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Biomedical subjects

L Roberts

Publications and source records attributed to L Roberts.

At least 91 records · Page 5Linked to original sources
PubMed1998

Compliance of hand washing practices: theory versus practice.

Hand washing remains an important preventative method for making the transmission of nosocomial infections redundant. Despite awareness by health workers of the practices required and of the legislation governing hand washing, the study reported here found that compliance to these procedures was quite poor. The results of two surveys distributed to health workers and direct observation by clinical staff in an aged care hospital found that 45% of health workers did not wash their hands and 24% did not change their gloves between patient consultation. Methods for increasing effective hand washing in clinical settings must be identified if hygienic practice is to be improved.

Clinical Competence↗
PubMed1998

Why do GPs perform investigations?: The medical and social agendas in arranging back X-rays.

OBJECTIVE: We aimed to determine the most important medical and psychosocial reasons GPs report for requesting back X-rays. METHODS: All GPs in a single health district were mailed a questionnaire and asked to document their reasons for requesting back X-rays. RESULTS: A total of 166/236 (70%) of GPs responded. There were 445 comments (mean 2.7 per doctor): 319 (72%) were medical indications (mean 1.9 per doctor) and 126 (28%) psychosocial reasons (mean 0.8 per doctor). GPs' medical criteria for requesting back X-rays were mainly in line with current guidelines. The most common psychosocial reasons were patient satisfaction (17%), work related (14%) and reassurance (8%). CONCLUSION: GPs' reported medical criteria for arranging back X-rays are mainly 'appropriate', but psychosocial reasons-especially patient satisfaction and reassurance-are also likely to be important factors. If psycho-social agendas are important in ordering investigations, then clinical guidelines which discuss only medical criteria may not be effective in reducing 'inappropriate' investigations.

Back Pain↗
PubMed1998

The effect of soap distribution on diarrhoea: Nyamithuthu Refugee Camp.

BACKGROUND: In January 1993, Nyamithuthu Camp in Malawi housed 64000 Mozambican refugees. Communicable diseases, primarily diarrhoea, pneumonia, malaria and measles, contribute to substantially higher mortality rates in refugee populations compared to similar non-displaced populations. METHOD: A systematic sample of 402 households in one portion of the camp were surveyed for diarrhoeal risk factors, and then interviewed twice weekly for 4 months regarding new diarrhoea episodes and the presence of soap in the household. Two-hundred grams of soap per person was distributed monthly. RESULTS: Households had soap on average only 38% of the interview days. Soap was used primarily for bathing and washing clothes (86%). Although 81% of mothers reported washing their children's hands, only 28% of those mothers used soap for that purpose. The presence of soap in a household showed a significant protective effect: there were 27% less episodes of diarrhoea in households when soap was present compared to when no soap was present (RR = 0.73, 95% CI: 0.54 < RR < 0.98). Potential confounding factors were assessed and did not appear to be responsible for the association between the presence of soap and reductions in diarrhoea incidence. CONCLUSION: In summary, our findings suggest that the provision of regular and adequate soap rations, even in the absence of a behaviour modification or education programme, can play an important role in reducing diarrhoea in refugee populations. If subsequent study confirms the soap as a cheap and effective measure to reduce diarrhoea, its provision in adequate amounts should be a high priority in refugee settings.

Adolescent↗
PubMed1998

Intercessory Prayer for ill Health: A Systematic Review.

OBJECTIVES: To review the effectiveness of prayer as an additional intervention for those with health problems already receiving standard medical care. SEARCH STRATEGY: Electronic Searches of Biological Abstracts, CINAHL, The Cochrane Controlled Trials Register, EM-BASE, MEDLINE, PsycLIT, and Sociofile were undertaken. All references of articles selected were searched for further relevant trials. SELECTION CRITERIA: Randomised and quasi-randomised trials of personal, focused, committed and organised intercessory prayer on behalf of anyone with a health problem were considered. Outcomes such as achievement of desired goals, death, illness, quality of life and well-being for the recipients of prayer, those praying and the caregivers were sought. DATA COLLECTION AND ANALYSIS: Studies were reliably selected and assessed for methodological quality. Data were extracted by 4 reviewers working independently. Dichotomous data were analysed on an intention-to-treat basis, and continuous data with over 50% completion rate are presented. MAIN RESULTS: There was no evidence that prayer affected the numbers of people dying from leukaemia or heart disease (OR 0.64, CI 0.32-1.27), or that it decreased coronary care complications (OR 1.05, CI 0.49-2.26) or the time participants stayed in hospital. There were significantly fewer 'intermediat//poor outcomes' for those with heart disease in the prayed-for group (OR 0.49, CI 0.30-0.80), and this finding was robust to some changes in definition. CONCLUSIONS: This review provides no guidance for those wishing to uphold or refute the effect of intercessory prayer on the outcomes studied in the available trials. Therefore, in the light of the best available data, there are no grounds to change current practices. There are very few completed trials of the value of intercessory prayer. The evidence presented so far is interesting enough to justify further study. If prayer is seen as a human endeavour it may or may not be beneficial, and further trials could uncover this. It could be the case that any effects are due to elements beyond present scientific understanding that will, in time, be understood. If any benefit derives from God's response to prayer it may be beyond any such trials to prove or disprove.

Journal Article↗
PubMed1998

Assessment of clinical outcomes in acute stroke trials.

BACKGROUND AND PURPOSE: Adequate outcome assessment is crucial to randomized trials. We wished to assess the types of outcomes used in acute stroke trials and the appropriateness of these outcomes and their analyses. METHODS: Acute stroke trials from the Cochrane Stroke Group's database were included from 1955 to 1995 if they were published in full text in English. For each trial we collected year of publication, number of patients randomized, blinding of outcome assessment, the specific outcome instruments used, the statistical methods used for analysis, and the significance of the results. The validity and reliability of each outcome measure were assessed by review of the literature. RESULTS: Our study included 174 trials. Outcomes were assessed blindly in 69%. Death was recorded in only 76% of trials, impairment in 76%, disability in 42%, and handicap or quality of life in only 2%. Of the trials that measured impairment, 35% used a measure of established validity or reliability. For disability and handicap, the proportions with valid or reliable measures were 70% and 25%, respectively. Impairment and handicap measures were primarily analyzed as continuous variables, while disability was mainly analyzed as a dichotomous variable. Continuous data were usually analyzed with inappropriate parametric statistics. There was no relationship between the method of analysis, the type of outcome, and the statistical significance of results. CONCLUSIONS: Most acute stroke trials up to 1995 have used clinical outcome measures that were inadequate in terms of their content, reliability, validity, blinded assessment, and statistical analysis. This has important implications for future stroke research.

Acute Disease↗
PubMed1998

Water distribution system and diarrheal disease transmission: a case study in Uzbekistan.

Deteriorating water treatment facilities and distribution systems pose a significant public health threat, particularly in republics of the former Soviet Union. Interventions to decrease the disease burden associated with these water systems range from upgrading distribution networks to installing reverse osmosis technology. To provide insight into this decision process, we conducted a randomized intervention study to provide epidemiologic data for water policy decisions in Nukus, Uzbekistan, where drinking water quality is suboptimal. We interviewed residents of 240 households, 120 with and 120 without access to municipal piped water. Residents of 62 households without piped water were trained to chlorinate their drinking water at home in a narrow-necked water container with a spout. All study subjects (1583 individuals) were monitored biweekly for self-reported diarrheal illness over a period of 9.5 weeks. The home chlorination intervention group had the lowest diarrheal rate (28.8/1,000 subjects/month) despite lack of access to piped water in their homes. Compared with the two groups that did not receive the intervention this rate was one-sixth that of the group with no piped water (179.2/1,000 subjects/month) and one-third that of the households with piped water (75.5/1,000 subjects/month). More than 30% of the households with piped water lacked detectable levels of chlorine residues in their drinking water, despite two-stage chlorination of the source water, and were at increased risk of diarrhea. Forty-two percent of these municipal users reported that water pressure had been intermittent within the previous two days. The dramatic reduction in diarrheal rates in the home-chlorination intervention group indicates that a large proportion of diarrheal diseases in Nukus are water-borne. The home-chlorination group had less diarrhea than the group with piped water, implicating the distribution system as a source of disease transmission. Taken together, these epidemiologic data would support the hypothesis that diarrhea in the piped water group could be attributed to cross-contamination between the municipal water supply and sewer, due to leaky pipes and lack of water pressure. Relatively inexpensive steps, including chlorination, maintaining water pressure, and properly maintaining the distribution system, rather than reverse osmosis technology, should reduce diarrheal rates.

Adult↗
PubMed1997

The muscle of lawrence in Drosophila: a case of repeated evolutionary loss.

The muscle of Lawrence (MOL) is a bilaterally symmetrical muscle spanning the tergite of the fifth abdominal segment of adult male Drosophila melanogaster. It is not, however, a general feature of male-specific development within the subfamily Drosophilinae. Of 95 species surveyed within this subfamily, 67 exist with no MOL at all. By drawing comparisons with published cladograms of species relatedness, three conclusions regarding the evolutionary history of the MOL are made: (i) The MOL predates the major radiations of the genus Drosophila, given its presence in earlier-branching Chymomyza and Scaptodrosophila; the MOL has been subsequently excluded in at least one present species of each of these two primitive genera. (ii) Within the genus Drosophila the MOL is present sporadically in the radiation of the subgenus Sophophora, showing repetitive loss even in very close evolutionary lineages. (iii) The MOL may have been entirely excluded from the prolific radiation of the subgenus Drosophila. Thus the MOL shows a uniquely incongruous pattern of presence or absence relative to accepted drosophilid phylogeny.

Animals↗
PubMed1997

Truncation of the amino terminus of human apolipoprotein A-I substantially alters only the lipid-free conformation.

An amino-terminal deletion mutant (residues 1-43) of human apolipoprotein A-I (apo hA-I) has been produced from a bacterial expression system to explore the structural and functional role of these amino acids, encoded by exon 3, in apo hA-I. Lipid binding of apo delta (1-43)A-I and lipid binding of apo hA-I are very similar as assessed by surface activity, lipid association with palmitoyloleoylphosphatidylcholine (POPC) vesicles, and lipid association with plasma lipoproteins. Preliminary kinetic measurements appear to show that the reactivity of lecithin:cholesterol acyltransferase (LCAT) with the mutant is slightly decreased compared to wild-type apo hA-I. Collectively, these results indicate that the N-terminal region is not necessary for lipid binding or activation of LCAT. In contrast, there are significant structural differences between lipid-free apo delta (1-43)A-I and apo hA-I, as judged by denaturant-induced unfolding, binding of the fluorescent probe 1-anilinonaphthalene-8-sulfonate, surface balance measurements, and far- and near-ultraviolet circular dichroic spectroscopy. All spectral and physical measurements indicate apo delta (1-43)A-I has a folded, tertiary structure, although it is significantly less stable than that of apo hA-I. It is concluded that the N-terminal 43 residues are an important structural element of the lipid-free conformational state of apo hA-I, the absence of which induces a fundamentally different fold for the remaining carboxy-terminal residues, compared to those in native apo hA-I.

Anilino Naphthalenesulfonates↗
PubMed1997

Pharmacokinetics and safety of single intravenous and oral doses of dolasetron mesylate in healthy women.

Twenty-four healthy women received 2.4 mg kg-1 dolasetron mesylate (1.8 mg kg-1 dolasetron base) by a 10 min intravenous administration and by oral administration. Pharmacokinetics of dolasetron and of its active reduced metabolite MDL 74156 were monitored for 48 h in plasma. Urine was collected from 0 to 48 h, blood pressure and heart rate were measured at 0, 0.08, 1, 2, 12, 24, and 36 h, and ECGs were measured at 0, 0.08 (intravenous only), 1, 2, and 36 h after dosing. Dolasetron was widely distributed and rapidly reduced (mean t1/2 = 0.23 h) to MDL 74156 (mean t1/2 = 8.05 and 9.12 h after intravenous and oral administration respectively). MDL 74156 was extensively distributed; between 27 (oral route) and 33% (intravenous route) was eliminated unchanged in urine. Safety assessment showed mild to moderate headache, dizziness, and hot flushes after the intravenous administration and headache, abdominal cramps or pain, and constipation after oral administration. Small and clinically non-significant changes in PR, QRS, and QTc intervals were observed. We conclude that there is no obvious difference in dolasetron pharmacokinetics between healthy women and men and that dolasetron can be used as safely in women as in men.

Administration, Oral↗
PubMed1997

Rat hepatocytes isolated from alcohol-induced fatty liver have an increased sensitivity to anoxic injury.

The aim of this study was to determine whether rat hepatocytes isolated from steatotic or nonsteatotic livers have different thresholds for injury due to anoxia-reoxygenation. Rats were fed ethanol or control diets for 8 weeks. Histology showed that more than 75% of the hepatocytes in alcohol-fed and less than 3% in control animals contained fatty vacuoles. The glycogen content was significantly reduced in steatotic livers. Isolated hepatocytes were cast in agarose gel threads and perfused with Krebs-Henseleit bicarbonate buffer. Cell viability was determined by Trypan Blue (TB) exclusion; cell injury was determined by lactate dehydrogenase (LDH) release; and superoxide anion (O2.-) was determined by lucigenin-enhanced chemiluminescence (LCL). During the pre-anoxic basal perfusion the following occurred: viability was 86% +/- 1% and 85% +/- 1%; LDH release was 16 +/- 3 and 15 +/- 3 mU/min; and LCL was 4 +/- 1 and 5 +/- 1 nA in steatotic and nonsteatotic hepatocytes, respectively. Cell viability decreased slightly under 4 hours of aerobic perfusion without differences between the two groups. In contrast, fatty hepatocytes died much faster than did control hepatocytes during anoxia; after 3 hours viability was 17% +/- 8% vs. 60% +/- 2% (P < .001), respectively. With reoxygenation following 2 hours of anoxia, the changes in viability, in LDH release, and in LCL were similar in both groups. These results indicate that in hepatocytes isolated from alcohol-fed rats when compared with control hepatocytes: 1) cell viability under aerobic conditions is not influenced; 2) anoxic injury is significantly increased; 3) a reduction in the hepatic glycogen stores, which may contribute to the enhanced sensitivity to anoxia, can be demonstrated; and 4) O2.- generation and cell injury occurring immediately after reoxygenation do not appear to be affected.

Animals↗
PubMed1997

Proteins but not nucleic acids are molecular targets for the free radical attack during reoxygenation of rat hepatocytes.

Isolated rat hepatocytes generate large amounts of reactive oxygen species and suffer a significant cell injury during postanoxic reoxygenation. The aim of this study was to determine whether oxidation of proteins and nucleic acids occurs during reoxygenation and whether their damage is related to the development of hepatocyte injury. Isolated perfused rat hepatocytes were exposed sequentially to 1 h of aerobic control, 2.5 h of anoxia, and 2 h of reoxygenation. Protein oxidation was determined by measuring the hepatocyte protein carbonyl content. DNA and RNA oxidation was assessed by measuring the 8-hydroxydeoxyguanosine and 8-hydroxyguanosine adducts, respectively. The control preanoxic carbonyl content was 6.48 +/- 1.03 nmol/mg protein. The preanoxic 8-8 hydroxydeoxyguanosine and 8-hydroxyguanosine levels were 4.76 +/- 1.22 pmol/ml and 14.19 +/- 2.17 pmol/ml, respectively. During anoxia, protein and nucleic acid oxidation did not change significantly. With reoxygenation, the protein carbonyl content increased significantly within 30 min, reaching a value of 10.25 +/- 1.58 nmol/mg. The nucleic acid oxidation level remained stable. Perfusion with 100 muM of during reoxygenation abolished protein oxidation. These results indicate that in rat hepatocytes during the early phase of reoxygenation: (1) the protein oxidation level increased significantly above the preanoxic aerobic values; (2) DNA and RNA oxidation does not appear to occur; and (3) free metal-mediated free radical reactions are involved in the oxidative protein damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

Biotherapeutic effects of probiotic bacteria on candidiasis in immunodeficient mice.

Four species of probiotic bacteria were assessed for their capacities to protect athymic bg/bg-nu/nu and euthymic bg/bg-nu/+ mice from mucosal and systemic candidiasis. Each bacterial species and Candida albicans colonized the gastrointestinal tracts of both strains of mice. The presence of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, or Bifidobacterium animalis) in the gastrointestinal tracts prolonged the survival of adult and neonatal bg/bg-nu/nu mice compared to that of isogenic mice colonized with C. albicans alone. The incidence of systemic candidiasis in bg/bg-nu/nu mice was significantly reduced by each of the four probiotic bacterial species. The numbers of C. albicans present in the alimentary tracts of euthymic bg/bg-nu/+ mice were significantly reduced by L. casei GG and B. animalis. None of the probiotic bacteria species completely prevented mucosal candidiasis, but B. animalis reduced its incidence and severity. Probiotic bacteria also modulated antibody- and cell-mediated immune responses to C. albicans. The prolonged survival of mice, decreased severity of mucosal and systemic candidiasis, modulation of immune responses, decreased number of C. albicans in the alimentary tract, and reduced numbers of orogastric infections demonstrated not only that probiotic bacteria have biotherapeutic potential for prophylaxis against and therapy of this fungal disease but also that probiotic bacteria protect mice from candidiasis by a variety of immunologic (thymic and extrathymic) and nonimmunologic mechanisms in this model.

Adjuvants, Immunologic↗
PubMed1997

Colonization of congenitally immunodeficient mice with probiotic bacteria.

We assessed the capacity of four probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, and Bifidobacterium animalis) to colonize, infect, stimulate immune responses in, and affect the growth and survival of congenitally immunodeficient gnotobiotic beige-athymic (bg/bg-nu/nu) and beige-euthymic (bg/bg-nu/+) mice. The bacteria colonized and persisted, in pure culture, in the alimentary tracts of both mouse strains for the entire study period (12 weeks). Although all adult and neonatal beige-euthymic mice survived probiotic colonization, some infant mortality occurred in beige-athymic pups born to mothers colonized with pure cultures of L. reuteri or L. casei GG. The probiotic bacteria manifested different capacities to adhere to epithelial surfaces, disseminate to internal organs, affect the body weight of adult mice and the growth of neonatal mice, and stimulate immune responses. Although the probiotic species were innocuous for adults, these results suggest that caution and further studies to assess the safety of probiotic bacteria for immunodeficient hosts, especially neonates, are required.

Animals↗
PubMed1996

Developed and resolving lesions in porcine proliferative enteropathy: possible pathogenetic mechanisms.

Proliferative enteropathy, caused by Lawsonia intracellularis, offers the opportunity to examine bacterial mechanisms that influence epithelial cell proliferation. Ultrastructural features of developed and resolving lesions included the presence of enlarged intestinal crypts containing undifferentiated immature epithelial cells and an absence of goblet cells. Numerous intracytoplasmic bacteria, identified as L. intracellularis, were consistently present within affected cells. In recovering intestinal tissue, additional features were (1) the common presence of pale, swollen, protruding epithelial cells, (2) shrunken, degenerate epithelial cells, (3) apoptotic bodies in both epithelial cells and macrophages, (4) the reappearance of normal goblet cells, and (5) reduced numbers of L. intracellularis within lesions. Bacteria were released from cells via cytoplasmic and cellular protrusions into the intestinal lumen. It is speculated that the presence of the intracytoplasmic bacterium, L. intracellularis, may disrupt normal processes of cell growth, differentiation or apoptosis in the intestinal epithelium.

Animals↗
PubMed1996

Smoking behaviours and beliefs of older Australians.

Reviews of the effects of smoking on health have concluded that older smokers can experience considerable health benefits from giving up smoking. In a representative population survey of people aged 15 years and over in South Australia, the percentage of people aged 60 years and over who were smokers was 13.5 per cent (95 per cent confidence interval 10.9 to 16.2 per cent). Compared with smokers aged under 60 years (n = 727), older smokers (n = 88) were significantly more likely: to be less convinced of the effects of smoking on health; to perceive that they were not personally at risk from their smoking in the future; to believe that smoking had not affected their own health so far; and to believe there was a daily level of cigarette consumption that was safe. Strategies to encourage older people to consider more objectively how smoking impairs daily living, including personal disclosure of smoking-related damage through lung-function testing, deserve further research.

Adult↗
PubMed1996

Trends in prevalence and acceptance of workplace smoking bans among indoor workers in South Australia.

OBJECTIVE: To compare the reported prevalence and acceptance of bans on smoking in the workplaces of a representative sample of adults in South Australia between 1989 and 1994. DESIGN: Independent cross-sectional representative population surveys. SETTING: South Australian population. PARTICIPANTS: Adults who indicated they were employed mainly indoors, for the years 1989 (875 respondents), 1991 (1472), 1992 (1288) and 1994 (1273). MAIN OUTCOME MEASURES: Percentage reporting total bans on smoking at work; percentage reporting compliance with bans all or nearly all the time; percentage reporting preference for total bans at work. RESULTS: The percentage of indoor workers subject to a total ban on smoking at work increased from 32% in 1989 to 62% in 1994 and preference for a total ban increased during the same period from 26% to 52%. Reported compliance with restrictions and bans was very high. In 1994, 16% of workers still had no restrictions on smoking at work, but only 3% preferred this arrangement. CONCLUSION: The data suggest that smoking bans are now the norm for indoor workers and that further gains in promoting and supporting workplace bans will be made by directing efforts at smaller workplaces, where unrestricted smoking is most prevalent.

Adult↗
PubMed1996

Nephrotic syndrome in Trinidadian children.

57 children with idiopathic nephrotic syndrome who were seen at two hospitals in Trinidad between 1989 and 1995 (median follow-up period, 38 months) were classified according to their response to glucocorticoids. 27 (47%) were two to six years old at presentation; 37 (65%) were of East Indian descent, 7 (12%) were of African descent, and 12 (21%) were of mixed race. 55 (96%) responded to glucocorticoids. Renal biopsies in 15 patients revealed membranoproliferative glomerulonephritis and membranous nephropathy in the two patients who had not responded to glucocorticoids. Ten patients showed mesangial hypercellularity, associated with immunoglobulin deposits in 7 cases. Age, presentation with nephrotic features, mesangial hypercellularity and immunoglobulin deposits did not predict for unresponsiveness to glucocorticoids. These findings may be explained by the predominance of East Indians in the study group.

Biopsy↗