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Biomedical subjects

R J Taylor

Publications and source records attributed to R J Taylor.

At least 19 recordsLinked to original sources
PubMed2005

More on RotaShield and intussusception: the role of age at the time of vaccination.

BACKGROUND: RotaShield, a vaccine intended to prevent severe rotavirus diarrhea, was withdrawn in July 1999, 9 months after it became available in the United States, because of a temporal association with intussusception events that occurred in vaccinated infants. We explore here the effect of age on the risk of intussusception. METHODS: We reanalyzed a case-control database of the Centers for Disease Control and Prevention by use of a 21-day window, to define vaccine-associated events. We obtained data on vaccine use from the National Immunization Survey and estimated the age-stratified background incidence of intussusception by use of Healthcare Cost and Utilization Project data. We combined these data to estimate how absolute risk varies with age and to model the projected population-attributable risk associated with 3 different vaccination schedules. RESULTS: We found that the incidence of intussusception associated with the first dose of vaccine increased with age. Infants > or = 90 days old accounted for 80% of cases of intussusception associated with a first dose but had received only 38% of first doses. Modeling of the recommended schedule of vaccination at ages 2, 4, and 6 months projected 1 intussusception event/11,000-16,000 vaccine recipients; modeling of a 2-dose schedule beginning in the neonatal period projected 1 intussusception event/38,000-59,000 vaccine recipients. CONCLUSIONS: The practice of initiating immunization after age 90 days, which we call "catch-up" vaccination, contributed disproportionately to the occurrence of intussusception associated with the use of RotaShield. A fully implemented 2-dose vaccination schedule begun during the neonatal period would lead to, at most, a 7% increase in the incidence of intussusception above the annual background incidence.

Age Factors↗
PubMed2005

Short-term safety evaluation of processed calcium montmorillonite clay (NovaSil) in humans.

NovaSil clay (NS) provides significant protection from the adverse effects of aflatoxins (AFs) in multiple animal species by decreasing bioavailability from the gastrointestinal tract. It is postulated that NS clay can be safely added to human diets to diminish exposure and health risks from AF contaminated food. To determine the safety and tolerance of NS in humans and establish dosimetry protocols for long-term efficacy studies, a randomized and double-blinded phase I clinical trial was conducted. Volunteers (20-45 yr in age), were clinically screened for confirmation of their health status. Fifty subjects (23 males and 27 females) were randomly divided into two groups: The low-dose group received nine capsules containing 1.5 g/day, and the high-dose group received nine capsules containing 3.0 g/day for a period of 2?wk. NS capsules were manufactured in the same color and size and were distributed to each participant three times a day at designated sites where follow-up was taken to record any side effects and complaints. Blood and urine samples were collected before and after the study for laboratory analysis. All participants completed the trial and compliance was 99.1%. Mild GI effects were reported in some participants. Symptoms included abdominal pain (6%, 3/50), bloating (4%, 2/50), constipation (2%, 1/50), diarrhea (2%, 1/50), and flatulence (8%, 4/50). No statistical significance was found between the two groups for these adverse effects (p > 0.25). No significant differences were shown in hematology, liver and kidney function, electrolytes, vitamins A and E, and minerals in either group. These results demonstrate the relative safety of NS clay in human subjects and will serve as a basis for long-term human trials in populations at high risk for aflatoxicosis.

Administration, Oral↗
PubMed2004

Restricted entry of R5 HIV Type 1 strains into eosinophilic cells.

A cell culture system previously developed by our laboratory demonstrated that T cell-tropic (CXCR4-using) but not macrophage-tropic (CCR5-using) HIV-1 strains productively infected eosinophilic cells. In the current study, an improved model was used to determine the level of this viral restriction by assessing viral entry and coreceptor usage. The model was improved by using AML14.3D10 cells that were engineered to express CCR3 in addition to the major HIV-1 coreceptors, CD4, CXCR4, and CCR5, thus making them more like primary eosinophils. A polymerase chain reaction (PCR) assay was used to detect viral entry. In the PCR assay, primers specific for early reverse transcription products were used to amplify minus strand viral DNA from HIV-1-infected AML14.3D10-CCR3 eosinophilic cells. Coreceptor blocking experiments, using the CXCR4 antagonist AMD3100, were performed to determine coreceptor usage by the CXCR4-using (X4) strain known to productively infect the cells. Virus production was measured by p24 immunoassay. As expected, viral DNA was detected in AML14.3D10-CCR3 cells infected with X4 HIV-1, and cell viability was decreased during maximal viral production. Conversely, viral DNA was not detected in eosinophilic cells exposed to a CCR5-using (R5) HIV-1 strain that is also capable of using CCR3, indicating that R5 HIV-1 is unable to enter eosinophilic cells despite the presence of the appropriate coreceptors. Infection of AML14.3D10-CCR3 cells by HTLV-III(B) was completely inhibited by AMD3100, indicating that X4 HIV-1 enters the AML14.3D10-CCR3 cell line by using the CXCR4 coreceptor exclusively. Since X4 strains predominate during the late stages of HIV-1 infection in many patients, when eosinophil numbers also tend to increase, the ability of these HIV-1 strains to infect eosinophilic cells has important implications for the involvement of eosinophils in the pathogenesis of AIDS.

Cell Line↗
PubMed2003

Eliciting the smoker's agenda: implications for policy and practice.

Existing health promotion messages and advice on smoking cessation focus upon the negative aspects of continuing to smoke and contrast these to the benefits of giving up. Benefits of cessation are invariably linked to reduced risks of illness and disease with the process of cessation framed as a largely positive and certainly a health enhancing one. In this paper we present an analysis of data from a cross-sectional, exploratory study in the city of Aberdeen, Scotland, undertaken with 54 people, aged 18-44, who are or have been smokers. The multiple and often contradictory agendas of everyday life, smoking and health are explored. Participants spoke of the dangers of smoking and the potential benefits of giving up as these are considered by health promotion and medical research. However, many smokers experienced a number of benefits from smoking (such as socialising with others and breaks from boredom), and health and social problems with the process of cessation (for example, weight gain, stress, colds, flu). Participants appeared to query the validity of the risks of continuing to smoke and yet indicate a range of health and social difficulties in giving up. The authors assert that an acknowledgement of the attractive, pleasurable aspects of smoking may be seen as unacceptable and irresponsible but this could well provide an opportunity to relate to the everyday and multiple practices of smoking and smokers themselves as illuminated by this research.

Adolescent↗
PubMed2003

Comparison of 3 tests to detect acaricide resistance in Boophilus decoloratus on dairy farms in the Eastern Cape Province, South Africa.

The susceptibility of the larval offspring of engorged female Boophilus decoloratus, and of the engorged females, collected from cattle on the dairy farms Brycedale, Sunny Grove and Welgevind in the Eastern Cape Province, South Africa, was tested against the acaricides amitraz, chlorfenvinphos and cypermethrin. Resistance was determined by means of the Shaw Larval Immersion Test (SLIT) for larvae and the Reproductive Estimate Test (RET) and Egg Laying Test (ELT) for adults. At Brycedale the tests all indicated resistance to chlorfenvinphos, and RET and ELT indicated resistance to amitraz and emerging resistance to cypermethrin. At Sunny Grove, B. decoloratus was resistant to cypermethrin using SLIT and exhibited emerging resistance to chlorfenvinphos with SLIT and to cypermethrin with both RET and ELT At Welgevind, resistance was recorded against chlorfenvinphos (SLIT) and against cypermethrin (ELT), and emerging resistance against permethrin (RET). The results obtained with RET and ELT were generally comparable, but often differed from those obtained with SLIT. Resistance could be detected within 7 days with ELT compared to 42 days with RET and 60 days with SLIT.

Animals↗
PubMed2003

Dryland salinity in Western Australia: managing a changing water cycle.

Clearing of agricultural land has resulted in significant changes to the surface and groundwater hydrology. Currently about 10% of agricultural land in Western Australia is affected by dryland salinity and between a quarter and a third of the area is predicted to be lost to salinity before a new hydrological equilibrium is reached. This paper develops a general statement describing the changes to the surface and groundwater hydrology of the wheatbelt of Western Australia between preclearing, the year 2000 and into the future. For typical catchments in the wheatbelt it is estimated that average groundwater recharge and surface runoff have increased about tenfold when comparing the current hydrology to that preclearing. Saline groundwater discharge and flood volumes have also increased significantly. Saline groundwater discharge and associated salt load will probably double in the future in line with the predicted increase in the area of dryland salinity. In addition, future increases in the area of dryland salinity/permanent waterlogging will probably double the volumes in flood events and further increase surface runoff in average years. The outcomes of surface and groundwater management trials have been briefly described to estimate how the hydrology would be modified if the trials were implemented at a catchment scale. These results have been used to formulate possible integrated revegetation and drainage management strategies. The future hydrology and impacts with and without integrated management strategies have been compared.

Agriculture↗
PubMed2002

CDP840. A prototype of a novel class of orally active anti-inflammatory phosphodiesterase 4 inhibitors.

The discovery, synthesis and biological activity of a series of triarylethane phosphodiesterase 4 inhibitors is described. Structure-activity relationship studies are presented for CDP840 (29), a potent, chiral, selective inhibitor of PDE 4 (IC(50) 4nM). CDP840 is non-emetic in the ferret at 30mgkg(-1) (po), active in models of inflammation and reverses ozone-induced bronchial hyperreactivity in the guinea pig.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2002

The cost-effectiveness of preoperative testing (basic office assessment vs. urodynamics) for stress urinary incontinence in women.

OBJECTIVE: To compare the cost-effectiveness of preoperative testing strategies in women with stress incontinence symptoms, as although urodynamic testing is used to improve the diagnostic accuracy in women with incontinence, the clinical and economic consequences of different levels of testing have not been evaluated. MATERIALS AND METHODS: Decision analysis was used to evaluate basic office assessment (BOA) and urodynamic testing for women with stress incontinence symptoms who were candidates for primary surgical treatment. Costs were calculated using the Federal Register. Parameter estimates for the effectiveness of treatment for different diagnoses of incontinence were based on published reports. Incremental cost-effectiveness was defined as the cost in dollars per additional patient cured of incontinence. RESULTS: Urodynamics did not improve the effectiveness of treatment; both strategies of a BOA and urodynamic testing resulted in a cure rate of 96% after initial and secondary treatments. The mean cost of care (including initial and secondary treatments and outcomes) was similar for the two strategies ($5042 for BOA, $5046 for urodynamic testing). With BOA reduced testing costs were balanced by increased costs for patients who failed the initial treatment. Under baseline assumptions, one additional cure of incontinence (incremental cost-effectiveness) using the urodynamic strategy cost $3847, compared with BOA. By sensitivity analyses, BOA was less costly than urodynamics when the prevalence of genuine stress incontinence was > or = 80%. CONCLUSION: These findings do not support the routine use of urodynamics before surgery in women likely to have genuine stress incontinence, and provide the justification for randomized trials of preoperative testing strategies.

Aged↗
PubMed2002

The effect of folic acid supplementation on plasma homocysteine in an elderly population.

BACKGROUND: Increased plasma homocysteine is associated with coronary artery disease, peripheral vascular disease and venous thrombosis. Folic acid is the most effective therapy for reducing homocysteine levels. The lowest effective supplement of folic acid is not known, particularly for the elderly who have the highest prevalence of these conditions. AIM: To explore the effects of daily supplements of 0, 50, 100, 200, 400 and 600 microg folic acid on plasma homocysteine in an elderly population. DESIGN: Randomized double-blind placebo-controlled trial. METHODS: Participants (n=368) aged 65-75 years were randomly allocated to receive one of the treatments for 6 weeks. Plasma homocysteine was recorded after 3 weeks and 6 weeks of supplementation. RESULTS: Only the 400 microg and 600 microg groups had significantly lower homocysteine levels compared to placebo (p=0.038 and p<0.001, respectively). Using multiple linear regression and each individual's total folic acid intake (diet plus supplement), a total daily folic acid intake of 926 microg per day would be required to ensure that 95% of the elderly population would be without cardiovascular risk from folate deficiency. DISCUSSION: A daily folic acid intake of 926 microg is unlikely to be achieved by diet alone. Individual supplementation or fortification of food with folic acid will be required to reach this target.

Aged↗
PubMed2002

Using an artificial neural network to predict healing times and risk factors for venous leg ulcers.

OBJECTIVES: This study aimed to identify the risk factors that influence the healing process of venous leg ulcers treated with compression bandaging, with a view to predicting healing time. METHOD: A retrospective cohort study was performed on data collected prospectively on 325 consecutive patients presenting with 345 venous ulcers at the Salford Primary Care Trust leg ulcer clinic between January 1997 and December 1999. Use of an artificial neural network (ANN) technique accurately predicted the healing times for 68% of the patients. RESULTS: The ANN demonstrated that healing was significantly related to a history of previous leg ulceration, 'quite wet' ulcer exudate, high body mass index, large initial total ulcer area, increasing age and male gender. CONCLUSION: The ability to identify at presentation ulcers that might be resistant to standard therapy would allow early consideration of more radical treatments such as hospitalisation, wound debridement or venous surgery.

Adult↗
PubMed2002

Acaricide resistance profiles of single- and multi-host ticks from communal and commercial farming areas in the Eastern Cape and North-West Provinces of South Africa.

A field study (February 2000 to August 2001) was conducted on communal and commercial farms in the Eastern Cape and North-West Provinces of South Africa to detect the levels of tick resistance to commonly used acaricides. The larvae obtained from engorged females of the one-host tick Boophilus decoloratus, the two-host tick Rhipicepalus evertsi evertsi and the three-host ticks Amblyomma hebraeum and Rhipicephalus appendiculatus were tested against various concentrations of amitraz, chlorfenvinphos and cypermethrin using the Shaw Larval Immersion Test method. Ticks from the communal farms showed higher levels of resistance to cypermethrin and some resistance to chlorfenvinphos whilst no resistance was detected against amitraz. However, ticks from commercial farms were equally resistant to amitraz, chlorfenvinphos and cypermethrin. The B. decoloratus populations tested were considerably more resistant to all the acaricides tested than the R. evertsi evertsi, A. hebraeum and R. appendiculatus populations. This supports the hypothesis that single-host ticks develop resistance faster than multi-host ticks. This trend was recorded on most of the farms where single- and multi-host ticks co-existed. It was concluded that the use of acaricides at high frequencies and high concentrations was one of the main causes of tick resistance in the study areas. Possible factors which caused the resistance problems are discussed and acaricide management strategies recommended.

Animals↗
PubMed2001

A short and efficient route to novel scyphostatin analogues.

[structure: see text]. Several novel scyphostatin analogues have been prepared in up to 18% yield over five steps from commercially available 4-bromoguaiacol, utilizing an organometallic addition to afford the desired syn-hydroxy-epoxides.

Amides↗
PubMed2001

In situ oxidation-imine formation-reduction routes from alcohols to amines.

Manganese dioxide is employed as an in situ oxidant for the one-pot conversion of alcohols into imines. In combination with polymer-supported cyanoborohydride (PSCBH), a one-pot oxidation-imine formation-reduction sequence is reported. This procedure enables alcohols to be converted directly into both secondary and tertiary amines.

Journal Article↗
PubMed2001

Sentinel node localization in oral cavity and oropharynx squamous cell cancer.

OBJECTIVE: To evaluate the feasibility and predictive ability of the sentinel node localization technique for patients with squamous cell carcinoma of the oral cavity or oropharynx and clinically negative necks. DESIGN: Prospective, efficacy study comparing the histopathologic status of the sentinel node with that of the remaining neck dissection specimen. SETTING: Tertiary referral center. PATIENTS: Patients with T1 or T2 disease and clinically negative necks were eligible for the study. Nine previously untreated patients with oral cavity or oropharyngeal squamous cell carcinoma were enrolled in the study. INTERVENTIONS: Unfiltered technetium Tc 99m sulfur colloid injections of the primary tumor and lymphoscintigraphy were performed on the day before surgery. Intraoperatively, the sentinel node(s) was localized with a gamma probe and removed after tumor resection and before neck dissection. MAIN OUTCOME MEASURES: The primary outcome was the negative predictive value of the histopathologic status of the sentinel node for predicting cervical metastases. RESULTS: Sentinel nodes were identified in 9 previously untreated patients. In 5 patients, there were no positive nodes. In 4 patients, the sentinel nodes were the only histopathologically positive nodes. In previously untreated patients, the sentinel node technique had a negative predictive value of 100% for cervical metastasis. CONCLUSIONS: Our preliminary investigation shows that sentinel node localization is technically feasible in head and neck surgery and is predictive of cervical metastasis. The sentinel node technique has the potential to decrease the number of neck dissections performed in clinically negative necks, thus reducing the associated morbidity for patients in this group.

Adult↗
PubMed2001

Cyclosporine challenge test revisited: does it predict outcome after solitary pancreas transplantation?

BACKGROUND: The selection of patients for solitary pancreas transplantation (PTA) requires identification of individuals who will not develop acute renal dysfunction in response to immunosuppressants. A cyclosporine challenge test (CCT) was developed to predict post-PTA kidney dysfunction secondary to calcineurin inhibitor immunosuppressants. We now report on the long-term follow-up of patients who received a PTA after undergoing a CCT. METHODS: Twelve potential PTA recipients were administered cyclosporine A (CsA) for 6 wk. Creatinine clearance (CrCl) was measured at 2, 4, and 6 wk. Those who did not fail the CCT received PTA. Baseline and post-transplant CrCl were retrospectively evaluated in the original cohort and in a group of matched patients who received PTA without a CCT. RESULTS: Of the original 12 recipients evaluated with the CCT, 6 received PTA. CrCl was followed for a mean of 45.8 months. Of the 4 who remained alive, 2 went on to develop renal failure (CrCl < 30 mL/min) at 18 and 65 months post-transplant. The baseline CrCl was higher in PTA recipients who had not been selected to be studied with CCT than those that were (117 +/- 32 vs 78 +/- 13 mL/min). By 12 months post-PTA, the CrCl was no longer different between the groups selected to be screened with CCT and those that were not. CONCLUSIONS: CCT may help predict risk for short-term changes in renal function (< 18 months) in response to CsA. CCT may be most helpful in candidates for PTA with borderline renal insufficiency (60-80 mL/min).

Adult↗
PubMed2001

Long-term results of en bloc transplantation of pediatric kidneys into adults using a vicryl mesh envelope technique.

En bloc transplantation of pediatric kidneys into adults is a suitable measure to help correct the shortage of available kidneys. This practice, however, is not widespread because of the high incidence of vascular complications. Our institution has previously described a vicryl mesh technique for en bloc kidneys, with an attempt to reduce the incidence of vascular complications. The purpose of this study was to evaluate the long-term results of recipients with en bloc kidneys stabilized with this technique. The charts of 644 adult renal transplants performed between July 1987 and July 1999 were reviewed. During this period, 14 adult patients have received 14 pairs of en bloc pediatric kidneys using the vicryl mesh technique. All patients received OKT3 as an induction immunosuppression with cyclosporine started 10-14 d after the transplant. The median donor age was 24 months (range 14-84 months), and the median recipient age was 49 yr (range 23-68 yr). The mean recipient weight was 79 kg (range 60-114 kg). The mean cold ischemia time was 14.2 hr. None of the patients developed vascular or urological complications. Delayed graft function and moderate acute rejection occurred in one patient each. At a mean follow-up of 51 months (range 7-96 months), all 14 patients maintained excellent renal function with a mean creatinine of 1.01 mg/dL. Renal measurements pre-operatively and at follow-up ultrasound examinations were available in 9 patients, and the mean length of the kidneys had grown approximately 5.0 cm. These data demonstrate that minimal vascular and immunological complication rates can be achieved with pediatric en bloc kidneys using the vicryl mesh envelope technique.

Adult↗
PubMed2001

Cervical screening in migrants to Australia.

OBJECTIVE: To examine differentials and time trends in self-reported Pap test rates by migrant status from the 1989/90 and 1995 Australian National Health Surveys (NHS). METHOD: Unit record data for females with the variables of interest were extracted from the 1989/90 and 1995 NHS and combined. The dichotomous outcome variables were 'ever had a Pap test' and 'had a Pap test within three years'. The principal study factor was country-of-birth, but language spoken at home (English or not) was also examined. The indirect age-standardised screening ratio was used to calculate proportions of 'ever had a Pap test' and 'had a Pap test within three years' and differences were tested statistically using logistic regression analysis for each year of survey by migrant status. RESULTS: Odds ratios for rates of reporting 'ever had a Pap test' were significantly lower in women born in southern Europe, Italy, other countries, southern Asia, Middle East, Greece and South-East Asia compared with Australian-born. Reported rates of 'ever had a Pap test' were significantly higher in the 1995 NHS (p<0.001). There were significant increases in screening for the Australian-born, New Zealand-born, and women born in southern Europe, South-East Asia, South Asia and Italy, and both English and non-English speakers over the 1989/90 and 1995 NHSs. Odds ratios for reporting 'had a Pap test within three years' showed significantly lower ORs for women born in the UK, Other countries, Middle East, Greece, and South-East Asia compared with the Australian-born. CONCLUSIONS: This study reveals differentials in reported Pap test behaviour by country-of-birth in Australia and that reported screening rates have improved from the 1989/90 NHS to 1995 NHS in most country-of-birth groups.

Adult↗