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Biomedical subjects

J Knight

Publications and source records attributed to J Knight.

At least 37 records · Page 2Linked to original sources

Communicating information on cardiopulmonary resuscitation to hospitalised patients.

AIM: The primary aim of the study was to evaluate two different methods of communicating information on cardiopulmonary resuscitation (CPR) to patients admitted to general medical and elderly care wards. The information was either in the form of a detailed information leaflet (appendix I) or a summary document (appendix II). The study examined the willingness of patients in seeking detailed information on cardiopulmonary issues. SETTING: The study was conducted over three months on a general medical ward and an acute elderly care ward in two district general hospitals. METHODS: A detailed information leaflet on CPR was provided to the nursing staff on the wards. An A4 summary document summarising the CPR decision making process and basic information on cardiopulmonary issues was placed in a folder at the foot of each bed on the elderly care ward. On the general medical ward it was displayed prominently over the head of all beds. RESULTS: Out of the 274 patients admitted to the general medical ward only two requests were received for the detailed information leaflet. On the elderly care ward there were 182 admissions but no patients or their relatives requested the leaflet. CONCLUSIONS: Availability of basic information on cardiopulmonary resuscitation to all patients is practical and does not lead to unnecessary distress or offence to patients or their carers. It makes the decision making process more transparent. Detailed information leaflets are of value for a minority of hospitalised patients.

Cardiopulmonary Resuscitation↗

"Care and feeding": the Asian environmental tobacco smoke consultants programme.

STUDY OBJECTIVE: To review the tobacco industry's Asian environmental tobacco smoke (ETS) consultants programme, focusing on three key nations: China, Hong Kong, and Malaysia. METHODS: Systematic keyword and opportunistic website searches of formerly private internal industry documents. MAIN RESULTS: The release of the 1986 US Surgeon General's report on second hand smoke provoked tobacco companies to prepare for a major threat to their industry. Asian programme activities included conducting national/international symposiums, consultant "road shows" and extensive lobbying and media activities. The industry exploited confounding factors said to be unique to Asian societies such as diet, culture and urban pollution to downplay the health risks of ETS. The industry consultants were said to be "..prepared to do the kinds of things they were recruited to do". CONCLUSIONS: The programme was successful in blurring the science on ETS and keeping the controversy alive both nationally and internationally. For the duration of the project, it also successfully dissuaded national policy makers from instituting comprehensive bans on smoking in public places.

Air Pollution, Indoor↗

"A phony way to show sincerity, as we all well know": tobacco industry lobbying against tobacco control in Hong Kong.

OBJECTIVE: To examine the tobacco industry's efforts to influence public policy and block the legislative process on tobacco control in Hong Kong, 1973 to 1997. METHOD: Systematic review of relevant tobacco industry documents made public via the Master Settlement Agreement. RESULTS: The tobacco industry in Hong Kong has sought to manipulate the policymaking process and delay the introduction of tobacco control legislation in Hong Kong from at least 1973. The industry ensured that each of the government's initial meagre steps toward tobacco control were delayed and thwarted by drawn out "cooperation" followed by voluntary concessions on issues the industry regarded as minor. By the 1980s the government had became increasingly active in tobacco control and introduced a number of initiatives, resulting in some of the tightest legislative restrictions on smoking in Asia. The tobacco industry was successful in thwarting only one of these initiatives. CONCLUSIONS: Throughout the 1980s and 1990s two factors played a significant role in hindering the tobacco industry from successfully blocking policy initiatives: a growing political imperative, and an active and sophisticated tobacco control movement. Political will to promote public health and a strong tobacco control advocacy presence can enable governments to resist the enormous pressure exerted upon them by multinational tobacco companies.

Advertising↗

"Asian yuppies...are always looking for something new and different": creating a tobacco culture among young Asians.

OBJECTIVE: To identify and analyse the themes employed by the Asian based transnational tobacco companies to construct a tobacco culture among Asian young men and women. METHODS: Systematic review of relevant tobacco industry documents made public through the Master Settlement Agreement. RESULTS: The industry utilised six vehicles and themes to construct a tobacco culture in Asia: music, entertainment (including nightclubs, discos, and movies), adventure, sport (including motorsports, soccer, and tennis), glamour (beauty and fashion), and independence. CONCLUSIONS: The tobacco industry set about constructing a tobacco culture that sought to make smoking desirable, even normal, for young men and women. Understanding the way industry constructed this culture provides insights into ways that culture might now be challenged. Countering the transnational nature of many activities will require coordinated effort at the international, regional, and national levels. Implementation of the Framework Convention on Tobacco Control (FCTC) will be a powerful tool in this process. All nations throughout Asia are encouraged to support the FCTC and its broad protocols addressing advertising and sponsorship. Measures are also required to disassociate smoking from progress in sex equality.

Adult↗

"Asia is now the priority target for the world anti-tobacco movement": attempts by the tobacco industry to undermine the Asian anti-smoking movement.

STUDY OBJECTIVE: To identify and examine the strategies utilised by multinational tobacco companies to undermine and discredit key anti-tobacco activists and organisations in the Asian region. METHOD: A series of case studies drawing upon material gathered through systematic reviews of internal tobacco industry documents. DATE SOURCES: Tobacco industry documents made public as part of the settlement of the Minnesota Tobacco Trial and the Master Settlement Agreement. RESULTS: The industry sought to identify, monitor, and isolate key individuals and organisations. The way industry went about fulfilling this mandate in the Asian region is discussed. Industry targetted individuals and agencies along with the region's primary anti-smoking coalition. CONCLUSIONS: Attack by multinational tobacco companies is a virtual quid pro quo for any individual or agency seriously challenging industry practices and policies. Understanding their tactics allows anticipatory strategies to be developed to minimise the effectiveness of these attacks.

Asia↗

Breast screening outcomes in women with and without a family history of breast and/or ovarian cancer.

OBJECTIVES: To compare breast screening outcomes between women with a moderate or strong family history of breast and/or ovarian cancer with those without such a history. SETTING: The Ontario Breast Screening Programme (OBSP) is a population-based programme offering mammography and clinical breast examination to Ontario women of 50 and older. METHODS: Data from a cohort of 143,574 women screened by the OBSP from 1996 to 1997 were included. Referral rates, cancer detection rates, positive predictive values and the histological features of screen-detected cancers were examined within family history groups, age groups and screening modalities. Logistic regression analysis of cancer detection was conducted to adjust for potential confounding variables; subgroup analysis by hormone replacement therapy (HRT) use was also undertaken. RESULTS: Compared with women with no family history, women with a moderate or strong family history of breast and/or ovarian cancer were more likely to have their cancer detected (odds ratio [OR]=1.44, 95% confidence interval [CI] 1.20-1.74 and OR=1.42, 95% CI 1.10-1.83, respectively). Among women using HRT, however, there was no association observed between family history and cancer detection (moderate: OR=0.98, 95% CI 0.65-1.48; strong: OR=1.17, 95% CI 0.68-2.02) with history. The histological features of invasive tumours were similar among family history groups. CONCLUSIONS: Greater cancer detection rates and high proportions of invasive tumours with good prognosis indicate that women aged 50 and over with a family history may have the potential to benefit from regular breast cancer screening. Further studies are required to identify optimal screening guidelines and to examine whether HRT reduces the ability to detect cancer in these women.

Breast Neoplasms↗

A protein interaction map of Drosophila melanogaster.

Drosophila melanogaster is a proven model system for many aspects of human biology. Here we present a two-hybrid-based protein-interaction map of the fly proteome. A total of 10,623 predicted transcripts were isolated and screened against standard and normalized complementary DNA libraries to produce a draft map of 7048 proteins and 20,405 interactions. A computational method of rating two-hybrid interaction confidence was developed to refine this draft map to a higher confidence map of 4679 proteins and 4780 interactions. Statistical modeling of the network showed two levels of organization: a short-range organization, presumably corresponding to multiprotein complexes, and a more global organization, presumably corresponding to intercomplex connections. The network recapitulated known pathways, extended pathways, and uncovered previously unknown pathway components. This map serves as a starting point for a systems biology modeling of multicellular organisms, including humans.

Animals↗

Studies of quantitative parameters of virus excretion and transmission in pigs and cattle experimentally infected with foot-and-mouth disease virus.

Foot-and-mouth disease virus (FMDV) can be spread by a variety of mechanisms and the rate of spread, the incubation period and the severity of disease depend on a multitude of parameters, including the strain of virus, the dose received, the route of introduction, the animal species and the husbandry conditions. More knowledge with regard to these parameters is urgently needed to improve resource-efficient disease control. This report describes detailed studies of FMDV load, excretion and transmission in pigs infected with FMDV O UKG 2001, O TAW 1997 and C Noville virus and in cattle infected with the O UKG 2001 virus to facilitate use of a "FMDV load framework" for the assessment of transmission risks. Virus replicated rapidly in pigs and cattle exposed by direct contact. The mean incubation period was around 3-4 days for cattle-to-cattle and 1-3 days for pig-to-pig transmission, depending on the intensity of contact. The results confirmed that a strong relation exists between dose and length of incubation period. Clinical disease was severe in pigs but relatively mild in inoculated cattle; contact infection of cattle appeared to increase the severity of lesions. FMDV RNA was recovered in nasal and mouth swabs from inoculated animals soon after they developed a viraemia and probably reflected the early production and excretion of virus. FMDV RNA in nasal and mouth swabs from contact animals could be detected several days before they showed other signs of infection, indicating the possibility of detecting exposed animals during the incubation period. FMDV RNA could also be detected in swab samples after the viraemic phase. This may have represented background environmental virus that had been trapped in the respiratory tract and mouth. Alternatively, it may have indicated a somewhat slower clearance or half-life of viral RNA or an extended low level of FMDV replication at these sites. The pattern of FMDV RNA concentrations in pigs was closely similar to that in cattle, but the amounts of FMDV RNA were higher.

Animals↗

Human chromosome 17 in essential hypertension.

Hypertension affects up to 30% of the adult population in Western societies and is a major risk factor for kidney disease, stroke and coronary heart disease. It is a complex trait thought to be influenced by a number of genes and environmental factors, although the precise aetiology remains unknown at this time. A number of methods have been successfully used to identify mutations that cause Mendelian traits and these are now being applied to the investigation of complex diseases. This review summarises the data gathered, using such approaches, that suggest there is a gene or genes on chromosome 17 causing human essential hypertension. Studies in rodent models are discussed first, followed by studies of human hypertension that include the investigation of pseudohypoaldosteronism type II, a monogenic trait that manifests with hypertension alongside other phenotypic variables. In addition, candidate gene studies, genome screens and linkage studies based on comparative mapping are outlined. To date no gene has been identified on human chromosome 17 that influences blood pressure and causes human essential hypertension. However, results of ongoing fine mapping and candidate gene studies in both rodents and man are eagerly awaited.

Animals↗

Prevalence of back and neck pain amongst ENT consultants: national survey.

Back and neck pain is an established occupational disease for many professions. No previous studies have shown the association of back and neck pain with ENT surgery. Our objective was to determine the prevalence of neck and back pain in ENT consultants in the United Kingdom and which sub-specialties were most at risk. A national survey from 325 ENT consultants in the UK revealed that 72 per cent had either back pain or neck pain or even both. Of those with pain 53 per cent attributed their symptoms directly to ENT surgery. Highest figures were received from otologists, related to microscope work and prolonged sitting. The importance of these findings has demonstrated the lack of awareness and adequate training to prevent long-term disability in ENT surgeons.

Back Pain↗

Development of a sensitive whole blood chemiluminescence method for assessing the bioactivity of calcium phosphate powders.

The development of simple, but highly sensitive and accurate in vitro methods for assessing the bioactivity of biomaterials is a key requirement for assuring their successful clinical application. Moreover, screening techniques that will allow various materials to be recommended, or otherwise, for further testing, have the potential to make appreciable savings in the time and expense associated with product development. This paper gives details of a novel whole blood chemiluminescence method, based on the photoprotein Pholasin, which emits light in the presence of the free radical superoxide. other reactive oxygen species and the enzyme myeloperoxidase. This whole blood assay may have the potential as a screening method for assessing calcium phosphate (Ca-P) bioceramic powders according to their relative bioactivity. The method employed involves exposure of samples of anti-coagulated (heparinised) blood to the various Ca-P materials and stimulating the contacted leukocytes in the blood with phorbol-12-myristate-13-acetate (PMA). PMA stimulates protein kinase C directly and sets in motion a cascade of events in the leukocytes leading to the activation of the superoxide generating NADPH oxidase system. PMA also promotes degranulation, which is the fusion of the granule membrane with the plasma membrane and the extracellular release of granule enzymes. Changes in the free radical and degranulation activity of the cells, as measured by the luminescent response of Pholasin to cells stimulated with PMA, after exposure to the Ca-P powders, are presented as percentage differences from the response to (control) blood samples not exposed to the powders. The resultant data clearly indicate significant differences in the light detected via Pholasin from the blood exposed to the bioceramic materials compared to that from the relevant controls. These differences correlate well with the ascribed bioactivity of the Ca-P powders. as assigned from the measured chemical and structural properties. Furthermore, the method can also be applied to samples of blood, which have been diluted in the ratio 1:100 in standard blood dilution buffer. The light output response in the diluted blood experiments is exactly the same as that observed with undiluted whole blood but occurs immediately as compared to the many minutes required to give response in the latter case. Thermally processed (800 degrees C) Ca-P materials have also been studied. A relationship between the heat-induced properties of the powders and the chemiluminescence responses recorded from blood cells stimulated with PMA has been established.

Biocompatible Materials↗

Microbial influenced degradation of solidified waste binder.

Ordinary cement pastes with water/cement (w/c) ratios of 0.2, 0.4 and 0.5 were used to examine the chemical and physical effects of microbial influenced degradation (MID). Samples were exposed to an active culture of Thiobacillus thiooxidans or to sterile media containing sulphuric acid using an intermittent immersion technique. Acid consumption and Ca, Al and Fe releases are presented for an exposure period of 90 days. Exposed samples were also sectioned and analysed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). All cement paste samples were subject to significant degradation in either sterile acid media or the T. thiooxidans lixiviant. Corrosion depths observed from SEM examination of exposed samples were affected by the w/c ratio of the cement. The extent and rate of degradation were not apparent from the calculated rate of hydrogen ion consumption, or the leaching rates of Ca, Al and Fe. It was not possible to distinguish differences in corrosion due to the chemical and microbial influenced degradation from the results obtained to date and further work is focusing on modified procedures to address this.

Acidithiobacillus thiooxidans↗

Influence of dentifrices and dietary components in saliva on wettability of pellicle-coated enamel in vitro and in vivo.

In vitro salivary pellicles were found to be less hydrophobic by water contact angles than clinically formed pellicles. In this study, water contact angles were measured on enamel coated with pellicles adsorbed from reconstituted human whole saliva (RHWS) and after exposure to dentifrices or dietary components. In addition, adhesion of Streptococcus oralis J22 to pellicles formed from RHWS with minor amounts of milk added and after exposure to dentifrices was studied. Exposure of RHWS-pellicles to milk or salad oil yielded an increase in the hydrophobicity of in vitro pellicles to values observed in vivo, but a decrease was seen after exposure to a sugar solution. Pellicles formed from saliva with 0.4% milk added attracted less S. oralis cells than pellicles formed in the absence of milk components. Exposure of pellicles formed from saliva with milk added to various dentifrices had a variable effect on bacterial adhesion: markedly lower numbers of adhering S. oralis were found for a dentifrice with NaF, but exposure to dentifrices containing SnF2 or hexametaphosphate showed slightly increased adhesion. In summary, dietary components have influence on the hydrophobicity of enamel pellicles, while combinations of dietary components and dentifrices certainly influence the adhesiveness of the pellicles. The effects of dietary components on pellicle conditioning film should be taken into consideration in research on the development of ingredients to control intraoral surface chemistry and microbiology, as well as in the development of oral products.

Animals↗

A comparison between midazolam co-induction and propofol predosing for the induction of anaesthesia in the elderly.

In a prospective, double-blind, randomised, placebo-controlled trial, we have compared the effects of midazolam co-induction with propofol predosing on the induction dose requirements of propofol in elderly patients. We enrolled 60 patients aged > 70 years, attending for urological surgery. The patients were allocated randomly to one of three groups, to receive either midazolam 0.02 mg.kg(-1), propofol 0.25 mg.kg(-1), or normal saline 2 ml (placebo) 2 min prior to induction of anaesthesia using propofol 1% infusion at 300 ml.h(-1). The propofol dose requirements for induction were recorded for two end-points (loss of verbal contact and insertion of an oropharyngeal airway). Cardiovascular parameters were recorded at 1-min intervals for each patient until induction was complete. The midazolam group showed a significant reduction in propofol dose requirements for induction (p = 0.05) compared to the placebo group. The propofol group did not show a significant dose reduction compared to placebo. There were no demonstrable differences in terms of improved cardiovascular stability between groups. We conclude that propofol predosing does not significantly reduce the induction dose of propofol required in the elderly, and there were no cardiovascular benefits to either midazolam co-induction or propofol predosing in the elderly.

Aged↗

Paraoxonase gene cluster is a genetic marker for early microvascular complications in type 1 diabetes.

BACKGROUND: Paraoxonase is a serum enzyme, which prevents oxidation of low-density lipoprotein (LDL) by hydrolyzing lipid peroxides. Two polymorphisms in PON1 gene have been associated with cardiovascular and microvascular diseases in both diabetic and non-diabetic patients. AIMS: The current project was designed to investigate the association between the polymorphisms of two PON genes and diabetes microvascular diseases (retinopathy and microalbuminuria) and any potential linkage between Met54Leu of PON1 and Cys311Ser of PON2 gene. METHODS: Diabetic retinopathy and albumin excretion rate were assessed in 372 adolescents with Type 1 diabetes who were genotyped for the two polymorphisms. RESULTS: We confirmed the increased susceptibility for diabetic retinopathy for the Leu/Leu genotype (odds ratio (OR) 3.34 (confidence interval (CI) 1.95, 5.75), P < 0.0001). The Ser/Ser genotype was significantly more common in those patients with microalbuminuria (albumin excretion rate > or = 20 microg/min) compared with those with albumin excretion rate < 20 microg/min (OR 4.72 (CI 2.65, 8.41), P < 0.0001). The Ser311 of PON2 was in strong linkage disequilibrium with Leu54 of PON1 gene (Delta = 23 x 10(4), P < 0.001). The delta value was higher for those without complications (28 x 104, P < 0.001) compared with those with complications (15.5 x 10(4), P < 0.001). CONCLUSIONS: This study supports the hypothesis that diabetic microangiopathy is genetically heterogeneous. PON1 Leu/Leu increases the risk for retinopathy and PON2 Ser/Ser increases the risk for microalbuminuria.

Adolescent↗

Paediatric day-stay myringoplasty: a review of 74 consecutive cases.

Day-case surgery is particularly attractive for children, allowing post-operative recovery in the safe environment of the family home. Myringoplasty using the traditional method of underlay temporalis fasia is usually performed as an in-patient. From 1995 to 2000, 74 myringoplasties were performed in a dedicated paediatric day surgery unit at the Mayday University Hospital. We have retrospectively reviewed the outcome results of these procedures and reported them here. Only three patients required admission overnight (four per cent) and six grafts failed (8.5 per cent) complying with accepted standards. This series suggests that day-case surgery is a safe and desirable practice for children undergoing myringoplasty. However, there should be the facility for admission if required.

Adolescent↗