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K Griffiths

Publications and source records attributed to K Griffiths.

At least 19 recordsLinked to original sources
PubMed2006

Dynamics of D2 released from the dissociation of D2O on a zirconium surface.

Hydrogen is efficiently released during water dissociation on zirconium (Zr), while even very rapid temperature programmed heating of a hydrogen covered Zr surface predominantly leads to dissolution (approximately 99% dissolution). To help resolve these apparently contradictory observations, we have studied the dynamics of water (D2O) dissociation on a crystalline Zr surface by probing the rotational and vibrational energy distributions of the D2 produced using resonant enhanced multiphoton ionization spectroscopy. The internal-state energy distribution of the D2 product was found to be rotationally cold and vibrationally hot with respect to the temperature of the surface. The rotational distribution shows slight deviations from Boltzmann's law, with a mean rotational temperature of 426 K while the surface is at 800 K. The population of the nu"=1 vibration is at least four times higher than a 800 K temperature would allow, this corresponding to a vibrational temperature of 1100 K. Information on the translational energy of the D2 product have also been obtained by time-of-flight spectroscopy and it is found to be nearly thermally equilibrated with the surface temperature. Similar results were obtained from studies of D2 scattered from a clean Zr surface, and of D2 released by a slow thermal desorption process which involves dissolved hydrogen as the source. The reconciliation of the present results with those for thermal desorption of preadsorbed hydrogen implies a role for both surface and subsurface adsorption sites on the Zr surface and clearly demonstrates that at high temperatures, the release of D2 arises from the recombinative desorption of adsorbed hydrogen formed by the complete dissociation of D2O.

Journal Article↗
PubMed2005

Urinary albumin levels in the normal range determine arterial wall thickness in adults with Type 2 diabetes: a FIELD substudy.

AIM: Cardiovascular disease (CVD) rates are substantially higher among patients with Type 2 diabetes than in the general population. The objective of this study was to identify the determinants of carotid intima media thickness (IMT) in patients with Type 2 diabetes. METHODS: We measured the thickness of the intima media layer of the carotid artery, a strong predictor of the risk of future vascular events, in 397 Type 2 diabetic patients drawn from the Fenofibrate Intervention and Event Lowering in Diabetes study, prior to treatment allocation. RESULTS: The mean IMT was 0.78 mm [interquartile range (IQR) 0.23 mm], and the maximum IMT was 1.17 mm (IQR 0.36 mm). By multivariate analysis, age, sex, duration of diabetes, triglycerides, and total cholesterol were independently correlated with IMT, as was urine albumin-creatinine ratio (ACR) (P < 0.001). The effect of ACR on IMT was further examined by tertile. Clinically significant differences in IMT were associated with ACR > 0.65 mg/mmol, approximately one-fifth the standard clinical threshold for microalbuminuria (P < 0.01). Long-term diabetes, independent of other parameters, was associated with a 50% increase in age-related thickening. CONCLUSIONS: IMT in people with Type 2 diabetes is independently and continuously related to urine albumin levels and to the duration of diabetes. These results support previous data linking urine albumin measurements within the normal range with increased ischaemic cardiac mortality in the setting of Type 2 diabetes, and strongly suggest that urine albumin levels within this range should trigger a formal evaluation for CVD.

Aged↗
PubMed2004

Antibiograms of resistant Gram-negative bacteria from Scottish CF patients.

BACKGROUND: Over a 19-month pilot phase, 93 multiply resistant Gram-negative isolates from Scottish cystic fibrosis patients were sent to a referral laboratory for further investigation. METHODS: In common with the referring diagnostic laboratories, disc diffusion testing was carried out. Antibiotic susceptibility testing was also established by MIC methodology. NCCLS methods were used throughout. Twenty antibiotics were tested. RESULTS: Comparing disc diffusion results against MIC results, there were 167 (14%) major errors. By MIC, Pseudomonas aeruginosa (n = 59), Stenotrophomonas maltophilia (n = 16), Burkholderia cepacia (n = 10) and Alcaligenes xylosoxidans (n = 7) were susceptible to 18%, 11%, 4% and 35% of the antibiotics tested, respectively. Colistin and tobramycin were the most active agents against P. aeruginosa with 60% and 49%, respectively, testing susceptible. Minocycline and gentamicin were most active against S. maltophilia with 58% and 18%, respectively, testing susceptible. B. cepacia were most susceptible to co-trimoxazole (10%) and ciprofloxacin (10%). Five and six of the seven A. xylosoxidans isolates were susceptible to piperacillin and imipenem, respectively. CONCLUSIONS: Improved methods for susceptibility testing of such clinical isolates need to be employed in routine diagnostic laboratories. Levels of resistance in referred isolates were very high and similar to those described in the USA.

Cystic Fibrosis↗
PubMed2003

Biological efficacy of electroless-deposited silver on plasma activated polyurethane.

Silver coating of catheters has been shown to have inhibitory effects on bacterial growth and adhesion to catheter surfaces. In this study, plasma-modification was used to enhance the adhesion of an electroless silver coating on polyurethane. Both the antibacterial and antiadhesive properties of these coatings were investigated. Bacterial growth was inhibited in cultures exposed to silver-treated polyurethane compared to unmodified polyurethane. Higher growth inhibition was observed for polyurethane surfaces with lower silver coverage. Bacterial adhesion was completely inhibited on all silver-coated surfaces.

Anti-Bacterial Agents↗
PubMed2003

Identification of a fibrinolytic enzyme in Schistosoma mansoni eggs and modulated blood fibrinogen metabolism in S. mansoni-infected mice.

Aqueous extracts of Schistosoma mansoni eggs have been shown to have fibrinolytic activity inhibitable by a serine protease inhibitor. Fibrinolytic activity was not present in extracts of either adult worms or cercariae. A 27 kDa enzyme that was proteolytically active on fibrinogen in zymography and that degraded fibrinogen in a pattern similar to that of plasmin, is presumed to be responsible for the schistosome egg fibrinolytic activity. Anti-human fibrinogen antisera were shown to have antibodies that cross-reacted with mouse fibrinogen in Western immunoblots. Electroblotted sera from S. mansoni-infected and control uninfected mice displayed different antigenic profiles when probed with the cross-reactive anti-human fibrinogen antibodies, suggesting an alteration in mouse host fibrinogen metabolism as a result of the parasitic infection. We discuss the possibility that modulation of fibrinogen metabolism is a factor in a recently discovered anti-atherogenic effect exerted by schistosomes.

Animals↗
PubMed2002

Pregnancy postponement and childlessness leads to chronic hypervascularity of the breasts and cancer risk.

Epidemiologists have established that women with small families, and particularly nulliparae, are prone to develop breast cancer later in life. We report that physiological mammary hypervascularity may be an intermediate reason against the background that breast-core vascularity is normal in pregnancy but pathological in the vascularisation of cancer. We examined breast 'core' vascularity in nulliparae during their potential reproductive life and in parous women after their last birth but before their menopause. Fifty clinically normal pre-menopausal non-pregnant women (100 breasts) were studied daily for one 'luteal positive' menstrual cycle. Their parity history varied from zero to five babies. Under controlled domestic conditions each wore a special electronic thermometric bra to automatically record breast 'core' temperature changes as a measure of mammary tissue blood flow. In the nulliparae there was a rise of breast vascularity throughout reproductive life. In the parous women, a year or so after each birth, breast vascularity was reset at a lower level than before the pregnancy; thereafter, as in nulliparae, there was progressive increase in mammary vascularity until the menopause.

Adult↗
PubMed2002

An anti-atherogenic effect of Schistosoma mansoni infections in mice associated with a parasite-induced lowering of blood total cholesterol.

In affluent societies the prevalences of so-called 'Western' diseases such as atherosclerosis, allergies and autoimmune disorders appear to have increased, while many diseases caused by communicable infections are now relatively less common. To test whether there may be a causal relationship we examined the effects of Schistosoma mansoni infections in mice that develop cardiovascular pathology as a result of a genetic deficiency in apolipoprotein E (apoE-/-). The development of atherosclerotic lesions in the aortic arch and brachiocephalic artery of the apoE-/- mice was reduced by approximately 50% in mice with the parasitic infection, when comparison was made with uninfected control mice fed the same diet. Observations on S. mansoni-infected conventional laboratory mice indicate that patent schistosome infections could be counteracting the effects of an atherogenic diet by modulating host lipid metabolism and inducing a reduction in blood total cholesterol concentrations.

Animals↗
PubMed2000

International Consultation on Urological Diseases: a decade of progress.

The International Consultation on Urological Diseases (ICUD), under the cosponsorship of the World Health Organization (WHO), the International Society of Urology (SIU), and the International Union Against Cancer (UICC), is active in the organization of global consultations on urological diseases. The major urological associations from the five continents (the American Urological Association (AUA), the Urological Association of Asia (UAA), the Confederation Americana Urologia (CAU), and the European Association of Urology (EAU)), together with societies with expertise in specific programs such as the International Continence Society, the International Society for Impotence Research, the International Prostate Health Council, the American Cancer Society, the International Union Against Cancer, and the European Organization for Research and Treatment of Cancer, came together in the late 1980s on the basis of their proven record in organizing successful international meetings on urological cancer to initiate the concept of the ICUD. At the suggestion of the WHO, a First International Consultation on Benign Prostatic Hypertrophy (BPH) was organized in 1991, not only to provide recommendations to medical practitioners but also to define and plan future research on the subject. The formula, based on global multiprofessional collaboration and expertise, exceeded expectations, and other consultations were to follow, e.g., on prostate cancer, incontinence, erectile dysfunctions, and nosocomial infections. In 1994 it became necessary to establish a legal nongovernmental organization to foster the goals of the ICUD, essentially for the creation of awareness, knowledge, and recommendations on the diagnosis and treatment of urological diseases.

Humans↗
PubMed2000

Enhanced peripheral vasodilation in humans after a fatty meal.

OBJECTIVES: We sought to study the effects of a fatty meal on vascular reactivity, including endothelial function and maximal vasodilation. BACKGROUND: Recent reports regarding the physiological changes in peripheral vasculature after eating a fatty meal have been controversial. METHODS: Twelve volunteers were studied before, 3 h after, and 6 h after a high-fat meal (1030 kcal, 61 g fat) rich in saturated fatty acids, and 10 were restudied after a similar meal rich in monounsaturated fatty acids. Endothelial function was assessed as flow-mediated dilatation (FMD) in the brachial artery using ultrasound. Resting and postischemic forearm blood flow (FBF) were recorded using venous occlusion strain-gauge plethysmography, before, and every 10 to 15 s after, 5 min upper arm ischemia. RESULTS: Brachial artery basal diameter, resting FBF and postischemic hyperemia increased after high-fat meals (all p<0.001), whereas FMD did not change. The increase in resting FBF correlated with increases in postprandial insulin (r = 0.80, p<0.002) and triglyceride (r = 0.77, p<0.005) levels. CONCLUSIONS: We concluded that eating a fatty meal induces vasodilation and increases resting and stimulated FBF and that these observations are probably mediated by postprandial changes in insulin and/or triglyceride levels. The metabolic changes that occur after meals are not associated with impaired endothelial nitric oxide release in the conduit arteries.

Adolescent↗
PubMed2000

The Internet and mental health literacy.

OBJECTIVE: This paper describes the informational and treatment opportunities offered by the Worldwide Web (WWW) and comments on the advantages, disadvantages and potential dangers of its role in mental health and mental health research. METHOD: Two perspectives are taken: (i) the impact of the Web from the point of view of the clinician (the practitioner view) and (ii) the impact of the Web on the public's knowledge of mental health (mental health literacy; the community or public health view). These perspectives are applied to two areas of impact: (i) information and knowledge; and (ii) treatment and self-help. RESULTS: The Web, due to its accessibility, has advantages in providing access to information, online therapy and adjunctive therapy in mental health. Problems include information overload, poor information quality, potential harm and lack of scientific evaluation. CONCLUSIONS: Issues of overload and quality of information, the potential for harm and the need to evaluate interventions are not unique to the Internet. However, the Internet has special features which make these issues more prominent. The Internet is likely to increase the general public's access to information and to decrease unmet need. Sites and interventions on the Internet need to be formally evaluated.

Austria↗
PubMed2000

Attitudes to fertility issues among adults with cystic fibrosis in Scotland. The Collaborative Group of Scottish Adult CF Centres.

BACKGROUND: With increasing life expectancy, issues of fertility and pregnancy are pertinent to patients with cystic fibrosis. For this reason, the four Scottish Cystic Fibrosis centres asked men and women with cystic fibrosis about their attitudes to fertility and to information given to them by health professionals. METHODS: A postal questionnaire was sent to 116 men and 79 women aged 16 years and over attending four Scottish Cystic Fibrosis clinics. RESULTS: There was a 70% response rate (82 men, 54 women). All but two men knew that they were likely to be infertile. 37% of respondents lived with a partner; 14 women (26%) and five men (6%) had children. For 85% of men and 72% of women having children was important now or would be in the next 10 years. 43% of men and 26% of women had never had any discussion on fertility issues with cystic fibrosis health professionals. 56% of men thought that first discussion with a health professional about infertility should be before the age of 16 years; 12% remembered having a first discussion at that age. Learning of their infertility was associated with strong negative emotions for most men. Women were more likely than men to have initiated first discussion (17 (32%) versus eight (10%); p<0.01). Twenty five men (31%) and 32 women (59%) were currently using contraception. Ten men (12%) and 15 women (28%) had discussed contraception at the Cystic Fibrosis clinic (p = 0.01). CONCLUSIONS: Parenting and fertility issues are important for men and women with cystic fibrosis but many patients do not find out what they want to know from discussion with health professionals. Patients want discussion to begin in early adolescence. Men in particular are likely to be reluctant to introduce these issues; health professionals should be aware of the need actively to initiate discussion.

Adult↗
PubMed1999

Finasteride in association with either flutamide or goserelin as combination hormonal therapy in patients with stage M1 carcinoma of the prostate gland. International Prostate Health Council (IPHC) Trial Study Group.

BACKGROUND: It was very reasonable to consider that the combination of the 5alpha-reductase, finasteride, and a pure antiandrogen such as flutamide should provide an effective form of maximal androgen blockade (MAB). Finasteride decreases intraprostatic levels of 5alpha-dihydrotestosterone (DHT), and the antiandrogen would restrain the biological action of the residual DHT by interfering with its association with androgen receptor. This form of MAB should sustain the concentration of testosterone in plasma, thereby maintaining sexual function and reasonable quality of life. In order to investigate this, a randomized multicenter phase II clinical trial of patients with untreated M1 cancer of the prostate was developed and undertaken. METHODS: Patients were randomly allocated to one of three treatment schedules: 1) goserelin, 3.6 mg, s.c., monthly in combination with flutamide, 250 mg., t.i.d. and a placebo, daily, in the image of 2 x 5 mg finasteride; 2) goserelin, 3.6 mg., s.c., monthly in combination with finasteride, 10 mg (2 x 5 mg, daily) and a placebo (t.i.d.) in the image of flutamide; and 3) finasteride, 10 mg (2 x 5 mg, daily) in combination with flutamide (250 mg, t.i.d.). The reduction in concentration of serum PSA at 24 weeks was the endpoint of interest. RESULTS: Baseline prostate-specific antigen (PSA) levels of the patients in the three groups were very similar. There was a substantial decrease in levels of PSA in the three groups prior to the end of the study, the percent decrease in the groups being: 1) goserelin and flutamide combination, 99.1% (95% Confidence interval (CI), 97.7, 99.6); 2) goserelin and finasteride combination, 98.75% (95% CI, 97.1, 99.5); and 3) finasteride and flutamide combination, 97.6%, 95% CI, 94.5, 98.9). In the Generalized linear model (GLM) analysis, there was no center by treatment group interaction (P = 20), and there were no significant differences between centers (P = 0.059) nor among the three treatment groups (P = 0.16). CONCLUSIONS: The decrease in levels of PSA in such a group of patients with M1 cancer of the prostate over a 24-week period was surprisingly large, and the differences in these decreased levels between the three treatment arms were remarkably small. There were no apparent differences in bone scan scores, World Health Organization (WHO) performance status, and pain scores between the arms. With regard to sexual function associated with quality of life, there were the understandable difficulties of data collection from patients treated with goserelin.

5-alpha Reductase Inhibitors↗
PubMed1999

A prospective randomized trial evaluating tissue effects of finasteride therapy in benign prostatic hyperplasia.

Finasteride is widely used for the treatment of benign prostatic hyperplasia (BPH). Its therapeutic efficacy is believed to be mediated through selective inhibition of prostatic 5alpha-reductase (type II). This prospective, controlled, randomized study examines various relationships between changes in tissue 5alpha-reductase isozyme activity, epithelial proliferative index and morphology in men with BPH treated with finasteride for 6 months, and correlates these with clinical response. Thirty-one patients presenting with symptomatic bladder outflow obstruction were prospectively randomized to receive either finasteride or placebo (2:1) for 24 weeks. Of these, 27 men aged 55-80 y (median 69 y) completed the study, including 18 patients on treatment. Symptom score determination, uroflow and prostate volume were assessed at baseline and end of study. Prostatic tissue was obtained by ultrasound-guided needle biopsy at baseline and by transurethral resection (TURP) at end of study for biochemical and morphometric analysis. Epithelial proliferation was examined quantitatively in the resected tissue using MIB-1 antibody to Ki-67 and counting the percentage of positively staining cells. Type II 5alpha-reductase activity was strongly inhibited by finasteride in resected BPH tissue, with over 100-fold decrease in V(max) (P=0.001), whereas the type I isozyme was inhibited 5-fold (P=0.005). Selective inhibition of type II 5alpha-reductase was demonstrated in all treated patients. No significant difference in epithelial proliferation was observed between the finasteride and placebo groups. Epithelial proliferation was, however, greater in prostatic tissue with histological manifestation of inflammation (2.02% vs 0.89%, P=0.001). Positive correlation between the total epithelial volume and the ratio of transition zone volume/total prostate volume was observed in the placebo group (r=0.834), whereas there was no such correlation in men taking finasteride (r=-0.300), consistent with a reduction in epithelial content in the treatment group. Improvement in uroflow and reduction in prostatic volume in patients treated with finasteride did not reach statistical significance. This study shows that finasteride causes inhibition of 5alpha-reductase activity in human BPH tissue with selectivity for the type II isozyme. In spite of this, no significant effects in epithelial proliferation or tissue morphology were demonstrated. The presence of inflammation was, however, associated with significantly greater proliferative activity. The power of this study was limited by the small number of recruited patients, and a larger study would be required for further investigation of morphological changes induced by finasteride in BPH tissue and their biochemical basis.

Journal Article↗