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Biomedical subjects

N J Williams

Publications and source records attributed to N J Williams.

At least 19 recordsLinked to original sources
PubMed2005

Observations on salpingitis, peritonitis and salpingoperitonitis in a layer breeder flock.

A flock of 13,951 hens and 1379 cockerels was monitored from 26 to 58 weeks of age for the complex of salpingitis, peritonitis and salpingoperitonitis (sps). Two hundred and forty-three hens (78 per cent of the hens that died) were examined postmortem, and sps was recognised by gross examination for inflammatory exudate, in the body cavity or oviduct in 111 (46 per cent) of them. Salpingoperitonitis was the most common form, followed by salpingitis and then peritonitis. There were acute and chronic cases in all three conditions, but only in peritonitis were acute cases more common than chronic cases. Seventeen birds that had died of sps were cultured for aerobic bacteria within 12 hours of death. Escherichia coli was recovered from a variety of tissues from all of them, and other bacteria, including staphylococci, Mannheimia haemolytica and Streptococcus bovis, were isolated from a few carcases, either alone or together with E coli. Relatively few isolations of E coli were made from normal hens cultured 48, 72 and 96 hours after death.

Animals↗
PubMed2005

Prevalence and genetic diversity of Campylobacter spp. in environmental water samples from a 100-square-kilometer predominantly dairy farming area.

Water samples were taken systematically from a 100-km2 area of mainly dairy farmland in northwestern England and examined for Campylobacter spp. Pulsed-field gel electrophoresis-restriction fragment length polymorphism (PFGE-RFLP) and flaA strain typing of Campylobacter jejuni and Campylobacter coli isolates were done. Data on the water source and the adjacent environment were recorded and examined as explanatory variables. Campylobacter spp. were isolated from 40.5% (n = 119) of the water samples tested. C. jejuni was isolated from 14.3%, C. coli was isolated from 18.5%, and Campylobacter lari was isolated from 4.2% of the samples. Campylobacter hyointestinalis was not isolated from any water source. The difference in prevalence between water types (trough, running, and standing) was significant (P = 0.001). C. jejuni was the species most commonly isolated from trough-water and running-water sources, while C. coli was the most frequently isolated from standing water (P < 0.001). No association was found between the presence of Escherichia coli and that of Campylobacter spp. The final multivariable logistic regression model for Campylobacter spp. included the following variables: water source, soil type, aspect, and amount of cattle fecal material in the environment (fecal pat count). Strain typing demonstrated a diverse population of C. jejuni and the presence of a common C. coli flaA type that was widely distributed throughout the area. Most of the isolates within the common flaA type were discriminated by PFGE-RFLP. These findings suggest a possible role for environmental water in the epidemiology of Campylobacter spp. in a farming environment.

Agriculture↗
PubMed2004

Development and application of a spiral plating method for the enumeration of Escherichia coli O157 in bovine faeces.

AIM: To develop and validate a direct plating method applicable to epidemiological studies for enumerating Escherichia coli O157 in cattle faeces. METHODS AND RESULTS: The spiral plate count method was used to enumerate E. coli O157 in faecal samples. The accuracy and variation of counts was then assessed using faecal samples inoculated with E. coli O157. There was good agreement between inoculated levels of E. coli O157 and those recovered from faeces, particularly when counts were > 10(2) CFU g(-1) of faeces. The method was applied to a small study assessing short-term survival of E. coli O157 in naturally infected cattle faeces. E. coli O157 was found to survive in faeces for over 10 days at concentrations above 10(3) CFU g(-1) of faeces. Populations of E. coli O157 were also found to increase 100-fold in the first few hours after defecation. CONCLUSIONS: The enumeration method is easy to implement and enables a quick throughput of large numbers of samples. The method is accurate and reliable and enables the inherent variation in count data to be explored but needs to be used in combination with a more sensitive method for samples containing < 10(2) CFU g(-1) of faeces. SIGNIFICANCE AND IMPACT OF THE STUDY: The method described is appropriate for enumeration of E. coli O157 in cattle faeces in large-scale epidemiological studies.

Animals↗
PubMed2004

Frequency and spatial distribution of environmental Campylobacter spp.

Humans are exposed to Campylobacter spp. in a range of sources via both food and environmental pathways. For this study, we explored the frequency and distribution of thermophilic Campylobacter spp. in a 10- by 10-km square rural area of Cheshire, United Kingdom. The area contains approximately 70, mainly dairy, farms and is used extensively for outdoor recreational activities. Campylobacter spp. were isolated from a range of environmental samples by use of a systematic sampling grid. Livestock (mainly cattle) and wildlife feces and environmental water and soil samples were cultured, and isolates were presumptively identified by standard techniques. These isolates were further characterized by PCR. Campylobacter jejuni was the most prevalent species in all animal samples, ranging from 11% in samples from nonavian wildlife to 36% in cattle feces, and was isolated from 15% of water samples. Campylobacter coli was commonly found in water (17%) and sheep (21%) samples, but rarely in other samples. Campylobacter lari was recovered from all sample types, with the exception of sheep feces, and was found in moderate numbers in birds (7%) and water (5%). Campylobacter hyointestinalis was only recovered from cattle (7%) and birds (1%). The spatial distribution and determinants of C. jejuni in cattle feces were examined by the use of model-based spatial statistics. The distribution was consistent with very localized within-farm or within-field transmission and showed little evidence of any larger-scale spatial dependence. We concluded that there is a potentially high risk of human exposure to Campylobacter spp., particularly C. jejuni, in the environment of our study area. The prevalence and likely risk posed by C. jejuni-positive cattle feces in the environment diminished as the fecal material aged. After we took into account the age of the fecal material, the absence or presence of rain, and the presence of bird feces, there was evidence of significant variation in the prevalence of C. jejuni-positive cattle feces between grazing fields but no evidence of spatial clustering beyond this resolution. The spatial pattern of C. jejuni is therefore consistent with that for an organism that is ubiquitous in areas contaminated with cattle feces, with a short-scale variation in infection intensity that cannot be explained solely by variations in the age of the fecal material. The observed pattern is not consistent with large-scale transmission attributable to watercourses, wildlife territories, or other geographical features that transcend field and farm boundaries.

Animals↗
PubMed2004

Genotypic and antibiotic susceptibility characteristics of a Campylobacter coli population isolated from dairy farmland in the United Kingdom.

Campylobacter infections are the most common cause of bacterial enteritis in humans, and nearly 8% of such infections are caused by Campylobacter coli. Most studies have concentrated on Campylobacter jejuni, frequently isolated from intensively farmed poultry and livestock production units, and few studies have examined the spread and relatedness of Campylobacter across a range of geographical and host boundaries. Systematic sampling of a 100-km2 area of mixed farmland in northwest England yielded 88 isolates of C. coli from a range of sample types and locations, and water was heavily represented. Screening for antibiotic resistance revealed a very low prevalence of resistance, while genotyping performed by using three methods (flaA PCR restriction fragment length polymorphism [RFLP], pulsed-field gel electrophoresis [PFGE], and fluorescent amplified fragment length polymorphism [fAFLP]) provided insights into the genomic relatedness of isolates from different locations and hosts. Isolates were classified into 23 flaA groups, 34 PFGE groups, and five major fAFLP clusters. PFGE banding analysis revealed a high level of variability and no clustering by sample type. fAFLP and flaA analyses successfully grouped the isolates by sample type. We report preliminary findings suggesting that there is a strain of C. coli which may have become adapted to survival or persistence in water and that there is a group of mainly water-derived isolates from which unusual flaA PCR fragments were recovered.

Agriculture↗
PubMed2002

The relationship between socio-demographic characteristics and dental health knowledge and attitudes of parents with young children.

OBJECTIVE: To determine if parental socio-demographic characteristics are associated with dental knowledge and attitude. DESIGN: A questionnaire survey of 500 consecutive parents with children aged approximately 8-months, attending clinics in 1999/2000, in Burnley, Pendle and Rossendale, for health visitor distraction-hearing tests. OUTCOME MEASURES: Scores were obtained for dental knowledge and attitudes. The socio-demographic variables of parental ethnicity, age, education and area of residence were used to determine any associations. RESULTS: Parental age ranged between 16-46 years. Child age ranged between 7-11 months. Significant differences were detected for parental dental knowledge according to ethnicity (P = 0.003), educational status (P = 0.000), and area of residence (P = 0.016). Significant differences were also found in dental attitudes; ethnicity (P = 0.000), educational status (P = 0.004) and area of residence (P = 0.005). Parental age was not significant for either knowledge or attitude. CONCLUSIONS: Lack of further education, being Asian and living in a deprived area means parents have less chances of high dental knowledge and positive dental attitudes.

Adolescent↗
PubMed2000

Telomerase and breast cancer: from diagnosis to therapy.

BACKGROUND: Telomeres are believed to be responsible for chromosomal stability during cellular proliferation. They are created by telomerase, an enzyme present in many human neoplasms. Telomerase is considered to be important in breast cancer since reactivation of the enzyme ensures cell stability allowing malignant cells to divide indefinitely. AIMS: This article aims to discuss the role of telomerase in breast cancer and explore the future of telomerase research. METHOD: We have reported on the literature to date in order to present this current review. RESULTS: Telomerase is found in significant levels in breast neoplasms and is reliably detected in fine needle aspirations aiding the diagnosis of breast cancer. There is also a correlation between telomerase and disease prognosis, and there is current work assessing if telomerase can be of benefit in monitoring the efficacy of systemic treatment. CONCLUSION: The role of telomerase in breast cancer is still being investigated however by understanding the action it has on chromosomal stability, and its detection in tumour cells, there are possibilities to enhance the methods employed to detect and treat breast cancer.

Biomarkers, Tumor↗
PubMed1999

Interleukin-12 administration in retroviral infection of mice increases the potential to produce functional dendritic cells from bone marrow stem cells.

Rauscher leukaemia virus (RLV) infection in mice causes production of lymph node and skin dendritic cells (DC) that fail to stimulate a primary mixed leukocyte reaction (MLR). Treatment of mice with IL-12 around the time of infection results in DC with normal stimulatory function (N.J. Williams, J.J. Harvey, I. Duncan, R.F.G. Booth, S.C. Knight, Cell Immunol. 183 (1988) 121-130). Here we derived DC from mouse bone marrow by culture with granulocyte macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor-alpha (TNF-alpha) for 10-12 days; DC were generated from bone marrow cells taken from normal mice, from mice injected 15 days earlier with RLV or from those receiving RLV plus five daily doses of 100 ng of IL-12 starting 2 days before infection. Infection of the DC with RLV was assessed from nested PCR with doubling dilutions of DNA and the capacity of DC to stimulate a MLR was tested. DC derived from bone marrow of IL-12 treated animals showed at least twice the level of infection with RLV as those from non-treated animals although infection never exceeded 20% of the cells. DC derived from bone marrow of mice given RLV caused negligible stimulation of the MLR but those from mice additionally treated with IL-12 functioned normally. Thus, treatment of mice with IL-12 promoted the potential of stem cells taken 12 days after the last IL-12 injection to develop into functional DC despite increased infection with virus. Treatment of mice with IL-12 may have a long term effect on the potential growth of DC from stem cells which may contribute to the potency of this cytokine in promoting cell mediated immune responses.

Animals↗
PubMed1998

Interleukin-12 restores dendritic cell function and cell-mediated immunity in retrovirus-infected mice.

The effects of IL-12 treatment on the defects in DC function and on the reduced cell-mediated immunity induced in mice infected with Rauscher leukemia virus (RLV) were studied. DC from RLV-infected mice failed to stimulate significant allogeneic T cell proliferation but T cells from RLV-infected mice showed normal responses to allogeneic DC. In RLV-infected mice treatment with 5 doses of 100 or 300 ng IL-12 around the time of infection resulted in DC that stimulated normal T cell proliferation. Treatment of mice with 300 ng IL-12 but not 100 ng reduced T cell responses. RLV-infected mice showed reduced delayed hypersensitivity to a contact sensitizer. Infected animals receiving the low dose of IL-12 which allowed normal DC and T cell function gave normal delayed hypersensitivity reactions; IL-12 thus resulted in both normal T cell stimulation by DC and cell-mediated immunity. A failure of T cell stimulation by DC is associated with immunosuppression in retrovirus infection and the enhanced capacity of DC to stimulate T cells after IL-12 treatment may be beneficial.

Animals↗
PubMed1996

Double-blind, randomized trial of cessation of smoking after audiotape suggestion during anaesthesia.

We studied the use of intraoperative tape suggestion to improve the rate of cessation of smoking in 363 smokers who wanted to stop smoking. They were allocated randomly to hear a taped message encouraging them to stop smoking or to a blank tape, played during general anaesthesia. Overall 56 patients (15.4%, 95% confidence interval (CI) 11.7-19.1%) had claimed to have stopped smoking at 2 months and 29 patients (8.0%, 95% CI 5.9-10.1%) were confirmed to have stopped smoking at 6 months. There was no significant difference between the groups at either 2 or 6 months (risk ratios 1.06 and 1.09, respectively, P = 0.78). A preoperative:postoperative ratio of a visual analogue scale measuring the patient's motivation to stop smoking was not significantly different (control group 1.13 vs message group 1.10, P = 0.55). This study does not support the hypothesis that intraoperative tape suggestion can change smoking behaviour.

Adolescent↗
PubMed1994

The use of minisatellite variant repeat-polymerase chain reaction (MVR-PCR) to determine the source of saliva on a used postage stamp.

In this paper we report the identification of an individual using the MVR-PCR technique on DNA extracted from single and multiple discs (3 mm) punched from a licked stamp attached to an envelope. The individual's code was successfully and uniquely matched to one already present within a database of 500 MVR codes which had been generated in a separate laboratory. The exercise illustrates the suitability of MVR-PCR for forensic samples and demonstrates the power of this rapid and novel identification system.

DNA, Satellite↗
PubMed1993

Microbial DNA challenge studies of variable number tandem repeat (VNTR) probes used for DNA profiling analysis.

DNA probes commonly used for forensic DNA profiling analysis were hybridized to Hinfl digested DNA isolated from various common microbial species. Extended exposures to light sensitive film failed to detect any DNA fragments of a microbial origin following hybridizations to radio-labeled DNA insert single-locus probes (SLPs) and nonisotopically labeled oligonucleotide SLPs.

DNA Fingerprinting↗