1
|
Abstract
The physiological role of glucagon-like peptide-1 7-36 amide (GLP-1 7-36) in man was investigated. GLP-1 7-36-like immunoreactivity was found in the human bowel; its circulating level rose after oral glucose and after a test breakfast. When it was infused into seven volunteers at a rate to mimic its postprandial plasma concentration in the fasting state, plasma insulin levels rose significantly and glucose and glucagon concentrations fell. During an intravenous glucose load, it greatly enhanced insulin release and significantly reduced peak plasma glucose concentrations, compared with a control saline infusion, even inducing postinfusion reactive hypoglycaemia. By comparison, infusion of glucose-dependent insulinotropic peptide (GIP) to physiological levels was less effective in stimulating insulin release. These observations suggest that GLP-1 7-36 is a physiological incretin and that it is more powerful than GIP. The observation of greatly increased postprandial plasma GLP-1 7-36 levels in patients with postgastrectomy dumping syndrome suggests that it may mediate the hyperinsulinaemia and reactive hypoglycaemia of this disorder.
Collapse
|
Clinical Trial |
38 |
1266 |
2
|
Abstract
Human and animal solid tumors elaborate a factor which is mitogenic to capillary endothelial cells. This factor has been called tumor-angiogenesis factor. The important components of TAF are RNA and protein. It is suggested that blockade of this factor (inhibition of angiogenesis) might arrest solid tumors at a tiny diameter of a few millimeters.
Collapse
|
research-article |
54 |
1078 |
3
|
Urwin M, Symmons D, Allison T, Brammah T, Busby H, Roxby M, Simmons A, Williams G. Estimating the burden of musculoskeletal disorders in the community: the comparative prevalence of symptoms at different anatomical sites, and the relation to social deprivation. Ann Rheum Dis 1998; 57:649-55. [PMID: 9924205 PMCID: PMC1752494 DOI: 10.1136/ard.57.11.649] [Citation(s) in RCA: 724] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND Epidemiologically-based rheumatology healthcare needs assessment requires an understanding of the incidence and prevalence of musculoskeletal disorders in the community, of the reasons why people consult in primary care, and of the proportion of people who would benefit from referral to secondary care and paramedical services. This paper reports the first phase of such a needs assessment exercise. SPECIFIC OBJECTIVE To estimate the relative frequency of musculoskeletal pain in different, and multiple, anatomical sites in the adult population. SETTING Three general practices in the former Tameside and Glossop Health Authority, Greater Manchester, UK, a predominantly urban area. DESIGN Population survey. METHODS An age and sex stratified sample of 6000 adults from the three practices was mailed a questionnaire that sought data on demographic factors, musculoskeletal symptoms (pain in the past month lasting for more than a week), and physical disability (using the modified Health Assessment Questionnaire--mHAQ). The areas of pain covered were neck, back, shoulder, elbow, hand, hip, knee, and multiple joints. The Carstairs index was used as a measure of social deprivation of the postcode sector in which the person lived. RESULTS The response rate after two reminders was 78.5%. Non-responders were more likely to live in areas of high social deprivation. People who lived in more deprived areas were also more likely to report musculoskeletal pain, especially backpain. After adjusting for social deprivation the rates of musculoskeletal pain did not differ between the practices and so their results were combined. After adjustment for social deprivation, the most common site of pain was back (23%; 95% CI 21, 25) followed by knee (19%; 95% CI 18, 21), and shoulder (16%; 95% CI 14, 17). The majority of subjects who reported pain had pain in more than one site. The prevalence of physical disability in the community rose with age. It was highest in those with multiple joint problems but was also high in those with isolated back or knee pain. CONCLUSION Musculoskeletal pain is common in the community. People who live in socially deprived areas have more musculoskeletal symptoms. Estimates of the overall burden of musculoskeletal pain that combine the results of site specific surveys will be too high, those that do not adjust for socioeconomic factors will be too low.
Collapse
|
research-article |
27 |
724 |
4
|
Green A, Williams G, Neale R, Hart V, Leslie D, Parsons P, Marks GC, Gaffney P, Battistutta D, Frost C, Lang C, Russell A. Daily sunscreen application and betacarotene supplementation in prevention of basal-cell and squamous-cell carcinomas of the skin: a randomised controlled trial. Lancet 1999; 354:723-9. [PMID: 10475183 DOI: 10.1016/s0140-6736(98)12168-2] [Citation(s) in RCA: 590] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The use of sunscreens on the skin can prevent sunburn but whether long-term use can prevent skin cancer is not known. Also, there is evidence that oral betacarotene supplementation lowers skin-cancer rates in animals, but there is limited evidence of its effect in human beings. METHODS In a community-based randomised trial with a 2 by 2 factorial design, individuals were assigned to four treatment groups: daily application of a sun protection factor 15-plus sunscreen to the head, neck, arms, and hands, and betacarotene supplementation (30 mg per day); sunscreen plus placebo tablets; betacarotene only; or placebo only. Participants were 1621 residents of Nambour in southeast Queensland, Australia. The endpoints after 4.5 years of follow-up were the incidence of basal-cell and squamous-cell carcinomas both in terms of people treated for newly diagnosed disease and in terms of the numbers of tumours that occurred. Analysis of the effect of sunscreen was based only on skin cancers that developed on sites of daily application. All analyses were by intention to treat. FINDINGS 1383 participants underwent full skin examination by a dermatologist in the follow-up period. 250 of them developed 758 new skin cancers during the follow-up period. There were no significant differences in the incidence of first new skin cancers between groups randomly assigned daily sunscreen and no daily sunscreen (basal-cell carcinoma 2588 vs 2509 per 100,000; rate ratio 1.03 [95% CI 0.73-1.46]; squamous-cell carcinoma 876 vs 996 per 100,000; rate ratio 0.88 [0.50-1.56]). Similarly, there was no significant difference between the betacarotene and placebo groups in incidence of either cancer (basal-cell carcinoma 3954 vs 3806 per 100,000; 1.04 [0.73-1.27]; squamous-cell carcinoma 1508 vs 1146 per 100,000; 1.35 [0.84-2.19]). In terms of the number of tumours, there was no effect on incidence of basal-cell carcinoma by sunscreen use or by betacarotene but the incidence of squamous-cell carcinoma was significantly lower in the sunscreen group than in the no daily sunscreen group (1115 vs 1832 per 100,000; 0.61 [0.46-0.81]). INTERPRETATION There was no harmful effect of daily use of sunscreen in this medium-term study. Cutaneous squamous-cell carcinoma, but not basal-cell carcinoma seems to be amenable to prevention through the routine use of sunscreen by adults for 4.5 years. There was no beneficial or harmful effect on the rates of either type of skin cancer, as a result of betacarotene supplementation.
Collapse
|
Clinical Trial |
26 |
590 |
5
|
Popay J, Rogers A, Williams G. Rationale and standards for the systematic review of qualitative literature in health services research. QUALITATIVE HEALTH RESEARCH 1998; 8:341-51. [PMID: 10558335 DOI: 10.1177/104973239800800305] [Citation(s) in RCA: 468] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Despite growing recognition of the need for qualitative methods in health services research, there have been few attempts to define quality standards for assessing the results. This article acknowledges the desirability of a plurality of standards. However, it is argued that three interrelated criteria can be identified as the foundation of good qualitative health research: interpretation of subjective meaning, description of social context, and attention to lay knowledge. These criteria can be examined in relation to different dimensions of any research report, including theoretical basis, sampling strategy, scope of data collection, description of data collected, and concern with generalizability or typicality. But if the concern is with the appropriateness of care and with understanding the factors that shape lay and clinical behavior, then these criteria must form the basis of a hierarchy of qualitative research evidence.
Collapse
|
|
27 |
468 |
6
|
Williams G. The genesis of chronic illness: narrative re-construction. SOCIOLOGY OF HEALTH & ILLNESS 1984; 6:175-200. [PMID: 10268832 DOI: 10.1111/1467-9566.ep10778250] [Citation(s) in RCA: 420] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In this paper I demonstrate the way in which people's beliefs about the aetiology of their particular affliction (arthritis) need to be understood as part of a more comprehensive imaginative enterprise which I refer to as narrative reconstruction. The intrinsically teleological form of this enterprise means that identified 'causes' represent only putative efficient connexions between the disease and antecedent factors but also narrative reference points between the individual and society in an unfolding process which has become profoundly disrupted. Through the presentation of case material taken from lengthy interviews I illustrate the way in which my question to the subjects about the cause of their disease: 'Why do you think you got arthritis?' was translated by them into a narrative reconstruction of their changing relationship to the world in which they live and the genesis of illness within it.
Collapse
|
|
41 |
420 |
7
|
Williams G, Bing C, Cai XJ, Harrold JA, King PJ, Liu XH. The hypothalamus and the control of energy homeostasis: different circuits, different purposes. Physiol Behav 2001; 74:683-701. [PMID: 11790431 DOI: 10.1016/s0031-9384(01)00612-6] [Citation(s) in RCA: 389] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The hypothalamus regulates many aspects of energy homeostasis, adjusting both the drive to eat and the expenditure of energy in response to a wide range of nutritional and other signals. It is becoming clear that various neural circuits operate to different degrees and probably serve specific functions under particular conditions of altered feeding behaviour. This review will discuss this functional diversity by illustrating hypothalamic neurones that express neuropeptide Y (NPY), the melanocortin-4 receptor (MC4-R) and the orexins. NPY neurones in the arcuate nucleus (ARC) release NPY, a powerful inducer of feeding and obesity, in the paraventricular nucleus (PVN) and the lateral hypothalamic area (LHA). ARC-NPY neurones are inhibited by leptin and insulin and become overactive when levels of these hormones fall during undernutrition. They may function physiologically to protect against starvation. With disruption of the inhibitory leptin signals due to gene mutations, the NPY neurones are overactive, which contributes to hyperphagia and obesity in the ob/ob and db/db mice and fa/fa Zucker rat. The MC4-R is activated by alpha-melanocyte-stimulating hormone [alpha-MSH; a cleavage product of pro-opiomelanocortin (POMC), which is expressed in the other ARC neurones] and inhibits feeding. This effect is antagonised by agouti gene-related peptide (AGRP), which is coexpressed by the ARC-NPY neurones only. Activation of MC4-R, possibly mediated by blockade of AGRP release, appears to restrain overeating of a palatable diet. This response may be programmed by a transient rise in leptin soon after presentation of palatable food, and rats that fail to do this will overeat and become obese. Orexin-A and -B (corresponding to hypocretins 1 and 2) are expressed in specific LHA neurones. These have extensive reciprocal connections with many areas involved in appetite control, including the nucleus of the solitary tracts (NTS), which relays vagal afferent satiety signals from the viscera. Orexin neurones also have close anatomical connections with LHA glucose-sensitive neurones. Orexin-A induces acute feeding but does not cause obesity. Orexin neurones are stimulated by hypoglycaemia partly via the NTS and inhibited by food ingestion. These neurones may therefore be involved in the severe hyperphagia of hypoglycaemia and short-term control of feeding.
Collapse
|
Review |
24 |
389 |
8
|
Williams G, Watts DC, Dev SB, North AM. Further considerations of non symmetrical dielectric relaxation behaviour arising from a simple empirical decay function. ACTA ACUST UNITED AC 1971. [DOI: 10.1039/tf9716701323] [Citation(s) in RCA: 388] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
|
54 |
388 |
9
|
Galton CJ, Patterson K, Graham K, Lambon-Ralph MA, Williams G, Antoun N, Sahakian BJ, Hodges JR. Differing patterns of temporal atrophy in Alzheimer's disease and semantic dementia. Neurology 2001; 57:216-25. [PMID: 11468305 DOI: 10.1212/wnl.57.2.216] [Citation(s) in RCA: 384] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To characterize and quantify the patterns of temporal lobe atrophy in AD vs semantic dementia and to relate the findings to the cognitive profiles. Medial temporal lobe atrophy is well described in AD. In temporal variant frontotemporal dementia (semantic dementia), clinical studies suggest polar and inferolateral temporal atrophy with hippocampal sparing, but quantification is largely lacking. METHODS A volumetric method for quantifying multiple temporal structures was applied to 26 patients with probable AD, 18 patients with semantic dementia, and 21 matched control subjects. RESULTS The authors confirmed the expected bilateral hippocampal atrophy in AD relative to controls, with involvement of the amygdala bilaterally and the right parahippocampal gyrus. Contrary to expectations, patients with semantic dementia had asymmetric hippocampal atrophy, more extensive than AD on the left. As predicted, the semantic dementia group showed more severe involvement of the temporal pole bilaterally and the left amygdala, parahippocampal gyrus (including the entorhinal cortex), fusiform gyrus, and the inferior and middle temporal gyri. Performance on semantic association tasks correlated with the size of the left fusiform gyrus, whereas naming appeared to depend upon a wider left temporal network. Episodic memory measures, with the exception of recognition memory for faces, did not correlate with temporal measures. CONCLUSIONS Hippocampal atrophy is not specific for AD but is also seen in semantic dementia. Distinguishing the patients with semantic dementia was the severe global but asymmetric (left > right) atrophy of the amygdala, temporal pole, and fusiform and inferolateral temporal gyri. These findings have implications for diagnosis and understanding of the cognitive deficits in AD and semantic dementia.
Collapse
|
|
24 |
384 |
10
|
Elwood PC, Cochrane AL, Burr ML, Sweetnam PM, Williams G, Welsby E, Hughes SJ, Renton R. A randomized controlled trial of acetyl salicylic acid in the secondary prevention of mortality from myocardial infarction. BRITISH MEDICAL JOURNAL 1974; 1:436-40. [PMID: 4593555 PMCID: PMC1633246 DOI: 10.1136/bmj.1.5905.436] [Citation(s) in RCA: 338] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The results of a randomized controlled trial of a single daily dose of acetyl salicylic acid (aspirin) in the prevention of reinfarction in 1,239 men who had had a recent myocardial infarct were statistically inconclusive. Nevertheless, they showed a reduction in total mortality of 12% at six months and 25% at twelve months after admission to the trial. Further trials are urgently required to establish whether or not this effect is real.
Collapse
|
research-article |
51 |
338 |
11
|
Stüve O, Dooley NP, Uhm JH, Antel JP, Francis GS, Williams G, Yong VW. Interferon beta-1b decreases the migration of T lymphocytes in vitro: effects on matrix metalloproteinase-9. Ann Neurol 1996; 40:853-63. [PMID: 9007090 DOI: 10.1002/ana.410400607] [Citation(s) in RCA: 274] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In multiple sclerosis (MS), the influx of activated T lymphocytes into the brain parenchyma leads to the subsequent damage of oligodendrocytes, the cells that produce central nervous system (CNS) myelin. We report here that interferon beta-1b (IFNbeta-1b), a drug shown to be efficacious in the treatment of patients with MS, decreases the in vitro migration of activated T lymphocytes through fibronectin (FN), a major component of the basement membrane that surrounds cerebral endothelium. At 1,000 IU/ml, IFNbeta-1b reduced the migratory rate to that of unactivated T cells. In contrast, IFNgamma at 1,000 IU/ml, which caused a similar decrease (25%) in the proliferation rate of T lymphocytes as IFNbeta-1b, did not affect migration. All T-lymphocyte subsets and natural killer (NK) cells were demonstrated by flow cytometry to be equally affected by IFNbeta-1b treatment. 125I-Western blot analyses revealed that IFNbeta-1b treatment resulted in a marked reduction of the ability of T cells to cleave FN. The substrate-degrading capability of T lymphocytes was shown to be due predominantly to the activity of a 92-kd matrix metalloproteinase, MMP-9, whose levels were decreased by IFNbeta-1b. We suggest that the clinical benefits of IFNbeta-1b treatment in MS patients may be in part a result of the ability of this drug to significantly decrease MMP-9 activity, leading to a reduction of T-lymphocyte infiltration into the CNS.
Collapse
|
|
29 |
274 |
12
|
Abstract
Abstract
Two hundred and seventeen patients presenting with abdominal aneurysms in the Department of Surgery at the Manchester Royal Infirmary between the years 1958–69 were surveyed retrospectively.
One hundred and eighty-seven of the patients underwent operation for resection of their aneurysms; of these, 19 (10 per cent) showed excessive thickening of the aneurysm walls and perianeurysmal adhesions at operation.
Subsequent histological examination of the walls of these unusual aaneurysms showed extensive active chronic inflammatory changes, including plasma-cell infiltration.
This group of patients whose aneurysms we describe as ‘inflammatory’ presented with different clinical features in comparison with the atherosclerotic group.
Retrospective investigation has not yet revealed any aetiological factors. We feel that ‘inflammatory’ aneurysms are a discrete entity with significant differences from atherosclerotic aneurysms and previously described arteritis.
Collapse
|
|
53 |
252 |
13
|
Pitt B, Williams G, Remme W, Martinez F, Lopez-Sendon J, Zannad F, Neaton J, Roniker B, Hurley S, Burns D, Bittman R, Kleiman J. The EPHESUS trial: eplerenone in patients with heart failure due to systolic dysfunction complicating acute myocardial infarction. Eplerenone Post-AMI Heart Failure Efficacy and Survival Study. Cardiovasc Drugs Ther 2001; 15:79-87. [PMID: 11504167 DOI: 10.1023/a:1011119003788] [Citation(s) in RCA: 231] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
|
24 |
231 |
14
|
Cai XJ, Widdowson PS, Harrold J, Wilson S, Buckingham RE, Arch JR, Tadayyon M, Clapham JC, Wilding J, Williams G. Hypothalamic orexin expression: modulation by blood glucose and feeding. Diabetes 1999; 48:2132-7. [PMID: 10535445 DOI: 10.2337/diabetes.48.11.2132] [Citation(s) in RCA: 226] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Orexins (hypocretins), novel peptides expressed in specific neurons of the lateral hypothalamic area (LHA), stimulate feeding when injected intracerebroventricularly. We investigated their role in feeding in the rat by measuring hypothalamic prepro-orexin mRNA levels under contrasting conditions of increased hunger. Prepro-orexin mRNA levels increased significantly after 48 h of fasting (by 90-170%; P < 0.05) and after acute (6 h) hypoglycemia when food was withheld (by 90%; P < 0.02). By contrast, levels were unchanged during chronic food restriction, streptozotocin-induced diabetes, hypoglycemia when food was available, voluntary overconsumption of palatable food, or glucoprivation induced by systemic 2-deoxy-D-glucose. Orexin expression was not obviously related to changes in body weight, insulin, or leptin, but was stimulated under conditions of low plasma glucose in the absence of food. Orexins may participate in the short-term regulation of energy homeostasis by initiating feeding in response to falls in glucose and terminating it after food ingestion. The LHA is known to contain neurons that are stimulated by falls in circulating glucose but inhibited by feeding-related signals from the viscera; orexin neurons may correspond to this neuronal population.
Collapse
|
|
26 |
226 |
15
|
Yong VW, Chabot S, Stuve O, Williams G. Interferon beta in the treatment of multiple sclerosis: mechanisms of action. Neurology 1998; 51:682-9. [PMID: 9748010 DOI: 10.1212/wnl.51.3.682] [Citation(s) in RCA: 224] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Interferon beta (IFN-beta) has been shown in several clinical trials to have efficacy in MS. Its mechanism of action, however, remains unclear. In this review, several biological activities of IFN-beta are highlighted, including its inhibitory effects on proliferation of leukocytes and antigen presentation. Furthermore, IFN-beta may modulate the profile of cytokine production toward that of the anti-inflammatory phenotype, and this appears to occur in the systemic circulation and within the CNS. Finally, IFN-beta can reduce T-cell migration by inhibiting the activity of T-cell matrix metalloproteinases. These activities are likely to act in concert to account for the mechanism of IFN-beta in MS.
Collapse
|
Review |
27 |
224 |
16
|
Doull J, Cattley R, Elcombe C, Lake BG, Swenberg J, Wilkinson C, Williams G, van Gemert M. A cancer risk assessment of di(2-ethylhexyl)phthalate: application of the new U.S. EPA Risk Assessment Guidelines. Regul Toxicol Pharmacol 1999; 29:327-57. [PMID: 10388618 DOI: 10.1006/rtph.1999.1296] [Citation(s) in RCA: 222] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The current United States Environmental Protection Agency (EPA) classification of di(2-ethylhexyl)phthalate (DEHP) as a B2 "probable human" carcinogen is based on outdated information. New toxicology data and a considerable amount of new mechanistic evidence were used to reconsider the cancer classification of DEHP under EPA's proposed new cancer risk assessment guidelines. The total weight-of-evidence clearly indicates that DEHP is not genotoxic. In vivo administration of DEHP to rats and mice results in peroxisome proliferation in the liver, and there is strong evidence and scientific consensus that, in rodents, peroxisome proliferation is directly associated with the onset of liver cancer. Peroxisome proliferation is a transcription-mediated process that involves activation by the peroxisome proliferator of a nuclear receptor in rodent liver called the peroxisome proliferator-activated receptor (PPARalpha). The critical role of PPARalpha in peroxisomal proliferation and carcinogenicity in mice is clearly established by the lack of either response in mice genetically modified to remove the PPARalpha. Several mechanisms have been proposed to explain how, in rodents, peroxisome proliferation can lead to the formation of hepatocellular tumors. The general consensus of scientific opinion is that PPARalpha-induced mitogenesis and cell proliferation are probably the major mechanisms responsible for peroxisome proliferator-induced hepatocarcinogenesis in rodents. Oxidative stress appears to play a significant role in this increased cell proliferation. It triggers the release of TNFalpha by Kupffer cells, which in turn acts as a potent mitogen in hepatocytes. Rats and mice are uniquely responsive to the morphological, biochemical, and chronic carcinogenic effects of peroxisome proliferators, while guinea pigs, dogs, nonhuman primates, and humans are essentially nonresponsive or refractory; Syrian hamsters exhibit intermediate responsiveness. These differences are explained, in part, by marked interspecies variations in the expression of PPARalpha, with levels of expression in humans being only 1-10% of the levels found in rat and mouse liver. Recent studies of DEHP clearly indicate a nonlinear dose-response curve that strongly suggests the existence of a dose threshold below which tumors in rodents are not induced. Thus, the hepatocarcinogenic effects of DEHP in rodents result directly from the receptor-mediated, threshold-based mechanism of peroxisome proliferation, a well-understood process associated uniquely with rodents. Since humans are quite refractory to peroxisomal proliferation, even following exposure to potent proliferators such as hypolipidemic drugs, it is concluded that the hepatocarcinogenic response of rodents to DEHP is not relevant to human cancer risk at any anticipated exposure level. DEHP should be classified an unlikely human carcinogen with a margin of exposure (MOE) approach to risk assessment. The most appropriate and conservative point of reference for assessing MOEs should be 20 mg/kg/day, which is the mouse NOEL for peroxisome proliferation and increased liver weight. Exposure of the general human population to DEHP is approximately 30 microg/kg body wt/day, the major source being from residues in food. Higher exposures occur occupationally [up to about 700 microg/kg body wt/day (mainly by inhalation) based on current workplace standards] and through use of certain medical devices [e.g., up to 457 microg/kg body wt/day for hemodialysis patients (intravenous)], although these have little relevance because the routes of exposure bypass critical activation enzymes in the gastrointestinal tract.
Collapse
|
Review |
26 |
222 |
17
|
Frieden TR, Munsiff SS, Low DE, Willey BM, Williams G, Faur Y, Eisner W, Warren S, Kreiswirth B. Emergence of vancomycin-resistant enterococci in New York City. Lancet 1993; 342:76-9. [PMID: 8100912 DOI: 10.1016/0140-6736(93)91285-t] [Citation(s) in RCA: 213] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Enterococci, a common cause of nosocomial infection, are intrinsically resistant to most antimicrobials and readily acquire additional resistance. Vancomycin-resistant enterococci (VRE) have caused clusters of nosocomial infections since 1988. In April, 1991, the New York City Department of Health asked all city laboratories to submit suspected VRE isolates for confirmation. Clinical and epidemiological characteristics of the first 100 patients with VRE were identified, and antimicrobial susceptibility testing, restriction enzyme analysis, and DNA-DNA hybridisation with the vanA gene probe were done. From September, 1989, to October, 1991, 361 patients with VRE were identified at 38 hospitals. The number of hospitals reporting VRE increased from 1 in 1989 to 38 by October, 1991. 98% of 100 VRE infections were nosocomially acquired and 83% patients had received vancomycin and/or a cephalosporin in the 30 days before isolation of VRE. Of 23 isolates from 21 of the first 100 patients, 19 (83%) were resistant to all available antimicrobials. Four vanA probing patterns were noted, and restriction enzyme analysis of the 23 isolates revealed 14 strains. VRE have emerged rapidly in New York City. Molecular analyses suggest that a highly mobile genetic element--eg, a transposon--is responsible for the rapid spread of vancomycin resistance.
Collapse
|
|
32 |
213 |
18
|
Sitia R, Neuberger M, Alberini C, Bet P, Fra A, Valetti C, Williams G, Milstein C. Developmental regulation of IgM secretion: the role of the carboxy-terminal cysteine. Cell 1990; 60:781-90. [PMID: 2107027 DOI: 10.1016/0092-8674(90)90092-s] [Citation(s) in RCA: 208] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
B lymphocytes do not secrete IgM, and plasma cells only secrete IgM polymers. Here we show that both events are attributable to the tailpiece found at the carboxyl terminus of mus chains, and we specifically implicate Cys-575. Thus, if Cys-575 was mutated, IgM was secreted by B cells. Similarly, a mutant IgG containing a mus tailpiece became largely retained within the cell; secretion was restored upon mutation of the tailpiece cysteine. Removal of Cys-575 also allowed hypersecretion of monomeric IgM by plasmacytoma cells. Following further removal of Cmu1, heavy chains were secreted in the absence of light chains. Thus, in B and plasma cells, Cys-575 is involved both in the polymerization of IgM and in intracellular retention of unpolymerized intermediates.
Collapse
|
|
35 |
208 |
19
|
Abstract
The fetal brain accumulates long-chain (C20 and 22) polyunsaturated fatty acids--arachidonic and docosahexaenoic--during cell division. De-novo synthesis of these acids does not occur and they are thought to be either directly derived from food or by metabolism from linoleic and linolenic acids, respectively. Administration of isotopically labelled linoleic and linolenic acids to pregnant guineapigs showed that only a small proportion of the label was converted to their respective long-chain polyunsaturated derivatives in the maternal liver. The proportion was increased within the phospholipids (structural lipids) by what appeared to be amultiple processing system which increased chain length and degree of polyunsaturation from maternal liver to placenta, fetal liver, and to fetal brain. Observations in man suggest a similar trend. The porportion of long-chain polyunsaturated acids increased in the phospholipids from maternal blood, cord blood, fetal liver, and fetal brain. These data show that the placenta and fetus are radically modifying the maternal phospholipids so as to achieve the high proportions of the C20 and C22 polyunsaturated fatty acids in the structural lipids of the developing brain.
Collapse
|
Comparative Study |
49 |
204 |
20
|
Finer N, James WP, Kopelman PG, Lean ME, Williams G. One-year treatment of obesity: a randomized, double-blind, placebo-controlled, multicentre study of orlistat, a gastrointestinal lipase inhibitor. Int J Obes (Lond) 2000; 24:306-13. [PMID: 10757623 DOI: 10.1038/sj.ijo.0801128] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To assess the efficacy and tolerability of orlistat (Xenical) in producing and maintaining weight loss over a 12-month period. DESIGN Patients were randomized to double-blind treatment with either orlistat 120 mg or placebo three times daily, in conjunction with a low-energy diet, for 12 months. SETTING Five centres in the UK. SUBJECTS 228 obese adult patients with body mass index between 30 and 43 kg/m2 and mean weight 97 kg (range 74-144 kg). INTERVENTIONS All patients were prescribed a low-energy diet, providing 30% of energy from fat, designed to produce an individually tailored energy deficit of approximately 600 kcal/day, for a run-in period of 4 weeks and then 12 months, plus orlistat 120 mg or placebo three times daily. MAIN OUTCOME MEASURES Change in body weight (the primary efficacy parameter), waist circumference and adverse events were reviewed regularly, together with serum lipids, insulin, glucose and plasma levels of fat-soluble vitamins and beta carotene. RESULTS Based on an intent-to-treat analysis, after 1 y of treatment patients receiving orlistat had lost an average of 8.5% of their initial body weight compared with 5.4% for placebo-treated patients; 35% of the orlistat group lost at least 5% of body weight compared with 21% of the placebo group (P < 0.05), and 28% and 17%, respectively (P = 0.04) lost at least 10% of body weight. Orlistat-treated patients showed significant decreases (P < 0.05) in serum levels of total cholesterol, low density lipoprotein cholesterol, and in the low density lipoprotein: high density lipoprotein ratio in comparison with placebo. Both groups had similar adverse-event profiles, except for gastrointestinal events, which were 26% more frequent in the orlistat group but were mostly mild and transient. To maintain normal plasma levels of fat-soluble vitamins, supplements of vitamins A, D and E were given to 1.8%, 8.0% and 3.6%, respectively, of orlistat-treated patients, compared with 0.9% of placebo-treated patients for each vitamin type. After 1 y, the decrease in vitamin E and beta carotene was significantly greater in orlistat-treated patients compared with those receiving placebo (P < 0.001). No significant change was found in the mean vitamin E:total cholesterol ratio in either group after 52 weeks. CONCLUSIONS Orlistat, in conjunction with a low-energy diet, produced greater and more frequent significant weight loss than placebo during 1 y of treatment. One-third of orlistat-treated patients achieved clinically relevant weight loss (> or = 5% initial body weight). There was also an improvement in relevant serum lipid parameters. Fat-soluble vitamin supplements may be required during chronic therapy. Orlistat was well tolerated and offers a promising new approach to the long-term management of obesity.
Collapse
|
Clinical Trial |
25 |
192 |
21
|
Welham J, Scott J, Williams G, Najman J, Bor W, O'Callaghan M, McGrath J. Emotional and behavioural antecedents of young adults who screen positive for non-affective psychosis: a 21-year birth cohort study. Psychol Med 2009; 39:625-634. [PMID: 18606046 DOI: 10.1017/s0033291708003760] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Birth cohort studies have shown that individuals who develop non-affective psychoses display subtle deviations in behaviour during childhood and adolescence. We had the opportunity to examine the widely used Child Behavior Checklist (CBCL) and the Youth Self-Report (YSR) to explore the antecedents of non-affective psychosis. METHOD Based on a birth cohort of 3801 young adults, psychopathology was assessed at years 5 and 14 using the CBCL and/or the YSR. Screen-positive non-affective psychosis (SP-NAP) was assessed at year 21 by using the Composite International Diagnostic Interview (CIDI) or a self-report checklist. The association between childhood symptoms and SP-NAP was examined using logistic regression. RESULTS Of the cohort, 60 subjects were classified as SP-NAP. In males, SP-NAP was associated with higher scores: (a) on year 5 CBCL 'Total', 'Aggression' and 'Social, Attention and Thought' scores; (b) on year 14 CBCL 'Social', 'Attention' and 'Delinquency' scores, and (c) YSR 'Total' and many YSR subscores. These associations were less clear for females. Hallucinations at year 14 were associated with SP-NAP for both sexes. Boys with high 'Total' scores at both years 5 and 14 were at greatest risk of SP-NAP (a 5-fold risk), followed by boys and girls whose 'Social, Attention and Thought' scores either increased or remained high from years 5 to 14 (3- to 13-fold risk). CONCLUSIONS Individuals who screen positive for non-affective psychosis show increased psychopathology during childhood and adolescence. The psychopathological trajectory of children who go on to develop schizophrenia anticipates the heterogeneity associated with the full clinical syndrome.
Collapse
|
|
16 |
191 |
22
|
Williams G, King J, Cunningham M, Stephan M, Kerr B, Hersh JH. Fetal valproate syndrome and autism: additional evidence of an association. Dev Med Child Neurol 2001. [PMID: 11263692 DOI: 10.1111/j.1469-8749.2001.tb00188.x] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Autism has been described in association with a variety of medical and genetic conditions. We previously reported on a patient whose clinical phenotype was compatible with both fetal valproate syndrome (FVS) and autism. Here we present five additional patients with FVS and autism. In all five of our patients, there was evidence of cognitive deficits, manifestations of autism, and typical phenotypic characteristics of FVS. The association between this known teratogen and autism has both clinical and research implications.
Collapse
|
Journal Article |
24 |
189 |
23
|
Crossley M, Whitelaw E, Perkins A, Williams G, Fujiwara Y, Orkin SH. Isolation and characterization of the cDNA encoding BKLF/TEF-2, a major CACCC-box-binding protein in erythroid cells and selected other cells. Mol Cell Biol 1996; 16:1695-705. [PMID: 8657145 PMCID: PMC231156 DOI: 10.1128/mcb.16.4.1695] [Citation(s) in RCA: 189] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
CACCC boxes are among the critical sequences present in regulatory elements of genes expressed in erythroid cells, as well as in selected other cell types. While an erythroid cell-specific CACCC-box-binding protein, EKLF, has been shown to be required in vivo for proper expression of the adult beta-globin gene, it is dispensable for the regulation of several other globin and nonglobin erythroid cell-expressed genes. In the work described here, we searched for additional CACCC-box transcription factors that might be active in murine erythroid cells. We identified a major gel shift activity (termed BKLF), present in yolk sac and fetal liver erythroid cells, that could be distinguished from EKLF by specific antisera. Through relaxed-stringency hybridization, we obtained the cDNA encoding BKLF, a highly basic, novel zinc finger protein that is related to EKLF and other Krüppel-like members in its DNA-binding domain but unrelated elsewhere. BKLF, which is widely but not ubiquitously expressed in cell lines, is highly expressed in the midbrain region of embryonic mice and appears to correspond to the gel shift activity TEF-2, a transcriptional activator implicated in regulation of the simian virus 40 enhancer and other CACCC-box-containing regulatory elements. Because BKLF binds with high affinity and preferentially over Sp1 to many CACCC sequences of erythroid cell expressed genes, it is likely to participate in the control of many genes whose expression appears independent of the action of EKLF.
Collapse
|
research-article |
29 |
189 |
24
|
Cutler DJ, Morris R, Sheridhar V, Wattam TA, Holmes S, Patel S, Arch JR, Wilson S, Buckingham RE, Evans ML, Leslie RA, Williams G. Differential distribution of orexin-A and orexin-B immunoreactivity in the rat brain and spinal cord. Peptides 1999; 20:1455-70. [PMID: 10698122 DOI: 10.1016/s0196-9781(99)00157-6] [Citation(s) in RCA: 187] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The orexins are recently identified appetite-stimulating hypothalamic peptides. We used immunohistochemistry to map orexin-A and orexin-B immunoreactivity in rat brain, spinal cord, and some peripheral tissues. Orexin-A- and orexin-B-immunoreactive cell bodies were confined to the lateral hypothalamic area and perifornical nuclei. Orexin-A-immunoreactive fibers were densely distributed in the hypothalamus, septum, thalamus, locus coeruleus, spinal cord, and near the ventricles, but absent from peripheral sites investigated. In contrast, orexin-B-immunoreactive fibers were distributed sparsely in the hypothalamus. Orexin cells are strategically sited to contribute to feeding regulation, but their widespread projections suggest that orexins have other physiological roles.
Collapse
|
|
26 |
187 |
25
|
Abstract
Social science research into the social patterning of health and illness is extensive. One important aspect of this has been work on lay knowledge about health and illness. In this paper we develop three main arguments. First, we suggest that recent developments in social science understanding of the nature and significance of lay knowledge should be more widely recognized within the social sciences themselves. Second, we argue that if public health research, whatever the disciplinary perspective, is to provide an understanding of contemporary health problems that is simultaneously more robust and more holistic, it must incorporate and develop the theoretical and conceptual insights offered by this recent work on lay knowledge and with lay people. Finally, we argue that in order to accomplish this it will be necessary to construct research questions in such a way that the conventional distinctions between science and non-science, and the methodological wrangles associated with this distinction, become marginal to the research process. This will inevitably involve conflicts between members of different professional groups. These conflicts provide the opportunity for open debate on the science and politics of public health research and represent a challenge for the many disciplines involved in this field.
Collapse
|
|
29 |
186 |