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Biomedical subjects

P Williams

Publications and source records attributed to P Williams.

At least 145 records · Page 8Linked to original sources
PubMed1999

Planning to meet the needs of offenders with mental disorders in the United Kingdom.

During the last decade the planning of services for offenders with mental disorders in the United Kingdom has been geared toward diverting them from the criminal justice system to appropriate levels of psychiatric and social care. Although a seamless service system is yet to be developed, the central government has made a concerted effort to promote a better understanding of the needs of offenders with mental disorders and encourage collaboration between the relevant agencies. A major program of research has been initiated, and local health authorities have been encouraged to use a consortium approach to planning and delivery of specialist services. The authors discuss the activities of the Wessex consortium, composed of five local health authorities and a social services department serving a catchment area with a population of 2.5 million in southern England. The consortium has commissioned needs assessments for all offenders with mental illness from the catchment area and a survey of the resources for secure residential treatment in the region. Based on data from this research, the consortium is planning the development of two long-stay secure units to accommodate offenders with a history of repeated inpatient and prison stays and poor response to previous treatment and rehabilitation efforts.

Commitment of Persons with Psychiatric Disorders↗
PubMed1999

Orientation-specific possibility priming for novel three-dimensional objects.

Priming effects on the object possibility task, in which participants decide whether line drawings could or could not be possible three-dimensional objects, may be supported by the same processes and representations used in recognizing and identifying objects. Three experiments manipulating objects' picture-plane orientation provided limited support for this hypothesis. Like old/new recognition performance, possibility priming declined as study-test orientation differences increased from 0 degree to 60 degrees. However, while significant possibility priming was not observed for larger orientation differences, recognition performance continued to decline following 60 degrees-180 degrees orientation shifts. These results suggest that possibility priming and old/new recognition may rely on common viewpoint-specific representations but that access to these representations in the possibility test occurs only when study and test views are sufficiently similar (i.e., rotated less than 60 degrees).

Humans↗
PubMed1999

Acute lung injury after hepatic cryoablation: correlation with NF-kappa B activation and cytokine production.

BACKGROUND: Previous clinical reports have documented multisystem organ injury after hepatic cryoablation. We hypothesized that hepatic cryosurgery, but not partial hepatectomy, induces a systemic inflammatory response characterized by distant organ injury and overproduction of nuclear factor kappa B (NF-kappa B)-dependent, proinflammatory cytokines. METHODS: In this study, rats underwent either cryoablation of 35% of liver parenchyma or a similar resection of left hepatic tissue. Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels and NF-kappa B activation were assessed by electrophoretic mobility shift assay at 30 minutes 1, 2, 6, and 24 hours after either procedure. RESULTS: Cryoablation of 35% of liver (n = 22 rats) resulted in lung injury and a 45% mortality rate within 24 hours of surgery, whereas 7% treated with 35% hepatectomy (n = 15 rats) died during the 24 hours after surgery (P < .05, cryoablation vs hepatectomy). Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels were markedly increased in rats (n = 10 rats) 1 hour after hepatic cryoablation compared with rats that underwent partial hepatectomy (P < .005). We evaluated NF-kappa B activation by electrophoretic mobility shift assay in nuclear extracts of liver and lung after cryosurgery and found that NF-kappa B activation was strikingly increased in the liver but not the lung at 30 minutes and in both organs 1 hour after cryosurgery, and returned to baseline in both organs by 2 hours. In rats undergoing 35% hepatectomy, no increase in NF-kappa B activation was detected in nuclear extracts of either liver or lung at any time point. CONCLUSIONS: These data show that hepatic cryosurgery results in systemic inflammation with activation of NF-kappa B and increased production of NF-kappa B-dependent cytokines. Our data suggest that lung injury and death in this animal model is mediated by an exaggerated inflammatory response to cryosurgery.

Acute Disease↗
PubMed1999

The epidemiology of mentally disordered offending: a systematic review of studies, based in the general population, of criminality combined with psychiatric illness.

BACKGROUND: The international literature, from 1990 onwards, on the epidemiology of mentally disordered offending (MDO) was systematically reviewed. Studies based solely in the general population are reported in this article. METHODS: Database searches were made back to 1990, followed by citation tracing with the authors or major publications. RESULTS: Two cross-sectional surveys and seven cohort studies were found that have given rise to epidemiological data about MDO in the general population. The most useful data come from cohort studies in Scandinavia. In Scandinavia, the prevalence of MDO up to age 26-30 years is 2.1-2.8 per 100 for men and about half this amount for women. Conduct problems in childhood and deprivation seem to be predictors of future MDO. Mental disorder is associated with acts of crime, most particularly acts of a violent nature. CONCLUSIONS: No systematic epidemiological study of MDO in its own right was found. Those studies which provide data on MDO generally make poor use of statistical methodology. Professional epidemiological and statistical input is required to fully exploit existing data and adequately plan future studies of MDO.

Adolescent↗
PubMed1998

Construction and analysis of luxCDABE-based plasmid sensors for investigating N-acyl homoserine lactone-mediated quorum sensing.

Plasmid reporter vectors have been constructed which respond to activation of LuxR and its homologues LasR and RhlR (VsmR) by N-acyl homoserine lactones (AHLs). The expression of luxCDABE from transcriptional fusions to PluxI, PlasI and PrhlI respectively, occurs in the presence of activating AHLs. A profile of structure/activity relationships is seen where the natural ligand is most potent. The characterisation of individual LuxR homologue/AHL combinations allows a comprehensive evaluation of quorum sensing signals from a test organism.

4-Butyrolactone↗
PubMed1998

Engineering the luxCDABE genes from Photorhabdus luminescens to provide a bioluminescent reporter for constitutive and promoter probe plasmids and mini-Tn5 constructs.

The luxCDABE operon of Photorhabdus luminescens has been cloned and engineered as an easily mobilisable cassette flanked by sites for commonly used restriction enzymes. Constitutive and promoter probe plasmids utilising the P. luminescens luxCDABE have been constructed using a number of compatible replicons and antibiotic markers. Complementary to these plasmids, a range of promoterless and constitutive luxCDABE mini-Tn5 derivatives has been constructed. The potential of coupling mini-Tn5 luxCDABE promoter probe transposons with automated luminometry and photometry to screen for mutants that exhibit growth phase variation in gene expression is demonstrated.

Cloning, Molecular↗
PubMed1998

An unusual case of hyperdontia [corrected].

The presence of supernumerary teeth is not uncommon but there have been very few documented cases of bilateral maxillary and mandibular supernumeraries distal to third molars. This case study looks at the frequency of and complications arising from supernumeraries as well as specifically covering the presentation and subsequent removal in practice of five supernumeraries distal to third molars. Good and thorough radiographs are essential for correct diagnosis.

Adult↗
PubMed1998

Lutzomyia longipalpis: pH in the gut, digestive glycosidases, and some speculations upon Leishmania development.

Screening for digestive glycosidases in different parts of the gut and associated organs of Lutzomyia longipalpis is reported. Searches for the enzymes were made in blood-fed and non-blood-fed females and the enzymes were characterized as soluble or membrane-bound molecules. A total of four different activities were detected, corresponding to the following specificities: an alpha-glucosidase, an N-acetyl-beta-d-glucosaminidase, an N-acetyl-beta-d-galactosaminidase, and an alpha-l-fucosidase. Their possible role and importance for Leishmania development are discussed and the alpha-glucosidase enzyme was partially characterized. The pH inside the gut of non-blood-fed phlebotomines was measured with pH indicator dyes. The pH ranges obtained for crop, midgut, and hindgut were, respectively, higher than pH 6, pH 6, and lower than pH 6. A hypothesis concerning these data and Leishmania development is proposed.

Animals↗
PubMed1998

Training 'greeble' experts: a framework for studying expert object recognition processes.

Twelve participants were trained to be experts at identifying a set of 'Greebles', novel objects that, like faces, all share a common spatial configuration. Tests comparing expert with novice performance revealed: (1) a surprising mix of generalizability and specificity in expert object recognition processes; and (2) that expertise is a multi-faceted phenomenon, neither adequately described by a single term nor adequately assessed by a single task. Greeble recognition by a simple neural-network model is also evaluated, and the model is found to account surprisingly well for both generalization and individuation using a single set of processes and representations.

Computer Simulation↗
PubMed1998

Differential effects of intracerebroventricular glucagon-like peptide-1 on feeding and energy expenditure regulation.

Intracerebroventricular (i.c.v.) administration of glucagon-like peptide-1-(7-37) amide (GLP-1) has been shown to modulate food and water intake. The present studies further characterize the effects of i.c.v. GLP-1 in the regulation of energy balance in lean and obese animals. In both obese and lean Zucker rats, a single i.c.v. infusion of GLP-1 (1-30 microg) resulted in a dose-dependent reduction of food intake and decrease in respiratory quotient relative to the saline control during the first 2 h of the nocturnal cycle. In obese Zucker rats, the food intake was reduced by 73 +/- 11% of the control at the 30 microg dose, whereas a modest 45 +/- 18% reduction was observed in lean rats. Despite the large reduction in food intake seen with GLP-1, there was no compensatory decrease in nocturnal oxygen consumption in the obese Zucker rats. Interestingly, low doses of GLP-1 (1 microg) in lean Zucker rats, which had minimal effects on food intake, caused a 19 +/- 7% increase in O2 consumption during the first 2 h of the nocturnal cycle. These data suggest that central GLP-1 may be an important factor controlling negative energy balance in both the lean and obese Zucker rats.

Analysis of Variance↗
PubMed1998

Clinical significance of CMV-specific T helper responses in lung transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) disease continues to be a major problem for lung transplant patients who generate an inefficient immune response to control this viral infection. Both T helper and cytotoxic T cells are thought to play an important role in prevention and control of CMV disease. We investigated the clinical significance of CMV-specific memory responses in lung transplant recipients. METHOD: Peripheral blood samples (140) were collected from 99 lung transplant recipients. Patients were grouped according to their pre-transplant CMV serological status as recipient/donor (R-/D+, 25 patients), 28 R+/D+ patients, 35 R+/D- patients and 11 R-/D- patients. Memory responses to CMV whole antigen, 5 CMV proteins, and tetanus toxoid (TT) were measured in a 6-day proliferative assay. Results were expressed as the stimulation index (SI = experimental cpm/background cpm), and were considered positive if the SI was >3 and the cpm values were over 1,000. RESULTS: The frequency of positive CMV memory responses was similar in three groups: 64% for R-/D+, 63% for R+/D+ and 56% for R+/D- except for R-/D- (21%). The memory response to TT was similar for all four groups (70% of samples were positive). The level of responsiveness to individual CMV proteins was much higher in R+/D+ group (65%) than the other two groups (35% for R+/D-, and 31% for R-/D+). We determined the temporal relationship between the presence of CMV-specific memory responses and the diagnosis of CMV disease. In the R-/D+ group, 16 of 17 patients who had CMV disease eventually developed CMV-specific memory. In those patients (n = 3) who failed to develop CMV-specific T helper response for a prolonged time, all had recurrent CMV disease. In the R+/D+ group, 4 of 8 patients with CMV disease exhibited CMV-specific memory responses. Three of 4 patients in whom we observed a persistent absence of CMV-specific memory had multiple episodes of CMV pneumonitis. In the R+/D- group, only one of 4 patients with CMV disease had suppressed CMV-specific memory response after first episode of CMV pneumonitis and had recurrent disease. CONCLUSION: In lung transplant recipients, the loss or persistent lack of CMV-specific memory following infection was associated with chronic CMV disease. These data suggest that monitoring T helper memory responses following primary CMV infection or after augmented immunosuppression for treatment of rejection may identify those patients at risk for morbidity associated with recurrent CMV disease.

Antigens, Viral↗
PubMed1998

A practice-based randomised controlled trial of the efficacy of an electric and a manual toothbrush on gingival health in patients with fixed orthodontic appliances.

OBJECTIVES: The aim of the present study was to evaluate the efficacy of an electric toothbrush with a specially designed orthodontic brush head compared with a manual toothbrush in controlling plaque and gingivitis in patients with fixed orthodontic appliances over an 8-week period in a dental practice setting. METHODS: This was a randomised controlled, single blind, stratified, parallel group trial conducted in two specialist orthodontic dental practices by a specialist orthodontist. Group 1 comprised 41 subjects who used the electric toothbrush and Group 2 consisted of 43 subjects who brushed with a manual toothbrush around the orthodontic appliance for a timed 2 minutes twice daily for 8 weeks. Plaque around the fixed appliance attachments was measured using an orthodontic modification to the Silness and Loe plaque index, while gingival condition was scored using the gingival index and Eastman interdental bleeding index. RESULTS: There was baseline balance for all clinical variables (p > 0.05). Both groups had significantly less plaque after 8 weeks than at baseline (p < 0.001) but the group using the electric brush also had significantly less interdental gingival bleeding, as determined by the Eastman interdental bleeding index both at week 4 (p < 0.001) and week 8 (p = 0.004). The majority of subjects (n = 54, 64.3%) preferred the electric toothbrush. CONCLUSIONS: In conclusion, the results from this study would suggest that use of an electric toothbrush with an orthodontic brush head may be of benefit in promoting gingival health in fixed orthodontic appliance patients; however, the long-term effects (over at least 6 months) need to be evaluated.

Adolescent↗
PubMed1998

How to create awareness and ensure broad dissemination of health informatics standards.

There is a range of organisations with responsibility for information standards development within Australia. These include Standards Australia, which is formally linked to the International Organisation for Standards (ISO), the National Health Information Management Group, which deals with the government sector and several statutory organisations such as the Australian Institute of Health and Welfare and the National Centre for Classification in Health. The different constituencies involved with each of these organisations, the scope of healthcare informatics and the rate of organisational and technological change in the industry present a significant challenge in ensuring that the standard setting process is highly visible, responsive and capable of demonstrating its value through effective implementation. Creating awareness and ensuring broad dissemination of healthcare informatics standards is a key component in meeting this challenge. This can operate at a number of levels from strategic to operational. At the strategic level, it requires active engagement and commitment of the key decision-makers, both political and professional. This may require directly lobbying and promoting the benefits of standardisation to those decision-makers but can be achieved even more effectively by creating industry awareness and demand through carefully targeted presentations on the impact of standards to broader health industry forums. At the tactical level, the standards development medium itself can be used to engage and gain commitment from government, professionals, vendors and the health industry by operating as an inclusive, open and effective process. At the operational level, there is the opportunity for much more efficient use of technology to create awareness of both these processes and their outcomes. The establishment in Australia of a web enabled National Health Information Knowledge base built around ISO standards is one example of the type of development which will assist in the acceleration of awareness of standards and standardisation, which is needed to cope with the increasing demand.

Australia↗
PubMed1998

Quorum sensing and the cell-cell communication dependent regulation of gene expression in pathogenic and non-pathogenic bacteria.

Although it has been clear for some time that individual bacterial cells employ intra-cellular signalling systems to sense, integrate and process information from their surroundings, their widespread capacity to perceive information from other bacterial cells is only just beginning to be recognised. Recent work has established that diverse bacteria exploit a cell-cell communication device to regulate the transcription of multiple target genes. This communication device termed 'quorum sensing', depends on the production of one or more diffusible signal molecules termed 'autoinducers' or 'pheromones' which enable a bacterium to monitor its own cell population density. Quorum sensing is thus an example of multicellular behaviour in prokaryotes and regulates diverse physiological processes including bioluminescence, swarming, antibiotic biosynthesis, plasmid conjugal transfer and the production of virulence determinants in animal, fish and plant pathogens. In Gram-negative bacteria, the best understood family of signal molecules are the N-acylhomoserine lactones (AHLs) which vary predominantly in the presence or absence of an acyl chain C3 substituent (oxo- or hydroxy-) and length of the N-acyl side chain. However not all quorum sensing signal molecules are AHLs; in Gram-positive bacteria, they are often post-translationally modified peptides. Irrespective of the chemical 'language' employed, interference with either the synthesis or transmission of a quorum sensing signal molecule in pathogenic bacteria offers an exciting new strategy for controlling infection.

Gene Expression Regulation, Bacterial↗