusion of nitroprusside, both groups showed significant reduction in SVR. Nitroprusside plus either inotropic agent resulted in augmentation of cardiac index and an additional reduction in SVR, both changes being greater in the group given dopamine. Larger doses of dobutamine than dopamine were needed to achieve similar hemodynamic improvement. We conclude that the addition of an inotropic agent to vasodilator therapy during IABP results in a greater increase in cardiac index and a greater decrease in afterload than a vasodilator alone. In addition to its beneficial effect on renal perfusion at the dose required to effect these improvements, dopamine appears a better inotropic agent than dobutamine for postcardiotomy low-output syndrome.

Aortic Valve↗